Fixed Wing

SWEARINGEN, SA226TC
SDR # 20090106005
Ruptured Hose Causes Flapless Landing

SDR submitted:

Upon climb-out the aircraft's hydraulic warning lights illuminated and hydraulic pressure was lost. The aircraft returned to the airport and performed a flapless landing with the emergency gear handle activated.

Maintenance discovered the hydraulic flexible hose from the hydraulic power pack to the accumulator in the L/H wheel well ruptured at a bend radius. The design of the aircraft required this hydraulic hose to have a significant bend in the hose so it could be routed correctly.

Minor chaffing of the steel braiding on the hose was found but was not significant enough to cause the rupture in the hose.

The hose was replaced and the aircraft returned to service.

Ruptured hose

SWEARINGEN, SA226TC
SDR # 20090106005
Bleed Air Control Valve - Improper Assembly

SDR submitted:

Maintenance replaced the bleed air valve solenoid after it was being reported as defective. Valve Part Number (P/N) 320250-4-1 is located in the R/H wheel well of the aircraft and by design is in fairly close proximity to the landing gear tires when the gear is retracted.

After replacement of the valve, the AME did not notice the electrical connection for the valve was oriented differently than the valve previously removed. The wire harness and connector could be connected in this different configuration.

Normally with the valve installed, looking forward the connector is at the 2 o’clock position. This replacement valve has the connector located at approximately the 6 o’clock position. The aircraft was dispatched and after takeoff, the crew retracted the gear and noticed the R/H main landing gear (MLG) remained in transit rather than locking in the up position. The gear was recycled with no success. The crew elected to return to the airport and landed without any further problems.

Maintenance immediately noticed that the No. 3 tire had rub markings on it from contacting the bleed air valve solenoid’s connector during retraction attempts. This damaged the valve bracket and the cannon connector; the valve itself was not damaged.

AMEs realigned the cannon plug connector and reinstalled the valve with a new bracket. They then, performed a gear swing and released the aircraft.

The company has inspected the remaining valves in their fleet stock for any discrepancies that may cause this same occurrence.

Transport Canada Comments:
Ensure correct orientation of parts before installation.Hammer and wrench in X formation indicating end of article

Bleed air control valve

Beech B200
SDR # 20090728011
Wing Rib Cracks (WS 121.966)

SDR submitted:

During inspection, the technician found cracked wing ribs at both the R/H and L/H wing rib leading edges located at Wing Station (WS) 121.966. The affected ribs were L/H wing ribs part numbers (P/N) 50-980002-825 &000-11-133-21, and R/H wing ribs P/Ns 50-98002- 826 &000-110133-22.

The submitter stated that the cracks appeared to be caused from fatigue, as there was no evidence of a manufacturing tooling mark or other induced causes.

It is of interest to note that three additional aircraft in the operator’s fleet also reported cracking of wing ribs. These cracks were all located at WS 121.966, which is immediately outboard of the engine nacelle.

Transport Canada Comments:
Engineering specialists opined that these wing rib cracks located at WS 121.966 were likely the result of vibrations coming from the propellers and engine mounts. A secondary factor may have been that landing loads were transferred to the subject wing ribs. In this case, the 3 aircrafts operate from gravel strips and have “approved STC” for larger tires and brakes installed.

The Type Certificate Holder has been notified regarding this defect. Hammer and wrench in X formation indicating end of article

SWEARINGEN, SA226TC
SDR # 20090925005
Smoke in the Cockpit

SDR submitted:

On approach the crew had just selected full flap on the final landing checks when they noticed smoke in the cockpit. Since they were less than 5 km final, they elected not to put on their oxygen masks. The crew dumped cabin pressure, turned the bleed air off and turned the fresh air fan to override. Smoke continued to accumulate in the cockpit.The crew turned both generators off and continued on approach.

After landing the crew informed Air Traffic Control that they had smoke in the cockpit, they immediately stopped the A/C and evacuated.

Maintenance found that a flap down hydraulic line had ruptured at the L/H wing center section in the vicinity of the bleed air-mixing valve. The hydraulic fluid found its way into the air conditioning system and created the mist vapor event in the cockpit and cabin. There was no fire.

The company replaced the line and cleaned the air conditioning system and released the aircraft. The company will be doing a fleet wide inspection to check for damaged hydraulic lines in these areas and ensure correct installation of the gaskets on the air conditioning valves.

Transport Canada Comments:
Although sometimes fretting is unavoidable, the need to inspect rigid lines and wires for chaffing cannot be stressed enough. Hammer and wrench in X formation indicating end of article

Smoke in the cockpit

GULFSTREAM - ISRAEL, GULFSTREAM 200
SDR # 20090715002
Windshield Terminal Arcing

SDR submitted:

While conducting the 1200 hour inspection of the R/H windshield, "the Anti Static Coating" on the G200 was found unserviceable and did not meet the specifications required in the manufacturer’s maintenance manual. The windshield required replacement and upon removal found that, one of the power cables arced to the aircraft’s structure due to poor insulation on the terminal end. The windshield and terminal end of the power cable were replaced.

Transport Canada Comments:
The operator ensured that the adequate clearance between the terminals and aircraft structure was obtained. Hammer and wrench in X formation indicating end of article

Windshield terminal arcing

DHC 8 100 series
SDR # 20090604007
Main Landing Gear (MLG) - L/H Door Roller Seized

SDR submitted:

The sircraft landed with a L/H MLG indication snag. Maintenance crew put the aircraft on jacks and commenced troubleshooting. The first functional gear check was fine, however on the second selection, the L/H gear door did not open and the gear was "hanging up" on the door. The gear was then successfully selected back to the "up" position. However, when the Alternate (Emergency) Gear "down" selection was made, the gear still hung-up on the door, preventing full extension.

Whenever the maintenance crew disconnected the door linkage, the landing gear extended as per normal. Further investigation revealed that the door roller for the L/H door was seized. This prevented normal door operation and subsequently prevented full gear extension.

The SDR submitter stated that the forward door actuator and door roller is visually inspected at "A" check interval. The operator could not find any specific instructions for lubrication of the actual door roller.

Transport Canada Comments:
Bombardier have completed their investigation and determined that rigging related issues and damaged door linkages were the primary cause of this problem.Hammer and wrench in X formation indicating end of article

Main landing gear - door roller seized

Beech 1900C
SDR # 20090619002
Flap Shaft Cable - Severed

SDR submitted:

During routine ground flap functional checks, the L/H outboard flap did not move, however the flap asymmetry switch activated as per design to prevent a split-flap condition.

Upon further investigation, maintenance crew discovered that the L/H outboard flap cable was broken at the flap actuator end.

The SDR submitter stated that corrosion was evident at the area of the cable breakage. It appears that if the flap outer cable sheath, is damaged or cracked, then pressurization air can force the lubricating grease out, thereby allowing moisture to enter the housing. This can result in binding and corrosion.

Transport Canada Comments:
A service history review revealed several previous flap cable failures where cable corrosion was evident in the flap drive sheathing and flap cable.

The FAA issued AD 2001-18-07 (SB 27-3397) to inspect for any incorrectly configured flap flexible shaft assemblies that could result in an asymmetrical flap condition.Transport Canada recommends that owners/ operators pay frequent and particular attention to the condition of the flap cables. Hammer and wrench in X formation indicating end of article 

Flap Shaft Cable - Severed

Fairchild, SA227 AC
SDR # 20090715001
Ignition Wiring Burns

SDR submitted:

During an engine start on the ground, it was noted that several circuit breakers popped at 10% engine speed when the auto ignition cut-in. After an in-depth inspection, wiring at the L/H wing lower fairing area was found burnt at multiple locations. The wiring was repaired and the aircraft returned to service.

Transport Canada Comments:
The operator is conducting a fleet inspection to determine if there are similar defects.
Hammer and wrench in X formation indicating end of article

Ignition wiring burns

BOMBARDIER, CL600 2D15 (705) 2D24 (RJ900)
SDR # 20090624003/20090820010
Brake Line Quick Disconnect Fitting

SDR submitted:

After landing, the flight crew reported that the aircraft required a lot of power to taxi and the L/H side brakes seemed to be dragging. Once clear of the runway, they stopped on the taxiway and the tower confirmed that their No.1 Main Wheel was flat. Maintenance Personnel found the No.1 Main Wheel had a large flat spot and hole in it indicative of landing with a locked brake. The No.1 brake quick disconnect fitting was loose; it came off with only ½ turn. The loose fitting allowed hydraulic pressure to be trapped in the brake causing it to remain locked on landing. The quick disconnect fitting, product number H155006-191-001 (IPC 32-11-35, FIG. 1-180) was tightened and locked, both main wheels were replaced and the aircraft returned to service.

The AME that completed this work mentioned that he has seen this issue before more then once, where the quick disconnect fitting is loose or in one case completely off (which caused the brake not to work at all). It appears that this fitting is susceptible to backing off if it is not correctly locked.

Transport Canada Comments:
The OEM is currently investigating this issue. In the interim, Transport Canada strongly recommends maintenance personnel to pay extra attention during maintenance activity around the wheels and brakes area.
Hammer and wrench in X formation indicating end of article

Fitting is not locked

Fitting in the locked position

Bombardier CL415 Turbo
SDR # 20090129008
Cable Tension Compensator (Aileron/Rudder Interconnect)

SDR submitted:

During a routine inspection, the AME found the compensator assembly completely "jammed".

The operator then conducted similar inspections on all 8 remaining aircraft in their respective fleet. Several of the cable tension compensator assemblies were found seized and distorted (bent).

Transport Canada Comments:
On each aircraft both the cable compensator assemblies are installed on the fuselage roof between FS434.84 & FS481.50 Fuselage Stations. The interconnect between the rudder and aileron system is linked through a cam/ pulley, bellcrank and summing lever. The purpose of this assembly is to assist the pilot in making coordinated turns during flight operations.

It is recommended that owners/operators closely inspect this assembly at the next opportunity. Hammer and wrench in X formation indicating end of article

Aileron/rudder interconnect

GULFSTREAM - ISRAEL, GULFSTREAM 200
SDR # 20090724004
L/H Engine Fire Loop Failure

SDR submitted:

On climb out at approximately 18 000 feet, the pilots reported that the L/H engine fire detection system indicated failed. The pilots reported that the checklist had been completed and as a precautionary measure proceeded to shut down the engine in flight.

The aircraft was re-routed and declared an emergency. The tower reported that no flame or smoke could be seen from the L/H engine.

After an uneventful landing, maintenance was called to investigate and found the Fire Loop in Zone 2 had failed.

Gulfstream and Pratt &Whitney were informed of the failure.

Further investigations revealed that the cause of the failure was a missed and unused clamp at the end of the loop.

The Zone 2 Fire Loop was replaced, utilizing this last clamp a ¼ inch from the end of the loop, limiting frequency vibration.

The aircraft was ground run and a functional check was carried out on the Fire Loop and all systems operated serviceable.

Image of engine fire loop failure

Diamond DA42 series
SDR # 20090122002
Nose Landing Gear (NLG) Tubular Pivot Assembly

SDR submitted:

Several recent SDRs have described a misalignment problem regarding the NLG gudgeon (D60-3233-82- 31) within the tubular pivot shaft (D60-3233-82-32). The SDR submitter stated that the misalignment only occurs on the L/H gudgeon and always opens toward the aft direction; when the nose gear is down and locked. Another SDR reported the NLG failed due to shearing of the L/H gudgeon within the tubular shaft. As a result, the L/H wall of the wheel well was damaged directly due to NLG component mislocation.

The NLG spring assembly and the NLG actuator driving the down lock mechanism can create excessive forces that the tubular pivot assembly cannot tolerate. Repeated forces on the gudgeon may result in a "belling" deformation on the tubular pivot shaft.

Transport Canada Comments:
Diamond Aircraft (Austria) has taken corrective action and recently issued Mandatory Service Bulletin (MSB) 42-070/1. The subject MSB provides instructions to check for excessive wear and gap between the Tubular Pivot and L/H Gudgeon. If the gap exceeds specified limits, the tubular pivot tube assembly will require replacement.

Transport Canada (TC) strongly recommends that owners/operators comply with the aforementioned MSB. Failure to do so could possibly result in the collapse of the NLG. Hammer and wrench in X formation indicating end of article

PILATUS - SW, PC 12 47E
SDR # 20090805001
Passenger Door Shoot Bolt Unsafe

SDR submitted:

After a flight, the crew attempted and was unable to open the passenger door.

The crew noted that the upper forward shoot pin indicator remained "green" with the handle in the open position. The door panel was removed for inspection and maintenance noted that the retaining bolt for the upper forward shoot pin had migrated out of position.

The nut for the retaining bolt was found dislodged and had fallen within the door.

The bolt and nut were reinstalled into the shoot pin linkage, the nut was torqued in safety and the aircraft was returned to service.

Transport Canada Comments:
The operator noted that no maintenance had been performed in this area since the manufacture of the aircraft and suspected that the nut was never torqued in safety during its initial installation.
Hammer and wrench in X formation indicating end of article

Image of unsafe door shoot bolt

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