There have been a number of accidents involving the ignition of vapours in
aircraft fuel tanks. Airplanes generate large amounts of entropy when in
service. There is an uncontrolled risk of an explosion. For a fuel tank, the
entropy density does not go on increasing forever. There is a maximum
entropy. Above this maximal entropy the entropy is again zero and the energy density increases toward maximum. This condition (false vacuum) can easily be met in a fuel tank ullage before an explosion. This scenario leads to an explosion, when the false vacuum state finally ends.
The explosion is a complete surprise to the crew.

TWA Flight 800:
While the accident airplane was being fueled at JFK the fuel system's
automatic VSO (volumetric shutoff) activated due to fuel weathering before
the fuel tanks were full. A mechanic "overode" the safety system and
finished fueling manually.
Conclusion: the vents of the fuel tanks were closed and left closed.

The flight was delayed because of fuel weathering. Official: a disabled
piece of ground equipment (a fleet service vehicle was blocking the accident
airplane at the gate) and concerns about a suspected passenger/baggage
mismatch (the "missing" passenger was on board the whole time).

The TWA 800 "arrow of time".
1. Refueling, fuel weathering due to entropy, long wait for the
stabilization of fuel.
2. Due to permanent fuel weathering the vents at the Main Tank № 4 and
Reserve Tank № 4 were left closed.
3. Time about 20:19 - The airplane became airborne.
4. Time 20:25:41 - Boston ARTCC: "TWA 800 climb and maintain [19,000
feet] and expedite trough [15,000 feet]."
5. Time 20:27:47 - The airplane reached its assignated altitude.
- Fuel weathering.
- Reserve Tank № 1, Main Tank № 1, Main Tank № 2,
Main Tank № 3 overfilled, fuel out-flow, streaks of light.
- Reserve Tank № 4 overpressured, decay of the
false vacuum.
- Right wing on fire, Main Tank № 4 overheated and
overpressured.
6. Time 20:29:15 - The captain: "Look at that crazy fuel flow indicator
there on number four . . . see that?"
7. Time about 20:30 - Main Tank № 4 overpressured, in the Main Tanks
№ 1, № 2 and № 3 fuel weathering, engines № 1,
№ 2 and № 3 power loss,
- Lose height.
- Fuel leak from the Reserve Tank № 4 penetrated
the fuselage.
8. Time 20:30:15 - Boston ARTCC: "TWA800 climb and maintain [15,000
feet].”
- The captain: "climb thrust!"
9. Time 20:30:25 - The captain: "climb thrust!"
10. Time 20:30:35 - The flight engineer: "power's set!" (on fire?)
11. Time 20:30:42 - Movement in the cockpit. Decay of the false vacuum in
the CWT, explosion.
- The CVR recorded a "very loud sound".
12. Time 20:31:12 - The CVR recording ended.
- "Arrow of time" vanishes in fire.

Almost ten years after the crash, many people still have questions about
what caused this tragedy. Thus aviation engineering cannot abolish the
entropy law and arrow of time.


[edit on 23-9-2005 by elpasys]

The Air France Concorde Flight 4590, July 25, 2000.
A Concorde jet, registered F-BTSC, Air France Flight 4590, bounded for New York has crashed in Gonesse two minutes after taking-off from Paris, killing 113 people. The plane exploded like an atomic bomb. The drama had begun as the plane has been preparing to take-off.

The "arrow of time".
1. about 16:35 - Refueling, fuel weathering (nucleate boiling) due to entropy, long wait for the stabilization of fuel. An innordinate amount of fuel had escaped the tanks. Official: replace a part in a thrust-reverser. Mechanics took half an hour to complete the "repairs".
- Taxi.

2. Time 16:42:17 - Decay of the false vacuum in the left wing fuel tank, "left engines on fire", tyres on fire. The initial fire began under the wing, between the left engine nacelles and the fuselage, a few seconds before the start of takeoff rotation, the aircraft being in the vicinity of W7 or S5. A small flame apparently appeared suddenly, similar to a blowtorch, and then got wider (enveloping the left engines) and longer (about the length of a fuselage). This flame was accompanied by thick black
smoke.
- Controller: “Air France 4590, runway 26 right, wind zero 90 knots, authorized take-off.”
- Pilot: “Is evryone ready?”
- Co-pilot: “Yes”, Mechanic: “Yes”
- Start to take-off, tyre blow - out.
- Controller: “Concorde zero . . . 4590 you have flames . . . you have flames behind you”
- Engine № 1 - transient loss of power.
- Take-off on fire.

3. Time 16:44 - Fuel shortage. Engines № 1 and № 2 lost power. The jetliner flammed out at the altitude of 200 feet, with its nose up, went down in a huge fireball.

The investigators were trying to determine what started the fire. It is still not clear why the aircraft lost so much fuel so quickly. What went wrong?
The decision to retire Concorde marks a retrograde step in the history of commercial aviation. Entropy won?

Exist a relationship between entropy generation and both efficiency and lifetime of an aircraft and a space shuttle, i.e. the power systems far- from- equilibrium. A huge number of components in an aircraft interact with each other, sometimes in ways that engineers do not anticipate. In complex, chaotic systems interplay of the components leads to surprising outcomes.

Deterministic chaos is only one possible consequence; form of self-organisation in which there is an overload of entropy. In a closed power system where there is a state of maximum entropy the existence of both "negative absolute temperature" and "false vacuum" is possible. "Absolute" fuel filtration techniques have become an important operation in aviation. One of the major concerns in the absolute fuel filtration is the exergy destruction or entropy generation on the membrane surface. During the filtration the fuel has a natural tendency to undergo irreversible processes and thereby increase the entropy of an aircraft. Entropy generation in an irreversible process during membrane filtration is associated with production of cold plasma (electrons and positrons i.e. fermions). Due to absolute fuel filtration unexpectedly the airplane is more far- from- beginning equilibrium.

Simple way to express the entropy law in aviation is that in a lubrication system of a turbine, and in a fuel tank, the parts and subsystems tend to disintegrate over time. The break, break down, break up, friction, cavitation (or nucleate boiling, or fuel weathering), chemical reactions, water production from oil/fuel, rust, die, decay, wear out, fuel tank explosions, aircraft
engines thrust power reduction, roll back and/or shut down, and generally move from a state of higher organisation to one of lower organisation, from order to disorder. Entropy is imperceptible, therefore it is impossible to determine what caused those problems. The destroyed exergy, or the generated entropy is responsible for the less-than-theoretical efficiency and lifetime
of a turbine, an aircraft and a space shuttle. The thermodynamical "arrow of "time" is characterized by the increase of entropy according to the Second Law. Shorter aircraft lifetime ("arrow of time") can be very expensive and tragic. Second Law analysis techniques gives a powerful design tool, and can be used to evaluate the performance of an aircraft. Fuel tank explosions are a byproduct of a complex system and only fundamental change in the system thinking can extinguish them.

Minimal entropy generation is a general evolution criterion for an aircraft.

Thailand - authorities in Thailand were investigating possible sabotage in
March 3, 2001 fire aboard a plane. One flight attendant was killed in the
blaze that gutted the Thai Airways Boeing 737-400 just 35 minutes before its scheduled take-off. Seven other people - cabin crew and ground staff - were injured. "Many people" heard explosive sounds (nucleate boiling) before the aircraft caught fire at gate 62 of Bangkok Airport's domestic terminal. Workers had finished refueling the plane shortly before the blast occurred. The plane's jet engines were not on when the fire started. At the time of fire, most of the 148 passengers were waiting to board.

What went wrong? - "a piece of debris" ???

The center wing tank exploded, according to initial reports. Moreover, the
sound signature on the cockpit voice recorder (CVR) of the Thai jet was
similar to that of the Philippine Airlines jet. In 1990, 737-300 EI-BZG, operated by PAL also suffered a centre fuel tank explosion.


[edit on 26-9-2005 by elpasys]

The Pinnacle Airlines Flight 3701 crashed on October 14, 2004 in a residential area in Jefferson City, Missouri. The two crewmembers, who were the only occupants on board, were killed, and impact forces and a postcrash fire destroyed the airplane.

The flight data recorder (FDR) data indicate that while the airplane was at 41,000 feet, the stick shaker and stick pusher activated several times before the airplane entered an aerodynamic stall. Almost simultaneously, both engines shut down. The air-driven generator was automatically deployed and supplied the backup alternating current power to the airplane. The two engines were shipped to Lynn, Massachusetts for detailed examination. The examination found that the cores of both engines were free to rotate and there was no indication of any pre-existing problems that would have led to the accident.

According to the emergency checklist for a dual engine failure, there are two ways to restart or relight the engines. One option is to use a windmill restart, which requires at least 300 knots indicated airspeed and the core of the engine to be either 12 percent rpm above 15,000 feet or 9 percent rpm below 15,000 feet. The FDR data show that the computed airspeed did not get above 300 knots and that there was no measured rotation of the engine core. The second option is to use auxiliary power unit (APU) bleed air, which has to be accomplished at 13,000 feet or below. The target best glide speed depends on the weight of the aircraft and is either 190 knots indicated airspeed or 170 knots indicated airspeed. The FDR data indicate that the APU was on after the aerodynamic stall and that the airspeed was sufficient for an APU start. The FDR and CVR indicated that the flight crew tried to start the engines several times but were unsuccessful.

What went wrong? Once again the fuel’s entropy?

[edit on 29-9-2005 by elpasys]

The pilots wanting to see how high they could go, and exceedig the performance envelope of the airplane. Entropy had NOTHING to do with it. Pure human stupidity with no help from anything else.

[edit on 9/29/2005 by Zaphod58]

my only problem with fuel tanks exploding is that you need 3 things. fuel vapor, an ignition source and most importantly oxygen

with out oxygen, hydrocarbons will not ignite. you can also have to much fuel for the oxygen and be in a fuel rich situation where it will not ignite either.

There has been an issue with fuel tanks exploding for awhile, but in every case it's due to a wiring issue, or a fuel pump sparking in the tank. Three KC-135s were lost due to the fuel pumps in the center wing tank scavenging the fuel used to lubricate the pump, and metal hit metal and sparked, causing the fuel pump to blow apart, ripping through the tank which caused the entire airplane to explode. TWA 800 was a 747-100. The 100 series had a problem with center tank overheating on climbout. They also had occasional problems with wire chafing causing short circuits in the older planes.

Minneapolis, December 23, 1970, Boeing 727.
The airplane was being refuelled using under-wing refuelling at the RH wing station. Approximately 3,000 pounds of fuel had been loaded when a muffled explosion was heard. Fuelling was immediately stopped and a minor leak was noticed coming from the area of the inboard boost pump in the LH wing. There was no fire and no injuries. The investigation that followed the incident indicated that the probable cause of the explosion was delivery by the ground fuelling system of highly charged (high entropy!) fuel into the airplane. However, the investigation was unable to pinpoint the exact source of ignition that triggered the combustion of the fuel vapor. The evidence is very strong, that the source of ignition was static discharge internal to the No.2 fuel tank.

Arrow Air Flight 1285, December 12, 1985.

A DC-8 plane registered N950JW around 6:45 in the morning took off from Gander International Airport in Gander, Newfoundland, Canada bound for Kentucky. Shortly after take-off, the aircraft experienced a reduction in thrust power due to fuel's entropy, which resulted in a low-altitude stall from which recovery was impossible. The aircraft crashed to the ground, creating a post-crash fire. The Safety Board's member were split on the matter of the probable cause of the accident. The five-member supported the official report which concluded the crash was caused by a failure to adequately de-ice the wings prior to takeoff.

However, the other four members of the board issued an minority report, which suggested the disaster grew of much more nefarious origins:
"We cannot agree - indeed, we categorically disagree - with the majority findings . . . The evidence shows that the Arrow Air DC-8 suffered an on-board fire and a massive loss of power before it crashed. The fire may have been associated with an in-flight detonation from an explosive or incendiary device."

256 people died.

Your beating this to death aren't you?

Chaos theory is NOT responsible for these crashes.

Sure the fuel will heat during pumping, but it will not explode without a ignitier (spark), fuel tank explosions will usually be the result of an electrical fault or a metal/metal contact producing a spark - as has already pointed out.

Originally posted by kilcoo316

Sure the fuel will heat during pumping, but it will not explode without a ignitier (spark), fuel tank explosions will usually be the result of an electrical fault or a metal/metal contact producing a spark - as has already pointed out.

Taiwan, September 17, 1967, Boeing 727.
The airplane was undergoing routine scheduled maintenance of the interior of the left wing tank. Both No.1 (wing) and No.2 (cheek tank) tanks had been drained ("false vacuum" state) and were open. Tank No.1 had been purged and No.2 tank was to be purged. A flash fire occurred followed in a few seconds by an explosion which ruptured the integral section comprising the RH end of tank No.2. An 8 ft. by 12 ft. section of upper wing structure was blown off. A small fire flared up in the damaged area which was quickly put out. There were 74 people in the immediate area. 16 persons were injured; five of these received serious injuries. The precise source of ignition could not be determined. All power was off the airplane, the ground power unit had been shutdown nearly two hours earlier, and the battery had been removed.

The tanks were open? So the vapour was dispersing (osmosis), there would not have been a pressure build up so therefore no explosion due to 'entropy'

Indeed, due to the propagation of vapour from the plane, the ignition may not have occured within the airframe itself.

Originally posted by kilcoo316
The tanks were open?

The top of each fuel tank is vented to outside atmosphere.

elpasys, has explosions etc due to this entropy effect you speak of ever been simulated in a laboratory?

Originally posted by kilcoo316
elpasys, has explosions etc due to this entropy effect you speak of ever been simulated in a laboratory?

Yes!