U.S. aviation officials should quickly order airlines to reduce the risks of fuel tank explosions like the one that brought down TWA Flight 800 off the coast of New York almost nine years ago, U.S. transport safety officials said on Wednesday.
TWA Flight 800, headed to Paris, crashed shortly after taking off from New York’s John F. Kennedy International airport, killing all 230 people aboard the Boeing 747 jumbo jet. The National Transportation Safety Board determined the cause was an explosion in the center wing fuel tank.
A Thai Airways Boeing 737 in March, 2001, exploded on the ground killing one person, and investigators attributed the cause to flammable fuel/air mixtures in the center wing tank.
After the TWA crash, the NTSB urged the Federal Aviation Administration to order airlines to immediately change operating procedures to cut the chance of the tanks exploding as well as require aircraft design changes, which would take longer.
While the acting NTSB chairman, Mark Rosenker, said fuel tank explosions were “rare events,” he pressed the FAA to stop dragging its feet, particularly since the agency said early in 2004 it was close to proposing design changes.
“I urge the FAA to act quickly on our urgent recommendation to implement airline operational actions,” he said in a statement. “I would remind everyone that we are still awaiting issuance by the FAA of a proposed rule announced 17 months ago that would require inerting of airliner fuel tanks.”
Onboard air conditioning units located beneath center fuel tanks can heat the fuel when operated while aircraft are parked and raise the risk of creating flammable vapor.
The NTSB suggested that airlines could cool planes on the ground with externally supplied air, a recommendation passed on to carriers by the FAA. However, an FAA study last year found only about 6 percent rely exclusively on ground-based air conditioning, according to the NTSB.
An FAA spokesman said the agency, in conjunction with the Department of Transportation, was working to propose rules for neutralizing fuel risks, and said Boeing Co. was already outfitting new aircraft with flammability reduction systems.
“The ultimate solution is inerting and we have that rule in the works and we want to get it out the door as quickly as we can,” said FAA spokesman Les Dorr. “It is better to have a proposed rule that is correct and makes sense than to have one that gets out the door too early.”
He also noted that ground-based cooling systems were only useful in some instances and were not available at all airports.
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By: wysiwyg - 17th July 2005 at 21:23
Yes, Boeing types use high outlet pressure pumps to feed the engines directly from the center tanks before running dry and transferring towing tanks whereas Airbus types always feed from wing tanks.
By: wysiwyg - 15th July 2005 at 15:37
Center fuel pumps supplying engines running down to empty is standard Boeing fuel system architecture on all their products. I would have thought that inerting would be one of theirmain priorities. Although the Airbus fuel delivery uses a different strategy I’m sure they will similarly be looking at inerting too.
By: HP81 - 15th July 2005 at 14:22
A very obscure occurrence, I should think that there are more pressing issues that need attention.
The TWA accident is controversial & I believe that the Thai 737 had fuel pumps running in an empty tank.
By: wysiwyg - 14th July 2005 at 22:34
Difficult to say this without being accused of bias but…the requirement to carry around hundreds of kilos of unusable extra fuel in the center tanks at vast additional cost to the operator to reduce risk of explosion has only been applicable to products originating from Seattle!
By: Cking - 14th July 2005 at 20:06
The air con units are all servicable during the winter and all the de icing rig are fine during the summer, NEVER the other way round!!!!!
Rgds Cking
By: Cking - 14th July 2005 at 13:24
Virtualy all jet airliners built in the west have fuel tanks that are not inerted and also have air conditioning units that sit underneath the centre fuel tank. So two explosions after foty years of jet operation by thousands of jet aircraft all over the world is pretty good going in my opinion!. The airlines are proberbly dragging thier feet for this reason. The additional costs of fitting, operating and sevicing an inerting system would run into millions and would have to be passed onto the passengers.
Air conditioning trucks on the ground SOUND like a good idear untill you think of the sheer amount of them needed for your average airport!. (Hear in Britain they would only get used about twice a year too!). And again the operating costs would have to be passed onto the passengers.
The average passenger’s overriding concern is COST!. They don’t care about how safe the aircraft is. Just look around the cabin the next time you fly. During the safety briefing most passengers don’t eaven look up from thier paper. And that is information the will save thier lives. They certainly won’t give fuel tank inerting a thought!
The good news is by the time the airlines and manufacturers get aroud to fitting an inerting system the oil woud have run out any way!!
Rant over
Rgds Cking
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July 14, 2005 at 9:30 am