FAA proposes new fuel tank systems for airliners

Tuesday, November 15, 2005; Posted: 11:42 a.m. EST (16:42 GMT)

WASHINGTON (AP) -- The government said Monday that it plans to order all airlines to make changes that will reduce the chance of fuel tank explosions like the one that destroyed a TWA Boeing 747 more than nine years ago.

The Federal Aviation Administration proposed a rule that would give airlines the option of meeting minimum standards forfuel flammability or eliminating the sources of sparks that can cause an explosion.

Since the TWA Flight 800 accident, the FAA has ordered at least 60 changes to eliminate possible sources of sparks, such as chafed wiring.

FAA and Boeing Co. also have developed so-called "fuel tank inerting" systems that reduce the oxygen in fuel tanks, making an explosion much less likely. The new technology wouldn't be required on airplanes, but it would satisfy the proposed regulation.

"We're proposing to increase the level of aircraft safety by reducing the potentially explosive ingredient of flammable fuel vapors," FAA chief Marion Blakey said in a statement.

The FAA estimates it will cost $313 million to retrofit 3,200 large passenger jets over the next seven years. Boeing spokesman Jim Proulx said the company will install the systems on new 747s and 737s in mid-2006. New 777s will be outfitted with the devices in 2007 and 767s in 2008. Existing models of those planes, along with 757s and Airbus A320s and A330s, would be covered by the new rule.



Fuel tank explosions are rare, but they have resulted in 346 deaths since 1989, including the TWA accident.

All 230 people aboard that flight perished when the Boeing 747 crashed off the coast of Long Island, New York, on July 17, 1996, en route to Paris.

Federal safety regulators said a spark in the wiring ignited vapors in the Boeing 747's partly empty fuel tank. Air conditioning units underneath the fuel tanks are believed to have heated the vapors inside the tank -- making them more vulnerable to explosion -- during the plane's two-hour delay at New York's John F. Kennedy International Airport.

The public has 120 days to comment on the proposal, which does not cover cargo airplanes.   from this link

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Press Release
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Contact: Alison Duquette
Phone: 202-267-3883
AOC 39-05
Date Posted: November 14, 2005
FAA Proposes Rule to Reduce Fuel Tank Explosion Risk

WASHINGTON, D.C. The U.S. Department of Transportation's Federal Aviation Administration (FAA) today proposed a rule that would make aviation significantly safer by requiring more than 3,200 existing and certain new large passenger jets to reduce flammability levels of fuel tank vapors.

"Safer fuel tanks on aircraft will help prevent the possibility of future explosions and the tragic loss of lives," U.S. Transportation Secretary Norman Y. Mineta said.

The Notice of Proposed Rulemaking (NPRM) would require aircraft operators to reduce the flammability levels of fuel tank vapors on the ground and in the air to remove the likelihood of a potential explosion from an ignition source. The proposed rule is designed to reduce the likelihood of a repeat of the four fuel tank explosions over the past 16 years, including the 1996 TWA 800 accident, that together have resulted in 346 fatalities.

"This proposed rule is the next step to close the book on fuel tank explosions," said FAA Administrator Marion C. Blakey. "We're proposing to increase the level of aircraft safety by reducing the potentially explosive ingredient of flammable fuel vapors."

Blakey added that today's proposed rule builds on more than 70 directives during the past nine years designed to eliminate ignition sources and to change fuel tank design and maintenance. Previous directives have addressed issues such as pump manufacturing discrepancies, wire chafing, and protection of the Fuel Quantity Indication System.

One possible solution allowed by the rule is fuel tank inerting. In May 2002, FAA engineers unveiled a prototype to replace oxygen in the fuel tank with inert gas, which prevents the potential ignition of flammable vapors. Boeing has since developed its own system, which will be installed on new airplanes. The FAA will consider data supporting other means of compliance.

The FAA's proposal would apply to new large airplane designs. In addition, since the FAA would require a retrofit of more than 3,200 Airbus and Boeing aircraft with center wing fuel tanks over seven years, Boeing 737, Boeing 747, and Airbus A320 models would be retrofitted first. The preliminary estimate for the total cost for the U.S. fleet is approximately $808 million over 49 years, including $313 million for retrofitting the existing fleet. The following is the projected U.S. aircraft fleet that would be retrofitted:

Airbus Models Number of Aircraft
Airbus A320 906
Airbus A330 44

Boeing Models Number of Aircraft
Boeing 737 1,149
Boeing 747 93
Boeing 757 581
Boeing 767 347
Boeing 777 157

The NPRM is on display today at the Federal Register. It is available on the Internet at http://dms.do t.gov, docket FAA 2005-22997 and on the FAA's website at http://www.faa.gov/regulations_policies /rulemaking/recently_published/. The 120-day public comment period closes on March 20, 2006.