MD

An insulation fire on a Delta Air Lines MD-11 is being investigated by
the National Transportation Safety Board.
The fire broke out on Nov. 8 at Delta's base in Atlanta, as the aircraft
was being loaded for a flight to London. The airline notified the safety board
the next day, and two investigators were dispatched to examine the aircraft on
Nov. 11.
Initial indications are that a cargo pallet inadvertently was pulled
over a cable powering one of the cargo deck floor rollers. An electronics box
to which the cable was connected immediately began sparking, apparently
igniting the metallized Mylar shielding on the glass-fiber insulation behind
it. The fire quickly burned itself out, scorching patches on the face of a
4-ft. X 16-in. section of the blanket. The 10-amp. circuit breaker for that
cable apparently did not trip.
The damaged components were sent to the NTSB laboratory in Washington
for analysis. Investigators are reviewing the electrical system's design and
the protection its circuit breakers provide against overloads.
The incident also is being reviewed by investigators for the
Transportation Safety Board of Canada, who are looking into the Sept. 2 crash
of a Swissair MD-11 off Nova Scotia.
The incident followed warnings by FAA officials that that particular
type--as well as other types--of insulation blankets certified as nonflammable
are in fact prone to support and sustain fires. The agency has declared that
almost all thermal/acoustic insulation in use on commercial aircraft is
flammable and has ``urged'' airlines to replace the insulation as soon as
practical. It has not ordered airlines to do so, however. One major problem
is that there is no nonflammable replacement
insulation available.--AW&ST 11/16/98

NTSB AVIATION ACCIDENT/INCIDENT DATABASE REPORT (mylar)

Report Number: DCA99SA051
Local Date: 03/29/1999
Local Time: 12:00 PDT
State: CA
City: SAN BERNARDINO
Aircraft Make/Model: DOUG MD-11-11F
Operator Name: WORLD AIRWAYS, INC.

Narrative

On March 29, 1999, maintenance personnel in San Bernardino,
California, discovered evidence of a fire on board a McDonnell Douglas MD-11, N274WA, operated by World Airways. The time and circumstances of the fire went
unreported and are unknown. The airplane received minor damage, and no
injuries associated with the event were reported.

Maintenance personnel at Santa Barbara Aerospace in San Bernardino
contacted the Safety Board when they noted evidence of the fire while
opening up the aft cargo bay floorboards during a scheduled "4 C" maintenance check.
The airplane, a freighter, was manufactured in 1992 and accumulated about
18,300 hours since delivery. A deferred maintenance item dated February 22,
1999, was noted in the aircraft logbook that reported a inoperative electric cargo
loading system. A routine task card was scheduled to remove the floorboards, so
the operator opted to defer this item until the 4C check (the floorboards had
never been removed). Upon removal of the floorboards, the insulation blanket
between stations 1661 and 1681 was found burned.

An detailed inspection of the area revealed that a wiring harness,
containing 20-guage wires insulated with Kapton, was routed across and onto frame
1681. One wire was separated, and the insulation of seven other wires were
damaged and chaffed where they contacted the frame. The bundle emanated from the
aft cargo loading system control box, which routes 115 volt 3-phase power to electric floor rollers when the aft cargo door is in the fully open position.

Evidence of wire chaffing and arcing was present on the wire bundle and
the frame where the bundle was contacted it. The metalized mylar that covered
the entire insulation blanket (measuring about 60 inches feet by 20 inches)
that fit into the bay between frame 1661 and 1681 had completely burned away,
exposing partially burned insulation material beneath it. A 1.25-inch
hole in the blanket was found underneath the chaffed portion of the wire bundle.
The mating edge of the adjoining insulation blanket (forward of frame 1681)
was also burned. The metalized mylar is DMS 2072K, type 2, class 1, grade A, lot
no.2024. The tape that held the mylar in place is DMS 1984 tape. Two wire
bundle "stand-offs" were installed on either side of the arced area of the
wires. The wire run was 14 inches between the stand-offs. The outboard stand-off
was 1 inch high, and the inboard stand-off was 1.5 inches high, with an
effective stand-off clearance of 3/4-inch from the frame.

Probable Cause -----Registration Number: 274WA

AND
NTSB AVIATION ACCIDENT/INCIDENT DATABASE REPORT (Mylar)

Report Number: ATL99IA015
Local Date: 11/08/1998
Local Time: 21:00 EST
State: GA
City: ATLANTA
Category of Operation: SCHEDULED, PART 121
Aircraft Type: AIRPLANE
Aircraft Make/Model: DOUG MD-11-XXX
Operator Name: DELTA AIR LINES

Narrative

On November 11, 1998, about 2100 eastern standard time, a McDonnell
Douglas MD-11, N811DE, experienced a fire in the center cargo compartment
while the airplane was standing at the gate in Atlanta, Georgia. The airplane
was operated by Delta Air Lines, under the provisions of Title 14 CFR Part
121. There was no flight plan and weather conditions were undetermined. There
were no passengers nor crewmembers aboard the airplane and no injures. The
airplane received minor damage. The airplane was standing at the time of the fire.
According to Delta Air Lines maintenance personnel, a mechanic had
removed a cargo container powered roller to replace it. While he was obtaining the
replacement part, a shift change occurred with the airport customer service personnel, who load the cargo containers. A container was loaded, cutting the cannon plug wires of the removed powered roller. The cargo control unit that controls the activation of the powered rollers caught fire, when power was applied to the airplane. Metalizer mylar insulation behind the cargo control unit caught fire, then extinguished shortly afterwards.
Probable Cause -----

Registration Number: 811DE

Both items regarding mylar incidents came from the NTSB Aviation Accident/Incident Database.

Instructions for retrieval follow;

Search > http://nasdac.faa.gov/asp/asy_ntsb.asp

Under > "Enter a word or phrase for which to search" , type in "mylar"

Click > "Begin Search" (at bottom)

Then click either "ATL99IA015" or "DCA99SA051" for either report in full text.