Tue, Jul 14, 2009
Probable Cause Of San Francisco Ground Fire Was Wiring Near O2
System
The NTSB has issued a
safety recommendation for Boeing 767 aircraft based on a fire that
badly damaged a cargo aircraft in San Francisco last year. The 14
page document reads, in part:
"On June 28, 2008, about 2215 Pacific daylight time, an ABX Air
Boeing 767-200, N799AX, operating as flight 1611 from San Francisco
International Airport (SFO), San Francisco, California, experienced
a ground fire before engine startup. The captain and the first
officer evacuated the airplane through the cockpit windows and were
not injured, and the airplane was substantially damaged. At the
time of the fire, the airplane was parked near a loading facility,
all of the cargo to be transported on the flight had been loaded,
and the doors had been shut.
The NTSB determined that the probable cause of this accident was
the design of the supplemental oxygen system hoses and the lack of
positive separation between electrical wiring and electrically
conductive oxygen system components. The lack of positive
separation allowed a short circuit to breach a combustible oxygen
hose, release oxygen, and initiate a fire in the supernumerary
compartment that rapidly spread to other areas. Contributing to
this accident was the Federal Aviation Administration’s (FAA)
failure to require the installation of nonconductive oxygen hoses
after the safety issue concerning conductive hoses was initially
identified by Boeing."
There is a lengthy list of recommendations for the FAA from the
NTSB regarding this incident. Among them:
- Require operators to replace electrically conductive
combustible oxygen hoses with electrically nonconductive hoses so
that the internal hose spring cannot be energized. (A-09-43)
- Prohibit the use of electrically conductive combustible oxygen
hoses unless the conductivity of the hose is an intentional and
approved parameter in the design. (A-09-44)
- Formalize the airworthiness directive process so that, when an
aircraft manufacturer or other source identifies an airworthiness
issue with an appliance, coordination with the appliance
manufacturer occurs to ensure that the possible safety risks to all
products using the appliance are evaluated and addressed.
(A-09-45)
- Require airplane manufacturers and modifiers to provide
positive separation between electrical wiring and oxygen system
tubing according to, at a minimum, the guidance in Advisory
Circular (AC) 43.13-1A, “Acceptable Methods, Techniques, and
Practices—Aircraft Inspection and Repair,” and AC
65-15, “Airframe and Powerplant Mechanics Airframe
Handbook.” (A-09-46)
- Require airplane manufacturers and operators to ensure that
oxygen system tubing in proximity to electrical wiring is made of,
sleeved with, or coated with nonconductive material or that the
tubing is otherwise physically isolated from potential electrical
sources. (A-09-47)
- Develop minimum electrical grounding requirements for oxygen
system components and include these requirements as part of the
certification process for new airplanes and approved supplemental
type certificate modifications to existing airplanes.
(A-09-48)
- Once electrical grounding requirements for oxygen system
components are developed, as requested in Safety Recommendation
A-09-48, require airplane operators and modifiers to inspect their
airplanes for compliance with these criteria and modify those
airplanes not in compliance accordingly. (A-09-49)
- Develop inspection criteria or service life limits for flexible
oxygen hoses to ensure that they meet current certification and
design standards. (A-09-50)
Also, the National Transportation Safety Board reiterates the
following recommendation to the Federal Aviation
Administration:
Provide guidance to aircraft rescue and firefighting personnel on
the best training methods to obtain and maintain proficiency with
the high-reach extendable turret with skin-penetrating nozzle.
More News
Aero Linx: International Business Aviation Council Ltd IBAC promotes the growth of business aviation, benefiting all sectors of the industry and all regions of the world. As a non->[...]
"During the annual inspection of the B-24 “Diamond Lil” this off-season, we made the determination that 'Lil' needs some new feathers. Due to weathering, the cloth-cove>[...]
Also: Bushcat Woes, Hummingbird 300 SL 4-Seat Heli Kit, Carbon Cub UL The newest Junkers is a faithful recreation that mates a 7-cylinder Verner radial engine to the airframe offer>[...]
Also: Seaplane Pilots Association, Rotax 916’s First Year, Gene Conrad After a decade and a half of struggling with the FAA and other aero-politics, G100UL is in production a>[...]
Also: Martha King Scholarship, Montaer Grows, Textron Updates Pistons, FlySto The FAA is hiring thousands of air traffic controllers, but the window to apply will only be open for >[...]