A quick Question

In the early days of the 777-300ER Boeing “Toyed” with the idea of fitting a big APU as a sort of APU/boost engine to improve it’s take off performance. They forgot about it rather rapidly when GE produced the BIG GE90.
On the subject of Boeing the 777’s tail cone is sort of fishtail shaped and the APU exhaust exits side ways but the 797 tail is the traditional shape. Why go back to that shape???

wysiwyg.
what I mean is that anything that pushes air backward produces a opposite reaction how ever small. As you rightly say the APU does nothing for thrust production but I wouldn’t like to put my hand into the exhaust stream!:)

Rgds Cking

I think the devil smiley inthe original post that mentioned APU thrust means it was intended as a joke! 😀

Paul

I was responding to CKing.

Barking up the wrong tree here. The APU does nothing for thrust production. It is present for 2 purposes: electrical power generation and bleed air supply (air conditioning and engine starting) and consequently is not normally used in flight.
If there is a minuscule amount of thrust from the jet eflux then that is probably cancelled out by the drag from the air inlet.

I think the devil smiley inthe original post that mentioned APU thrust means it was intended as a joke! 😀

Paul

Barking up the wrong tree here. The APU does nothing for thrust production. It is present for 2 purposes: electrical power generation and bleed air supply (air conditioning and engine starting) and consequently is not normally used in flight.
If there is a minuscule amount of thrust from the jet eflux then that is probably cancelled out by the drag from the air inlet.

So…just how much thrust can an APU provide?:diablo:

Very little. Whilst any thrust backwards will reduce the fuel consumption an APU’s contribution will be small. Some aircraft have the APU exhaust blowing out sideways. The 146, 707 and 727 spring imidiatly to mind. The 777’s exhast is offset from the centre line too.

Rgds Cking

Well, the Avro/BAe146 family has 5 of them, so can’t be that much.

LOOOOOOOOL:D Genious idea!!!!!

So…just how much thrust can an APU provide?:diablo:

Well, the Avro/BAe146 family has 5 of them, so can’t be that much.

So…just how much thrust can an APU provide?:diablo:

Thanks

It’s the exhaust for the auxiliary power unit (APU), a small engine that powers the aircraft’s internal systems whilst on the ground and the main engines are switched off. 😉

What is the whole at the back of the planes for? I take it that it its some sort of exhaust?

That is the APU (auxiliary power unit) exhaust. A small turbine used on the ground to power the plane when the main jets are not used. It is also used to kickstart the main engines in case no ground equipment is available.

W O W – I have never seen that before. That Caravelle taking off- that must have been the last flying one and to think of all the years they used to come into Turnhouse with the French rugby fans…

http://www.badongo.com/vid.php?file=UN+missions+with+IL76,+Caravelle,+C130,+727+in+Africa.__2005-12-20_FK02.avi

here it is

The e-mail thingy won’t work as the file is too large. I am now uploading it to badongo.com. It is free of charge so I think the connection won’t be fast, and I won’t be surprised either if some pop-ups popped up. I will post the link when it is done (now at 11%).

Kindly appreciated Tenthije.

Rgds

Andy
🙂

P.S. the file is 32mb large so your email box should have some space left! If MY email box is unable to handle attachments that large I will give you my MSN adress and you can download it through MSN.

Give me a PM or email. I got it on file and will email it to you.

thank’s for the info

My Dad said when he went, although he isn’t a plane spotter, he noticed alot of obvious spotting areas, and the traffic there is amazing! If you have a chance to go there, do!