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-   -   When are you allowed to put your hand back on thrust levers after V1? (https://www.pprune.org/tech-log/607582-when-you-allowed-put-your-hand-back-thrust-levers-after-v1.html)

tdracer 14th Apr 2018 23:42

Many years ago, Boeing did a study of high speed RTOs - and not surprisingly found that a large percentage of aborts above V1 ended badly, often very badly. Boeing then started a campaign to educated pilots of the importance of NOT rejecting above V1 unless the aircraft simply wasn't airworthy. Part of that was the instruction to remove the hand from the throttles at V1 to prevent a 'startle' reaction retarding the throttles and initiating an RTO.
I fully agree to keep the hands off the throttles until 400 ft. AGL.

LEM 15th Apr 2018 09:27

Thanks tdtracer, I like the expression STARTLE REACTION :ok:

sonicbum 15th Apr 2018 10:15


Originally Posted by LEM (Post 10118961)
Thanks tdtracer, I like the expression STARTLE REACTION :ok:



Originally Posted by sonicbum (Post 10114591)
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.

Startle effect was not good enough ? :E:E:ok:

Deepinsider 23rd Apr 2018 11:15

tdracer is exactly right. (as you would expect from Everett!)
Not flown the 'bus' but don't imagine an important difference.
400 ft... that's the answer for this question.

pineteam 23rd Apr 2018 11:43

I don’t see any valuable reasons to rush the hand back on the thrust levers just after v1. It takes a fraction of second to put it back in the very unlikely you need to use them. As mentionned many times before, the startle effect is too dangerous, so I keep my hand well rested on my leg usually until gears are up.
When you are driving your car, you don’t put your foot exactly on top of the brake pedal so why would you put your hands on the levers...

Bergerie1 23rd Apr 2018 13:34

I totally endorse what tdracer has said. Stopping a large aircraft at max weight from V1 is a serious manoeuvre in its own right, stopping after V1 is sheer folly - - unless you know beyond any shadow of doubt that the aircaft is unairworthy.

And what he says about the 'startle effect' is so true. 400ft AGL is a good rule of thumb, but it isn't absolute!

Centaurus 24th Apr 2018 01:39


400ft AGL is a good rule of thumb, but it isn't absolute
This 400 feet thing as a safe altitude. Does that originate from the fact that 400 feet is the minimum height for certification of the beginning of the 3rd segment part of take off climb profile?

Killaroo 24th Apr 2018 04:05

Think of it like a gun. Don’t put your hand on it (after takeoff) unless you intend to use it.
What you planning to do with them at 400ft if the donks are running normally anyhow?
Leave them alone.

FlightDetent 24th Apr 2018 07:15

Completely agree.

172_driver 24th Apr 2018 10:34


Think of it like a gun. Don’t put your hand on it (after takeoff) unless you intend to use it.
Some Boeing pilots, me included, like feedback what the automatics is doing. There have been cases where the A/T has misbehaved. Thrust retarding to/towards idle at thrust reduction is one example.

I don't tend to use them, unless they misbehave, which I likely will pick up by resting my hands on them.

When in a steady climb and the runway is way out of my sight, gear is retracting, I am probably around 400 ft.. or soon there.. what's wrong with one hand gently resting on the thrust levers. I wouldn't think my startle would cause me to try a straight ahead landing. Only in an ASEL. For good reason, too.

Bergerie1 24th Apr 2018 13:00

centaurus,

There is no magic in 400ft AGL - which is why I said rule of thumb. I used to fly 747 Classics, thus the flight engineer watched and trimmed the power during the initial climb. I did not handle the thrust levers until I needed to either adjust the ROC or level out at an intermediate altitude on the departure. I only suggested 400ft because tdracer suggested it.

I am really amazed this thread has generated so much comment. My only hard and fast rule was to take my hands off at V1, partly because it was an SOP but mainly, as tdracer has said, to avoid any 'startle effect'. Otherwise I handled the thrust levers as required - it really doesn't need an SOP - just do what is necessary!

When using autothrottle I always rested my hands lightly on the trust levers so that I maintained the tactile feedback of what the automatics were doing.

RAT 5 24th Apr 2018 13:59

I am really amazed this thread has generated so much comment.

Indeed. At a time when there has been much discussion of airmanship v trained monkey where some people need to be told every minutiae of what & when.

When using autothrottle I always rested my hands lightly on the trust levers so that I maintained the tactile feedback of what the automatics were doing.

Indeed. I used to 'encourage' newbies to follow through the auto-throttle when large changes were commanded, e.g. a full power climb, idle descent etc. There was often quizzical look and a "where is that written down?" There then ensued an airmanship discussion including the what if an auto throttle clutch malfunctioned. A humph. I then asked "why do you follow through the TL's when selecting TOGA on take off?" "Because it's an SOP." "And why is that?" "Dunno." Oh dear.

Check Airman 24th Apr 2018 15:38

With all this talk about when to put hands where, and malfunctioning AT, I guess Airbus got it right then!

☺️☺️

Killaroo 25th Apr 2018 03:36

RAT5 - I agree wholeheartedly with you about Airmanship v v SOP's. But how did it get like this? Who created this situation? Not the pilots!

In almost 40 years in this business I've seen SOP's morph from being a set of guidelines for the wise, into a rigid and obscure labyrinth of Do's & Don'ts,
Pilots don't know WHY certain things are SOP? Who can blame them? Often the reasons are hangovers from a past incident or accident an airline had decades ago on a now defunct fleet, or from some personal obsession a Training Manager has carried with him.

New joiners aren't privy to all the history of a company, and the attitude of so many "Trainers" is - 'Don't ask stupid questions, just do what you're told'.
Asking a stupid question (why do we do that SOP) may be taken as a sign of impertinence (you're NEW here, are you questioning us?), or lack of knowledge (keep your mouth shut or you'll show your ignorance). Rote Learning and Robotic Repetition is all that is REQUIRED of them.

Quite often new SOP's are a knee jerk reaction by Management to a recent 'undesireable event' and are clearly efforts at slamming the stable door after the horse has bolted. In modern parlance 'Management Ass Covering'. These are often operationally impractical directives that get filed in the OM-A, until some poor guy gets cornered and falls foul of them, and then it's a Gotcha! I can give tons of examples of those!

Training Managers will tell you they have to write EVERYTHING down because of cross cultural/language impediments that make it necessary to cater to the 'lowest common denominator' in their pilot group. There's some truth in that. Unfortunately the result is that EVERYBODY is dragged down to that level - the performing monkey.

Lets not forget the Fear Factor either.
I don't know if you've worked outside of Europe (you're Ryanair, right?) - but in many parts of the world, pilots live in a Fear and Punishment Culture. Certain societies believe human error or failure is best prevented or dealt with by punishment. This creates an atmosphere of fear. Fear to question. Fear to think for yourself. The reasoning becomes 'If I just follow the SOP's they can't punish me, even if they're stupid SOP's'. So fear of punishment and fear of losing your job/upgrade becomes the driving behaviour. Not Airmanship.

Oh, here's a good one for starters. One of my personal favourites.
You push back in icing conditions and start #1. You then turn on the Eng Anti Ice to protect that engine while starting #2.
But the Airbus SOP is to NOT switch on the anti ice until you do the After Start Checklist.
Airmanship would tell you otherwise. But in my airline, if you switch on the #1 Anti Ice before doing the After Start Checklist - you will be marked down on the PC/RT.
Its not SOP.

PS Airbus is a large part of this problem because of the often inexplicable and mind bogglingly prescriptiveSOP's they produce. I believe their agenda is indeed to engineer pilots into being Robots, all the more easily replaced in a future generation of Artificially Intelligent aircraft . Flown Robotically.

sheppey 25th Apr 2018 13:04


Some Boeing pilots, me included, like feedback what the automatics is doing. There have been cases where the A/T has misbehaved. Thrust retarding to/towards idle at thrust reduction is one example.
See: https://en.wikipedia.org/wiki/China_...es_Flight_3943
This is what happened when one throttle failed to advance on levelling out and the crew did not notice it. Automation addiction at its most dangerous.

On another occasion during simulator training of a crew from the above mentioned country, the clutch motor of No 1 thrust lever was failed while the engine was at flight idle. As gear and flaps were lowered during an ILS and power increased by autothrottle to maintain coupled approach, only the No 2 throttle advanced while No 1 throttle remained at idle. The crew did nothing even through the throttle split was obvious. Eventually the autopilot disengaged itself, the aircraft rolled over to the left and entered a spiral dive while the crew watched in horror and did nothing and were mere spectators to the crash. Good job it was a simulator. if the PF had kept his hand on the throttles during the coupled approach he could not have failed to notice only one throttle was working and hopefully(?) would have fixed the problem by disconnecting the A/T and used both throttles manually. Again Automation addiction at its most dangerous..

RAT 5 25th Apr 2018 13:13

Killaroo: Spot on in so many ways, and I don't admit to anywhere in my past other than it was very varied on type (all Boeing), operators & XAA's (all EU), but I recognise a lot of your sentiments. As a TRE/TRI the first rule was 'there are no stupid questions.' And your other comments, I always used to try, time allowing, to explain why some of the SOP's had been designed. The good ones that is.

It's interesting your story about EAI during engine start. I, as a TRE, 'tried' to have a discussion with the training dept about this. I had been doing a winter ops RST. It was blowing snow and freezing conditions. I started the first engine and selected EAI ON and started 2nd engine. In the debrief the TRE commented that EAI was an After Start Cx-list item, and showed me where it was written. I countered with the FCTM and Vol 2. where it says that "when operating in icing conditions, or anticipated icing conditions EAI should be ON."
He understood my argument, but was obliged to enforce SOP's. OK. Let's change the SOP then. That was like asking the Pope to allow priests to marry. That means I'll be a SOP monkey in the sim and an airman of the line. My bum is firmly on the ground in the sim, but on the line.............There were others.

Killaroo 25th Apr 2018 14:16


He understood my argument, but was obliged to enforce SOP's. OK. Let's change the SOP then. That was like asking the Pope to allow priests to marry.
Very true. This is the corner we paint ourselves into with this nonsense.
Incidentally, in the above example the RT scenario included an aborted start on the #2 followed by a second failed auto start, and a subsequent successful Man Start. The whole process took at least 10 minutes including time spent digging out the Man Start checklist and pre-reading the procedure. All that while the #1 engine is meant to be left running in icing conditions with no Eng Anti Ice.
Because that's the SOP.
Madness.

Check Airman 25th Apr 2018 14:23


Originally Posted by Killaroo (Post 10129866)
Very true. This is the corner we paint ourselves into with this nonsense.
Incidentally, in the above example the RT scenario included an aborted start on the #2 followed by a second failed auto start, and a subsequent successful Man Start. The whole process took at least 10 minutes including time spent digging out the Man Start checklist and pre-reading the procedure. All that while the #1 engine is meant to be left running in icing conditions with no Eng Anti Ice.
Because that's the SOP.
Madness.

Doesn't the Airbus FCOM include a statement about using good judgment where the SOP fails to adequately address the situation?

RAT 5 25th Apr 2018 18:40

Doesn't the Airbus FCOM include a statement about using good judgment where the SOP fails to adequately address the situation?

That presupposes that captains, especially, and in only 4 years experience, have acquired the knowledge to make good judgment and have the courage to deviate and apply it. That is a big IF.

Busserday 25th Apr 2018 21:03


Originally Posted by Intruder (Post 10112497)
What is the altitude where you can begin your immediate action procedures if an engine fails? Until then, concentrate on flying and trimming the airplane.

Maybe a wind shear at 100 feet with a large loss of airspeed may have you thinking about something to do with your thrust leavers.


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