A friend says " Prior to every landings of the Jet planes the rest of the fuel has to be spilled out ?

Question

Is that true?

Answer 1

The dumping of aviation fuel is an extremely rare event.
Aviation Kerosene is a valuable commodity, and airlines
will not want to waste it. Article 56 (3) (b) of the Civil
Aviation Air Navigation Order 2000 permits the dumping
of fuel in an emergency. It is recommended that
jettisoning fuel should be carried out over the sea, or if
this is not possible, above 10,000 feet to allow it to
evaporate before it reaches the ground.

Answer 2

If a plane needs to return after taking off they may be to heavy to land. It is not as uncommon as many might think. It is the abnormal, non-routine flight where landing weight can be an issue.

If a flight takes off at the maximum structural takeoff weight and then faces a situation where they must return to the departure airport (due to certain mechanical problems, or a passenger medical issue) they will not have had time to consume the fuel getting to their original destination, and will be over the maximum structural landing weight to land back at the departure point.

Actual fuel dumping operations are coordinated with air traffic control (ATC), and precautions are taken to keep other aircraft clear of such areas. Fuel dumping is usually accomplished at a high enough altitude where the fuel will dissipate before reaching the ground. Fuel leaves the aircraft through a specific point on each wing, usually closer to the wingtips and further away from engines, and initially appears as more liquid than vapor.

Answer 3

It's total rubbish. If there is a major problem just after take-off, the plane may be too heavily loaded with fuel for the undercarriage to take the load of landing - then the pilot may dump fuel. Most people don't appreciate kerosene being dumped on them, so its very rarely done. Generally the pilot takes enough fuel for each trip plus a little in reserve, so the tanks are low when the plane lands.

Answer 4

This is mainly backing up some of the people here. No they don't dump gas before every landing, but,Federal Aviation Regulation (FAR) Part 23.473 Ground load conditions, and 23.1001 Fuel Jettisoning Systems says, and this is considerably shortened, any aircraft certified to have a max takeoff wieght greater than its max landing weight must have a way to dump fuel to get to an allowable landing weight. But it must not be able to dump everything by design. Enough left to make it about an hour. Not really for fire reasons, but wieght. You dont want the gear to collapse or anything drastic. Tanks are usually kept full, this helps with keeping out moisture. And dumping is supposed to be done over water, if not, above 10,000 ft so it evaporates before it gets to the ground. Many years ago I remember a flight that dumped over a north Chicago suburb for an emergency. They weren't high enough and people's yards and pools ended up with a sprinkling of Jet-A.

Answer 5

Just to clarify...
No, there is no dumping of fuel prior to every landing.
Yes, planes do have the ability to dump fuel.
No, fuel would not normally be dumped in an emergency to reduce the chances of fire or explosion. The goal of an emergency landing is to get on the ground without breaking the plane into pieces.
Yes, fuel is dumped in cases of emergency landings shortly after takeoff. This is done only to reduce the weight of the airplane. Many planes takeoff much heavier than the maximum landing weight. Planes have a maximum weight which they can safely land, based on the strength of the wings, landing gear, etc. If a plane takes off over the max landing weight, and needs to land immediately, it must dump fuel to reduce the weight in order to land.

Answer 6

YES & NO.

We will consider an actual example.

Before a jet plane takes off for say a non-stop flight of exactly 11 hours the amount of fuel filled in the tanks is accurately calculated + an added 1 hour's fuel in case of the necessity of diversion to another nearby airport on arrival. Diversion may occur for various unpredicted reasons eg weather conditions etc.
.
The computer calculate the aircraft's need in terms of tons(1ton=1000kg) of jet fuel required eg.in the case under consideration it may be about 60 tons.

if the flight is on time with no undue delays or diversion en route it will be landing with only one hour of fuel reserve left in the tank i.e. a fuel weight of 60/12=5 tons. This is considered as acceptably safe and there is no need to dump that remaining one ton for a safe landing. That fuel weight only represents the weight of (5000/70) about 71 average size passengers.

If for some reason ,eg. a windscreen blows off half an hour after takeoff and the aircraft has to return to point of departure ,it would have used only one hour's fuel i.e. 5 tons only. So it has an added (60-5) 55 tons of fuel to its landing weight .This is equivalent to having 785 extra average size passengers on board. This landing weight would be very unsafe and it would be a sure crash and disintegration. Hence the reason why the fuel has to be dumped in the atmosphere below .

Being very volatile the fuel evaporates quickly.

I hope your friend understand that his statement is partially correct.

Answer 7

No your friend is incorrect. The only time that an aircraft would dump fuel is in the case of an emergency, and that is usually a last option. Aircraft take on the amount of fuel that they need for the specific flight and burn that fuel off during the flight, obviously they have enough if they need to divert to another airport. So when they land they have burnt enough fuel to meet the weight requirements for a safe landing.

Answer 8

Your friend is partly true. An aircraft that has too much fuel in it on landing will cause excess impact forces on it's undercarriage and cause preventable damage, but this is not a normal situation. If the aircraft flies it's planned sortie/flight, then it will not have too much fuel in, and can land without a problem.

If, however, the aircraft has a problem slightly after takeoff, then it will have to jettison some fuel. They tend to do it over the sea, as it dissipates quickly there and has a much smaller risk of causing any environmental damage.

I used to work on Jaguar Ground Attack aircraft, and when they had a problem, they dumped their fuel over the wash, a bay and bombing range near Norfolk, then returned to base.

It's not really to prevent long fires, it's to prevent undue stress on the airframe due to the extra weight.

BTW, Escort Turbo, I know what I am talking about, as it is my Career and I have been in the Aviation world for 6 years now!
They do still have this problem, although many now simply burn the fuel to get rid of it (flying in circles). I did say that it would occur slightly after take-off in emergencies, not on every flight! If the small jets take 5 Tonnes of fuel, then imagine how much extra weight an airliner would have on take-off! I know for a fact that Airliners take only enough fuel to complete it's journey (With some extra for a safety margin, of course). This is because carrying extra fuel is dead weight, and therefore a waste of energy to get it airborne. Airline companies, like all companies are there to profit, and this is a big area for profit, as AvGas and AvTur is very expensive!

Answer 9

The answer is NO.
It is not mandatory to dump fuel prior to EVERY landing. However, its done sometimes for safety reasons due to aircraft performance constraints and/or emergency situations. If safety permits, it is logical and practical (and off course economical) to retain excess fuel in the aircraft. There can be an aborted landing or the common case that this is just a stopover.

Answer 10

definately not true. Fuel is too expensive to even consider this on a routine landind. However, if a jet is loaded with fuel, has an emergency requiring imediate landing, it sometimes has to dump it's fuel because the aircraft is too heavy to land