B757 ENGINEERING CONTINUATION TRAINING

Transcription

1 B757 ENGINEERING CONTINUATION TRAINING Q3 & Q4 2013

2 Contents 1 DHL Air Procedures Review 2 EATL Procedures Review 3 ETCS & AENs Airworthiness Directives UK Maintenance Related MOR

3 1 DHL Air Procedures Review For clear and precise instructions on how DHL Air require their Technical Logs to be completed, refer to the following! See DHL Air DAEP CD for DAEP No 6. Tech log completion See DHL Air DAEP CD for DAEP No 8 (General Section) Deferred Defect See DHL Air DAEP CD for DAEP No. 14 for AWOPS operations See DHL Air DAEP CD for DAEP No. 15 for RVSM operations. DAEP s: B757 Maintenance Tips: Available on CD Available on TechCom 2 EATL Procedures Review EATL CAME Part 1.1 Aircraft Technical Log Utilization and MEL Application. See EATL CAME for RVSM operations See EATL CAME for All Weather Operations

4 3 B757 ETC & AENs Below is a summary of all Engineering Technical Circulars recently issued by EATL and AENs issued by DHL Air SBs & ADs in TRAX Pitot Cover Installation

5 Cold Weather Operation IDG Thermal Relief Drain Line

6 ELT Hex Codes Fire Detection Cards

7 Rudder Trim Correction in Flight EFIS Symbol Generator OPS upgrade -012

8 Introduction of SDR (Structural Defect Report) Spinner Installation Preventing Damage

9 Exhaust Collector Fairing Repair Scheme AEN Number: 71E Protection of Aircraft from Precipitation / FOD & Insects

10 AEN Number: 72E Flight Deck Window Sun Shades AEN Number: 73E MCD Inspection RB211

11 4 B757 Airworthiness Directives Below is a listing of Airworthiness Directives issued over the last period: AD Reference: Loss of Boost Pump Pressure AD Reference: Foreign Object Penetration AD Reference: Broken Support Fittings Inboard Track / Inboard Flap

12 AD Reference: Standby Power Relay Failure 5 B757 Maintenance Related MOR The following are technical related extracts from the UK CAA MOR data base related to the B757 family. The information is protected by the UK CAA and the monthly digest are now strictly controlled by them. It is respectfully requested that with this in mind, the content of the following is not copied or distributed in any way. DHL Air Ltd MAYDAY declared and aircraft diverted due to cabin pressurisation failure. LH engine 'bleed off' message on take-off roll. Message cleared and take-off continued. QRH completed in climb which included removing LH pack. Climb stopped at FL340, approx 10mins afterwards, EICAS message, master warning and aural warning of 'cabin altitude' activated. Recall items completed, QRH actioned and decision made to divert. MAYDAY was declared and flight crew donned oxygen masks. During the QRH procedure it was noted that the cabin outflow valve was fully closed and cabin altitude indicating 11000ft and rising. On ground, during 4psi ground pressurisation cycle, most of the doors had notable or significant leaks reported by maintenance. Jet 2 Electrical wires found cut and protected with heat shrink. No Tech Log entry/add for inoperative panel lights. On inspection of wiring on panel area the four wires from the a/c to the panel were found cut and protected with heat shrink. Reporter suspects cables severed at hinge point of door and were cut to prevent refuel C/B popping. CAA Closure: Review of the maintenance history noted that no entry for capping of these wires can be found. It is not known how long or why these wires were terminated incorrectly. Engineers have been reminded to remain vigilant for wiring issues and a wiring defects review will be carried out to work towards additional training for all Engineers related to the operators aging fleets wiring issues.

13 Jet 2 Landing gear indication fault due to incorrectly installed part. After check flight on arrival, crew reported that half of Nose Wheel green indication was U/S on standby power, engineers found that light assembly installed should not be on that position. Part found P/N is for parking brake indication, defect card and photo of part found installed in attachment. DHL Air Incorrect installation/routing of RH aileron control cables. Crew had complained of aileron controls being 'heavier than normal' in flight. Investigation found that the RH control cables had been wrongly routed which had also caused chafing/damage to the pulley assemblies. CAA Closure: During engineering investigations, it was discovered that the RH aileron cables, A2A-4 and A2B-4, were replaced at the last C Check in August During the following 18 months, numerous attempts were made to rectify reports of stiff ailerons. Records showed that the cables were disconnected during the replacement of the lateral control override mechanism in Sep 2012, but it would not have been necessary to rethread the effected cables through the pulley guards. A fleet wide inspection of the aileron cables of both the LH and RH wings were found routed incorrectly on another company aircraft, which again was the wrong side of the pulley guard causing damage to the guard. This aircraft had no reports of stiff ailerons. Investigation found no evidence of cable replacements during line maintenance or during the previous C Check. However it was noted that a zonal inspection performed in the area at the previous C Check should have allowed the misrouted cable and pulley guard damage to be identified. From the investigation, the evidence indicates it is highly probable the cables were routed incorrectly during installation at C Check in August The third party maintenance organisation that carried out the C Checks has discussed this issue with their certifying staff and a Quality Notice has been issued to remind all certifying engineers of the need to check the complete cable run following cable replacements and during zonal inspections, to ensure correct cable routing. DHL Air RH engine failure. MAYDAY declared. EICAS 'Gen Off' message and caution sounded at approx 1000ft. FO started the APU. Shortly after, the a/c started to yaw slightly to the right and Captain noticed the RH engine running down. Captain disconnected autopilot and autothrottle and continued manually. FO declared MAYDAY to ATC and advised a/c would be stopping on runway. Engine failure QRH carried out once stopped. No signs or fire or smoke. Fire services gave the go ahead to move to secure stand. Engineers attended and engine start carried out. Start was normal. Engine shut down. The engine concerned subsequently ran down on two further occasions. CAA Closure: Due to the variety of component changes carried out during the rectification of the three separate engine shut down events, it was difficult to allocate a root cause to a single item. The maintenance organisation made a closure recommendation based upon test cell findings of HP bleed valve and fuel flow governor failings. After rectifying the faults identified at the test cell, the engine was again tested and passed tests satisfactorily. A rundown failure did not occur. Jet 2 Excessive oil consumption nr1 engine. IDG QAD ring found to be coming loose. The mounting bolts were found to be finger tight and the ring not held securely. When removed, the ring was found to be worn around the mount bolt holes. QAD ring, gaskets and mount bolts all replaced and ground tested with no further evidence of oil leaking.

14 Thomas Cook Forward cargo bay liner tape applied incorrectly. During cleaning of the forward cargo bay it was noticed that the cargo liner tape had not been applied correctly. The side walls had only the fastener heads sealed but none of the panel joints had been taped allowing leakage of fire retardant out of the cargo compartment. The cargo hold did not comply with the requirements of a Class C smother type bay. Investigation under Jet 2 Loss of left hydraulic system. LEFT HYD QTY and left RSVR lights illuminated after take-off. QRH actioned and Maintrol advised. Aircraft given instruction to proceed to destination unless any further loss was experienced. Intermittent RUDDER RATIO and LEFT ENG PUMP EICAS alerted. Crew elected to divert and PAN declared. L HYD SYS EICAS alerted and emergency upgraded to MAYDAY. Multiple EICAS messages received on lowering landing gear and all remaining fluid lost. Normal landing made but nose steering failed as expected. Hydraulic fluid found around nose gear bay and underside of a/c and inner starboard wing. CAA Closure: It was determined that the NLG actuator retraction hose had split. Hose replaced without any further investigation as to the cause of the hose splitting as the aircraft in question was a lease aircraft and the age of the hose was not known. During replacement, it was noted that the NLG actuator housing had been incorrectly installed causing the hose to be incorrectly routed. Thomas Cook LH flight control valve closed during flight. On final approach, and fully configured, the 'L FLT CONTROL HYD' EICAS illuminated and increasing aileron was needed to fly straight. The a/c landed safely. CAA Closure: The LH flight control shut-off valve did not close and was replaced as a precaution. LH flight control shut-off valve replaced, rudder trim indications checked and 'S4 L HYD FLT CONT SHUTOFF' light on the P61 panel inspected for serviceability. Subsequent report from Boeing confirms that there was no EICAS indication of valve fault. Strip report for valve found slight internal leak and switch isolation fault. Thomas Cook Take-off rejected twice, on both occasions due to lack of thrust on RH throttle. Lever would not move. Same occurrence happened three days earlier. CAA Closure: RH engine throttle cable run inspected at engine and full and free movement checks performed. After further troubleshooting, fuel flow governor (FFG) replaced as problem suspected but fault not confirmed. Autothrottle clutch pack fault confirmed and pack replaced. Removed unit stripped and repaired. Jet 2 Elevator control problems experienced during landing. EICAS 'Stab Trim' message received and remained illuminated until a/c shut down. Autopilot was disconnected at 500ft. A/c was in trim. At 200ft the elevator felt heavy and attempts to trim appeared to have no effect. During flare the elevator felt difficult to pull back. Smooth landing carried out. After nose gear touchdown EICAS message 'Stab Trim' and overhead 'Stab Trim' light illuminated and remained on until aircraft shutdown. FO reset stab trim during taxi successfully.

15 Ground engineers attended aircraft at stand and requested hydraulics were switched on and tested elevator. Engineers agreed the elevator was extremely difficult to move. CAA Closure: Significant leak from LH centre elevator PCA ram gland seal found during troubleshooting. Visual inspection of elevator feel unit carried out with no apparent faults. During MRO repair several faults were found which required the reseal of the ram gland seal, rework of the piston, drive link and summing lever. Other faults were found with the relief valve operation and internal leakage. There have been no further reports of elevator control difficulty noted with this aircraft since the PCA replacement. Thomsonfly Unsupported APU bleed duct resulting in reports of noise and vibration. Following reports of cabin vibration and noise over a period of three months the aft cargo bay was inspected. During this inspection it was found that the APU bleed duct was unsupported along a length of 34ft and was due to eight of the support brackets being broken. It was also seen that the excessive movement of the duct had caused the elevator feel computer static pipe to become chaffed in two locations. Manufacturer is aware of the problem only on a different series of this aircraft type. Investigation under (vibration and burning smell) Thomsonfly Fuel tank wiring harness damaged. Aircraft currently undergoing Winglet modification and additional work. During installation of L/H Wing Main Tank FQIS Wiring Harness found wire damaged. The wire insulation was damaged exposing the wire conductor. The area of damage is approximately 5mm between L/H wing stations and Wiring harness replaced. Engineering report. An examination of the removed harness confirms that the wire insulation is damaged, although it is extremely difficult to tell if the conductor is exposed. As the harness had been removed and the damage only noticed during re-installation, it is not clear whether the damage to the harness occurred whilst on or off the aircraft. An inspection of the left wing in-tank harness, is included in the maintenance program, but has not so far been carried out on this aircraft. This task has been carried out on twelve aircraft so far, with no findings. All records were also checked for damaged tank harnesses, but nothing was found. The cause of the damage to the cable could not be determined. Thomsonfly Incorrect maintenance action. Inlet rivet head missing on nr2 engine. Aircraft released using a Technical Variance (previously used specifically for another aircraft) to clear a deferred defect using unapproved data for this aircraft. Aircraft AOG. CAA Closure: Investigations found that the Maintrol engineer on duty recalled the same incident on another company aircraft and found a copy of the with the Technical Variance attached. As there were no maintenance actions on the Technical Variance he thought he could apply the same parameter of the 50hr re-inspection, whilst Engineering waited for a Technical Variance to be issued specifically for the aircraft. The engineer was aware of operational pressures of the aircraft being able to complete the flying programme, with the root cause identified as a human factors error whilst having a can do attitude, as advice was not sought from the Airworthiness Department, within a prompt timescale.

16 On return to UK, the aircraft was taken out of service until a Technical Variance from the manufacturer was obtained. The engineer involved was advised of the erroneous situation and the impact of the error. All Duty Engineers were verbally communicated to making them aware of the occurrence and to advise them of the correct action to take for the future. It was also notified to the Training Department for use in Human Factors Continuation Training. Jet 2 Incorrectly assembled nose gear door actuator discovered during scheduled maintenance. Retract hose connector on nose undercarriage door actuator found to be incorrectly orientated, sufficient to cause the hose to foul on the door operating bellcrank. A/c had recently had a down route incident where the hose had ruptured causing total loss of LH hydraulic system contents. The hose had been replaced but whilst in maintenance it was noticed that the replacement hose was showing signs of wear. The actuator fitted had the retraction hose port incorrectly orientated. The new replacement was then found to be similarly at fault. CAA Closure: The aircraft in question was new to the operator under a lease agreement and had as such not been through any 'A' Check by the operator's own maintenance organisation. Further investigation is not possible as the records for this aircraft have been passed across to the new owner. DHL Air During investigation of autoland and ILS system malfunctions it was found that MEL was outside time limits. A/c operating with a known defect. Autoland status was downgraded for C ILS/Autoland discrepancy due to crew report of Autoland 2 status. Tech Long entry identifies the C ILS as the cause. No corrective action taken. Reporter states that the defect was 6 days passed the MEL time limit of 10days. Additionally a second fault of the ILS was not recorded with a suitable MEL reference. Furthermore the Tech Log 'Autoland Capability' boxes were marked Status "LAND 3" on several occasions even though there was no actual entry to this effect. The aircraft should have remained 'LAND 2' throughout this period as no successful rectification had been achieved. CAA Closure: Following full investigation by both the operator and the third party maintenance organisation associated with this report, it was confirmed that the engineer who carried out the task had incorrectly deferred the defect. This also highlighted a procedural deficiency which allowed this action to have taken place. Engineer involved briefed on the correct process, this in turn was supported with a Notice to engineering staff on the background and to advise of correct procedure.