The list of actions to correct electrical classification deficiencies in MD-11 aircraft continues to be augmented presenting operators with an increasing cargo of repairs.

The list of actions to correct electrical classification deficiencies in

MD-11 aircraft continues to be augmented presenting operators with an increasing cargo of repairs.

In its latest spate of activity, the Federal Aviation Administration (FAA) published eight airworthiness directives forward a single day last week. All of them dealt with various aspects of the aircraft's electrical scheme It would seem that the airplane's electrical scheme is being rebuilt a piece at a time. In the latest circular operators are faced with the puzzle of scheduling work to satisfy compliance times of six month or undivided year.

The latest batch of ADs tread in the steps ofs 15 that were issued in February, and single issued earlier this month onward the cockpit map lights (see ASW, March 6 March 27 and April 10) All of these ADs appear to be an result of the Sept. 1998 fatal crash of a Swissair MD-11 at Halifax. An electrical fire is suspected. The latest batch of 8 ADs brings to 55 the number of ADs issued in the roughly 20 month since the crash. That's five times the number of ADs published in succession the MD-11 over the 20 month before the crash.

As in the February hurry of ADs, April's shower of activity hints at an original equipment design fault (incompatible CB's and connector ratings). If that flaw escaped FAA notice during certification, the oversight is now neatly camouflaged by the agency of airworthiness directive. The FAA was asked if further ADs can be expected; an answer was not provided by the agency of our press time. ?

Eight More MD-11 Mandated Fixes

MD-11: AD, final command requires a one-time detailed visual inspection of the electrical connections to discover corrosion; repair, if necessary; and installation of just discovered circuit breakers and associated wiring. The actions are intended to interrupt a disparity between the ratings of certain circuit breakers and their associated electrical connector contacts. Completion date of single year. Docket No. 99-NM-264-AD; Amendment 39-11669; AD 2000-07-15

MD-11: AD, final direction requires a general visual inspection of wiring behind the sway panel of the auxiliary power unit (APU) located in the cockpit to find out chafing; repair if necessary; and modification of the wiring. The actions are intended to intercept such chafing and resultant arcing suitable to insufficient clearance between the wire parcels and the airplane structure. Completion date of single in kind year. Docket No. 99-NM-270-AD; Amendment 39-11675; AD 2000-07-21

MD-11 and MD-11F: AD, final regularity requires a one-time detailed visual inspection of the generator power feeder wires to discover chafed or damage wires; repair, if necessary; and a modification of the generator power feeder wire installation. The actions are intended to impede chafed and burnt generator power feeder wires. Completion date of six month Docket No. 99-NM-267-AD; Amendment 39-11672; AD 2000-07-18

MD-11: AD, final domination requires a one-time detailed visual inspection of a certain passenger seat wire assembly to find chafed or damaged wires; repair, if necessary; and installation of protective sleeving. The actions are intended to intercept chafing of the passenger seat wire assembly against a bracket at the lower sidewall panel fit to insufficient clearance between the bracket and seat wire assembly. Completion date of six month Docket No. 99-NM-263-AD; Amendment 39-11668; AD 2000-07-14

MD-11: AD, final direction requires electrical resistance measurements of the land studs of the No. 2 generator in the electrical power center of the center accessory compartment for adapted electrical bonding and of the territory studs and circuit breaker terminations in the forward cargo compartment to discover looseness and for proper electrical bonding; and corrective actions, if necessary. The actions are intended to interrupt arcing and overheating of terminals and following smoke and fire in the forward cargo compartment. Completion date of the same year. Docket No. 99-NM-269-AD; Amendment 39-11674; AD 2000-07-20

MD-11 and MD-11F: AD, final empire requires modification of the external power feeder cable clamping installation. This amendment also requires a detailed visual inspection of the external power feeder cables to discover chafed or damaged wires; and repair, if necessary. The actions are intended to intercept arcing from occurring under the forward cargo compartment floor as a eventuate of damaged external power feeder cables. Completion date of single year. Docket No. 99-NM-265-AD; Amendment 39-11670; AD 2000-07-16

MD-11: AD, final mastery requires a general visual inspection to verify that the circuit breaker panel largely opens, follow-on inspections, and corrective actions, if necessary. The actions are intended to make secure that the upper main circuit breaker panel spreads fully. Completion date of six month Docket No. 99-NM-266-AD; Amendment 39-11671; AD 2000-07-17

MD-11: AD, final control requires a detailed visual inspection of the external power feeder cables in the forward cargo compartment between certain stations to lay open chafing or damage; repair, if necessary; and installation of spiral wrap. The actions are intended to obstruct chafing and damage to external territory power feeder cables. Completion date of individual year. Docket No. 99-NM-268-AD; Amendment 39-11673; AD 2000-07-19