Is it ever legitimate to use reverse thrust before touchdown?

[gkrangers]

I mean a few feet off the ground, for whatever reason.

Is it?

 

[MOONBEAM]

Sorry, thats why jets have air/ground sensors.

 

[con-pilot]

Sorry, thats why jets have air/ground sensors.

Well, not all jet aircraft. The 727, DC-8 and a few more types one can go into reverse thrust anytime you lift up on the TR levers, as long as you are at idle thrust that is.

Many years ago during recurrency training on the 72 we were just screwing around to finish up the required time period on the final secession. The instructor ask me if I would like to try something a little out of the ordinary. I answered sure.

He repositioned the 72 over the outer marker for 26 left at LAX. At 10,000 feet and 250 knots, clean. Then he said "Land it, straight in, no turns." He let me think about for a little bit and turned the sim lose.

I called for gear down, at the same time raised the spoilers and placed all three engines into reverse. Then I told the guy in the right seat (who was another captain) to put the flaps/LEDs down to 30 on speed.

I made it, I do admit I was about a third way down the runway and a little fast but we stopped with a couple of thousand of feet left.

I would really hate to have try to do that in real life.

 

[landlover]

i was riding on a g3 once that was doing 300kts at the marker, the captain threw out the buckets to slow it down.

 

[gkrangers]

So how about legitimately?

 

[CA1900]

Well, here's what happened when Colgan tried it in a turboprop:

http://ntsb.gov/ntsb/brief.asp?ev_id=20001204X00107&key=1


Granted, overwing props have more of an impact on lift, but it still strikes me as a really, really bad idea, even in a jet.

 

[landlover]

So how about legitimately?

i cant see a time or place it should or need to be done if your following the rules. heck thats what spoilers/airbrakes are for. even still, if you're stabilized and atc gives you lower when you ask, you can even get rid of the air brakes and spoilers(as far as being in the air is concered). i'll still use them on the ground, thank you very much.

 

[gkrangers]

Yeah, I didn't think so.

I thought I remember reading a story here about Alaska 737's that would engaged just above touchdown when landing on short strips.

I could be making that up, tho.

 

[mzaharis]

Not really legitimate, but the G-II that NASA uses to simulate Space Shuttle landings uses reverse thrust to enable a Shuttle-like 20 degree glideslope. Don't think that this would carry over to any legitimate operations outside of NASA, though.

 

[mushroom]

The DC-8 doesn't have spoilers to use in the air unless the gear is down, and then those are only roll augmentation spoilers and not speed brakes. You can run engines #2 and 3 in reverse in flight if you need to, to help get down or slow down. It is hard on the engines, though, and not usually advised unless absolutely necessary.

 

[crash-proof]

On airliners.net you can find a bunch of photos of the old ruskies and their Il-62s, Tupolevs et al with their buckets open prior to touching down - though they may have had only the buckets open without applying thrust. Couldn't hear the noise by looking at the picture.

 

[AC560]

So how about legitimately?

Concorde could deploy reversers in flight on engines 2/3 and one or more of the [SIZE=-1]De Havilland's is approved for in flight reverse on the props.[/SIZE]

 

[Rez O. Lewshun]

Why would one need to?

 

[con-pilot]

Why would one need to?

Best post on this thread. :laugh:

 

[JediNein]

Why would one need to?

In case you're behind SWA on final and have 30 knots on them, again, and ATC is threatening you with vectors to the back of the line if you don't slow NOW.