Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

When are you allowed to put your hand back on thrust levers after V1?

Tech Log The very best in practical technical discussion on the web

When are you allowed to put your hand back on thrust levers after V1?

Old 11th Apr 2018, 04:16
  #21 (permalink)  
 
Join Date: Aug 1999
Location: England
Posts: 1,004
Originally Posted by sheppey View Post
There is sure some quaint thinking in aviation.
There is no need to remove your hand off the thrust levers at V1. It was originally an old airline taught "tradition" that you intended to "Go".

Traditions have their use-by date in flying aeroplanes. It is just as easy to rotate with one hand on the control column wheel as it is to use the computer joy stick on an Airbus type. IMHO, It is common sense and good airmanship to keep one hand on the thrust levers during the take off roll and initial climb even with autothrottle system engaged.
What type do you fly?

Have you ever worked as a sim trainer?

My anecdotal observations: So many trainees leave hands on the TLs and reject after V1. Like 90% will have their hands in the wrong place at some point during their first few takes offs on their first multi type. If they are still messing that up (or slide back to it in later sessions) during a v1 cut they are 50% likely to reject above v1.
Capt Pit Bull is offline  
Old 11th Apr 2018, 04:26
  #22 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 2,300
Taking your hand of at V1 ensures that you don't reject. It's a mental message. This manoeuvre requires predetermined action since there is no time to think. Keeping your hand there you are tempting yourself. On another day you may live to regret.
vilas is offline  
Old 11th Apr 2018, 07:44
  #23 (permalink)  
 
Join Date: Apr 2010
Location: in the sky allways
Posts: 65
It's too simple ...Hands off the thrust leavers at V1,. Passing thrust reduction altitude hand back on the thrust lever and pull it back to CLB gate if it's an Airbus .....And if you need additional thrust for what ever reason in between hand OFF and ON..Just select TOGA...It doesn't take ages to get your hands back on the Thrust levers.( It does take some time for people to recognize that they need TOGA ..But once you know it does not take long)..I have seen people in the sim retarding thrust just after takeoff when they have hands ON
speedbird787 is offline  
Old 11th Apr 2018, 10:27
  #24 (permalink)  
 
Join Date: Jun 1999
Location: Oztrailia
Posts: 2,701
KISS method.

Do exactly what the MANUFACTURER stipulates in their FCOM, nothing more nothing less.

Stop making your own crap up.

Ok
ACMS is offline  
Old 11th Apr 2018, 10:52
  #25 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Age: 100
Posts: 1,408
Whenever You need to, if You need to. Guarding the thrust levers in any phase of flight other than approach will most likely do more harm than good as there is nothing You need to do with these thrust levers except if you experience wind shear. All the other possible scenarios of thrust levers handling are pretty much covered by non normal procedures.
sonicbum is offline  
Old 11th Apr 2018, 11:09
  #26 (permalink)  
 
Join Date: Jan 2006
Location: Between a rock and a hard place
Posts: 1,077
Whenever You need to, if You need to. Guarding the thrust levers in any phase of flight other than approach will most likely do more harm than good as there is nothing You need to do with these thrust levers except if you experience wind shear. All the other possible scenarios of thrust levers handling are pretty much covered by non normal procedures.
I doubt the romanian A310 crew had much time to contemplate non-normal checklists when they flipped over due to a throttle jam. Enlighten me as to what harm my hands do on the thrust levers after gear is selected up.
172_driver is offline  
Old 11th Apr 2018, 13:16
  #27 (permalink)  
 
Join Date: Aug 2011
Location: Australia
Posts: 373
I doubt the romanian A310 crew had much time to contemplate non-normal checklists when they flipped over due to a throttle jam. Enlighten me as to what harm my hands do on the thrust levers after gear is selected up.
One particular 737 operator (Asian) had a policy during an instrument approach of both pilots putting their hands on their knees unless operating a lever or MCP panel switch. The simulator instructor suggested it was a good idea for the PF to rest his hand lightly on the thrust levers during the latter part of a coupled ILS approach. The PF, who was chief pilot, rejected that recommendation.

The next sequence was a 15 DME arc leading to an ILS. As the 737 was descending during the arc with 18 track miles to touch down, it was clean at 210 knots at idle thrust. Both pilots had their hands on knees. With the thrust levers at idle power, at this point the instructor failed the No 1 thrust lever clutch motor. There is no warning light of this in the 737 and the pilots would not have been aware of anything unusual until an increase of power was needed

Turning final, the PF called for the usual sequence of flap extension to slow up including gear down and final flap. The autothrottle system then increased power to counter drag and set up the three degree still coupled approach. Due to the "failed" clutch motor on the No 1 thrust lever, that lever stayed closed at idle while the No 2 engine spooled up to high power required by gear and landing flap down. Initially about 75% N1. The PF must have seen the control wheel deflection - in fact both pilots would have been aware of it as they were both experienced on type. Yet, neither pilot said a thing.

The autopilot reacted by applying considerable control wheel rotation to counter the increasing yaw and roll. The PF and PM still had their hands on their knees as per company SOP. At 1500 feet the autopilot suddenly disengaged itself, unable to cope with gross control wheel angle.

Under the influence of high thrust on one engine and idle thrust on the other engine, with the PF taking absolutely no action (not even rudder) to prevent the aircraft from rolling into a spiral, the PF then, to the astonishment of the simulator instructor, called for the engine failure and shut down checklist. The PF's hands were still glued to his knees. There was nothing wrong with the idle power engine that manually pushing up its thrust lever would not have fixed.

While the PM was heads down scrabbling around the floor trying to locate the QRH page on engine failures, the 737 went into an ever steepening spiral past 90 degrees angle of bank all the time the PF kept both hands on his knees shouting for the PM to hurry up and read the QRH

The simulator instructor then mercifully "froze" the simulator to prevent further "loss of face." The apparent culture of the operator meant that the PM would not dare to speak up.

if the PF had kept his hand on the thrust levers during the ILS approach, he would have quickly picked up the ever increasing split thrust levers and (hopefully) take the appropriate action of disengaging the autothrottles and operated them manually.
sheppey is offline  
Old 11th Apr 2018, 13:55
  #28 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Age: 100
Posts: 1,408
Originally Posted by 172_driver View Post
I doubt the romanian A310 crew had much time to contemplate non-normal checklists when they flipped over due to a throttle jam. Enlighten me as to what harm my hands do on the thrust levers after gear is selected up.
Do not know well the details of the accident You have mentioned so I will refrain from any comments. The harm is to act instinctively and erroneously below a safe height to a possible engine malfunction as a result of startle effect, this is why when You deal with NNC thrust levers closure does require confirmation by both pilots.
On the other hand, as I have mentioned earlier, there are multiple very valid reasons to guard the thrust levers in approach.
sonicbum is offline  
Old 11th Apr 2018, 15:29
  #29 (permalink)  
 
Join Date: Mar 2002
Location: Florida
Posts: 5,115
I doubt the romanian A310 crew had much time to contemplate non-normal checklists when they flipped over due to a throttle jam
This accident as well as the earlier one (B737)in China both involved thrust lever anomalies over several seconds that were not detected nor acted on by the crew. The upset was a culmination rather than a primary cause.
lomapaseo is offline  
Old 11th Apr 2018, 16:43
  #30 (permalink)  
 
Join Date: Mar 2012
Location: Having a margarita on the beach
Age: 100
Posts: 1,408
Originally Posted by lomapaseo View Post
This accident as well as the earlier one (B737)in China both involved thrust lever anomalies over several seconds that were not detected nor acted on by the crew. The upset was a culmination rather than a primary cause.
Fully agree.
sonicbum is offline  
Old 11th Apr 2018, 16:53
  #31 (permalink)  
 
Join Date: Sep 2007
Location: BLQ
Posts: 1,146
I think is mainly a matter of risk assessment here.
Personally, the only occasion I could think I may need to move my hand back on the thrust levers after V1 is if we have to deal with an engine failure after V1 during a flex take off, on a wet runway with a big split between V1 and Vr, a very heavy aircraft on an hot/humid day.
If I have any doubt (especially regarding the second segment) I may elect to use TOGA immediately when still on ground, touching the thrust levers after V1.
Obviously, if that were the case, I would have already informed my colleague during the emergency part of the take off briefing so as to prevent him / her from thinking that I am rejecting the take-off after the V1.
Personally I cannot think of other contingencies for which I would go back to getting my hands on the thrust levers during climb out and below a safe altitude (except wind shear of course, that’s a memory item anyway …).
Just my 2 cents …

Last edited by EI-PAUL; 11th Apr 2018 at 17:03. Reason: corrections
EI-PAUL is offline  
Old 11th Apr 2018, 16:57
  #32 (permalink)  
LEM
Thread Starter
 
Join Date: May 2003
Location: The Roman Empire
Posts: 828
In the beginning of aviation, there was no V1.

Then they realized a V1 was needed. Good.

But why to remove one's hand, if only for increased awareness about commitment to go, as some say?
Answering "Checked!" would be enough.

But no, you MUST REMOVE your hand from there!

Why?
Because it' dangerous.

Countless accidents have happened because the captain initiated a reject beyond V1.

Either because:
A wrong decision.
An instinctive reaction in panic or whatever.
A heart attack or similar.

The captain of a BOAC Trident suffered one, and the takeoff was rekected when just airborne.... all dead.
Or, the captain of a Garuda DC10 rejected after V1 because eng2 exploded... 150 deads....

And the list is very long.

It is nowadays universally accepted that the ***** hand must be removed at V1 because leaving it there IS DANGEROUS!

Why is it so dangerous?

Because the mishap is NOT REVERSIBLE at low altitude.

Now, if it is true that the hand MUST be removed, the question is:

WHEN CAN I PUT IT BACK THERE?

Isn't it ridiculous to remove it at V1 and put it right back after a couple of seconds, as many do?

How come nobody in aviation culture has raised this matter so far???

I get scared when my FO put their hand there during rotation right after I've removed mine!
(When I see that, I promptly put mine back again behind theirs to guard from a catastrophic mishap!!!)

This thing is written nowhere, so I can't blame them.

I can only blame the general lack of insight.

Now, as it is also universally agreed to take no action below 400ft in case of failure, BECAUSE A POSSIBLE MISHAP WOULD NOT BE REVERSIBLE, I suggest to use the same value as the earliest time when one can put his hand back on the thrust levers, as a mishap would then be reversible.

Once again, and to all my fella, I DONT WANNA SEE ANY HAND THERE BELOW 400 feet during takeoff!!!

On the contrary, putting your hand there is a MUST during the approach, and even during taxi!!! (see the Pegasus Trabzon accident for what can happen during taxi....)
LEM is offline  
Old 11th Apr 2018, 17:02
  #33 (permalink)  
LEM
Thread Starter
 
Join Date: May 2003
Location: The Roman Empire
Posts: 828
Being ready to advance Thrust levers to TOGA in case you need, as many say, is nonsense!

Except for winshear, there is no reason to do that!
And increasing thrust on the working engine when one fails is a very bad idea!

The risks of an instinctive wrong decision to abort are way higher than the microsecond it takes to put your hand back there in case of windshear!
LEM is offline  
Old 11th Apr 2018, 17:07
  #34 (permalink)  
 
Join Date: Apr 2009
Location: A place in the sun
Age: 78
Posts: 746
LEM,

BOAC never operated Tridents. It's a good idea to check the facts before posting.
Bergerie1 is offline  
Old 11th Apr 2018, 17:24
  #35 (permalink)  
LEM
Thread Starter
 
Join Date: May 2003
Location: The Roman Empire
Posts: 828
Youre right, it was BEA.
LEM is offline  
Old 11th Apr 2018, 18:06
  #36 (permalink)  
 
Join Date: Jul 2014
Location: Germany
Posts: 339
Originally Posted by sheppey View Post
One particular 737 operator (Asian) had a policy during an instrument approach of both pilots putting their hands on their knees .....
....
...

The simulator instructor then mercifully "froze" the simulator to prevent further "loss of face." The apparent culture of the operator meant that the PM would not dare to speak up.

if the PF had kept his hand on the thrust levers during the ILS approach, he would have quickly picked up the ever increasing split thrust levers and (hopefully) take the appropriate action of disengaging the autothrottles and operated them manually.
So they wouldn't have handled an actual engine failure any better would they?

Apart from that engine failure means putting the other engine on MCT which would involve the thrust levers does it not?
Sounds to me they normally only trained engine failures after being told: now we train engine failure.

Surprising autopilot disconnects sound like something that should be sprinkled all over other simulator training. But i guess that doesn't leave time for the required items that are to be trained.
wiedehopf is offline  
Old 12th Apr 2018, 00:43
  #37 (permalink)  
Cak
 
Join Date: Feb 2010
Location: At home
Age: 37
Posts: 91
Originally Posted by LEM View Post
I get scared when my FO put their hand there during rotation right after I've removed mine!
(When I see that, I promptly put mine back again behind theirs to guard from a catastrophic mishap!!!)
If you are scared and donít believe your FO, you should takeover and fly yourself, but not having both hands around thrust levers as itís not standard procedure and you havenít briefed it probably.
Also, putting your hands behind will make FO suprised and he will be looking what are you doing. You will be also focusing more then neccessary to thrust levers which means that both of you are not completely focused on instruments when you should be to the maximum.
Donít invent procedures! That is one of the most dangerous things in aviation today.
Following your logic, do you have your hands behind levers also during short finals. What if your FO cuts power at 100ft?
Do you check where your FO holds his feet during TO when you are PF? Fully on pedals or heels on the floor?
Do you ever go out on a toilet during cruise, crossing Atlantic? Do you believe that your FO will handle engine fail correctly? Do you brief him before exiting cockpit?
There are too many Ďif situationsí and itís impossible to guard against all of them.
Type rating should mean that you know how to operate the aircraft safely and in accordance with SOP. We all know there are better and worse guys, but most are in standard. Germanwings FO was probably quite standard FO....
Cak is offline  
Old 12th Apr 2018, 03:31
  #38 (permalink)  
 
Join Date: Nov 2004
Location: bkk
Posts: 286
My favourite exercise in the sim is EFTO followed by NPA using LNAV/VNAV AUTOPILOT FLIGHT DIRECTOR to minimums.For some reason more than 60% of trainees end up losing control and crash due to poor thrust/trim management (not an issue on an airbus due to auto rudder trim and a/t).They can fly a S/E ILS without a problem but this exercise causes a LOT of grief.........strange.
piratepete is offline  
Old 12th Apr 2018, 07:11
  #39 (permalink)  
 
Join Date: Apr 2018
Location: Switzerland
Posts: 13
I fly on a business jet, and we always include in the emergency briefing "no actions below 400ft, except gear retraction". So I put my hands back on the thrust levers at 400ft. For example in case of an engine fire, the flying pilot takes the appropriate engine back to idle, after reaching 400ft. The PNF then confirms it and shuts it off according to the checklist (memory items). This is according to our OM(B) and I think it makes sense.
moswey4a is offline  
Old 12th Apr 2018, 07:36
  #40 (permalink)  
 
Join Date: Jun 2000
Location: Australia
Posts: 3,865
Taking your hand of at V1 ensures that you don't reject. It's a mental message. This manoeuvre requires predetermined action since there is no time to think. Keeping your hand there you are tempting yourself. On another day you may live to regret
Read the following accident report where because of the particular circumstances at the time, the pilot rejected the takeoff seconds after airborne. If he had elected to continue the take off, the fire was so severe that the aircraft would have surely crashed in flames.

ASN Aircraft accident British Aerospace BAe-748-378 Srs. 2B G-OJEM London-Stansted Airport (STN)

There may be one time in a pilot's career he may be forced to throw away the book and make an instant decision far removed from a company SOP.
That accident was one such case.
So it is a false premise to say dogmatically "Taking your hand off at V1 ensures that you don't reject."
Centaurus is offline  

Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.