The following are the wire incidents reported in the FAA wire incidents report for January 2009 Advisory Circular 43-16A – Alert Number 366.
Incident #1
- Aircraft Make: Beechjet
- Aircraft Model: 400A
- Part Name: Wire
- Part Condition: Chafing
- Part Location: Right Forward Galley
“The pitch-trim (was found to be) inoperative. (I) removed the right forward galley and the right forward partition. A wire bundle was found chafed behind the partition. I repaired three wires that were chafed (completely) through to the conductors. Clearance was provided between the wire bundle and the partition, and anti-chafe material was installed. At the time of the repair no other components had malfunctioned from the other two chafed wires.”
Incident #2
- FAA Control Number: CA081113002
- Part Name: Wire
- Part Condition: Chafed
- Difficultly Date: 11/13/2008
- Part Location: Magneto
(can) coil to points wire worn through to strands due to rubbing on frame of distributor block.
Incident #3
- FAA Control Number: CA081207001
- Aircraft Make: LYC
- Aircraft Model: DC981
- Part Name: Magneto
- Part Condition: Failed
- Difficultly Date: 12/2/2008
- Part Location: Engine
(Can) after start MAG check performed and LT MAG failed. MX was notified and when MAG was looked at found that the breaker point wires had vibrated off. Wires repaired and reinstalled.
This is where one power wire chaffed against the fwd partition
Incident #4
- FAA Control Number: CA081118001
- Aircraft Make: Beech
- Aircraft Model: 300Beech
- Part Name: Relay
- Part Condition: Unserviceable
- Part Number: MS24166DI
- Difficultly Date: 11/15/2008
- Part Location: Windshield heat
(Can) crew defect pilot windshield heat not working, troubleshoot to low heat relay, terminal a2 melted off the relay assy, damaging wires attached to the terminal approx 3 inches back the wire cover melted off. Relay was replaced and sys operates properly.
Incident #5
- FAA Control Number: 2008FA0000842
- Aircraft Make: Bell
- Aircraft Model: 206B3
- Part Name: Ground Wire
- Part Condition: Missing
- Difficultly Date: 11/24/2008
- Part Location: Boost Pump
Mfg has removed a ground wire from both electric boost pumps. Ground has been on earlier models, removed since SAN: 4205 JAW wiring diagrams. Caution lights for boost pumps not operational since no ground available to base of pressure switch. Ground wire installed from motor housing to base of boost pump. Mm shows ground wire to base of boost pump 206-062-681-101. Ops normal after ground routed to base of boost pump.
Incident #6
- FAA Control Number: CA081125001
- Aircraft Make: Boeing
- Aircraft Model: 75728A
- Part Name: Wire Harness
- Part Condition: Chafed
- Difficultly Date: 11/25/2008
(CAN) in flight crew noticed smoke and flashes above row 4DEF. MX found wiring harness chafed by ceiling panel resulting in exposed wires arching.
Incident #7
- FAA Control Number: CA081114001
- Aircraft Make: Bombardier
- Aircraft Model: DHC8400
- Part Name: Wire Harness
- Part Condition: Shorted
- Location: Proximity Switch
- Difficultly Date: 11/13/2008
(CAN) crew selected gear down and got 3 greens and LT MLG door amber light. Alternate extension c/o and crew observed alternate indication showed LT MLG (unsafe). Crew declared emergency and landed. Pax deplaned on runway and after gears were pinned acft taxied to gate. Fault confirmed by pseu to be LT LGDNLK2 open circuit. Proximity switch harness assy PN 46460-5 replaced and acft returned to service.
Incident #8
- FAA Control Number: CA081112002
- Aircraft Make: Bombardier
- Aircraft Model: DHC8400
- Part Name: Shroud
- Part Condition: Mis-manufactured
- Location: Wing Box
- Difficultly Date: 5/29/2008
(CAN) during production of 4208 it was discovered that the center wing lower shroud RT drain holes were not present. A discrepancy was raised and cleared by drilling new holes in siter. Upon the delivery/acceptance flight, it was discovered that the aft coffee marker was unserviceable. A technical investigation revealed 6 of 9 (115 VAC) wires damaged. A repair was made JAW WDM 20-16-00. A SMS/SRS was raised.
Incident #9
- FAA Control Number: 2008FA0000853
- Aircraft Make: Cessna
- Aircraft Model: T303
- Part Name: Alternator
- Part Condition: Shorted
- Location: Engine
- Difficultly Date: 11/30/2008
Have had multiple failures, both in flight and during maintenance ground operations. Hours on failed alternators range from as low as 30 to a maximum of 220 hours time in service. The one common factor in all failures has been the discovery of loose hex head case bolts installed and safety wired by manufacturer. This problem is not restricted to one side only, both engines drive the same alternator with same part number.
Incident #10
- FAA Control Number: CA081024006
- Aircraft Make: Lear
- Aircraft Model: 45Lear
- Part Name: Ground Wire
- Part Condition: Open
- Location: Trim System
- Difficultly Date: 10/10/2008
(Can) on landing, a white CAS message (secondary trim fault) appeared. Sys troubleshot and found an open ground wire at rba0664n-22 at splicesp322. Splice repaired and function checked serviceable.
Incident #11
- FAA Control Number: CA081001006
- Aircraft Make: Urocop
- Aircraft Model: EC130B4
- Part Name: Wire
- Part Condition: Shorted
- Location: Comm1
- Difficultly Date: 9/24/2008
(CAN) No pilot or copilot side tone on comm 1. Tech found the audio phone wire shorted by the shielding. Repaired and side tones were returned to normal.
This article was written by the Lectromec technical team. Aircraft wiring is our passion and we strive to make a contribution to the field by sharing our expertise through blogs, podcasts, and videos. We hope you find this information helpful. We also encourage you to submit comments and spur discussions.