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A320 Single Engine Missed Approach

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A320 Single Engine Missed Approach

Old 31st Mar 2023, 04:34
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Originally Posted by BraceBrace
On the Boeing OPT there is the standard MACG check where we can adapt the MACG to check single engine performance on the missed approach. But there is nowhere a check that verifies how long it takes to fly the full procedure up to clean-up. I might be missing something...
Can you assume a minimum climb rate and ground speed then determine the time taken to reach a specified altitude or distance?
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Old 31st Mar 2023, 09:59
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Originally Posted by ScepticalOptomist
Can you assume a minimum climb rate and ground speed then determine the time taken to reach a specified altitude or distance?
That's the whole point I'm trying to make: performance calculations won't cover you in every aspect. If people claim it's covered, I presume these are things done and checked in the simulator by a standard set of procedures.

Take Geneva 22 with a 3,4% climb gradient starting from 1500ft up to 7000ft. Standard 2,5% is 400-500fpm, (a performance check that we used to include in single engine go-arounds). 3,4% requires more like 600-700fpm. If with 10' thrust, you have to climb 5500ft you know it is going to take you already 8 minutes and there is 2 minutes left to accelerate. We have a 5' TOGA limit, but the performance tool we use is never going to warn us, it is up to the pilots to know and adapt and not think "it is covered".
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Old 31st Mar 2023, 10:42
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Originally Posted by BraceBrace
That's the whole point I'm trying to make: performance calculations won't cover you in every aspect. If people claim it's covered, I presume these are things done and checked in the simulator by a standard set of procedures.

Take Geneva 22 with a 3,4% climb gradient starting from 1500ft up to 7000ft. Standard 2,5% is 400-500fpm, (a performance check that we used to include in single engine go-arounds). 3,4% requires more like 600-700fpm. If with 10' thrust, you have to climb 5500ft you know it is going to take you already 8 minutes and there is 2 minutes left to accelerate. We have a 5' TOGA limit, but the performance tool we use is never going to warn us, it is up to the pilots to know and adapt and not think "it is covered".
At 66T GW for OAT 40°C and PA2000ft. the OEI GA gradient works out to 4•7%. So it should take even less than 8mts. That's why I said 10mts should take care off most if not all missed approach altitudes.
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Old 31st Mar 2023, 11:00
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Geneva has standard GA gradient only thing is the missed approach altitude is high. What happens mostly is you climb at gradient much steeper than the required. So you may get sufficiently distanced from the obstacle clearance plane. In that case it may be possible to accelerate, clean up and resume climb at MCT without penetrating the plane. But that needs to be studied by the operator. More restrictive are high GA gradient go arounds like hongkong which is 7%plane.
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Old 31st Mar 2023, 22:36
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Originally Posted by vilas
Geneva has standard GA gradient only thing is the missed approach altitude is high. What happens mostly is you climb at gradient much steeper than the required. So you may get sufficiently distanced from the obstacle clearance plane. In that case it may be possible to accelerate, clean up and resume climb at MCT without penetrating the plane. But that needs to be studied by the operator. More restrictive are high GA gradient go arounds like hongkong which is 7%plane.
Depends which minimum you use. CAT III/II and the lowest CAT I minimum require a climb gradient of 3,4% up to 4.500ft, 3,7% to 4.500ft to remain inside controlled airspace (good idea, there is a lot of VFR traffic around). On an A320 that is not limiting, on an A319 it can be, but choosing a higher minimum can assure the minimum required climb gradient, but will not keep the aircraft in controlled airspace which means that pilots might not even get traffic information, let alone separation and might have to deviate from the published missed approach to avoid unpowered VFR traffic, not ideal in an OEI situation close to terrain.

At least flysmart lets us check the OEI G/A climb gradient up to a given altitude, and that can sometimes be surprising at an otherwise benign airport like FRA where a climb gradient of at least 5% (up to 2.000ft) has to be met on 25R, which meant we could nearly never use that runway with an A319 and rarely with an A321, but nearly always with an A320. All subject to the power rating the airline buys/uses.
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Old 1st Apr 2023, 14:18
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Originally Posted by api
BraceBrace Yes, i know i am mixing up the EOSID where it does not naturally belong, but as you said yourself:

And my company just loves grey zones. Here i am trying to figure out the hard truth.

vilas

Thats what I’ve been taught in my TR and so i started my crusade against all the TRE/TRI and chief pilot.

So can you two back this with any written proof?
I have tried the FCTM and FCOM and ICAO Doc 8168. I did not find any smoking gun. Just some vague things.

cheers,
​​​​​​​
So let me put this straight, you're literally saying that the OMB of every single airline in Europe (or most of them) is... Wrong?

Mate, that's like shooting to your own foot.

You have a nice thingy on the OMB saying what to put on the perf go around page, published miss approach altitude and that's it, that complies with everything and your airplane does meet the requirements ( hey, that's why you're doing the approach after all, right!?).

​​​​​​​Very nice attitude towards the TRE/TRI and chief pilot, sounds like someone is gonna look for a job soon.
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Old 2nd Apr 2023, 09:42
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Originally Posted by k.swiss
Some points to note:
  • 10 minutes TOGA//takeoff-thrust is a hard limit for OEI, you can damage a good engine if you exceed. It is not wise even by a few minutes.
  • If you encounter an engine failure on approach there is no EOSID, you have to follow the missed approach procedure. The question is good one, does it take into account the climb gradient to ensure obstacle clearance?
Rest I agree with you John, great analysis. Great question also from the poster very curious about this one.
I disagree with both those points.

First the 10 min TOGA limit. 3 issues with this really. First, is it 10 mins total? Is 10 mins continuous? If I use 8 mins during the first go around do I only have 2 mins left? Second, it's actually an EGT limit that's been converted to a time limit because us pilots are too stupid to look at the EGT gauge. If I climb to altitude TOGA, MCT, and Climb Thrust are all the same. Does my 10 min limit count now? Thirdly, and this is the most important, if I need it I'm going to use it. 10 min limit or no 10 min limit. However, it's in the manual that it's a 10 min limit, and so it should be respected where possible. But people need a deeper understanding of why the limit is there and what it's secondly trying to achieve, rather than 10 mins and that's it.

The next point I also disagree with. On an SE missed approach you can follow the EOSID, or the EFATO procedure, or the normal missed approach, or even the normal SID, or any combination of the above. YOU are the captain of your aircraft, its safety is YOUR responsibility, not the manuals, not ATCs, not managements, YOURS.

Last edited by Jonty; 2nd Apr 2023 at 10:09.
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Old 2nd Apr 2023, 12:33
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Originally Posted by Jonty
Thirdly, and this is the most important, if I need it I'm going to use it. 10 min limit or no 10 min limit. However, it's in the manual that it's a 10 min limit, and so it should be respected where possible. But people need a deeper understanding of why the limit is there and what it's secondly trying to achieve, rather than 10 mins and that's it.
You are mixing up things. The 10' limit is a hard limit that should be respected at all times, unless your life depends on it. From the moment you apply the rating, you can only keep it applied for consecutive 10 minutes. The idea that pilots need a "deeper understanding" is very dangerous as the story is usually not that simple and contains a wide series of domain, from insurance to airworthiness and maintenance. Claiming you "know" is usually an indication you don't know the full story and the consequences of your actions, and you're going to have to do a lot of explanations to cover those consequences. We've recently seen a very poor example with an A330 diverting with a fuel leak and keeping the engines running because they had different ideas than the procedures. The most standard black/white clear procedure of all procedures are limitations. We can all do what you say, easy. It's not about what we can or how much we know about it. The reason why is much less important than the possible consequences of not adhering to the limitation.

I think the topic makes clear that there are limits to what can be prepared and verified, and those limits provide a very good level of safety. However, that does not cover every single situation (every operator is very clear on this topic as well), and it is your job to be prepared and adapt as appropriatly.
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Old 2nd Apr 2023, 14:05
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Originally Posted by BraceBrace
You are mixing up things. The 10' limit is a hard limit that should be respected at all times, unless your life depends on it. From the moment you apply the rating, you can only keep it applied for consecutive 10 minutes.
You have made my point quite well. Its not a hard limit in that if you exceed it not much will instantly happen. It is however a limit. Like the MLM, or VNE, or all the other limits we have on aircraft.
Use it for 10 mins, but don’t crash into a hill because your 10 mins are up.

And here’s a thought with regards to the 10 min limit. If I use 10 mins for TOGA, what has to happen before I can use another 10 mins?

Having a deeper understanding of your aircraft is not a dangerous thing, it worries me that you think it would be. It stops you thinking you know better, but it also allows you to understand what the actual limits are and why they are there. If you do have a better understanding of your aircraft you are less likely to start arbitrarily disregarding set procedures, but you are more likely to chose the right procedure for your situation. You’re also far more likely to understand the outcome of any given procedure and its overall effect on your aircraft before you commence the procedure and therefore make decisions in a timely manner.
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Old 2nd Apr 2023, 15:25
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Originally Posted by Jonty
I disagree with both those points.

First the 10 min TOGA limit. 3 issues with this really. First, is it 10 mins total? Is 10 mins continuous? If I use 8 mins during the first go around do I only have 2 mins left? Second, it's actually an EGT limit that's been converted to a time limit because us pilots are too stupid to look at the EGT gauge. If I climb to altitude TOGA, MCT, and Climb Thrust are all the same. Does my 10 min limit count now? Thirdly, and this is the most important, if I need it I'm going to use it. 10 min limit or no 10 min limit. However, it's in the manual that it's a 10 min limit, and so it should be respected where possible. But people need a deeper understanding of why the limit is there and what it's secondly trying to achieve, rather than 10 mins and that's it.

The next point I also disagree with. On an SE missed approach you can follow the EOSID, or the EFATO procedure, or the normal missed approach, or even the normal SID, or any combination of the above. YOU are the captain of your aircraft, its safety is YOUR responsibility, not the manuals, not ATCs, not managements, YOURS.
Originally Posted by Jonty
You have made my point quite well. Its not a hard limit in that if you exceed it not much will instantly happen. It is however a limit. Like the MLM, or VNE, or all the other limits we have on aircraft.
Use it for 10 mins, but don’t crash into a hill because your 10 mins are up.

And here’s a thought with regards to the 10 min limit. If I use 10 mins for TOGA, what has to happen before I can use another 10 mins?

Having a deeper understanding of your aircraft is not a dangerous thing, it worries me that you think it would be. It stops you thinking you know better, but it also allows you to understand what the actual limits are and why they are there. If you do have a better understanding of your aircraft you are less likely to start arbitrarily disregarding set procedures, but you are more likely to chose the right procedure for your situation. You’re also far more likely to understand the outcome of any given procedure and its overall effect on your aircraft before you commence the procedure and therefore make decisions in a timely manner.
Do you notice all the nonsense you're talking? Like for real, aren't you worried about it? "OH THE 10 MIN TOGA IS NOT ACTUALL 10 MIN, WHAT IF WHAT IF..." 10min and then MCT, it's not about agreeing or not, IT IS LAW. You dont do the 10 min? Good, prepare your ass, if everything goes good you'd better have a very good explanation, if something goes SLIGHTLY wrong... Say goodbye to your license, job and maybe life ( jail time, remember not following procedures and the result is someone being injured could cost your free will ).

Also, you have a very nice app which calculates gradients for the go around/sid etc and if not, you'll most likely have several thousands of sheets on your ipad saying which gradient you'll have on an EFATO/EOSID/EOGA or EVEN your airline has a very VERY NICE study in which all or most part of the airports you fly to, with their procedures are withing the envelope of the aircraft. Might have to check again those ATPL subjects or some ICAO documents.

I cant believe you go flying not knowing that you aircraft complies with the gradients not to mention that you guys believe that the airline does that and you just follow blindly. That goes for maverick as well, the initial pilot warrior that started the post.
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Old 2nd Apr 2023, 20:26
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Originally Posted by WhatShortage
Do you notice all the nonsense you're talking? Like for real, aren't you worried about it? "OH THE 10 MIN TOGA IS NOT ACTUALL 10 MIN, WHAT IF WHAT IF..." 10min and then MCT, it's not about agreeing or not, IT IS LAW. You dont do the 10 min? Good, prepare your ass, if everything goes good you'd better have a very good explanation, if something goes SLIGHTLY wrong... Say goodbye to your license, job and maybe life ( jail time, remember not following procedures and the result is someone being injured could cost your free will ).

Also, you have a very nice app which calculates gradients for the go around/sid etc and if not, you'll most likely have several thousands of sheets on your ipad saying which gradient you'll have on an EFATO/EOSID/EOGA or EVEN your airline has a very VERY NICE study in which all or most part of the airports you fly to, with their procedures are withing the envelope of the aircraft. Might have to check again those ATPL subjects or some ICAO documents.

I cant believe you go flying not knowing that you aircraft complies with the gradients not to mention that you guys believe that the airline does that and you just follow blindly. That goes for maverick as well, the initial pilot warrior that started the post.
Oh dear.
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Old 2nd Apr 2023, 21:06
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Originally Posted by Jonty
I disagree with both those points.

First the 10 min TOGA limit. 3 issues with this really. First, is it 10 mins total? Is 10 mins continuous? If I use 8 mins during the first go around do I only have 2 mins left? Second, it's actually an EGT limit that's been converted to a time limit because us pilots are too stupid to look at the EGT gauge. If I climb to altitude TOGA, MCT, and Climb Thrust are all the same. Does my 10 min limit count now? Thirdly, and this is the most important, if I need it I'm going to use it. 10 min limit or no 10 min limit. However, it's in the manual that it's a 10 min limit, and so it should be respected where possible. But people need a deeper understanding of why the limit is there and what it's secondly trying to achieve, rather than 10 mins and that's it.

The next point I also disagree with. On an SE missed approach you can follow the EOSID, or the EFATO procedure, or the normal missed approach, or even the normal SID, or any combination of the above. YOU are the captain of your aircraft, its safety is YOUR responsibility, not the manuals, not ATCs, not managements, YOURS.
Let me ask you a practical question, engine failure on approach to destination, high enough to go around and not low enough that you would continue. Can you tell me the exact EOSID? No you can not, hence you will follow the missed approach procedure.

This is why the question is relevant and we are not considering the EOSID.
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Old 2nd Apr 2023, 22:48
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Originally Posted by k.swiss
Let me ask you a practical question, engine failure on approach to destination, high enough to go around and not low enough that you would continue. Can you tell me the exact EOSID? No you can not, hence you will follow the missed approach procedure.

This is why the question is relevant and we are not considering the EOSID.
The question shouldn’t come up during the go-around, but during the landing performance calculation in cruise and the subsequent approach briefing and TEM. At which point the EOSID would be briefed and prepared if required. Have done that, informed ATC about it (ZRH in that case) and flown the approach, alternative would have been to divert, as the OEI go-around performance has to be within limits.
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Old 2nd Apr 2023, 23:35
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Originally Posted by Jonty
Oh dear.
That's what the TRE next to me has said when he saw your comment about " respect a limitation where possible". Not worth
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Old 3rd Apr 2023, 08:28
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Originally Posted by WhatShortage
That's what the TRE next to me has said when he saw your comment about " respect a limitation where possible". Not worth
Im really not sure why this is controversial.
Just to highlight two very mundane times aircraft limitations cannot be respected. Overspeed during turbulence in the cruise, this happens on a regular basis all over the world. Second would be an overweight landing. There's even a check list for this one! Ive done it at least 3 times after shutting engines down inflight. Wasn't sacked, jailed, or even asked for a "very good explanation". Was thanked for my efforts on every occasion.
Just to go back to the OEI 10 min TOGA limit, should it be respected where possible? Yes, of course it should. And if you have TOGA selected and your EGT is red lining, then you need to keep a VERY close eye on it and 10 mins might be stretching it. But also, if I need to use 11 mins of TOGA to ensure the safety of my aircraft then I'm going to do it. I would hope every pilot would.

Just to reiterate my point.
Have a look at the A321 (CEO, NEO is far worse) gear down OEI performance. It’s a bit of an eye opener, especially at average take off weights. Anything over about 84/85T and you’re on your way down, and that’s vastly better than it used to be on the non sharklet aircraft. In such a situation I might just forego the 10 min TOGA limit if I have to.

Last edited by Jonty; 3rd Apr 2023 at 10:38.
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Old 3rd Apr 2023, 09:07
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Originally Posted by k.swiss
Let me ask you a practical question, engine failure on approach to destination, high enough to go around and not low enough that you would continue. Can you tell me the exact EOSID? No you can not, hence you will follow the missed approach procedure.

This is why the question is relevant and we are not considering the EOSID.
I fly to many destinations where the missed approach climb gradient is in excess of 8%. In some cases as high as 12%. If you are making an approach and lose an engine you are not doing the standard missed approach. What you’re probably going to do is fly the engine failure procedure. And as Denti states, this will have been calculated and briefed during the cruise.

Just as an aside to this, no airline I have flown for in over 25 years has has EOSIDs in the FMS.
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Old 3rd Apr 2023, 09:44
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Originally Posted by Jonty
Im really not sure why this is controversial.
Just to highlight two very mundane times aircraft limitations cannot be respected. Overspeed during turbulence in the cruise, this happens on a regular basis all over the world. Second would be an overweight landing. There's even a check list for this one!...

But also, if I need to use 11 mins of TOGA to ensure the safety of my aircraft then I'm going to do it. I would hope every pilot would.
Again, these are 2 diffferent cases from a pilot's perspective. The overspeed and also overweight landing when a checklist says "land at nearest suitable airport" end up in techlog entries and at the time deemed necessary end up in maintenance actions and are covered. The overspeed is a nice one. On my aircraft you can go 30 kts into overspeed and maintenance can still sign you off without any inspection. It is unprepared, it happens. Is that a reason to say "oh, what the hell, I'll just let in increase speed, it'll be fine"? No it isn't, it remains a limit. Boeing knows this happens, you are covered. The overweight is one where the situation should justify it and even for the overweight landing, the books explain pretty clear these situations.

However for the 10' limit, the books are also very clear in that it is a hard limit and you shouldn't exceed it unless "to save your ass". And you seem to have a very wide interpretation of that phrase. You seem to interpret this as any other limitation "oh, I know what I'm doing so I can go for 11 minutes, just like a go into overspeed". If that ended up being the case, you f$cked up pretty hard during your preparation as these are very remote situations. If everything is prepared well, you shouldn't end up in this situation.

The background knowledge you have as a pilot is one that should be comforting, so that you feel at ease the engine will help you out as required for 10 minutes. It's can't be a reason to think "with the necessary personal background limitations, I know I can even bend the 10 minutes limitation".

Last edited by BraceBrace; 3rd Apr 2023 at 10:15.
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Old 3rd Apr 2023, 10:35
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Originally Posted by BraceBrace

However for the 10' limit, the books are also very clear in that it is a hard limit and you shouldn't exceed it unless "to save your ass". And you seem to have a very wide interpretation of that phrase. You seem to interpret this as any other limitation "oh, I know what I'm doing so I can go for 11 minutes, just like a go into overspeed". If that ended up being the case, you f$cked up pretty hard during your preparation as these are very remote situations. If everything is prepared well, you shouldn't end up in this situation.
I haven’t found anywhere in any of the manuals where the 10 mins TOGA limit is deemed more or less limiting than any of the other aircraft limitations. Nowhere does it say “to save your ass”. The 10 min TOGA limit is a limitation, and should be respected as such. I don’t have a “wide” interpretation of that phrase because it doesn’t exist.

What I am saying here is that the 10 min limit can be exceeded, but only in very limited circumstances where it is used to ensure the safety of the aircraft. Yes these are very unlikely situations but if you need it you need it. my example of the gear stuck down and single engine operation (that actually happened to a colleague, fortunately in an A320) would be one such example of where the 10 min limit would be exceeded.

What I find very interesting is that everyone knows the 10 min limit, it says it in the book. What is that limit based on? How long is it before I can use another 10 mins? Does the engine need maintenance action before another 10 min TOGA timing? Is it cumulative over the entire flight? These are all questions that pilots should have answers too. Understand your aircraft. Not just spout the book answer. Anyone can do that.
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Old 3rd Apr 2023, 10:56
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Jonty: I appreciate where you are coming from. In the late '70s when I was flying the 707 my then company paid to use a procedure which had been devised by PanAm which allowed the use of MORE than Max Take Off Thrust out of Nairobi. So, the expected EPR was increased and the only "hard" limitation applied was to the max N1 rpm. This allowed an increase in both the field limit weight and also the second segment climb. We understood that effectively engine life was being "sold" at any rate I never had any engines give out using this procedure.
With more modern engines I suppose that the only time real TOGA is used is for the initial stage of a go-around and certainly seldom used for take-off.

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Old 3rd Apr 2023, 12:35
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Originally Posted by Jonty
I haven’t found anywhere in any of the manuals where the 10 mins TOGA limit is deemed more or less limiting than any of the other aircraft limitations. Nowhere does it say “to save your ass”...

What I am saying here is that the 10 min limit can be exceeded, but only in very limited circumstances where it is used to ensure the safety of the aircraft.

What I find very interesting is that everyone knows the 10 min limit, it says it in the book. What is that limit based on?
As a guy who has worked as an engineer in an engine workshop, and currently flying a B737...

1) The overspeed and overweight limitations and use are clearly explained in the FCTM. The books never say "to save your ass", that is my phrase. The books will always state the PIC is allowed to deviate in the interest of safety. However these situations are pretty clear and as said, the deviation should not be an excuse for lack of preparation.

2) your question on where the limit comes from. It comes from certification, it is related to airworthiness and maintenance plans and can be found in the AFM. If 20 years ago you would have asked me (the engineer) the question, my answer would be easy: the why is unimportant, it is a result of certification tests following a laid out plan that gives you a certainty it will work for 10', and continues to work for the remainder of the flight in MCT thrust situations. If you decide to deviate and bust limitations, you are entering a grey zone where engineers might not have valid test data, and basically nobody will certify your engine will continue to work as expected until you're back on the ground after a diversion.

So you might feel comfortable doing so based on your knowledge, the engineer will be very curious to look at your engine to answer some questions he didn't have the budget for in the testing phase.

Last edited by BraceBrace; 3rd Apr 2023 at 13:56.
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