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The F-111 has, like many aircraft, a fuel dump port so it can get rid of a lot of heavy fuel rather quickly. Most aircraft have the dump ports on the wings, the F-111 designers put it in the tail between the engines. End result is if you dump fuel and briefly light the afterburner you will ignite the liquid fuel in your wake creating a rather spectacular ...


64

There was at least one occasion when the dump-and-burn was used in combat. During the 1986 attack on Libya the U.S. pilots, desperate for fuel, jostling with one another in the air to get access to aerial refueling tankers. Unable to break radio silence, they could not locate the giant KC-10A Extenders and KC-135R Stratotankers that would keep them from ...


48

For many medium and large sized jets the maximum gross takeoff weight is higher than the maximum landing weight. If the airplane has an emergency that requires an air return or other landing in the early part of flight, it is very likely overweight for landing. The plane has 3 options at this point: Land overweight Dump fuel (if able) Fly around at low ...


46

Fuel dumping is almost always an emergency maneuver, and it is never good for the environment. So the alleged danger from the dumping must be balanced with the imminent danger to the 200–400 passengers involved. It is never an easy decision but that's why the Captain gets paid the big bucks... Dumping fuel sounds dangerous but it is not. It is not ...


41

To supplement Jimmy's answer, if they had to land right away, they could have; it just would've resulted in an overweight landing being recorded, and which on most airliners triggers a special inspection of the landing gear and its attaching structure, and if nothing is permanently bent or cracked or broken, you are good to go. An overweight landing in ...


31

This question (sorry to say) is sort of moot because: if you have an urgency to land (e.g. cargo fire), you don't care if you are overweight and you'd land anyway if you have time to dump fuel, the situation isn't as desperate, and you can easily wait just a bit longer. The large jets (e.g. Airbus A380, Boeing 777) have a fuel dumping system because, with ...


31

Can a wide body airliner land with a full fuel tank? Yes! But it is safer to land an aircraft below its published MLW. Wikipedia has the relevant specifications for the B777 and the A330 Using the B777-200 as an example. Maximum take off weight: 545,000 lb / 247,200 kg Maximum landing weight: 445,000 lb / 201,840 kg So this particular aircraft may have ...


30

Commercial aircraft have fuel dump nozzles located under the wings for dumping fuel. Fuel is gravity jettisoned from the tanks located in the wings and the fuselage. Large commercial aircraft such as the 747 can dump upto 6000 lbs of fuel per minute with all fuel jettison pumps open. Interestingly, the fuel dump nozzles are in different places on ...


30

They can land safely with full tanks but they will need the gear checked before they can take off again. It's not unheard of, if you search for "overweight" on avherald you can see a list of them They will be marked as A38* or B77*. For example this flight landed with a weight of 523t while the max landing weight of that aircraft is 394t. If possible they ...


27

Yes 07-NOV-1971 Sikorsky CH-124A Sea King (S-61B) Suffered single engine failure on take-off. Pilot attempted to return while also dumping fuel. From what I've read, fuel-dump systems are more common on military helicopters. Sometimes, a helicopter may not have enough power to hover in ground effect for a normal landing or take-off because of ...


25

No they can't. The cargo doors are secured and will not open mid-flight. Cargo holds are usually pressurized so opening the door anyway would cause depressurization. Also if the weight was too high the pilot should never have lifted off in the first place. Then after you theoretically throw the stuff off board think about what happens after to the stuff. ...


25

This aircraft does not have fuel dumping capability. In general, only large wide body airliners have fuel dumping capability. Aircraft can land overweight quite easily but getting stopped on the runway safely is the main problem. Even with fuel dumping, aircraft will often still plan to land overweight. The amount of fuel to be dumped would be planned to ...


24

I used to be an F111 test engineer; the jet can hold about 19000 liters of fuel (without external tanks). At 0.81kg/Liter, that's 15390Kg (33,939 Lbs) of weight, which is substantial (the empty weight of the jet is 45200 Lbs / 20,500 Kg). Basically with a full load of fuel, the jet is 75% heavier. Although the giant flame plume is cosmetic, the F111 can ...


24

The primary reason is to reduce the weight of an aircraft. Aircraft are designed to land at a maximum weight lower than their maximum weight. In order to be under that maximum landing weight, they must either burn that fuel during flight or dump it. There is no requirement for them to dump fuel. This decision is up to the pilot. They may choose to land the ...


24

I think the characterization that it's "too heavy to land safely" is erroneous; the fuel burning is probably out of circumspection and to allow for a better safety margin. The runway length may also be beyond the landing field length and/or the brake energy limit of the heavy weight, so decreasing weight would add to the safety if immediate return to land is ...


21

It's not really safe in an environmental sense, but it's not that bad. Jet fuel is essentially kerosene, which is harmful, but as far as engine/industrial fluids go, it's pretty benign. Additionally, when an airplane dumps it, it's diluted so much by the time it makes it anywhere that it's not a significant concern anymore. On the flip side, if an ...


21

Doesn't look like it was any 'tactical' reason- rather it was used to get a cool shot, which is totally OK with me. From rulit.me: While setting up for a filming pass, the camera crew had difficulty spotting the gray F-14 against the mountainous background. Over the radio, Rat asked the pilot to blip the fuel dump switch and make a mini-cloud. The ...


20

You may download the fuel system description for a B747-400 here. (wait for the 20s countdown to complete). This is a part of the "747 Flight Crew Operations Manual". (Note that all pictures are extracted from the Boeing Company documentation, available on several web sites. Some copyright applies, see Smart Cockpit which provide this copy. Also note ...


20

Fuel flow is proportional to air density, so it is advisable to stay low. Since the propulsive power requirement scales with the cube of airspeed, flying faster is also advised. However, when flying below 10.000 ft all civilian traffic has to obey a speed limit of 250 KIAS. My recommendation is to stay low and fly in approach configuration (gear, flaps and ...


18

TesterMen Tester provided some very good information which I think requires a bit of explanation. The older version of the regulation seems to require fuel dump capability if MTOW is more than 105 percent of MLW. None of the 737 versions have weight limits under this requirement, so based on that regulation, it seems like fuel dump would be required. But as ...


17

In reference to how much fuel is retained, in the 747-100 and -200 aircraft it was not possible to run yourself out of fuel by dumping. There were stand pipes in the the system that prevented that. A common call to the flight engineer in the simulator for certain emergencies was to "dump down to the stand pipes." Offhand I don't remember how much fuel was ...


15

Helicopters can take off when too heavy to hover, either by moving forward while in ground effect or by reducing the pitch of the anti-torque rotor to get a bit more power into the main rotor (there's a book called Chickenhawk by Robert Mason which describes using both of these processes on Hueys in Vietnam - not a bad read IMO). It's risky to use either of ...


15

We did have one "practical" application in "torching" as we used to call it: It was great way to find a Lead aircraft in a night formation to complete a night rejoin. Also we often considered it as a useful combat technique that if we got attacked by another fighter we would plan to start a dive towards the ground and we would do a short torch just before ...


15

If there's a serious time-sensitive emergency, landing overweight is likely to be a far better plan than waiting around while burning off or jettisoning fuel. As others have noted, an inspection, which involves time and money, is required after an overweight landing, as it stresses components, but aircraft are designed with structural tolerances to allow ...


14

Up-voting @skipmiller, I offer this addendum if it is dangerous what makes it worth it? Emergency Landing After Takeoff Large aircraft typcially cannot land as heavily as they can take off. It's a structural issue. So fuel dumping would be done if an emergency did not allow the time to burn down to allowable landing weight. Maintain flight with ...


13

I have never crewed on a helicopter that dumps fuel, nor have I known of any machine in the fleet that even has that capability - though I have been wrong before. It has been noted already that helos can take off and land at max Gross Take Off Weight (GTOW), or all up weight (AUW) and thus do not require weight shedding to land safely (as we don't have ...


12

The reason they dump fuel is to keep the landing gear intact during the landing. A plane at max takeoff weight will not be kind to its gear. Max takeoff weight has to be equal or higher is also higher than max landing weight. A plane where max takeoff weight is within 5% of max landing weight doesn't need to be able to dump fuel. When there isn't a ...


12

There's no benefit to burning dumped fuel, it actually introduces risk to the airplane which is dumping fuel and any other aircraft in the vicinity and possibly people on the ground depending on the altitude at which is done. Building a system to burn it is not worth the time, effort and money given there's no good reason to do it. Dumped fuel will ...


11

There are various examples in history where luggage and/or cargo was dump during flight to reduce weight: Embraer EMB-110P1 Bandeirante, 29 July 1998: To lose weight, the left overwing exit was opened and luggage of the passengers was jettisoned. Lockheed L-149 Constellation, 29 May 1972: Cargo was jettisoned, but the aircraft continued to lose ...


11

In practical terms, no. If you wanted to save/recover the dumped fuel then you would have only two basic options: dump the fuel as usual and then recover it somehow from the air; or, pump the fuel in a controlled way into a container outside the aircraft. The first option is probably impossible: how could you capture a huge cloud of fuel and fuel vapor ...


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