B ENGINEERING CONTINUATION TRAINING

Transcription

1 B ENGINEERING CONTINUATION TRAINING Q3 & Q4 2016

2 Contents: 1 Introduction 2 B Airworthiness Directives 3 B Maintenance Related MOR s 4 B Landing Gear Lever Jammed (AAIB) 5 B Engine Fire (NTSB)

3 1. Introduction The following relates to the B aircraft type. 2. B Airworthiness Directives EASA AD US Airworthiness Directives can be viewed at ATA 28 Chafing of the wire bundles inside the electrical conduit of the forward and aft boost pumps Manufacturer(s): Boeing Applicability: The Boeing Company Model , B, B SUD, B, C, F, , , D, F, 747SR, and 747SP series airplanes, certificated in any category, as identified in Boeing Alert Service Bulletin A2306, dated October 2, Reason: This AD was prompted by several reports of chafing of the wire bundles inside the electrical conduit of the forward and aft boost pumps of the numbers 1 and 4 main fuel tanks due to high vibration. These wire bundles can chafe through the wire sleeving into the insulation, exposing the wire conductors. This AD requires replacing the wire bundles inside the electrical conduit of the forward and aft boost pumps of the numbers 1 and 4 main fuel tanks with new, improved wire bundles inserted into conduit liners. This AD also requires adding a revision to the maintenance or inspection program, as applicable, to include critical design configuration control limitations (CDCCLs) for the fuel boost pump wiring. We are issuing this AD to prevent chafing of the wire bundles and subsequent arcing between the wiring and the electrical conduit creating an ignition source in the fuel tanks, which could result in a fire and consequent fuel tank explosion.

4 EASA AD US Airworthiness Directives can be viewed at ATA 28 Manufacturer(s): Applicability: Reason: Fastener type in the fuel tank walls has insufficient bond to the structure Boeing The Boeing Company Model , D, and F series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin , Revision 1, dated July 27, This AD was prompted by a determination that a certain fastener type in the fuel tank walls has insufficient bond to the structure, and an electrical wiring short could cause arcing to occur at the ends of fasteners in the fuel tanks. This AD requires the installation of new clamps and polytetrafluoroethylene (TFE) sleeves on the wire bundles of the front spars and rear spars of the wings. This AD also requires inspecting the existing TFE sleeves under the wire bundle clamps for correct installation, and replacement if necessary. We are issuing this AD to prevent potential ignition sources in the fuel tank in the event of a lightning strike or high-powered short circuit, and consequent fire or explosion. EASA AD US Airworthiness Directives can be viewed at ATA 28 Web and Fastener Replacement at station (STA) 320 Manufacturer(s): Boeing Applicability: The Boeing Company Model , -400D, and -400F series airplanes, certificated in any category, as specified in Boeing Alert Service Bulletin A2784, Revision 2, dated August 20, Reason: Superseding Airworthiness Directive (AD) for certain The Boeing Company Model , -400D, and - 400F series airplanes. AD required measuring the web at station (STA) 320 and, depending on findings, various inspections for cracks and missing fasteners, web and fastener replacement, and related investigative and corrective actions if necessary. This new AD requires, for certain airplanes, replacement of the web, including related investigative and corrective actions if necessary. This AD was prompted by a determination that there were no inspection or repair procedures included in AD for airplanes with a certain crown frame web thickness. We are issuing this AD to address the unsafe condition on these products.

5 3. B Maintenance Related MOR s The following are maintenance related MOR from the UK CAA MOR digest. As the information is protected and strictly controlled by the UK CAA, it is respectfully requested that this information is not circulated. No part of the MOR publication may be reproduced or transmitted outside of the organisation without the express permission in writing of the Civil Aviation Authority Safety Data Office. BOEING Eng surge fl350, egt exceedence and eng vib 5 units n3 Brief flame seen from window Surge chx carried out. Further flames. Engine shut down, no fire warning. Divert to JFK Req ils 13l Ils not turned on, when it was turned on, no GP. Unable to stabilise at 1000 so GA flown Gear disagree, flaps primary, demand pump press 4, and eventually hyd sys press 4. Qrh actioned, flaps extended with secondary sys, alt gear ext used. BRAKE SOURCE warning, press seen to drop to 2500 and reducing despite hyd press 1 and 2 normal. App requested for longest avail runway... Vectors to visual... Very poor vectors 2nm right of track, and poor atc advice. Normal 3 engine landing carried out. Brakes sufficient to stop with full rev. AC towed to stand. CAA Closure: Investigation Findings and Root Cause: Review of the flight data shows that the engine suffered a maximum EGT of 902 degc for one second during the exceedance. This put the exceedance in Area E of the AMM Engine Limits for EGT exceedances. This requires immediate engine rejection for disassembly and inspection. On return to LHR, boroscopes of the HPC R1 were carried out and revealed a single blade release and associated damage to the other blades in the rotor. IPC 7 boroscopes were also carried out and some damage was noted on the trailing edge. The engine was inducted into overhaul and the root cause of this event was determined to be the liberation of thirteen IP OGV vane feet. This is a known failure mode for this mod standard for engine. Hydraulic problems noted were attributed to the engine shutdown. This in turn caused the engine vibration. The engine had "small-foot" IP OGVs and was post SB 72-F026 and the failure mode seen is a known one. Remedial Action(s) Taken: All other engines in the fleet, which are of the same IP OGV mod standard, have been boroscoped with no findings. Additionally, all affected engines are currently inspected at regular intervals for signs of compressor damage. The operator is changing the standard of IP OGVs to "bigfoot" as engines go through the overhaul shop as a preventative action of this failure mode. The operator has not de-paired affected engines on the same aircraft as only one aircraft has two engines affected fitted to it - **** in positions 1 and 4. All affected engines are subject to routine inspections for the HP compressor stage 1 for signs of impending failures as per AMP inspections. No ETOPS aircraft are affected by this issue.

6 BOEING During deployment of the LH upper deck slide, it initially inflated correctly however the inlet valves stayed open causing the side barriers to rapidly deflate. Suspected cause - inlet valves failed to close upon full inflation. CAA Closure: Investigation Findings and Root Cause: Investigation performed by operator and slide manufacturer. SB , which superseded the unsuccessful previous SBs and , replaced the roll pins in the flapper valve with screws. During deployment it was found that the roll pin could break, allowing the flapper valve to become dislodged resulting in a loss of pressure within the inflatable chamber. This scenario was experienced during this deployment. On inspection, the roll pin was found broken and the flapper valve was found dislodged. As roll pins were fitted it could easily be identified that the assembly was in a pre-mod state. Remedial Action(s) Taken: MRO has stated that they have not embodied this SB on assemblies within the pool and results show that this defect hasn t occurred previously during deployment on any pool customers aircraft including their own fleet. As this is the first occurrence within the pool, MRO proposes to take no further action which is acceptable to Fleet Technical Management. With an OEM fix in place and the root cause determined this investigation can be considered closed at this time. If the need arises, i.e. a further failure occurs, then the MRO will be asked to carry out SB at the next workshop visit of on all assemblies. A follow up enquiry with them will be conducted on an annual basis to confirm that no other failures have occurred within the pool. BOEING Airport Operations reported piece of metal retrieved from runway turn-off after a/c landing. Item traced to #1 engine thrust reverser by use of IPC REF ITEM 786. Subsequent investigation shows item to be Fan Thrust Reverser Ring Front Fixed Structure item 570, Sheet 2, Section of part still remaining loose within cold stream duct but clear of t/r. Damage to 1-5 Cascade vein panels and 3 blocker doors became evident during GVI of area with T/R partially deployed. A further DVI inspection raised in tech log to ascertain full damage incurred. Note 2x Pieces retrieved in total and left on flight deck due Hangar input required for repair. CAA Closure: Root Cause: From the investigation carried out, it cannot be conclusively determined what caused the metal strip to liberate from the engine. Given the location of this component and it being subject to a very high-velocity air stream, it can be expected that the part does liberate if the fasteners holding it down are damaged/missing. As the engine was inspected one month prior to the event and having spoken to the engineers, it has been concluded that the zonal inspection currently being undertaken, is not sufficient to prevent a re-occurrence of the event. Remedial Action(s) Taken: In order to help prevent a re-occurrence of the event, a DVI of the affected area has been created.

7 BOEING Whilst working on an aircraft, we noticed the wing to body fairing 192aer below door 2 right was holed 1inch by 1 inch by the door access steps. Steps were pumped up to clear fairing. Aircraft was housed on the Wing to body fairing punctured by the door 2R access steps. Investigation : On investigation of the incident, I could not positively identify who was responsible for positioning the steps onto the aircraft. Conclusions : I do not feel that modification to the steps is required to prevent re-occurrence, as if the steps are at the correct height they will clear the structure with no danger of contact. However there is no clear makings on the steps as to what height they should be at, or how to ensure they are at the correct height for individual aircraft. Preventative Actions Taken : To prevent re-occurrence, a shift brief will be given to ensure all staff are aware of the importance of making sure the steps are clear of the aircraft structure, and installation of pictures onto the steps to show the correct height for the steps when docked on an aircraft. BOEING Prior to departure. upon removal of Pre-Conditioned Air from aircraft, ground handlers reported Ground Connection Cover Plate sheared-off from aircraft. Flight and passengers incurred 50 minute delay while Engineer replaced cover. Maintrol issued Damage. On completion of boarding the pushback crew noticed the clip to connect the PCA to the aircraft was broken. Engineers were called and needed to replace part. BOEING Task to replace the convoluted tubing between metal conduit and DV1 electrical connector on Pylon 1. Requires removal of No 1 Hydraulic SOV connector ref des DV1. DV1 inner insulation contact separator found in contaminated condition. i.e. melted/dissolved References: original task order, replace DV1 connector order. Supplementary 16/11/16: A review of the AML shows no in-service effects of this reported finding. This incident has been completed by Tech and will be monitored through trend analysis of event type.

8 BOEING On selection of gear down, loud bang heard. Gear disagree EICAS followed by Hyd Qty low 1 EICAS, followed by Hyd Press Sys 1 EICAS. Gear synoptic showed left body gear not down. Go around flown, diagnosis carried out, drills run in accordance with the QRH. Loss of hydraulic system 1 drill completed first, alternate gear deployment unsuccessful on left main body gear. Gear disagree drill carried out second, leading to a precautionary emergency landing for which the Passengers were briefed. Aircraft landed without further incident. Engineering team placed pins in undercarriage and confirmed left hand body gear not locked down. Aircraft towed to stand. Supplementary 27/10/16: When gear down selected left body gear down lock actuator ruptured. Total loss of nr1 hydraulic system fluid followed. BOEING During the troubleshooting of the failed css/access system fault today in which sparks were emitted from an OEU, it became apparent that the physical state of the aircraft and parts fitted is not correctly reflected in the approved aircraft data manuals some 7 months after the reconfig modification was carried out. Subsequently the modification paperwork/drawings are not readily available to enable effective troubleshooting of the defect or research into the parts installed/their make-up or repair capability, a failure of the Part M organisation with the Part 145 yet again left to make do/make it happen!! Supplementary 16/11/16: The correct documents were issued but not correctly published by the operator. This has now been resolved.

9 BOEING On the nightshift date 4nov into the 5 nov APU routine maintenance was carried out noting the apu doors were left in the open and secured position to facilitate an inspection on the security of the oil filler cap. I didn't have time to check and give clearance to close doors due to other workload commitments as such the doors were left in the open position PLEASE NOTE task card was still outstanding (this card gives the clearance to fit and closure of doors). Arriving back on nightshift 5 nov I find myself working the same zone as previous night and noted on the lecturn with task card a note saying...apu..doors to close after routine! At a distance the APU doors appeared to be closed..indeed from directly underneath they appeared closed it wasn't until I found myself carrying out the DART survey that it was noticed only the forward latch on the apu doors was engaged/locked position the other 5 latches were all disengaged. I have a question why would someone go the length of getting access via a high lift to this area and only closing 1 latch knowing that from ground level the doors would appear to be closed. I feel this to be very deliberate with the intention of this aircraft potentially going into service with unsecured APU doors. Had I been under pressure to get the aircraft out to meet its service I may have done a visual and been satisfied that the doors were correctly closed. (AREA CONCERNED is zone 2 dayshift 5 nov).the state the doors were found in has been witnessed. BOEING During the OP Test of the Passenger Oxygen Mask Flow checks, the following failures occurred: 1. Seat 37 DEFG deployed correctly and Oxy flow was correct but the masks were incorrectly packed..2. Seat 15 DEFG deployed correctly but ONE mask fell out of the PSU when the lid opened. 3. Aft Crew Rest Bunk 1 Oxy PSU failed to deploy. This PSU is to be returned U/S for the attention of ****During this OP test Representatives from **** were on site to witness the OP Test which was to be carried out under sea level conditions. BOEING On investigation of aft cargo door intermittently failing to open or close correctly found X3 cables burnt and severed in conduit at fwd hinge point. Conduit was partly broken internally, outer lacing still mostly intact. On rectification another cable found severed but held together by outer insulation. Conduit replaced and X4 cables replaced. Time taken: duration 12 hours (24 man-hours). Cables replaced:

10 4. B Landing Gear Lever Jammed (AAIB)

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15 5. B Engine Fire (NTSB)

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