Boeing 747-8 Fuel Jettison (or Dump)

Hello everyone how do you do. Today I show you in this video, the process of fuel jettison on the B747-8 ‘Superjet’. The requirement to jettison or dump fuel may be necessary to reduce aircraft weight for safety reasons in order to guarantee a safe stop on an available runway. Before you ask- the B747 can land at its maximum takeoff weight in a dire emergency such as an uncontrollable fire for example after takeoff. It can land on only two main gear at that! However for reasons of safety, it is better to reduce aircraft weight. High landing weights bring in landing distance requirements, hot brakes or possible tyre bursts or fusible plug release, runway overrun if approach is not correctly handled- excess fuel if a fire should restart after landing etc. The fuel is expelled via nozzles on the wing tip, as far away as possible from the main fuselage to eliminate any fuel spray blow back. An altitude of at least 6000 feet or more is ideal to guarantee that the fuel will evaporate and not reach the ground on to structures or people. It’s an expensive exercise but necessary sometimes with major aircraft malfunctions we’re continuing to destination would be unsafe. As usual, I’ve captioned it where I thought emphasis was needed. Hope you like it. ‘Chi Di Gin! Later!✈️✈️✈️✈️😀

[@Jorgeola757]

Captain , I really appreciate the information you provide. The information you provide are questions I have always thought of and now you provide the answers. Thank you Captain.

[@pilot_obet]

Thank you- my pleasure!

[@hariranormal5584]

in Ryanair they just dump the fatter ones out of the aircraft to reduce the weight, sometimes even the FO because yeah

[@pareshprajapati7916]

thank you captain highly detailed step by step information you explained. 🇮🇳

[@BritishLion2012]

Absolutely incredible demo! Such in depth and things we would never see, Many thanks Sir!

[@8953147]

As a 747-400/-8 mechanic, I appreciate watching your actions so I can perform maintenance with a better understanding of that system. I don't get to see what you guys experience, so a new light of understanding. Thanks Captain.

[@luukd]

Very good tutorial and explanation. Now I need for the 747 from PMDG for my flightsimulator😂

[@aerography6749]

Beautifully explained ,thank you so much Capt ☺️💙✈️

[@pilot_obet]

My pleasure

[@B747-4OO]

Thanks for showing this one, and for all your efforts to make those infos available for us! 👍

[@Leuel48Fan]

Wow I didn't realize it was THAT slow. Also I imagine company would prefer you don't dump that much since its such a waste. You said max landing was 340... maybe 250-300 would be a realistic safe weight to land if it was a real emergency? To reduce extra flight time as well.

[@jeanhuysse1227]

very very good Captain. A big hug from Brazil, thank you!

[@pilot_obet]

Hello in Brazil 😀👍🏾

[@goodo5691]

another awesome and clear explanation

[@mr2646]

We feel always safe with Captain Obet.

[@charlyrossier3415]

Excellent explanations like always, Captain ! I was a little surprised to see that jettisoning fuel could take more than an hour. It reminds me of an emergency on a B744 I had on FSX years ago (I fly on MSFS now), where the fuel was being jettisoned something like 5 tons per second (yeah, I know, a little unrealistic) which surprised me and almost run me out of fuel !

[@maptrking]

Could you imagine dumping too much fuel!!!!????

[@Silvera-Avian]

Great video - I have used this knowledge for my home flight simulator

[@747ALAIN]

how are you do you calculate the fuel to remain ? max landing weight sustractee from actual weight ?

[@mohammedalmukhtar5428]

Always , the Boeing 747 will goes in history as the most forgiving plane ever built..what a marvel man made piece of engineering …RIP JOE STUTTER

[@daftvader4218]

Yes....indeed !! You never fly the B747 .... She flies you. A love affair with a huge elegant fat ballerina who completely looks after you. Responsive and sensitive to your every need...... All you need is height, speed, brain. "What a feeling!!"

[@youdoyouplayer8529]

Never would have considered how long it would take to dump large amounts of fuel.

[@AbhikMallik]

My favourite aircraft is 747-8i 😋❤️❤️

[@dikarockafella]

Love the explanation, Capt.. but i got some question, why would there be a such condition? I mean, didnt they calculate how much fuel you have to put on the tank for such distance? Why the fuel dump happen?

[@pilot_obet]

The landing weight is lower than the takeoff weight for heavy operations

[@RankupAviation]

It’s me again 😂 with another question. When you dump fuel does it evaporate or does it rain down ? If it evaporates then why dump it over the sea/ocean ? 😊

[@messageobliquespe100]

@@RankupAviation from someone else’s answer - Depends on the type of fuel, altitude and weather conditions. Jet fuel atomizes in less than 6,000'. So, it's not completely evaporated, but it is so dispersed as to be considered harmless. Dumping below this altitude not so desired. The two most common are Jet-A (dosent evaporate very well, very similar to diesel fuel, and AVGAS (evaporates very well, similar to leaded auto gas from the 50’s) Both disperse into a fine mist but jet-a would probably make it to ground over a wide area if the aircraft was flying low enough while AVGAS would be more likely to evaporate before hitting the ground. Either way it’s not good for the Environment. I believe that the ATC would advise the area for an aircraft to go to for jettisoning fuel - over sea areas so that you’re not dumping fuel over habituated areas. I’ve seen this on flight radar where dumping of fuel carried out & the aircraft returning to same airport such as this demonstration. I wonder what makes the captains decision to do this - ie loss of 1 engine & returning back when one could theoretically carry on & monitor the situation & plan for landing along the route if circumstances dictate 🤔

[@mugundhann5905]

Lovely content & what happens to the aircraft when landing at more than rated load captain

[@pilot_obet]

Needs an inspection by maintenance

[@mugundhann5905]

Thanks for your reply captain

[@leonmareno4599]

Another very good video (for someone who never go into a plane). Thank you Pilot_obet. Question : is there some restrictions with altitude and speed when doing jettison ?

[@pilot_obet]

I mentioned it in the write up that came with video

[@Mravilet18]

Thank you sir!

[@markcardwell]

Thx Cap

[@Upwardsdown]

Is it common place to jettison after engine failure? At what point is it acceptable risk to fly on fewer than 4 engines vs the cost of jettisoning hundreds of tons of fuel? Great video, very interesting thanks

[@daftvader4218]

Safety First !!! A safe landing depends on the Captain's judgement of the circumstances as Capt Obet stated. What's a hundred tonnes of fuel when around four hundred lives are a stake... Keep flying on 3 engines??? What altitude can you maintain enroute on just 2 engines ....above safety altitude ? ? Also depends if you are on fire or not !!!! Safety First! Safety before economy. ....

[@DartzIRL]

It occurs to me that Jettison to Max Landing weight option might be confusing if you didnt have the space in your brain to think about it

[@pilot_obet]

Actually makes it easy if you didn’t want to think how much fuel you were going to end up with. Weather etc would have to be checked too so you have sufficient fuel at the end of it

[@RobTheSquire]

It's good to know that there's a preset and a custom setting for the jettison command. I would have thought that there would be a buzzer or some kind of audible message on completion though.

[@Leuel48Fan]

Would be a bad mistake to forget the switch on and the system lets it go done to 0!

[@daftvader4218]

Thank you Capt for the excellent differences course. Much more sophisticated than the 747-400 with everything worked out for you !! I used to work on about one tonne per wing tip pipe per min......2 tonnes per min ....plus 10% when ATC asked for a dumping time plus time to climb to above 6000ft agl.for fuel vaporisation. . Much more mental arithmetic required. What great improvements.... What a plane....

[@pilot_obet]

Thank you- yes it has improved a lot. When I flew the B747 classic, we had the flight engineer that did the calculations for us although we would cross verify too

[@daftvader4218]

@@pilot_obet I remember those amazing daze on the B707-300.....and the Flight Engineer's tea....!!☺🍵!!

[@GTechno13]

What was the difference between A and B on the selector?

[@pilot_obet]

No difference its really there for redundancy.

[@Prifly70]

Capt. what's the difference in selecting A or B on the fuel Jettison panel? Is it a redundant pump system?

[@pilot_obet]

Yes- just redundancy

[@Prifly70]

@@pilot_obet Copy that. Thank you. P.S. you remind me very much of my Uncle from Nigeria ! He's an accountant not a pilot, but my dad was. LOL

[@stenic2]

Very well explained Captain

[@pilot_obet]

Thanks

[@voyfan99]

Great video! Really cool to see procedures like this! Thanks for the effort!

[@nickrynenberg4364]

Thanks for a great video, always wanted to know how it done.

[@annapaolagrandini1052]

Very clear indeed, thank you so much for these videos.

[@apolloniaaskew9487]

Excellent video about the queen of the skies. My Uncle and I saw an Atlas Air 747-400F and a 747-8F takeoff within ten minutes of each other. Is an inert gas pumped in the center tank before fuel is pumped in?

[@pilot_obet]

The inert gas is available on the B747-8

[@Maersky-747]

Around 7 minutes into your video Obet, I've paused the video because my mind is blank! I can't work out the calculations. What I'm looking at (at 7 m : 02 s) into your video, the screen shows 'GROSS WT' as 377.4 KGS and the 'TOTAL FUEL' is 115.8. The 'TO REMAIN' is set at 25.0. If you deduct 25 from 377.4, that's 352.4. But when you've lost 25 tonnes of fuel, the display shows your gross weight as 286.8 KGS. Somehow is this video you've lost 90.6 KGS from your gross weight including the 25 jettisoned fuel. Where's the remaining 65.6 KGS gone?

[@pilot_obet]

The Gross weight is Fuel plus the zero fuel weight. The zero fuel weight is the weight of the aircraft plus payload. Add the fuel required for the trip and you get your gross weight at takeoff. Fuel jettison is removing all fuel until you have 25 tonnes only. Add 25 tonnes to the ZFW (Zero fuel weight), you get your new gross weight. The ZFW is not shown on the EICAS display- it is on the load sheet presented to the Captain before departure

[@Maersky-747]

@@pilot_obet Ah ok. Give me a few months to work this out 😁 ... thanks for taking the time to explain my question -- I think I speak on behalf of everyone who appreciates the response you give to people asking questions. 👌

[@theaveragepro1749]

@@Maersky-747 It's fuel to remain, not fuel to remove. Dump all the fuel until you only have 25 tons. So dumping 115.8-25 = 90.8 tons of fuel, reduces the gross weight by 90.8 tons, down to 377.4-90.8 = 286.6 tons. This is slightly lighter than the displayed gross weight, I imagine the valve shuts off a bit early to ensure it doesn't go under 25, but I don't know.

[@sebinamuwanga]

Thank you Skipper for the brilliant presentation. I noticed that fuel to the number 4 engine has been cut off, but the thrust lever has not been pulled all the way back to the idle position. I thought the first action item in the sequence of shutting down a problematic engine is to move the thrust lever (for the particular engine) to idle before selecting the fuel control switch to cut off??????????????? Kindly clarify.

[@pilot_obet]

That is exactly what happened when the engine was shutdown. after the checklist is complete, engine secure- some pilots like to bring up that thrust lever (Even though it is doing nothing even when moved) because they want the same feel as they manipulate the thrust levers. It simply goes like this ..PF (Pilot Flying)..'Engine shutdown checklist complete- Ill just bring up the number 4 engine thrust lever and line them up' Pilot monitoring: "Check'

[@sebinamuwanga]

@@pilot_obet Thanks!

[@grobbelm]

Expensive operation..

[@pilot_obet]

Very expensive

[@AstoundingAmelia]

less expensive than a crash tho

[@AKjohndoe]

Don't say sorry for the mask, be proud you are willing to follow the rules and protect other people. Also great video thank you!