Use of engine reverse in flight
 

I know the Galaxy is approved to do it. Any other military types?

C-17.........

Harrier ?!

Well, sort of, a bit.

And the Galaxy & C-17 probably try to avoid actually flying backwards.

Can the C-17 use reverse at idle on approach?

No - it can be used in the descent but not with the slats extended (due to the exhaust flow). Even so, and albeit with an acceleration, it can still achieve up to 20,000fpm RoD.

It certainly makes for an interesting (and mostly green) view from the flightdeck of a 200ton jet!

Uncle G:ok:

Not a military type, however, the DC-8 (some series) are approved, inboards only, as I recall.

411A you are indeed correct it was for the -71 & -73 fitted with the CFM motors, I was flying into Lagos with Southern when the Capt used them and for his trouble got wacked on the back of the head by the FE as He was worried about them stowing and being stuck there, as the flt mech I was not overly happy about the situation either:=

All DC8's had reverse thrust on the inboard engines as no speedbrakes were fitted. Flap settings were limited when reverse was used.

The Mk 1 Andover was cleared for STOL landings from a 6 degree approach selecting reverse just before touchdown.

I'm tempted to say 'no sh!t Sherlock' but it does sound fairly hairy! I've see empty ones go up like a rat up a drainpipe but 20K per min downwards (intentionally) must give you lots of options in a (mostly brown?) tactical environment.

Yak 40 centreline engine. It is used for some FSU Military transport.
pp

The Herc K can also do it - the only limitation on use of reverse thrust is a speed one - not above 115kts IIRC. It has been done in the sim to quite dramatic (and controllable) effect (1nm short finals, 5000ft agl, successful landing!)- however, it'd take some cojones to try it in the aircraft....prop hangup, anyone?

Reverse Thrust
 

The Trident reversed thrust, (outers) could be used anytime, any speed, right down to turning off the runway. Very useful on a shortish runway when you could be pulling reverse in the flare.

There's a YouTube video of a C-130 landing on the USS Forrestal. The comentary mentions that the pilot selected reverse thrust before landing.

Video here: YouTube - C-130 Hercules on an Aircraft Carrier!!

C-130 landing and take-off sequence starts about 2-mins into the video

Bakedwell are you sure that the JT 3s had a in flight reverse capability? as my memory thinks they could not, though no speedbrakes as such they had inboard and out ground/flight spoilers that deployed on touchdown spent many an hour in the german cargo hangar rigging them.:ugh:

At World, our DC8-63's with the JT3D-7 had inflight reverse capability on the inboards only.

Used to be relatively common procedure on C-130 in Viet Nam...

As mentioned, used during Forrestal trials...

Fairly frowned upon these days as it makes for a rather unpleasant landing!:}

...overall, not approved however.

With The Gripper you could achieve 15000fpm down and more if you dropped the main wheels at 300kts. Trouble was the self loading cargo didn't like it

Urban Myth?
 

Even though it's gated through the WoW on Tornado, it's still a bad idea to pre-select thrust-reverse on approach because if you make a hash of the landing, it kicks-in just as you bounce and makes your second landing even heavier!

N Joe

I think anybody who thinks the C-130,and the Andover could select reverse in flight are talking cobblers,as it would lead to an NTS disconnect,and a possible blade hang-up,and off the side you would go.What you can do in the sim.is not applicable to the a/c.Think about it,as soon as the blades go through zero pitch, you lose a large percentage of lift,and tailplane/elevator blanking,and therefore control,and even more in reverse.
For the Andover,in `73 I spent time as co-pilot doing steep approaches at Bedford,possibly up to 10deg,using an MLS for guidance,and I`m certain we used an extra notch of flap for drag,and power to control the flare, reverse only when down,otherwise one would `wheelbarrow`;these were also done later on the 748,-125,and VC-10,as 2- segment approaches,steep initially,then reducing to 3-4deg for obstacle clearance into tac.LSs.

Well somebody mentioned the C5 Galaxy using reverse thrust in flight , in the build up to GW1 a C5 crashed after take off at Ramstein with reverse thrust on 1 engine selected.

If you have to use reverse thrust in flight then you either some gucci display pilot , in **** and need to stop quick or just a spacker for selecting it.

who cares :ok:

Can most definitely be done.

Should it be done? Different question.

Was it done in the past? Absolutely.

There is no such thing as "NTS disconnect" - perhaps you're confusing the safety coupling with NTS? Regardless, you'd not reach -6000"/lb of torque unless at high speed, so no decoupling would occur.

Blade hang-up is another matter entirely and is unrelated to selecting reverse in flight.

As a semi-related tidbit of near-useuless information, newer models (H3 & up) have "beta lights" letting you know low-pitch stop has retracted and reverse can be selected.

Again, just because it can be done, does not mean it should...

Inflight reverse thrust
 

The DC-8 Series 62 and Series 63 both powered by JT3D-7s had inflight reverse thrust capability on the inboard engines.

I first experienced it on an SAS flight to LAX. The sudden roar and deceleration jolted me for a minute. Fortunately, my travelling companion was a former Douglas test pilot who quickly enlightened me.

Not a military type but wasn't Concorde approved to use the inboard reversers in flight? Or was that just an urban myth?

Here's the Andover blurb directly from the Pilot's Notes:

4. Short Landing

Note: STOL techniques may be used only as ordered by the Operating Authority.

(a) Technique:
(i) After the pre-landing checks have been completed (Prop Brake to Rev Idle) reduce speed to below 120 knots and select 27° flap.

(ii) Aim to be lined up with the touchdown area with 30° flap selected at VAT plus 15 knots.

(iii) When lined up, continue the approach reducing speed to cross the touchdown point at VAT. It is important that the speed is maintained at not less than the scheduled VAT otherwise the ability to round out will be impaired.

(iv) When near the ground, close the throttles and round-out to fly level, with the wheels just clear of the surface. Select reverse thrust in order to touchdown. Should the aircraft balloon, do not select reverse thrust until re-established close to the ground.

(v) Reverse thrust is usually selected at completion of round-out, but in some circumstances it may be required slightly earlier. The exact point at which to select reverse can only be determined by practice. Note that if selection is made too early a heavy landing will result.

(vi) After touchdown, lower the nosewheel, apply maximum braking and keep straight with nosewheel steering. Reverse thrust should be cancelled when the speed reaches 30 knots, or earlier if forward airflow past the propellers is detected.

C-130 Reverse Thrust / Pitch

Wasn't one of the RAF C-130 write-offs (the first?) on XV180 in 1969
due to reverse thrust being selected on take-off?

The DC8/JT3 reverse question. Yes, full reverse was available inflight on the inboards although it could only be applied outboard once the landing gear selector was in the down position. A wondrous system of push-rods, cranks and linkages both on the engine and in the throttle quadrant prevented incorrect reverse operation by physically locking the reverse levers.

The reverse logic system (for that is what it was) was on many occasions sufficiently cantankerous during landing to totally prevent reverse thrust operation, which provided a golden opportunity to fully test the antiquated anti-skid system with the feet pushing desperately hard on the brakes as the hand pulled frantically on four reverse levers which refused to budge from idle.

Magic stuff really: it's not like that today. Come to think of it, all the DC8s I flew are now in the knacker's yard so perhaps this would be better posted in the nostalgia section.

sycamore

The Chitterne Flyer beat me to it.

If you don't believe us its AP101B-0301-15 Part 3 Ch 6 Para 4.

I must confess, though, that I only have 4659 hrs 20 mins on the Andover.

Regarding the Forrestal landings the low pitch stops were removed as to reduce the chance of a low pitch stop hang up causing a swerve. Reverse was selected while inflight on the initial landings but this was found not to be required and thus discontinued.

S/F, FOG

Interesting - I've never heard that. What is your source?

The FE from the flight, he use to be an instructor at the Cherry Point RAG.

Doesn't seem like a good idea to remove them - regardless of LPS retraction concerns (something that's not at all common).

The low-pitch stop is the only thing that prevents the blades from moving into beta range in flight. The list of possible prop malfunctions goes up dramatically w/o the LPS. Additionally, w/o the LPS, NTS would no longer function normally during deceleration increasing the likelihood of overspeed, pitchlock, & fuel topping in a critical phase of flight...

Seems highly unlikely they'd remove one safety feature & effectively disable another that leads to all sorts of additional problems...:confused:

Kind of the idea in reducing the swerve. Hitting NTS would induce the swerve at the back of the boat/on deck, LPS hang up, etc.

Fuel topping would not be an issue on reverse and basic pilotage on takeoff. Overspeeding during the landing phase?

The 1st two passes the throttles were up and back over the tail of the boat. That was considered the least risky option.

I’ll take the word of someone who was there and the official debriefs.

Inflight Reverse Thrust
 

Sorry guys, as an ex-mil aviator I couldn't help chipping in. I remember doing 'short field length landings' in Nimrods to practise landing on the PSP surface at Stanley following the Falklands campaign. These were again practised in the mid-late 80s when Kinloss was on 'Bolthole' at Lossiemouth. Reversers were selected and accelerated at approximately 50ft to ensure a 'firm' touchdown with a stopping capability of approximately 1200ft. Two of the occasions were so firm it cost two full sets of mainwheels and a couple of days of heavy landing checks!:}

I've seen Fokker F28s (or were they 100s?) doing it regularly

Seem to recall my skipper calling for reverse in a Nimrod while we soared over the road at Gib still very much airborne. We did stop before our feet got wet but not by much. Can't say for sure if the engines actually spooled up before we hit the tarmac.

Till you've done 450kts at 2 miles finals, on glide path, and still landed - you ain't used reverse in flight!!!

Ilyushin Il-62s (CLASSICs for you NATO codename types) also could select it, at least on the inboard engines. It was quite surprising to see them do that on short finals at Heathrow....

Is there any chance that " sycamore " is going to accept the fact that he was the one "talking cobblers"?