A probably quite stupid question about aeroplanes.

[nick h.]

There are no planes with mechanisms to drive the wheels except for a handful of flying cars which double as cars and aeroplanes. None of them have ever been a success. (Here's one - it has a gearbox connecting the engine to the front wheels. You can taxi backwards in it http://en.wikipedia.org/wiki/Aerocar).

Most jets and lots of propeller-driven aircraft have a means of directing some of their thrust backwards. They use it for braking - that's what the roar is just after you land.

Theoretically they could use it to taxi backwards, but it's very inefficient and noisy and can damage the engines because the risk of sucking in junk that's lying on the ground can be very high. It's also a lot cheaper (in terms of fuel bills) to get a tug to do the work. And the pilot can't see where he's going. So the only aircraft that routinely do it are seaplanes.

Lots of good info and pics at wiki: http://en.wikipedia.org/wiki/Thrust_reverser

 

[DownwardDog]

Right termite man and crispy (clever people) - does that mean it COULD reverse in an emergency?

I need a definitive answer here.

Most can't but a few can - the C-17A Globemaster III is an example.

 

[felixthecat]

To be honest I suspect you were just thinking the planes wheels drove themselves instead of just spinning and the ground movement of the plane being powered by by the main engines so you were wrong too

Oh no no no! I am right! The question was, could planes go backwards. You all have told me they can - so I am right!!

Don't try and muddy the rapidly clearing water now by putting some sort of caveat on that 'yes they can go backwards' point!

 

[nick h.]

The short answer is: some can, some can't, hardly any do.

Some of the ones that can't really can't, not even in an emergency - it damages the engine through overheating, or the engine tries sucking in it's own exhaust gas and stalls. Each plane design is certified to be operated in a certain way.

Here's a terrific vid of a C-17 going backwards. The ramp is open so that someone can shout 'left hand down a bit' to the pilot.

 

[Maurice Picarda]

Avis ferrea non cancrizabit

 

[pogofish]

I've never seen one taxi backwards. If that helps.

Try military transport aircraft - Some of them can reverse their propellors & reverse.

 

[AnnO'Neemus]

The short answer is: some can, some can't, hardly any do.

Some of the ones that can't really can't, not even in an emergency - it damages the engine through overheating, or the engine tries sucking in it's own exhaust gas and stalls. Each plane design is certified to be operated in a certain way.

Here's a terrific vid of a C-17 going backwards. The ramp is open so that someone can shout 'left hand down a bit' to the pilot.

ooh, do like those C-17s and their short landings, clever stuff

 

[trashpony]

Yes, they have a reverse gear. I don't know how it works though. I do have a friend who's a commercial pilot who could bore the pants and socks off you explaining if you're really interested

 

[felixthecat]

Yes, they have a reverse gear. I don't know how it works though. I do have a friend who's a commercial pilot who could bore the pants and socks off you explaining if you're really interested

Thank you trashy!

However, I'll skip having it all explained to me. I'm not deperately interested in the workings of aeroplanes -I only want to win an argument!

 

[trashpony]

Thank you trashy!

However, I'll skip having it all explained to me. I'm not deperately interested in the workings of aeroplanes -I only want to win an argument!

Are you sure? He lives in Bristol you know, sure he'd be only too happy to pop round

 

[Maurice Picarda]

Felix, apologies for derail but re: "in the dark in the park"

"We will take him home. We will call him Clark. He will grow and grow. Will Mother like this? We don't know."? Or unrelated?

 

[derf]

What sort of emergency would make a plane need to reverse at speed on the ground ?

One where two aircraft are trying to take off using the same runway but in opposite directions. A portapotty in the seat would be more use.

 

[Jayen4]

The short answer is: some can, some can't, hardly any do.

Here's a terrific vid of a C-17 going backwards. The ramp is open so that someone can shout 'left hand down a bit' to the pilot.

The 'rampman' on a C17 would have a 'comms link' to the pilot for that pupose,surely ?? (As in...Oi ! You've just crushed a Land Rover !!)

And yes,most jets CAN reverse under their own power. I've seen commercial jets do exactly that at Leeds Bradford aiport.

 

[adsr]

Very occasionally passenger aircraft are allowed to do a 'power back' reverse from the terminal without using a tug, although not larger aircraft as they can blow in the glass of the terminal building

 

[Bob_the_lost]

The 'rampman' on a C17 would have a 'comms link' to the pilot for that pupose,surely ?? (As in...Oi ! You've just crushed a Land Rover !!)

And yes,most jets CAN reverse under their own power. I've seen commercial jets do exactly that at Leeds Bradford aiport.

Presumably it's so the person in the back can see where the landrover is. No wing mirrors on a C17.

 

[WouldBe]

yes , even if it's on a conveyor belt .

Unless you've got reverse thrust applied.

 

[liquidlunch]

What sort of emergency would make a plane need to reverse at speed on the ground ?

maybe an italian pilot that is used to a tank

 

[MikeMcc]

I've seen a Hercules being bump started, not very reassuring given that I was due to fly back from Benbecula in it! One in front used the airflow from it's engines to rotate the props of the one behind to get them started. Never been in one going backwards though.