Maintenance Alerts
| Title | Summary | Applicable Makes |
| Hawker: 800XP; Cracked MLG Door Bracket; ATA 5280 (November 2012) | A general aviation submitter writes, "During base maintenance, (we) found the R/H main landing gear door
support cracked (P/N 25FC5804)." (Photos included in reference document) |
|
Hawker Beechcraft/ Hawker
|
|
| Embraer: 120ER; Worn MLG Actuator Rod-end; ATA 3230 (November 2012) | An air carrier submission states, "After takeoff, the L/H main landing gear 'red' indication light remained
illuminated after the gear was up. The crew selected 'gear down'—all gear extended and locked down. The
aircraft returned to (base) and landed without incident.
"Maintenance found the left gear was not retracting fully up and locking into position. The problem was
(determined) to be excess play in the retract actuator rod-end (P/N 21126-000-00). This rod-end bearing (swivel)
was found seized to the attaching pin that secures the actuator to the MLG leg. This caused the rod-end to pivot
on the OD (outside diameter) of the pin—instead of the bearing rotating on the rod-end bearing race. The pin
(P/N 19872) was found worn 0.064 inches deep approximately 210 degrees around the OD circumference. The
actuator, pin, and bushings were replaced. The landing gear system checked 'good' and the aircraft was returned
to service." (This particular rod-end P/N is found four times in the SDRS database.) (Photos included in reference document) |
|
| Beechcraft: C90GTX; Failed Nose Wheel Steering; ATA 3250 (November 2012) | A repair station technician states, "Coming from the taxi holding bay, the aircraft went out of the runway—the
nose wheel steering was (apparently) inoperative. Investigation and inspection performed by maintenance found
a lack of grease on the steering brace (P/N 101-820024-15). No other findings or problems were detected on the
steering (assembly). After grease (application), operational and functional tests performed smoothly.
Recommendation: the steering brace must be greased with the aircraft both on and off jacks to guarantee full
(lubrication)." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Beechcraft: A36; Failed Landing Light Switch; ATA 3340 (November 2012) | "The landing light circuit breaker switch failed," says a mechanic. "This switch was replaced by AD2008-13-17
IAW SB24-3807. It is the third or fourth switch to fail since being installed in our fleet of Bonanza and Baron
aircraft, a total of nine (planes). This AD has caused a higher failure rate of our circuit breaker switches since
compliance with this AD. (I believe) this new switch called for in the AD is inferior to the switch it has replaced."
(Switch P/N: 35-380132-103. The SDRS database reflects this switch 74 times—see also the next Alerts article.
It would have been helpful had you indicated an estimated average time experienced from the old switch—Ed.) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Bell: 206B; Cracked Tail Rotor Gearbox Support; ATA 5302 (October 2012) | An Air Carrier provides the following defect report. "The tail rotor gearbox support bulkhead cracked at the
right-rear mounting hole—(progressing) to the second rivet inboard on the gear box support." (Photos included in reference document) |
|
| Pilatus: PC1247; Failed Brake Disk; ATA 3242 (October 2012) | "This aircraft was undergoing a 100 hour inspection," says this submitter. "(The mechanics) removed the L/H and
R/H main landing gear wheel assemblies to complete NDT (non-destructive testing)—and upon wheel removal
one of the wheel's brake disk assemblies fell onto the floor in two separate pieces. Both L/H and R/H brake
assemblies (presented) separated brake disks. These brake disk assemblies were not the original (units). They
were installed at an earlier date and (had been tagged) as removed from another aircraft. The operator did not
notice any abnormal sounds or conditions during aircraft operations. The technician did not notice any abnormal
sounds or conditions during operational run up, and the wear guide pins (indicating) 'normal system' functioned
properly." (Photos included in reference document) |
|
| Cessna: 550; Burned Wires Behind Multi-display; ATA 3497 (October 2012) | "(I) investigated a problem of smoke in the cockpit," states this repair station technician. "Smoke appeared to be
coming out of the anti-fog vents. After further investigation, some wiring behind the copilot's MFD
(multi-function display) were found to be shorted. In this mechanic's opinion, the wiring to the K10 relay chafed
inside the heat shrink, causing a short to ground. This area contains two resistors (1 each 7.5 OHM 10 watt; 1
each 10 OHM 5 watt) and a ground wire (all in the same shrink package). The round (solid-core) wire was
visibly burned. I repaired the damage wiring—replacing both resistors and both relays, then heat-shrinking the
resistors individually. I inspected the associated wiring in both circuits and found (these) to be okay. During
operational checks, the regulator valve was found to be faulty, although it checked 'good' with a multi-meter prior
to this (functional) test." (Photos included in reference document) |
|
| Cessna: 150B; Corroded Wing Spars; ATA 5720 (October 2012) | A general aviation submission provides the following defect report. "Corrosion was found on the forward and aft
wing spars under the fuel tank spacer blocks (P/N 0523524) in the fuel tank mounting bay. This problem was
discovered when the fuel tanks were removed for repair. No visual corrosion indications were noted around the
spacers when mounted. These spacers were removed on a 'hunch' that underlying corrosion might exist. This
condition (was found) in both wings." (Photos included in reference document) |
|
| Bell: 206B; Failed Transmission Oil Sight Indicator; ATA 6320 (September 2012) | "During a routine inspection," says this repair station submission, "(we) discovered the oil level indicated 'full'—
after the main rotor transmission oil was drained. After removal, inspection of the indicator (P/N 206040093001)
revealed the coating with the 'level markings' had separated from the metallic back plate. There is a ring of holes
on the circumference of the indicator. These were not aligned with the holes in the 'level mark' coating on the
back plate. This condition would not allow oil to drain from the sight glass—the only means to determine
(correct) oil level in the main rotor transmission. Improper servicing of the transmission presents a potential for
serious problems if left undetected." (Photos included in reference document) |
|
| Cessna: 680CE; Worn Brake Metering Valve Arms; ATA 5310 (September 2012) | "Upon removal of the R/H floor panel," say this repair station mechanic, "it was observed there was some fretting
material on the insulation bags and the surrounding area. Further investigation revealed the R/H and L/H arms
(P/N's 6964000-16 and -17) that connect the brake metering valve to the brake cable clevises were severely worn.
The bolts and clevises at the attach points are wearing into the brake metering valve arms. It looks like the
bushings (spacer P/N NAS43DD4-16FC) were never installed. (I) recommend during a 3A Emergency Battery
Service or inspection that this panel (162ET) is removed and the (valve) arms inspected for wear and spacer
installation." (Photos included in reference document) |
|
| Beech: 400A; Cracked Engine Mount; ATA7120 (September 2012) | A mechanic says, "During the removal of the L/H engine, the engine mount (was found) to have a large crack." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Beech: 58; Failed Throttle Control Rod; ATA 7603 (September 2012) | "The throttle control (rod) end—threaded for a rod-end—came off the control (rod)," says this submitter. "It
appears to have been swaged on to the end of the (now separated) control (rod)." (P/N: 1023890103. Are you
saying this rod end was—or was not suppose to have been swaged in the first place? Ed.) (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Beech: A36; Broken Aileron/Rudder Spring; ATA 2720 (September 2012) | A technician working a corporate aircraft states, "During flight, the pilot noticed the aileron control was pulling to
the right. The aircraft returned to base without incident. Upon inspection of the aileron control system, the upper
aileron/rudder interconnect spring (P/N 35-5524664) was found broken at the end of the bell crank arm
(P/N 002-524018-25). The probable cause for this failure is time in service." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Piper: PA34-200; Cracked Nose Gear Trunnion; ATA 3222 (August 2012) | A repair station mechanic states, "(During) an Annual inspection, (I) found the right pivot point of the nose gear
trunnion cracked (at the point...) where the trunnion is welded to the pivot bolt housing." (Trunnion
P/N: 9572300. This part is referenced at least four times in the SDRS database.) (August 2012) |
|
| Piagio: P180; Burned Wiper Relay; ATA 3040 (August 2012) | "Windshield anti-ice was found with inoperative sections during a 'B' check," says a technician. "(I) found
relays K59 and K6—with power terminals connecting wiring to the windshield—arced and burned, causing
complete separation of the terminal from the relay. This condition could also possibly cause smoke in the
cockpit." (Photos included in reference document) |
|
| Gulfstream: 690B; Cracked Main Gear Strut; ATA 3213 (August 2012) | "The left main gear strut was flat," writes a technician. "(We) tried to service (the strut), but when we applied
nitrogen pressure hydraulic fluid came out of a three inch crack in the strut body and bearing assembly...."
(P/N: ES12394.) (Photos included in reference document) |
|
| Cessna: CE-750; Water-separator Corrosion: ATA 2170 (August 2012) | A repair station mechanic states, "Both the L/H and R/H water separators have corrosion under the insulation
(P/N 5715526-8). This is an area not normally looked at during the water sock cleaning/restoration." (Reference
United Technologies, Hamilton Standard; model EC22DWS-1; P/N 79030103.)(Photos included in reference document) |
|
| Cessna: C680; Chafed Jet-pump tubes; ATA 2810 (August 2012) | "Extensive fretting damage (was found) on the primary jet-pump fittings—and the attaching line fittings where the
Wiggins clamps (W991-18DE) are installed," writes a repair station mechanic. "Damage occurs to adjacent
plumbing—P/N's 6926100-123, 6926100-13 (and -14, -15, -76). Damage has been found on Cessna 680 models
during tank inspection 28-10-00-201. This condition is dangerous and unairworthy." (Primary Jet-Pump
P/N: 9914682-1.) (Photos included in reference document) |
|
| Cessna: 208B; Collapsed Engine Vent Line; ATA 7261 (August 2012) | A general aviation submission states, "In compliance with a fleet campaign directive, and during an engine
inspection, a mechanic checking the vent line of the overboard breather found the rubber section swollen
internally. Left unchecked, an obstruction would cause the Pratt & Whitney PT6-114 engine of this (aircraft) to
start consuming large amounts of engine oil—compromising the engine bearing seals and resulting in expensive
engine repairs. The fleet campaign directive mentioned above was generated by this Caravan operator to address
the condition of these aging hose sections. Operators of older Caravans would be wise to check their aircraft for
similar defects." (Photos included in reference document) |
|
| CASA: C212-200; Wing Spar Corrosion; ATA 5711 (August 2012) | An Air Carrier technician says, "The left wing, upper forward spar's aft horizontal leg is exfoliated at
(approximately) Wing Station 3496. (There is) probable exfoliation at WS 2130 to 2450, and at WS 2900
to 3000." (Photos included in reference document) |
|
| Beechcraft: 200; Cracked Spar Shear Fitting; ATA 5740 (August 2012) | "While accomplishing a wing bolt inspection," says this unidentified technician, " the L/H lower wing spar attach
shear fitting was found cracked (P/N 1011100731). This crack is approximately 0.75 inches long and is located in
the forward flange area." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Beechcraft: B200; Bad Rivet Installation in Stabilizer Spar; ATA 5510 (August 2012) | A submitter working on this corporate aircraft writes, "After complying with Service Bulletin 55-3835
'Installation of Empennage Inspection Access Panels' and the 'Horizontal and Vertical Stabilizer' inspection, we
found the horizontal stabilizer forward spar and ribs not riveted correctly from the factory. Many rivets that go
through the forward spar are too short, and where the rib and forward spar come together, the rivet misses the rib.
We have found this same problem on other aircraft we have inspected." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Agusta: AW139; Cracked Tail Rotor Blade; ATA 6410 | "During the daily check after flight," says this submitter, "the mechanic noticed a crack on one tail rotor blade just
aft of the erosion shield, extending from the inboard end of the shield to within 8 inches of the outboard tip of the
blade. The maximum opening of the crack is 0.1875 inches at the inboard end. The crack is evident on both
upper and lower sides of the blade, indicating the leading edge plies are (separating). (Blade
P/N: 3G6410A00131.) (Photos included in reference document) |
|
| Piper: PA44-180; Throttle Cable Separation; ATA 7603 (July 2012) | "During climb out and around 600-700 AGL (above ground level)," says this submitter, "the instructor pilot
reduced the R/H throttle to idle to simulate engine failure. The student pilot simulated feathering the R/H
propeller—and when attempting to set zero thrust, the instructor discovered there was no thrust available.
The R/H engine was secured, and emergency declared, and an uneventful landing performed. Upon inspection of
the R/H engine (we found) the engine end of the swaged portion of the throttle cable had failed, allowing only the
cable housing to move when the throttle lever in the cockpit was (actuated). Further inspection of the failed
swaged area leads me to conclude that during initial assembly of this particular throttle cable (P/N 554528) the
cable housing had not been inserted into the cable end far enough before the end was swaged onto the cable
housing." (Photos included in reference document) |
|
| Mooney: M20TN; Loose Engine Isolator Mount Bolts; ATA 7120 (July 2012) | "(I) discovered all four engine isolator mount bolts loose during a 100 hour inspection, noting (these bolts) do not
have a safety wire or locking provision. I also found several areas of chafing related to the engine not being
secured to the engine bed mount. All engine isolators were removed and inspected. I found metal shavings
between the upper and lower isolators, and the left aft engine mount bracket thread insert pulled and cross
threaded. Both rear engine mount brackets were replaced with new, and the front engine isolator mounts replaced
with a new kit. I reinstalled the existing rear isolator mount kit IAW IPC and AMM (parts catalog and
maintenance manual).
"I found installing the isolator mounts and bolts very difficult. The engine mount brackets do not align with the
engine bed mount focal rings. With all the isolators installed and the bolts torqued, the isolators are displaced
from centerline and are laterally loaded. The isolators do not seat on the full circumference of the focal ring.
I removed all the isolator mounts for further inspection of the bed mount, and contacted the aircraft manufacturer
about the alignment issues. I measured the mount and found the engine bed mount focal ring centerlines are too
narrow by 0.2500 inches on all four corners. No deformities of the bed mount were noted." (Mount
P/N: 590030501. A Continental TSIO550G sits in this airplane's engine mount.) (Photos included in reference document) |
|
| Cessna: 208B; Collapsed Engine Vent line; 7261 (July 2012) | "The pilot reported an unusual amount of oil was being consumed," says a repair station mechanic. "And (during)
his inbound flight (he said) the oil pressure gauge was fluctuating. There were no visible signs of an external oil
leak. (While performing) a ground run maintenance noted the torque (indication) was (also) fluctuating. And
when bleed air was turned on, a fine mist of oil was emitted from the heater vents. Subsequent troubleshooting
found the engine vent line had collapsed, internally pressurizing the case and causing the oil to leak internally into
the compressor." (Photos included in reference document) |
|
| Cessna: 182T; Cracked Fuselage Bulkhead Flanges; ATA 5312 (July 2012) | "Cracks were found in the flange of both the L/H and R/H fuselage bulkheads at station 17," says a repair station
technician. "(These) cracks are radiating from the upper bolt hole where the fueling step attaches. The bolt
hole(s) is too close to the bend radius of the bulkhead, causing distress when the bolt is tightened. This is the
second instance (we have) found in 'Restart' aircraft (post 1996)." (Bulkhead P/N: 0713787110713787.
Indicating arrows have been added—Ed.)(Photos included in reference document) |
|
| Cessna: 172P; Cracked Seat Frame; ATA 2510 (July 2012) | A general aviation submitter writes, "The pilot's lower seat frame support legs cracked at the frame rail cut outs
(where they attach to the seat height adjustment arms)." (Seat frame P/N: 05142047.) (Photos included in reference document) |
|
| Piper: PA44-180; Stuck Throttle Cable; ATA 7603 (June 2012) | (This aircraft supports a pair of Lycoming O360A1H6 engines.)
A submission from another corporate operator states, "After practicing an instrument approach and go-around,'
the L/H engine throttle lever stuck at 25 inches of manifold pressure and 2500 RPM. Departing from the airport
control area, the instructor pilot was able to reduce the L/H throttle down to 16-18 inches of manifold pressure at
2500 RPM. After discussion with flight department personnel, it was decided...to shut down the L/H engine and
perform a single engine approach and landing. An emergency was declared, and the aircraft landed uneventfully.
"Since (there have been) previous instances of problems with engine control cables in this particular make and
model aircraft, the L/H engine throttle cable (P/N 554546) was replaced as part of a scheduled progressive
inspection." (Indeed—this throttle cable P/N reflects seven times in the SDRS database. It would have been most
helpful had you speculated as to the cause of the cable's binding—Ed.) |
|
| Piaggio: P-180; Improper Elevator Installation; ATA (N/A) (June 2012) | (The FAA's Small Airplane Directorate in Kansas City provides the following safety admonition. Aerospace
Engineer Mike Kiesov narrates the discussion; contact information follows the article.)
"The purpose of this Alerts article is to describe an event where the elevators on a Piaggio Aero P180 Avanti
airplane were installed incorrectly. The R/H elevator was installed upside down on the left side of the airplane,
and similarly, the L/H elevator was installed upside down on the right side of the airplane. The airplane was then
rigged within acceptable limits per the AMM (aircraft maintenance manual). During flight, this reversed elevator
installation greatly influenced elevator trim authority—additionally causing the airplane yoke to be in a noticeably
different longitudinal position.
"The airplane manufacturer has subsequently incorporated a note in the airplane manual for this model P180
Avanti—a similar note is intended for their model P180 Avanti II.
"A very simple way to ensure the correct elevator is installed on the proper side is to verify the location of the
static wicks—they must be on the upper surface of the elevator. This fact is reflected in the additional note added
to the P180 Avanti AMM." (Photos included in reference document) |
|
| Cessna: 525C; Failed Brake Rotors (friction pads); ATA 3242 (June 2012) | A submission from a corporate operator states, "The brake pads on both the L/H and R/H brake rotors are
debonding—with 'chunks' missing." (Rotor P/N: 90006028; Brake Assembly P/N: 90006022. Red arrows are
my insertions—Ed.) (Photos included in reference document) |
|
| Cessna: 404; Damaged Elevator Mount Brackets; ATA (N/A) (June 2012) | "While this aircraft was tied down," says a submitter, "the control wheel was secured in the full up position with a
seat belt—instead of the approved gust lock device. This (ad hoc arrangement) allowed the elevators to have
some movement—high winds prior to the intended flight (allowed the elevator) to hammer its lower stop until the
bracket's upper mounts failed.
"The pilot stated he conducted a flight control check prior to taxi—everything felt fine. It was not until the
control surface (incurred) an air load that he discovered a problem and aborted the takeoff." (Photos included in reference document) |
|
| Cessna: 208B; Frayed Flap Cable; ATA 2750 (June 2012) | A mechanic states, "During a routing inspection, (I) found a flap cable (P/N 2660001105) frayed at the connection
to the fairlead—about 30 percent of the (strands) were broken. (It) runs from the inner bell crank to the outer end
of the flap. This cable was original as far as can be traced back—the original P/N tag was still installed. (And)
judging from the slip mark, the cable had not (moved from its swaged fitting)." (Photos included in reference document) |
|
| Bombardier: CL600-2B19; Incorrect MLG Installation; ATA (N/A) (June 2012) | (Reminder to readers: Alerts' submissions often include admonitions, other agency publications, and "operator
error" descriptions. If a part has not actually failed, it doesn't wind up in the SDRS database; hence, no ATA
code is assigned. There are three such submissions in this month's edition—Ed.)
A technician for a repair station provides the following report of an assembly error and confusing assembly data.
"During clearance checks (I found) the locking ring of the (main landing gear) shock strut assembly incorrectly
clocked. (This caused) fouling of the aircraft structure and the failure potential for the L/H main gear extension.
"The CMM (maintenance manual) fails to note the 'dogged locking ring' requires installation in a specific
direction to maintain airframe clearance. (Reference the following) steps in CMM 6100, section 32-10-05: '(14)
Apply sealing and coating compound listed in paragraph 3 to both faces of dogged locking ring (6239-1); (15)
Install the dogged locking ring on the gland nut (6228-1). Install the gland nut on the flange of the cylinder S/A
(6217-1) using gland nut wrench CAT (4948-6C). Ensure the dogged locking ring is correctly centered on the
gland nut. Torque gland nut to 22.60-45.20 NM. Note: back off to nearest lock position only when necessary.
(16) Engage the tab of the locking segment (6233-1) with a slot in the gland nut. Secure the locking segment to
the dogged locking ring with 2 bolts (AN4-5), 2 washers (AN960-416L), and two nuts (MS17826-4). Torque
nuts to 5.65-7.91 NM. Safety the nuts with cotter pins (MS24665-151).'
"The data fails to state the dogged locking ring may be installed in either the 0500 or 1100 (o'clock) positions—
relative on the assembly. However, only the 0500 position provides adequate airframe clearance once the landing
gear is placed in the aircraft. Installation of the lock ring 180 degrees (out) or at the 1100 position allows the tab
of the lock ring to interfere with the aircraft structure at the aft side of the gear well." (Photos included in reference document) |
|
Bombardier Learjet/Canadair
|
|
| Beech: Burned Engine Indicator Electrical Wires; ATA 7797 (June 2012) | "A 'D' check inspection of the wiring in the aft baggage compartment (R/H, lower area) found some burned
wires," says this repair station technician. "These wires had shorted out—burning through their insulation.
(Noted strands include) W740 R/H Fan N1 RPM Indicator, and W748 R/H Turbine N2 Indicator.
"This (area/wiring) needs to be inspected thoroughly as (failed wiring) will cause indication problems in the
cockpit and possibly a fire. The damaged wires were replaced." (Photos included in reference document) |
|
| Beech: 390; Cracked Flap-fairing Hinge Fittings; ATA 5744 (June 2012) | A repair station technician writes, "During inspection of the wing flap actuator attachments, (I) found both the
L/H and R/H wing inboard flap-fairing hinge fittings cracked (P/N's 390-110440-0001 and 390-110440-0002)." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Beech: 58; Fuel Cell Sealant Deterioration; ATA 2810 (June 2012) | "This aircraft has factory installed, extended range fuel cells," says a mechanic. "The cells are sealed wing
bays—or 'wet wing' fuel cells located in each wing tip. These wing tip fuel cells were found leaking fuel through
the fuel vent tubes (P/N 60-170010) on both sides. The cause of the leak was found to be the deterioration of the
sealant around the tube slip-joint fittings. Also present in the fuel cells was an excessive amount of particulate
contamination. This (debris) is deteriorated fuel tank sealant that failed to remain bonded to the inner tank
surfaces. These particles were trapped in multiple locations throughout the entire fuel storage system with no way
of draining, accessing, or even (detecting) their presence. The upper wing skin must be removed to access the
trouble areas in the wing tip fuel cell—given inadequate inspection panel locations. The addition of a second
inspection panel to the aft, inboard area of the wing tip fuel cell may be necessary to (facilitate detection) of this
discrepancy. (This is) a potentially dangerous condition as fuel can enter the wing vent system, or (these
particles) may cause fuel contamination and (engine failure)." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Agusta: A119; Cracked Gleason Crown Gear; ATA 6320 (May 2012) | A quality control supervisor for this repair facility says, "During a 4800 hour overhaul inspection, the Gleason
Crown gear was found to have a crack." (Photos included in reference document) |
|
| Piper: PA28R200; Cracked Aileron Pulley Brackets; ATA 2710 (May 2012) | A General Aviation submission states, "During an Annual Inspection, both the L/H and R/H lower support aileron
pulley brackets were (found) cracked in the forward inboard radius mount (flange) at each wing rib. A piece of
one of these pulley brackets was detached." (Pulley bracket P/N: 67550000.) (Photos included in reference document) |
|
| Cessna: 208B; Rudder Torque Tube Corrosion; ATA 5540 (May 2012) | A repair station technician states, "This Hawaiian based aircraft arrived at our (facility) for maintenance. The
rudder was removed from the aircraft, and its skin (then removed) to allow access to the rudder torque tube
(P/N 263066-3). (This torque tube...) was scheduled to be replaced due to elongated holes in the bell crank.
Severe corrosion was found on the upper part of the torque tube which is located under the skin—(this area) is
not visible to any scheduled maintenance. The corrosion had reached the stage of 'blistered rust', and the 'L' angle
on one side was easily separated with (minor) force (about 11 pounds; and wiggled twice)." "By design the
rudder is not sealed on the top. The (torque tube top attach) bracket is located about a foot from the bottom—this
cross member seems to pool water running down from inside the rudder (even though) there are drain holes in the
design. Hawaii is listed as a 'moderate' corrosion environment.
"The operator had no way to inspect this location. A borescope would need to be used to (even) get an idea of the
health of this part—(but still) it is better to remove and disassemble the (rudder). I would suggest a rudder
inspection (hole be designed and implemented) so maintenance can easily inspect the torque tube for corrosion." (Photos included in reference document) |
|
| Cessna: 208B; Cracked Inertial Vane Shaft; ATA 7160 (May 2012) | "Bypass door loose—will not close all the way," states this report from a Part 135 operator. "Upon investigation,
(we) found the shaft cracked on the forward inertial vane assembly (P/N 200803511002). The mechanic also
noticed the inlet splitter (P/N 200803511002) was cracked at (its two ends, and one attach angle was broken)."
(Reader minder: the italicized parenthetical expressions are my insertions—Ed.) (Photos included in reference document) |
|
| Cessna: 182G; Cracked Main Landing Gear Attach Casting; ATA 5343 (May 2012) | A general aviation submission states, "A casting crack was found (visually) during the course of an Annual
Inspection. The crack is located on the forward end of the support casting (P/N 07416031), (starting) 0.25 inches
from the outboard mount holes and (ends) within 0.25 inches of the mount holes on the inboard side of the
casting." (Photos included in reference document) |
|
| Bell: 206L1; Improper Governor Assembly; ATA 7323 (April 2012) | "The governor allows the engine (Allison 250C28) to overspeed," says a mechanic. It failed the shop test. (I)
disassembled the unit and found it improperly assembled. The spool bushing anti-rotation tang was engaged in
the lever slot." (There are 16 SDRS database entries for the Honeywell Governor P/N: 252469211, and 6 entries
for the Bushing Assembly P/N: 2526146.) (Photos included in reference document) |
|
| Piper: PA46-500TP; Nose Gear Torque Link Missing Bolt, ATA 3220 (April 2012) | A general aviation report states, "The (aircraft owner/pilot) noticed a vibration shortly after landing. Inspection
of the nose landing gear assembly found the bolt, nut, washer, and cotter key missing from the center torque link,
and the tire was lightly flat-spotted." (Torque Link Component P/N: 106680002.) |
|
| Lear: 45; Broken Hydraulic Float Switch; ATA 2930 (April 2012) | "Maintenance was (experiencing) erratic indications when servicing hydraulic fluid," states this Air Carrier SDR
report. "When serviced correctly per the maintenance manual, hydraulic 'low fluid' or 'over filled' messages from
EICAS (Engine Indicating Crew Alerting System) would appear shortly thereafter. There was no evidence of
fluid loss, and the mechanics were properly trained and equipped for the servicing task. The hydraulic float
switch was removed for troubleshooting—it was found to have one float broken. The float switch assembly
(P/N 3L14F17) was replaced with a new unit, and the hydraulic system checked in consultation with Learjet Field
Support to ensure the possibility of system contamination was adequately addressed." (Photo included in reference document) |
|
| Hawker: 800XP; Failed Elevator Trim Rod-ends; ATA 2731 (April 2012) | A submitter writes, "When conducting a maintenance preflight inspection, the technician noticed rust stains
coming from the aft rod-ends (P/N CN635MESP56) of the elevator trim tab rod on both left and right elevator
trim tabs. Further inspection revealed the grease seals on one end of both the left and right trim tab rod-ends had
come off, and the ball bearings were mostly missing. Fortunately, the other rod-end on each of the trim tabs was
still intact. However, rust stains were also noticed coming through these grease seals. In the process of replacing
the rod-ends, it was noticed that TKS deicing fluid had penetrated into the hollow inner portion of the trim tab
control rod, (but) no evidence of corrosion existed. "Recommendation: Conduct a close-up visual inspection of the elevator trim tab rod-ends for rust staining and
grease seal separation on an annual basis. Any time rust staining is observed coming out of the rod-ends, replace
them. At each 48 month inspection, remove the rod-ends and visually inspect the control rods for corrosion." (Photos included in reference document) |
|
Hawker Beechcraft/ Hawker
|
|
| Cessna: 402C; Failed Nose Gear Microswitch; ATA 3260 (April 2012) | "The nose gear collapsed on landing," says this electrical technician. "The nose gear actuator was removed and
tested in a controlled environment. When the actuator was cold soaked, the microswitch (P/N 1CH16) failed to
activate properly, giving a false indication the gear was down and locked. Due to gear failure, both aircraft
propellers struck the ground and caused sudden stoppage to the engines. The aircraft also suffered structural
damage to the nose section." (Photo included in reference document) |
|
| Bombardier: BD100-1A10; Defective Tire; ATA 3244 (April 2012) | A commercial operator's technician says, "A bulge on the number two main tire (P/N 269K43-2) outer sidewall is
consistent with bulges found on previous tires (P/N 269K43-1). This tire is being sent to Goodyear for
evaluation." (Photos included in reference document) |
|
Bombardier Learjet/Canadair
|
|
| Piper: PA34-200T; Frozen Aileron/gap Seals; ATA 2710 (March 2012) | A general aviation pilot says, "I recently had the 'Knots 2U' aileron gap seals (Supplemental Type Certificate
SA729GL) installed on my PA34. In February I departed (my airport) and climbed through moderate to heavy
precipitation for 10 to 15 minutes, leveling off at 9,000 feet. This altitude was below freezing. I set my autopilot
for straight and level flight, (but) after ten minutes I noticed the airplane was veering off heading and beginning to
enter a slight bank. I shut off the autopilot and leveled the airplane, noticing the aileron control seemed very stiff.
I then pulled the circuit breaker for the autopilot and the electric trim to ensure they were disengaged. After four
to five more minutes in level flight the ailerons went from being very stiff to completely frozen. I was forced to
control the airplane with only rudder and elevator inputs. Later in the flight I descended to above freezing
temperatures and the aileron control slowly returned. Subsequent inspection on the ground revealed no aileron
control abnormalities. I believe the precipitation encountered during the climb froze the ailerons to the gap seals
when the airplane entered below freezing temperatures. I called the STC holder to discuss this issue...." "This
safety hazard could easily lead to a complete loss of aircraft control (and fatalities) if not addressed (in) the STC
or by an AD (Airworthiness Directive)." |
|
| Piper: PA31-350; Cracked Main Gear Fittings; ATA 3211 (March 2012) | (A technician for an air carrier operation provides the following report. His reference can be found at:
http://www.niar.twsu.edu/researchlabs/aa_overview.asp .)
"(Topic:) Cracks in the Aft Main Gear Side Brace Fitting Assembly (P/N 40294-00). The Aging Aircraft Lab at
the National Institute for Aviation Research (NIAR) in Wichita, Kansas recently produced a report titled, 'The
Aging Airplane Study: Piper Navajo Chieftain.' Based on their findings, we initiated a dye penetrant inspection
program on the forward and aft main gear Side Brace fitting assemblies on our Piper Chieftain Navajo fleet. The
inspection of our aircraft revealed several of the aft fitting assemblies on both the left and right landing gear have
cracks located in the lower inboard web of the Side Brace (Piper P/N 40294-00). As a result of finding these
cracks, we have added a 1,000 hour Special Inspection to our PA31-350 AAIP (Aging Airplane Inspection
Program) to monitor and replace any assemblies exhibiting the cracking found in the fitting assemblies. It is
interesting to note these cracks have only been found in the aft assemblies on our aircraft." (Photos included in reference document) |
|
| Piper: PA28-180; Worn Fuel-select Valve; ATA 2823 (March 2012) | A general aviation mechanic writes, "When the fuel tank selector valve (P/N 756645) was rotated it was stiff to
move, and the detents could not be felt at each position. A teardown showed the valve was very dirty inside, and
the detent ring was worn. A review of Airworthiness Directives (AD's) and Service Bulletins (SB's) revealed two
bulletins that directly involve problems with this valve. This defect (worn and dirty) led to improper fuel
selection (position), greatly reducing fuel flow and causing stoppage of the engine.
"1. SB 0355: Fuel Selector Valve Lubrication. I was unable to locate a sign-off in the maintenance records
of (compliance) with this bulletin.
"2. SB 0840: Fuel Selector Valve Cover Replacement. I was unable to locate a sign-off in the maintenance
records of (compliance) with this bulletin. This bulletin deals directly with preventing the pilot from
inadvertently moving the valve to the 'off' position. Piper considers this SB to be mandatory. No AD was found." (Photos included in reference document) |
|
| de Havilland: DHC8103; Corroded Aileron Control Shaft; ATA 2710 (March 2012) | An air carrier operation writes, "Roll control was very stiff. (We checked) the tension of the aileron fuselage
cables and lubricated the aileron quadrant bearings externally for (initial) troubleshooting." "We replaced the L/H
and R/H bearings in the aileron quadrant IAW Mod Kit 8MK0930-001 instructions and the AMM 27-12-31. The
control cable tensions (and their safeties) were not disturbed. The L/H aileron control shaft (P/N 82740083-101)
was replaced due to corrosion." (Photos included in reference document) |
|
| Cessna: 750; Bent Speed Brake Push Pushrod; ATA 2701 (March 2012) | "When deploying speed brakes, the handle must be continuously held in position or the air load will stow the
panels," says a corporate defect report. "A visual inspection revealed the speed brake pushrod to be installed
upside down and bent—causing it to rub against the thrust reverser solenoid and preventing full travel of the
speed brake handle. It was confirmed with Cessna Engineering that the pushrod should be installed with
adjustable end up—and the rod should be straight, not bent. The pushrod was replaced with new
(P/N 6760270-36). Operational checks were satisfactory." (Photos included in reference document) |
|
| Cessna: 208B; Cracked Bulkhead; ATA 5312 (March 2012) | This submitter states, "The aft canted bulkhead (P/N 2612060-5) at station 474.40 has two cracks, each
approximately 1.5 inches in length. During removal of this part, other damage was found. Both vertical stabilizer
webs (P/N's 2631021-15 and 2631022-2) were replaced because of significant fretting, (so too) the aft bulkhead
assembly (P/N 2612059-1)." (Photos included in reference document) |
|
| Bell, Robinson, Agusta Westland: (All) Hardware Failures; ATA (n/a) (February 2012) | (This second safety admonition also comes from Aerospace Engineer Charles C. Harrison from the FAA's
Rotorcraft Certification Office. Contact information is found at the article's end. "Thank-you" to our Rotorcraft
office for good counsel—Ed.) |
|
| Bell: 206L-3; Improper Pitch Link Hardware; ATA (n/a) (February 2012) | (The following safety admonition is provided by Aerospace Engineer Charles C. Harrison from the FAA's
Rotorcraft Certification Office. Contact information is found at the discussion's end—followed by another
hardware Alerts article.) |
|
| Piper: PA44-180; Cracked Nacelle Angles; ATA 5413 (February 2012) | "During a scheduled inspection, a crack was found in the nacelle angle," states this mechanic. "Upon further
investigation the crack was found to (run) between the two rivets that extend through the wing skin into the cap
(P/N: 67097-002 or -003) which is attached to a web (P/N 67079-000 or 001). (This web) is where the main gear
aft attach point is mounted.
"(I) suspect this failure is caused by fatigue." (Photos included in reference document) |
|
| Hawker: 800XP; Corroded Fuselage Attachment Links; ATA 5741 (February 2012) | A repair station technician says, "Severe corrosion was found in the L/H lower, wing-to-fuselage casting lug
during a 12/8 year links/brackets/bolts inspection.
"Probable cause: exposure to constant moisture from improper fuselage-to-wing fairing sealing practices
(produced the corrosion), and/or constant exposure to TKS anti-icing fluid from improper plumbing practices that
may have lead to system leaks (and then subsequent corrosion).
"Recommendation: proper sealing methods (should be employed) when attaching wing-to-fuselage fairings. And
proper plumbing practices (should be used) when performing maintenance on wing anti-ice systems. Note: Use
of a corrosion preventative compound...at this location may prevent this condition ...with scheduled applications."
(Wing-to-fuselage link/bearing P/N: 25-8WS3103-1. The following photos are distorted vertically—Ed.) (Photos included in reference document) |
|
Hawker Beechcraft/ Hawker
|
|
| Cessna: 560XL; Broken ECU Aspirator Tube; ATA 3600 (February 2012) | An unidentified submitter provides this defect report. "(I) discovered this ECU aspirator high pressure
tube...broken on preflight. I also found the bias bleed air tube chafed. This condition appears to be (caused) by
poor tube routing, (creating) ongoing chafing over an unknown amount of time." (No part numbers were
provided with this report. But a couple of nice photos leave little doubt as to which tube is in reference. The
photos are distorted vertically—Ed.) (Photos included in reference document) |
|
| Cessna: 335; Corroded Wing Attach Fittings; ATA 5741 (February 2012) | A technician for an air charter service says, "During a 100 hour inspection, the forward upper L/H wing attach
point (was found to have) corrosion on the wing attach fitting (P/N 08113507). After removing the upper
wing-fuselage fairing, inspection revealed intergranular corrosion on the fitting, and severe rust on the mounting
bolt heads. The fitting was replaced due to the severity of the corrosion. Probable cause (for this corrosion) is the
fuselage-wing fairing not being sealed properly in the area above the fitting. This allowed moisture to pool in the
recessed area of the fitting, causing the rust and corrosion. The fuselage-wing fairing is riveted to the fuselage,
making (detailed) inspection of the upper forward mounts difficult." (Photos included in reference document) |
|
| Cessna: 208B; Cracked Elevator Pulley Support; ATA 5320 (February 2012) | An air operator's submission states, "The left pulley support web below the floor at FS (fuselage station) 120.0
and LBL (butt line) 10.0 cracked—from the left elevator bell crank mount bolt access hole to the end of the web."
(Pulley Support P/N: 2613083-1.) (Photos included in reference document) |
|
| Bell: 206L (-1,-3,-4); Main Rotor Blade Fatigue Cracking; ATA (N/A) (January 2012) | (Transport Canada provides the following Civil Aviation Safety Alert.) |
|
| Diamond: DA20-C1; Cracked Nose Landing Gear Forks; ATA (N/A) (January 2012) | (Transport Canada provides the following Civil Aviation Safety Alert.) |
|
| Cessna: 560; Fuel Ejector Contamination; ATA 7313 (January 2012) | (This report references a Pratt and Whitney 535A engine.)
"After a normal start," states this mechanic, "the L/H power lever was advanced to 'taxi'—and when retarded
slightly to adjust power setting, the 'low fuel pressure' annunciator was noted to be illuminated briefly, then
followed by the 'L/H Fuel Pump On' annunciator. Turning the electric fuel pump switch to 'off' and back to
'normal' extinguished the 'L/H Fuel Pump On' annunciator. The throttle lever was advanced and retarded as
before—and the problem repeated itself. Conferring with Cessna Citation technical representatives, it was
suggested to inspect the engine fuel filter (which was done). No contaminates were found. The fuel pump
pressure switch (P/N 9912033-2) was swapped Right to Left, but the problem did not follow. These were
returned to their normal positions. Cessna sent a maintenance team to defuel, inspect, and troubleshoot the
problem. Their results: a small plastic fragment was found restricting the output of the L/H fuel ejector (jet)
pump (P/N 9912190-5). The aircraft was refueled, operationally and leaked checked (okay), and returned to
service. As of this writing, the (plastic) particle and its source have not been identified. The fuel control was
recently replaced on the L/H engine—this may have been the source as it provides the motive flow fuel pressure
to the ejector." |
|
| Cessna: 550B; Failed Landing Gear Retraction; ATA 3230 (January 2012) | A submission from a corporate charter operation reads, "After departure from (the airport) the crew was unable to
retract the landing gear. The left main gear initially retracted—then returned to a down and locked position. The
right (main gear) and nose landing gear operated normally. After completing the gear malfunction checklist, the
crew returned to (the airport) for a normal approach and landing.
"Upon inspection, the cable for the emergency release on the left main gear was found to be adjusted too tight."
(The SDRS database has six entries for this aircraft's gear up-lock actuator: P/N: 5527504-2.) |
|
| Cessna: 550; Cracked Seat Base Assembly; ATA 2510 (January 2012) | The previous Alerts submitter provides another seat defect report from a different airplane. "The upper Seat base
assembly (P/N 5519015-16) was found cracked at the chair back attach points (seat base P/N: 5519009-22).
Metal fatigue and stress on the chair back is the probable cause. This chair was repaired in accordance with STC
STO1042WI."
(Note: extra "plywood" has been eliminated from the following photos to save a little space—Ed.) (Photos included in reference document) |
|
| Cessna: 550; Cracked Seat Base Assembly; ATA 2510 (January 2012) | (Note the next Alerts entry for a similar report—Ed.)
"The upper Seat Base Assembly (P/N 5519015—15) was found cracked at the chair back attach points," states this
repair station mechanic. "Stress on the chair back and metal fatigue are the probable cause. Also (observed) was
a previous, inappropriate repair.
"This chair was repaired in accordance with STC ST01042WI." (Seat base P/N: 5519009-21.) (Photos included in reference document) |
|
| Cessna: U206F; Trim Tab Actuator Failure; ATA (N/A) (January 2012) | (Transport Canada provides the following Civil Aviation Safety Alert.) |
|
| Bombardier: 700-1A10: Loose Power Cable; ATA 2497 (January 2012) | A repair station technician states, "The customer noticed an amber 'electrical system fail' CAS message (crew
advisory system). (Inspection) found a power cable for the number two TRU (transformer/rectifier unit) had
come free. Also found were two charred wire harnesses at the number two SPDU (Secondary Power Distribution
Unit)—and 'arcing marks' on the unit (itself). This arcing appears to have been caused by the loose power cable.
"The power cable P/N is 3PB189A4. It connects at one end to the TRU2 post on the forward side of the unit
labeled 'DC Power Center'. This unit is located under the floorboard of the cockpit entry area. The other end
connects to the bus bar of a unit (P/N 7274-11-15) which contains two fifteen amp circuit breakers. (This too is
found) under the floorboards in the same area. The circuit breakers are marked 'Feeder 1' and 'Feeder 2'.
"The charred wire harnesses are P/N's A13P5/A13J5 F230 and A13P6/A13J6 F235. These two harnesses connect
to cannon plugs on the SPDU assembly.
"No cause has been determined for the power cable coming loose. Bombardier technical representatives have
been notified and (they) will evaluate this issue)." (Photos included in reference document) |
|
Bombardier Learjet/Canadair
|
|
| Piper: PA31-350; Cracked Mail Landing Gear Trunnion; ATA 3210 (December 2011) | "Dye penetrant inspection revealed a small crack beginning to form on the trunnion—just below the bushing area
along a casting ridge," states this mechanic. "This was the R/H aft MLG trunnion (P/N 40288000). The aft
trunnion (L/H side) is identical and is not cracked. The forward trunnions (different P/N's) were found not to be
cracked...." "Although total part time is not known, it is assumed these parts are original equipment. We have
never replaced these on any of our other eight Navajo Chieftains." (Photos included in reference document) |
|
| Eclipse: EA500; Failed Aileron Joint Assembly; ATA 5751 (December 2011) | A mechanic for a repair station begins this report with a note, "Reference Eclipse Alert Service Bulletin
number 500-27-004 Rev. B: 'Aileron Joint Assembly Inspection and Replacement'.
"This service bulletin has procedures for inspecting/testing both wing's aileron joint assemblies—and replacing
the aileron joint assembly whenever the aileron fails a 'friction test.' The assembly fails testing when the bell
crank is corroded and frozen in the bearing of the fitting assembly. The attached photo has this corroded/frozen
condition. This corrosion is due to dissimilar metals.
"Since this (reference) is just a service bulletin, I suggest this inspection be upgraded to an Airworthiness
Directive to prevent possible aileron malfunctions from (those aircraft) not complying with the service bulletin." (Photos included in reference document) |
|
| Cessna: 550B; Sheared Flap Actuator Shaft; ATA 2752 (December 2011) | A repair station technician states, "The flap actuator shaft (55651915) was found sheared while performing Phase
One inspection task 27-51-710—Flap Motor Operational Check. No obvious reason for this shaft to have sheared
was found; no other defects were noted." (Photos included in reference document) |
|
| Cessna: 337D; Frayed Flap Cables; ATA 2750 (December 2011) | A repair station technician says, "(I) removed the L/H and R/H inboard flap extend cables from both inboard flap
bell cranks to inspect for wear and damage (per information from Cessna Pilot's Association and fellow type
operators during 100 hour/Annual inspection processes). Approximately one inch behind the cable end threaded
fittings on both cables I found significant broken wire strands/bundles. Undetected, these would have led to
eventual failure. These cables were the steel type with 3,795.4 hours (original cables). All flap cables were
replaced with new, and the flap system rigged from scratch per service manual. I suggest these cables be removed
and inspected on a 500 hour minimum basis as this is becoming an issue on Skymasters fleet wide. These cables
MUST be removed from the bell crank for proper inspection; they looked fine when installed, but were obviously
not airworthy." (Photos included in reference document) |
|
| Cessna: 208B; Failed Oil Cooler Vernatherm; ATA 7922 (December 2011) | "While in cruise flight," says this corporate submitter, "the pilot reported engine oil indicators showing oil
pressure lower—and temperature higher than normal. Upon removal and inspection of the engine oil cooler
Vernatherm (P/N 723655), it was noted (this unit) had started to come apart due to the failure of an internal snap
ring. This caused a restriction of the engine oil cooling system, resulting in the abnormal readings. When this
Vernatherm was replaced, the engine oil parameters returned to normal." (Photos included in reference document) |
|
| Cessna: 150L; Cracked Spinner Bulkhead; ATA 6113 (December 2011) | A repair station mechanic states, "This bulkhead (P/N 0450046-5) was installed in 2007 at 1,476.4 flight hours...."
"The part has been inspected after every 100 hours of flight. Upon the latest inspection, a crack was discovered at
the base of the propeller hub. (The hub was removed) and severe cracking was then (found), (traveling) 85% of
the (distance) around the center of the bulkhead. The spinner and the propeller remain undamaged.
"The original bulkhead from the factory lasted 5,808.7 hours before a crack began to form. The replacement
bulkhead was installed and inspected as per Cessna 150 service manual—(and) with the proper preload on the
spinner." "In my opinion: to prevent catastrophic failure, mandatory propeller removal should take place at least
every 200 hours of operation for a more thorough inspection of the bulkhead." (Photos included in reference document) |
|
| Beechcraft: 58; Broken Nose Gear Retraction Arm; ATA 3233 (December 2011) | "The nose gear arm (P/N 35-825172-13) failed upon extension of the landing gear on approach...," writes this
mechanic. "The pilot reported hearing a 'bang'—and could not get a nose gear 'down' indication. After a fly-by
and attempts to extend the gear, it was determined the nose gear would not come down and lock. The pilot landed
the aircraft—(and) the nose gear collapsed. (This) caused significant damage to the aircraft, including propeller
strikes and sudden stoppages of both engines. Actual cause of the part failure has not been determined at this
time." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Beechcraft: V35A; Cut Rudder Control Tube; ATA 2720 (December 2011) | A general aviation submitter says, "During the performance of an Annual Inspection, an IA (inspection
authorization) found the right ruddervator trim control cable was routed incorrectly and had cut through the right
ruddervator control tube (approximately 75%). The tube also had signs of a crack originating from the damaged
section of the tube (cut area), and had begun to bend as a result of weakening of the tube as it was being cut.
There were no maintenance entries noted in the log book to determine when this may have occurred." (If this
doesn't rate a steak dinner reward...nothing does!—Ed.) (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Eurocopter: SA365N3; Failed Pinion Roller Bearing; ATA 6520 (November 2011) | A mechanic states, "Failure of the Input Pinion Tapered Roller bearing (in the Tail Rotor Gearbox) occurred
during ground run after maintenance. This gearbox is discolored due to overheating of the failed (seized)
bearing." (Bearing P/N: 704A33-652-044; Gearbox P/N: 365A33-6005-08.) (Photos included in reference document) |
|
| Eurocopter: SA365N3; Improper Safety on Rotor Shaft; ATA 6320 (November 2011) | "The incorrect application of locking washers on the Rotor Shaft Nut retainer lock (P/N 117-12118-01) occurred
during installation of the replacement Rotor Shaft," says this technician. It was discovered while performing
Main Gearbox lower casing repair (removal of the rotor shaft is required)." (Lock washer
P/N: LN9023B5-145449.) (Photos included in reference document) |
|
| Zenair: CH2000 (series); Nose Landing Gear Cracks; ATA (N/A) (November 2011) | (Transport Canada provides the following Safety Alert.) |
|
| Cessna: 560XLS; Loose Elevator Push-pull Tubes; ATA 2730 (November 2011) | "(Note: the location of this defect...) is the rear of the aircraft in the compartment below the horizontal stabilizer
attach point," says this repair station technician. "Two push-pull tubes that attach to the aft elevator bell crank
(have nuts) that shank-out on the bolt. This allows the bolts to be rotated by hand, causing wear in the bell crank
attach hole." "(Now) the bolt begins to rock back and forth in the hole, resulting in chafing between the attached
parts.
"Recommendation: When installing hardware, assure the nut does not shank-out on the bolt. Replace the bolt if
worn, and add washers as required to prevent the nut from (bottoming on the bolt's shank)." (Photos included in reference document) |
|
| Cessna: 560; Flap Pulley Brackets Missing Rivets; ATA 5320 (November 2011) | A repair station mechanic states, "Three each rivets were found missing from the upper and lower flap
interconnect pulley brackets (P/N's 6565059-5 and 6565059-3) at fuselage station 354.00. (These) rivets were
found missing while performing an under-floor inspection—presumably omitted during production." (Photos included in reference document) |
|
| Cessna: Cracked Main Landing Gear Casting; ATA 5343 (November 2011) | "The (main landing gear attach) casting crack was found by visual inspection," says the repair station technician.
"The crack is located on the forward end of the support casting, and (starts) 0.25 inches from the mount holes on
the outboard side (and extends) to within 0.25 inches of the mount holes on the inboard side of the casting
(P/N 07416031)." (Photos included in reference document) |
|
| Beechcraft: 200; Cracked Spar Attach Fitting; ATA 5740 (November 2011) | A general aviation submitter states, "While accomplishing a wing bolt inspection, the L/H lower wing spar attach
shear fitting was found cracked (P/N 1011100731). This crack is approximately 0.75 inches long—located in the
forward flange area." (Photos included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Piper: PA28R-180; Corroded Spar Attach Fittings; ATA 5711 (October 2011) | A mechanic writes, "During repair of the L/H wing, the aft spar attach fitting was removed. Severe corrosions
was found under the fitting. Possible cause is trapped moisture, lack of a preventing treatment(s), and lack of
proper inspection of the area." (L/H Aft Spar P/N 62054-000. This number is found three times in the SDRS
database—and several more times as the trailing zeros are removed in the search.) (Photos included in reference document) |
|
| Piper: PA25; Failed Landing Gear Shock Absorber; ATA (N/A) (October 2011) | (The following Civil Aviation Safety Alert is a reprint from our sister agency, Transport Canada.) |
|
| Gulfstream: GIV; Cracked Seat Torque Tube; ATA 2510 (October 2011) | "The co-pilot's seat was removed for recovering," states a submitter. "During the recovering (process) it was
noticed the seat height adjustment torque tube was cracked (P/N 2A0590174). The technicians working on the
seat said this was not an uncommon failure." |
|
| Gulfstream: G200; Burned Ice Detection Circuit Card; ATA 3097 (October 2011) | "After takeoff," states an unknown technician/pilot, "(I) noticed a very slight electrical smoke odor. After
climbing through 24,000 feet, and the left and right 'Ice Detect Fail' EICAS came on simultaneously (Engine
Indicating & Crew Alert System). These lights came on for about thirty seconds, then disappeared. Annunciators
appeared about thirty seconds later (for a few seconds) around (approximately) 20,000 feet. They remained
extinguished for the rest of the flight. No circuit breakers tripped, and everything looked normal on the electrical
and secondary EICAS pages.
"After landing, the odor appeared to be coming from wires from the avionics box located behind the pilot's seat—
on top of the potable water controls. I found the ice detectors to fail the self-test and the system test. The system
would heat normally, but no EICAS indication would (generate). We verified the ejector valve heater blankets
had not failed by performing resistance checks at relay 350H in the right relay junction box. We investigated this
right relay junction box for faults and damaged components. We found the PC diode card 82P to be discolored
and displaying burn marks. We removed and replaced card 82P with a new unit. Operational check was good.
No further faults were noted." (Circuit card P/N: SPE3508005001.) (Photos included in reference document) |
|
| Cessna: 680; Cracked Air Service Tube (rudder actuator); ATA 2722 (October 2011) | A repair station submitter says, "(I) found the service air tube assembly cracked in the bend radius that leads to the
rudder bias actuator in the tail cone." (Tube assembly P/N: 6914040-37.) (Photos included in reference document) |
|
| Cessna: Series 150/152; Seat AMOC for AD 2011-10-09; ATA (N/A) (October 2011) | (The following discussion and efforts are credited to Aerospace Engineer Gary Park of the Wichita Aircraft
Certification Office, and the Lead Organization Designation Authorization Administrator--Mr. John Bouma of the
Cessna Aircraft Company. Many others made contributions to help in this topic's publication; those whose names
appear on various documents, and those who remain in the background. "Thank-you" goes out to everyone's
labor.
The first part is Mr. Park's summation of the Airworthiness Directive difficulty and its Alternative Means of
Compliance solution. The second part is the Wichita Aircraft Certification Office's approval of the requested
AMOC, providing more background information. The third part is the actual Repair Definition from Cessna
Aircraft. This data stands published as received. Contact information follows at the end—Ed.)
"The FAA has provided a Global Alternate Method of Compliance (Global AMOC) letter to Airworthiness
Directive (AD) 2011-10-09 that allows repairs to the steel seat foot/roller housings on Cessna 150 and 152
airplanes—using Cessna Repair Definition document S-150-ATA25-01RD, Revision A, dated August 3, 2011
(attached). This Global AMOC is necessary since the effected parts cannot easily be removed from the seat and
replaced. October 2011 AC 43-16A
Page 8
"Readers might also reference the Government Docket: Number FAA-2010-1101 at the following website for
these documents:
http://www.regulations.gov/#!docketDetail;dct=FR+PR+N+O+SR;rpp=10;po=0;D=FAA-2010-1101
Here they will find the FAA Global AMOC, the Cessna Repair Definition document S-150-ATA25-01RD, and
the FAA Approval form 8100-9.
"Provided next for this Alerts publication are copies of the FAA Global AMOC, followed by the Cessna Repair
Definition." |
|
| Beechcraft: B58; Broken/loose Elevator Balance Weights; ATA 2730 (October 2011) | A repair station mechanic states, "During an Annual Inspection, (I) found the L/H elevator balance weight
(P/N 96-610022-7) detached from its mount. The R/H elevator balance weight was found (both) broken and loose
on its mount. The detached L/H weight was able to shift position inside the elevator and cause an out of balance
condition. This damage appears to be caused by vibration." (That—and toss in a ton of corrosion, too—Ed.) (Photo included in reference document) |
|
Beechcraft/ Hawker Beechcraft
|
|
| Eurocopter: AS350BA; Failed Hydraulic Pump; ATA 2913 (September 2011) | A submission from a Part 135 operator states, "The hydraulic pump failed in flight. (Our) pilot made a run-on
landing and shut down without damage. The hydraulic pump (P/N A50226780) was removed and replaced .
Splines on the pump drive coupling were found worn. (We) replaced this pump with a new, 0.0 TSN (time since
new) pump (P/N 704A34310006) and a serviceable drive coupling." (Pump manufacturer: Hydroperfect
International. The SDRS database finds the "new" pump with 23 entries—Ed.) |
|
| Eurocopter: EC135T1; De-bonded Tail Rotor Blades; ATA 6410 (September 2011) | A helicopter technician says, "While performing a 1200 hour/36 month inspection of the tail rotor assembly, (I)
found three tail rotor blade (P/N L642A2002101) balance weight pockets de-bonded from the blades. One is
cracked and has a piece missing. These three blades were installed together 696.5 hours ago." (Photos included in reference document) |
|
| Bell: 47G-3B1; Loose Fuel Control Pneumatic Line; ATA 7320 (September 2011) | A technician states, "The pneumatic (control) line (Pc) came loose at the fuel control unit, causing the engine to
spool down in flight. Numerous Allison (now Rolls Royce) Commercial Service Letters have been issued on this
topic—but they seem not to have been followed. An AD (Airworthiness Directive) should be considered to
enforce compliance with (this) line security. The pneumatic system lines on these series engines are a known and
continuing problem. (When) a pneumatic line to the engine fuel control comes loose on this series of engine, it
causes loss of engine power control." (Allison engine model: 250C10D; Line P/N: 6870035. The SDRS
database lists five of these pneumatic control lines.) |
|
| Swearingen: SA227AC; Burned Deice Boot Wires; ATA 6112 (September 2011) | "During a routine service check inspection," says a Chief Inspector, "two of the four propeller deice boot leads
(P/N SMR23692) were found to have broken and burned ground wires. The ground wires were broken in the
exact same place and showed small signs of burned or singed insulation at the point where the wire separates."
(Rotol propeller model R321482F8.)(Photos included in reference document) |
|
| Cessna: T337G; Wing Structure Damage; ATA 5710 (September 2011) | A repair station technician writes, "This aircraft was brought in for inspection per SAIB (Special Airworthiness
Information Bulletin) CE10-20, and an Annual Inspection. The aircraft is equipped with Aviation Enterprises
extended range fuel STC (Supplemental Type Certificate), and Aviation Enterprises winglet wing tip STC. The
aircraft is also equipped with (this company's) Stall Fence STC, and Boom to Vertical fairings. An inspection in
accordance with the SAIB was performed.
"Compression bulges of the (wing's) internal stringers (on the) upper surface were noted on both wings between
WS (wing station) 192 and WS 177. At the installation point of the long range fuel tank (WS 222), approximately
half of all the 8-32 (installation) screws had no washers or nuts installed. (The structure looks to have been
tapped for threads.) The L/H upper surface wing skin between WS 77 and WS 192 had 'smoking' rivets, and
compression was evident in the skin. The R/H wing between WS 177 and WS 192 had compression bulging,
'smoking rivets', and cracks in the skin at WS 177.
"At WS 222.0, a 2 inch section of the lower part of the end rib was cut down from the lightening hole in an
unacceptable fashion in both wings. The R/H wing at WS 55.0 (outboard of the boom) had a compression buckle
in the upper surface wing skin.
"The stall fences (at the time of removal) were installed at WS 132. It was (observed) these fences had been
previously located at three (different) areas in each wing. At WS 120, WS 90, and WS 81 the attachment
(fasteners) at each location were 8-32 machine screw holes—these drilled and tapped through both the forward
and rear spar caps for a total of 16 additional holes in each wing's upper spar caps.
"At R/H WS 121, the upper aft spar cap has one hole with no edge distance—this broken through the edge of the
cap. Additionally (and unexplained) this same cap has 10 counter-sink holes (hand-bored) too deep (and oblong)
for number 30 rivets.
"The (remainder) of the aircraft shows no evidence of structural overstress. My Chief Inspector has been
involved with hundreds of Cessna 337 aircraft in his 32 year career—he has owned 42 (such models). He has
seen the effects of overstressed Skymaster wings many times. This stress appears in the upper leading edge skin
just forward of the tank top at a 45 degree angle pattern (relevant to the leading edge), from WS 66 and/or
WS 79.6—sometimes extending to WS 93.6. Additionally, the counter-sunk 10-32 screws in the fuel tank top
covers often pull through the outer skin in cases of repetitive stress—with high total time cracks generally
appearing at the tank top cover screw locations.
"STC's: 1) Wing tip fuel tanks: STC CA02055AT, 2) Aviation Enterprises Lightening Wing Tip: STC
SA01094AT, 3) Tail to Boom fairings: STC SA01093AT.
"These three STC's were installed at Hobbs time 1,071.5 (for a total) 899.5 hours." (Aircraft total time: 2,778.5
hours. Thank-you for taking time to itemize this mechanical disaster. Had you included photographs I would
have needed "chalk" to settle my stomach—Ed.) |
|
| Bell: 407; Generator Relay Malfunction; ATA 2430 (August 2011) | "While enroute, an attempt was made to start the searchlight," states this pilot. "Upon noticing the searchlight did
not light off, (I) checked the instruments and found the voltmeter below 25VDC. I attempted to reset the
generator with no success. I noticed the ammeter at zero—and then returned to the airport without incident. The
next morning an inspection and ground run was performed to troubleshoot the system. We found the generator
output at 28VDC, no amperage, and no generator fault Master Caution Light illuminated. These indicators led us
to believe the generator relay to be at fault. Access was made to the DC power panel (FS 155). There we noticed
discoloration of the power panel cover. Upon removal of this panel we found a wire (P20A12) between the 2K3
generator relay and the 15A circuit breaker (2CB6) 'Generator Field' had melted insulation at the bus bar. And the
wire (D10A22) between (its) 5A circuit breaker (2CB2) 'Ammeter' and the 2R1 shunt (we found) to have a melted
wire terminal at the shunt. Neither circuit breaker had opened." (Part number for DC Power relay:
SM20ACD300A21; manufacturer name: Eaton. There are 31 of these relays listed in the SDRS database.) (Photos included in reference document) |
|
| Bell: 214ST; Cracked Tail Rotor Mounting Flange; ATA 6510 (August 2011) | "During a 25 hour check," states a technician, "the number six tail rotor driveshaft mounting flange was
discovered cracked on the output side of the IGB (intermediate gearbox) coupling. The cracks are (located)
around the bolt holes. The tail rotor drive shaft is on-condition (replaced if needed)." (Drive shaft
P/N: 214040622005. There are nine of these P/N's in the SDRS database.) (Photos included in reference document) |
|
| Taylorcraft: BC12D; Cracked Rear Wing Spars; ATA (N/A) (August 2011) | (The following submission was received as e-mail, and as of this time it has not been placed into the SDRS
database; hence, there can be no ATA code—Ed.)
"I am submitting these photos of the rear spars removed from a 1946 Taylorcraft BC12D," says this mechanic.
"The photos show several cracks on both spars. One spar was intentionally broken to show the extent of the
vertical crack. This aircraft has 185.8 hours since restoration, and 9 years in service. At some point in the history
of this aircraft it apparently had been ground looped on both wings before the previous fabric replacement. We
have now replaced all four spars due to questionable wood.
"I recommend very extensive visual inspection techniques using high intensity lights and mirrors. Pay particular
attention to the upper and lower spar surfaces for vertical cracks—especially near the butt end where the plywood
reinforcing plate ends and the spar mill taper begins. If in doubt, remove the fabric cover for better inspections." (Photos included in reference document) |
|
| Piper: PA28-RT201; Failed Landing Gear Power Pack; ATA 2913 (August 2011) | A repair station submitter says, "After (the pilot's unsuccessful attempt) to perform emergency main landing gear
extension several times, this aircraft made a successful, gear-up landing. The hydraulic (landing) gear Power
Pack motor (P/N HYC5005) failed during initial gear retraction after takeoff. Investigation and troubleshooting
determined the cause of the Power Pack failure was due to a fracture of a questionable solder joint that attached
one electric motor brush pigtail to the brush holder. The broken solder joint created enough heat from high
resistance to discolor the brush holder and anneal the brush spring. This re-heated spring's free length measured
0.330 inches instead of the (normal) 0.960 inches. The Power Pack had been overhauled 29 months earlier
(or 142.5 hours). Further troubleshooting revealed the static port in the left automatic MLG extension airspeed
mast was solidly plugged with a mud (type) insect's nest." (Brush P/N: ESQ12SBRUSHERH22. Power Pack
manufacturer: Prestolite; model HYC5005. This motor has 15 entries in the SDRS database.) (Photos included in reference document) |
|
|
