I heard on a program that when planes are about to land they dump some fuel before landing
2006-10-12 01:01:37 · 18 answers · asked by blazinsoulq 1 in Cars & Transportation ➔ Aircraft
Quick summary: Yes some larger aircraft have fuel dump valves (and pumps) for emergencies. They do not do this unless it is an emergency.
They have these because most planes take off with more weight than they can land with. Not all planes have the this capability and would need to orbit until enough fuel is burned off to safely land (the A300 for example this is optional). The 105% ratio requirement is very complicated and generally not required due to better engine performance (FAR 25.119-25.121 I think) and the real lack of adherence based on configuration and load dependencies.
2006-10-12 03:01:55 · answer #1 · answered by Drewpie 5 · 0⤊ 2⤋
No they do not dump before landing...typically. Only in EMERGENCY type situations do they dump fuel. Many aircraft have certain maximum weight limits. Often times, the take off weight is higher than the landing weight, so if there is an emergency right after take-off this may be neccessary as the plane will be too heavy for a safe landing. Having a plane land that is too heavy could carry structural consequences. Fire is also a big concern of course. Less fuel means less to burn. Most aircraft accidents are survivable, but the proceeding fire and smoke of an accident are what the real killers are.
2006-10-12 19:04:56 · answer #2 · answered by larsonface 1 · 0⤊ 0⤋
Many of the answers above are wrong. The only time airplanes dump fuel is when they are in an emergency situation and they need to reduce their weight because their current weight is greater than their maximum landing weight. Interestingly, on most large airplanes, the maximum landing weight is less than the maximum takeoff weight.
Again, however, they are only going to do this in an emergency situation. During the pre-flight process they plan for normal operations, which means that they are planning on burning off enough fuel during the course of the flight that they will be at or below their maximum landing weight by the time they land. However, if an airplane has an engine fire or some other malfunction before reaching their maximum landing weight, such as during takeoff, then they will dump fuel.
When you dump fuel you should tell ATC if you can. They will mark their radar scope and keep other airplanes away because the airborne fuel creates a hazard for the other airplanes
2006-10-12 06:10:58 · answer #3 · answered by Kelley S 3 · 3⤊ 0⤋
Planes do not dump fuel prior to landing, only in emergencies this is done and not all aircraft need to do so...for example an aircraft which maximum landing weight for structural reasons is 105 ton and has taken off with 165 ton considering payload plus proper wight of the aircraft plus fuel must either burn fuel to land at the limited landing weight (105 tons) in case this aircraft did not fly time enough to burn fuel in order to land with the minimum weight then it must dump fuel which is instructed by the Air Traffic Control authorities of the area in which the aircraft is flying and in altitude specified.
There are some air crafts that do not need to dump fuel therefore because the minimun landing weight is equal or little less than the Take Off weight..Hope this was usefull
2006-10-12 09:55:12 · answer #4 · answered by camilito 2 · 0⤊ 0⤋
That assumption is totally false. Small aircraft do not have that capability,(Well if they left their fuel cap off then they would lose it quickly, not good)
If a large aircraft is capable of dumping fuel, here is why they would.....
An aircraft has a MAXIMUM take off weight and a MAXIMUM landing weight.
For example; if an aircraft can take off at 120,000 lbs it will be able to land safely at 110,000 lbs.
The extra fuel weight is for long distance flying.
Now IF an aircraft had to dump fuel regulations have areas where they are allowed to dump, being over uninhabited areas and if they need to land IMMEDIATELY.
Otherwise they would circle the field to burn off the excess weight if the situation would warrant it.
Fighter aircraft are probably the best example of needing to dump fuel. If after takeoff they need to land they will dump fuel and long range tanks only IF they had to land quickly, otherwise they stay around the airport burning fuel to land within the design of the aircraft.
Planes DO NOT dump fuel every time they land. Fuel is measured and used precisely as it is a huge cost in the operation of the plane.
If an aircraft has to go around to land at an airport this will use up more fuel and the pilot would have to account for the extra fuel burn.
The program you watched could not have had the right information.
2006-10-12 02:25:39 · answer #5 · answered by dyke_in_heat 4 · 2⤊ 0⤋
no they dont unless
1.there a fueling plane that have to come back for an emergency landing and they have to much fuel so the landing gear wont handle all of that weight
2. there is a very high chance off the plane crashing when they land and they have a **** load of fuel
they try and dump it high up in the air so it desicnagrates before it hits the ground
2006-10-12 10:06:33 · answer #6 · answered by bill f 3 · 0⤊ 0⤋
Only in an emergency type situation. Most aircraft are not equipped with a fuel dump valve.
to NOTACLUE: while many commercial and military aircraft are equipped with fuel dump valves ; which can be used if a situation as outlined in another answer occurs may be used to dump fuel which equals weight; most general aviation type aircraft have no fuel dump valve or any means of getting rid of fuel in flight. That is why you may have seen aircraft on CNN circling the airport for hours burning off fuel in preparation for a gear up landing due to a mechanical malfunction. The reason for this is not only excess weight but a reduced chance of fire. If the nature of the emergency does not allow continued flight to burn off the fuel then measures are taken to reduce the chance of fire like shutting the main fuel valve to the engine off and turning of the main electrical power switch off prior to the landing. Unfortunately as the case may be many "engine failures" are due to the fact that the pilot ran the airplane out of fuel, so he now needs not worry about fuel feeding the fire.
2006-10-12 01:03:55 · answer #7 · answered by pecker_head_bill 4 · 1⤊ 1⤋
Passenger jets do NOT routinely dump fuel before landing. To conserve energy, they are loaded with just enough (plus a little extra, in case of 'holding' or a divert situation) to get to their destination. If an emergency happens in flight, and they are still heavily laden with fuel, they will, if there is time, circle around to burn off the excess or in some instances dump fuel.
2006-10-12 02:36:14 · answer #8 · answered by 13th Floor 6 · 2⤊ 0⤋
I'm confused with "pecker head"! If the plane doesn't have a fuel dump valve where does emergency play into the picture? Does it grow a valve when an emergency arises?
Jets have the capacity to dump fuel but I don't believe small planes are equiped to do so. I would suspect with the cost of fuel today that they DO NOT dump fuel for landing purposes and also the enviromental issues involved would prohibit that practice.
2006-10-12 01:13:36 · answer #9 · answered by Anonymous · 0⤊ 2⤋
An aircraft only has a fuel dump system if its max takeoff weight is more that 115% of it,s max landing weight. You only dump it you have an emergency, you need to land NOW, and u are a lot heavier than ur max landing weight. In 17000 hours (35 years) of flying I have dumped 3 times, always over water away from populated areas.
2006-10-12 02:26:42 · answer #10 · answered by bobcap757 1 · 3⤊ 0⤋