How did large quantities of oxygen enter the fuel tank of flight 800?

Question

Please tell me that our aircraft engneers don't have us flying around in aircraft that are only an ignition source away from a potential explosion.

Answer 1

It was empty. This is now illegal. It was a bad wire on a fuel pump that sparked the explosion.

Answer 2

There weren't "large quantities of oxygen" in the fuel tanks.

The tanks weren't full, specifically the center tank between the wings. When the fuel is used, air enters the tank in place of that. It's basic science. The tanks are not in a vacuum after the fuel is used. You car works the same way.

Every vehicle in the world is "only an ignition source away from a potential explosion".

As for all of the aircraft now being safer, thats a yes and no. All aircraft have had wiring inspections in the tanks to check for damage to the wiring. If there was damage, then the wiring was repaired or replaced. These inspections are ongoing. However, they are a band-aid.

SFAR 88 has been written to incorporate more inspections on the aircraft. However, fuel tanks, especially on older aircraft, were not designed with access in all areas, so even now, the maintenance programs are not updated with SFAR 88's rules in place.

It's not a perfect world we live in. If it was, TWA 800 would have never happened. Now that we think we know the cause, everyone is working towards a way to prevent it from ever happening again, but, as you also know, commerce drives everything, safety included. You only have to look as far as the Alaska MD-80 that went down in the pacific as proof. There was a clear and concise inspection rule in place, and they still found a way to circumvent it.

As for the commenter above on the device that replaces air with inert gas, that is not true as far as I know. There is no such device on any aircraft, and there is no AD (Airworthiness Directive) that requires such an action. I perform regulatory compliance audits on aircraft all over the world, and there is no such requirement on any aircraft. I would ask the commenter to provide a specific reference AD number. I for one would like to know if this requirement is real or not. Installing such a device would require the aircraft to carry a pressurized gas cylinder large enough to fill the emptied tanks on the aircraft. That would eat up an enourmous amount of cargo space, and would require that all wing tank vents be sealed.

I have provided links to SFAR88 and to AD 98-10-10, 99-08-02, 2001-21-07, 2001-12-21, and 2002-24-51 that were initiated because of the disaster.

*EDIT*

Upon doing some more research, since I was intrigued by the commenter above, I discovered that the FAA has put out some information concerning inert gases mixed into the 747 fuel tanks. This has not gone into effect yet, and it only applies to the design of new aircraft in the future, it does not address aircraft already in service.

The text of this document will help answer your question about flammability and fuel vapors.

Answer 3

Large quantities of oxygen were not allowed to enter the tank other than the amount of air that would have normally been inside. These tanks are for the most part gravity fed to pumps and a vacuum above the fuel line would not allow the fuel to flow.

Since that accident the FAA has made all operators of aircraft with center wing box fuel tanks to install a piece of equipment that senses fuel quantity and pumps out the air and replaces it with an inert gas as needed to prevent combustion of fuel vapors.

As with most FAA directives, the airlines are usually given a number of years to comply. I'm pretty sure that by this time all airlines have ungraded their fleet to these new safety standards. (?)

In the end it's was really faulty maintenance and a design flaw that led to the tragedy. Although wires running through a fuel tank was not the best idea, that particular aircraft (I'm pretty sure I flew on it to Paris once) was very old and had flown hundreds of hours without a problem. There was a failure to catch the worn out wire that caused the short on top of the design flaw.

Answer 4

Just like the cabin air filters in newer cars that filter out brake dust and other nasty stuff they are using plastic fuel tanks or fuel cells on newer cars to eliminate the posssibility of static electricity casuing an ignition inside the tank.

You'd be shocked to know how much static electricity is generated on the skin of an aircraft. When doing hook ups under a helicopter the first thing you do is touch a grounded copper wire to the bottom of the aircraft so you don't get "blown off" the load your standing on (Jeep/artillery piece/ ect.) from the static electricity "around" the aircraft frame.

Wait 'til some airplane gets hit with a Megacryometeor at altitude. This is a new global warming phenomenon.

Good Luck!