Can any non-Russian plane do this?

[galaxy flyer]

Con-pilot can correct me, but the Sabre 65 could deploy the TRs in-flight if they were armed. There was an arm switch on the pedestal; the lot I flew it with would at places like Hilton Head do this "non-standard" procedure.

[Wizofoz]

Whiz,

I did some homework (talked to a few pilots) and was told that the 777 needs to be on the ground before the reversers will work. Got similar answers from A320 and 767 pilots. Perhaps the 10ft limit is only on the older (727, 737) Boeing designs- lawyers maybe?

Hi Checky,

I just checked the FCOM, and it does indeed say "On the ground", but I'm sure they unlock at 10ft RA as I've done it in the Sim. I'm pretty sure that was also stated on the CBT on the type course, but in their wisdom we don't have access to that any more.

As yo know, Boeing can be a bit "Ecconomical" about what gets in their manuals.

[Check Airman]

Thanks Whiz.

Now, in the interest of academia, are you willing to try it next time you go fly?

[con-pilot]

Con-pilot can correct me, but the Sabre 65 could deploy the TRs in-flight if they were armed. There was an arm switch on the pedestal; the lot I flew it with would at places like Hilton Head do this "non-standard" procedure.

Boy, you're asking me to wake up some the old gray cells now. Yes, there was a switch that had to be turned on to arm the reversers, it also served as the emergency stow function.

But for some reason I want to say that one of the main gear squat switches had of have been made before the reversers would deploy. I'll try and find my old Flight Safety Sabre 65 training manuals and find out for sure.

Remember, a coupe of Sabre 40s did have accidental airborne deployments. This of course got the FAA's attention and all subsequential Sabre aircraft had the switch installed during its manufacturing and all others were retrofitted.

In any case, I never tried to deploy the reversers in flight, as just before touchdown, no matter how much I was tempted to operating in and out of Aspen.

I do remember the emergency stow procedure, if the throttle auto-snatch (retard)* did not bring the affected throttle (thrust lever for those that insist), you did and then move the reverser switch to auto/emergency stow and hope to hell it worked.

Oh, and just remembered, if a thrust reverser accidental unlocked, the hydraulic system would immediately force it back into the lock position and then (I think) keep the pressure on the reverser until the aircraft landed and shut down.

There were a lot of safe guards built into the 65 reverser system and I never heard of one actually opening without commanded to, with the switch armed.

It always worked in the sim.


* That was a one time only function, once the throttle was advance again, the auto-snatch (retard) function was no longer in the system.

[hawker750]

Trident inflight reverse:
Get a ex Trident pilot to desribe the "Westcott Snatch". That was when flying was fun!

[etudiant]

My mistake.

Dozywannabe said:

I'm pretty sure it was premature spoiler deployment rather than TR.




You are of course correct. That was premature spoiler deployment, nothing to do with thrust reversal.
Still feel that a squat switch is an important element of sensible design for passenger aircraft.

[Tableview]

Lauda Air 767 BKK-VIE crash in 1991 was due to thrust reverser deployment in flight.

[Check Airman]

That was a system fault though, wasn't it?

Along those lines, does anybody have uncommanded reverser deployment as an emergency memory item? If so, what airplane is it?

[westhawk]

Along those lines, does anybody have uncommanded reverser deployment as an emergency memory item? If so, what airplane is it?

Sure CA, the airplane is the IAI Westwind and the memory items follow:

Taken from the IAI 1124/1124A SimuFlite QRH: (from memory since I don't have the QRH handy at the moment)

Uncommanded T/R deployment in flight:

Take immediate command of the flight controls
Ensure affected engine thrust lever is in the idle position.

It should be noted that the T/R sub lever should be checked to ensure it's in the STOWED position too.

When a T/R deploys in (simulated) flight, significant yaw, roll and pitching moments will occur. Aggressive nose down elevator input will be required to overcome the nose up pitching moment created by a deployed reverser. Plenty of rudder will be required to counter the yaw and timely yet gentle use of ailerons will counter the rolling moments. Overcontrolling is the common pilot response in this situation so the value of previous exposure is notable. Really it's just like an engine failure only much more so!

The checklist for uncommanded T/R in flight deployment continues and calls for the following actions. (again paraphrased from memory)

Establish an airspeed at or below 150 KIAS.
Disengage the affected T/R power CB (leave the T/R indication CBs engaged)
If these actions are unsuccessful in stowing T/R, shutdown the affected engine and land at the nearest suitable airport

The normal initial and recurrent S/F sim scenarios involved a T/R deployment prior to V1 and another after liftoff at around V2+10. The reject prior to V1 was easy if you reacted quickly but the other could be a challenge, especially with a good sim instructor who knows how to make it a true surprise. At mid level training weight near SL, the sim would even climb 500 fpm or better. Don't ask about Aspen! One sim instructor popped a T/R on us while doing 300 plus on A/P. That checked off the "unusual attitude recovery" box nicely. I'm happy to report that I've never had this happen in the real airplane, but found the sim training to be enlightening.

[B Fraser]

As others have said, the DH121 Trident could do it with distinction. It also had the ability to drop the main wheels as a speedbrake. With wheels down and engines 1 and 3 in reverse, a descent rate of 20,000 feet a minute could be achieved. The engineer had to descend the cabin first otherwise the aircraft would overtake it.

They don't build them like that anymore

[Ex Douglas Driver]

On the 777 the applicable engine's EEC must see Airplane on Ground, Engine Running, and Thrust Lever angle in reverse range to energise the isolation solenoid valve and therefore allow hydraulic pressure to open the reverser sleeve.

i.e. no reverse available airborne

[B Fraser]

There are a few ex Trident drivers around who may know. I've only flown the DH Chipmunk and Beaver. I always thought that "The Westcott Snatch" was a term of endearment however others may know better.

The main gear use as a second stage airbrake was rated up to 300kts however it was deleted after the aircraft entered service. I understand somebody tried to land one with the nose gear retracted.

[DozyWannabe]

From Google's cached version of http://www.shockcone.co.uk/hs121/trident/tales.htm :

Originally Posted by R.G. (former Trident pilot)

Shuttle arrivals into Heathrow with easterly ops were routed to Westcott then onto Garston (now renamed Bovingdon) then a westerly radar heading towards Marlow, left turn to Maidenhead and then the ILS 10L.

If Heathrow was "quiet" there was always the chance of the infamous "Westcott Snatch", basically 180 degree heading from Westcott direct to Maidenhead with the speed kept up, reducing the track distance by about twenty miles. If the offer of the snatch was made overhead Westcott then speedbrake and/or reverse idle might be needed to get the height off.


On the approach in question we were flying with one of our very senior management Captains who obviously did very little flying and very very little Shuttle. The Captain had done the sector to Manchester with myself as P2 and it was the other copilots sector back to Heathrow.

The standard operation had the Captain handling the autopilot and the copilot doing the radio. It was relatively quiet so, about ten miles short of Westcott the copilot enquired of Air Traffic.. "What's the chance of a Westcott Snatch".. "Looking good " was the reply. The management type who had obviously not heard of the "Snatch" seemed confused. He obviously thought about it and after a short period turned to the copilot and asked "what heading do you think we will get?"... In a flash the copilot enquired of Air Traffic... "and the Snatch heading?" Air Traffic responded "You should get the standard heading".

It was by now getting rather too much for the Captain. His next question.. "And the speed?".. "I'll check with ATC"... "And the speed?"...Air Traffic were now enjoying the whole episode "Standard Snatch speed"

The Captain not having a clue what to expect then played his master card. He turned to the copilot and stated "I haven't done a Snatch in a while, perhaps you could demonstrate one for me" at which point he leaned down and moved the autopilot compass switch from Port to Starboard!

Reverse idle, full airbrake by the copilot and the situation was recovered.

Throughout the episode I just sat quietly as P3 and smiled.

And one I especially like (to those for whom this won't be stating the bleedin' obvious, Lord King was BA Chairman at the time):

Paris-Heathrow, Delays due to Paris Air Show, Airborne slot allocated but just before starting informed by Ops that Lord King's Kingair will be taking the slot and we are to get the next one.

By the time we got to Biggin the Kingair was only about three miles ahead, heading 280 degrees at FL70 for an easterly landing at Heathrow. The controller, having held us at FL80 suggested the Kingair was "doing 140kts so we might catch him and with no other traffic we can keep our speed up!"

What more could you want? Keeping you speed up in a Trident 1 meant 380Kts, so as we passed directly over the Kingair 1000' above him it looked as if he was going backwards at 240kts!

[blind pew]

Some bull here from R G dozy...
Shuttle started mid 70s long after Garston was renamed.
As is VNE of 380 knots...

[DozyWannabe]

Hey, I said the stories were good, I didn't vouch for accuracy.

[Georgeablelovehowindia]

G-LKOW

Furthering the thread drift, I'd just like to add that the pilot of Lord King's B200 was a laid-off Trident first officer ...

who amongst other things, went on to a command on Concorde.

[NWA SLF]

I thought that after the Lauda Air 767 crash which was determined to be Boeing's fault they had to instal an interlock that prevented reverse thrust until the plane was on the ground. Boeing had proven to the FAA that flying low and slow the plane could be controlled if one engine reverser deployed, but the Lauda Air deployed at high altitude and unexpectedly so a couple hundred souls on board died. But I guess in the time span since they could have made the alteration that allows reverse near ground level. Seems like companies always need bad news to convince them that an almost impossible occurrence happens, and really hurts when it does.

[FlightPathOBN]

1994 crash flight 427 737-300, mid air deployment of one rev thruster at 6000 feet

also found this...

The logic of thrust-reverser deployment, taken from the Boeing 737 Operations
Manual, revision 001.1, April 1988, p 21.20.08, is that the Boeing 737 can
deploy the thrust reverser on either engine if ...

EITHER: spin-up is detected on any two main gear wheels,
OR: at least one of Captain's and First Officer's Low Range Radio Altimeters reads below 10ft,
OR: right main gear strut is compressed,

[DaveReidUK]

Seems like companies always need bad news to convince them that an almost impossible occurrence happens, and really hurts when it does.

'Twas ever thus.

[BobM2]

Originally Posted by FlightPathOBN

1994 crash flight 427 737-300, mid air deployment of one rev thruster at 6000 feet

USAir 427 was a rudder hardover, not reverser deployment.


USAir Flight 427 - Wikipedia, the free encyclopedia