Incident - Incorrect thrust setting for takeoff
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Can someone who flies ops in a 3 man or more crew please tell me how with whatever the company SOP is to prevent this and at least 3 people supposedly independently cross checking the data entries and subsequent V speed and thrust setting results no one picked, eg 230 instead of 320 tonnes being used in the takeoff calcs???
ie ZFW 230 / TOW 232 or ZFW 320 / TOW 230 we also preset (Boeing) flap 20 V2 based on our TOW, if it's not within a couple of knots it's either a gross weight error or a flap 10 dept which is 5 knots faster.
It reminds me of a wheels up landing in a lite twin, everyone says ¨how on earth could you do that?¨until they go out and do it themselves.
We need to be very aware of the potential for this mistake and not assume that ït won't happen to me¨
We need to be very aware of the potential for this mistake and not assume that ït won't happen to me¨
Timing
45secs doesn't work for all types.
It can be any where between 30 secs (small jets) and 60 secs (jumbo)
I've also heard airspeed check (80 or 100kts) by the end of the first 3000 ft of takeoff run
Rules of thumb can give you a heads up warning but you need to assess for the type you fly.
It can be any where between 30 secs (small jets) and 60 secs (jumbo)
I've also heard airspeed check (80 or 100kts) by the end of the first 3000 ft of takeoff run
Rules of thumb can give you a heads up warning but you need to assess for the type you fly.
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Sorry I am very old fashion. Reduced power take-offs are like runway behind you. I know it is airline policy, but how much fuel is saved and what damage does power do to an engine. I am happy to pay a little extra for the seat,knowing everything is coing for me
Would you believe that according to Airbus, high flex temperatures actually consumes more fuel overall on the climb out.. About 4 kgs for the A320.
Anyways ..... I know I use a timing "in principle" method. On the A320 it takes about 5 seconds to accelerate from 80kts to 100kts at a high flex setting. This coincides with the reduction of forward pressure on the side stick.
Food for thought.
Anyways ..... I know I use a timing "in principle" method. On the A320 it takes about 5 seconds to accelerate from 80kts to 100kts at a high flex setting. This coincides with the reduction of forward pressure on the side stick.
Food for thought.
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Happy to be corrected.
Isn't engine maintenance dependant upon whether assumed / flex temperature method or TOGA thrust takeoff's are used.
I recall being told one time that it is a Yes/No determination for each takeoff.
Even if the thrust is reduced by 1 degree assumed temperature equating to a very small thrust reduction it is still considered to be other than a TOGA thrust Takeoff.
MC
Isn't engine maintenance dependant upon whether assumed / flex temperature method or TOGA thrust takeoff's are used.
I recall being told one time that it is a Yes/No determination for each takeoff.
Even if the thrust is reduced by 1 degree assumed temperature equating to a very small thrust reduction it is still considered to be other than a TOGA thrust Takeoff.
MC
I hope the ATSB have a good look at all the FSOs released recently that have changed the method by which the flex temp is calculated. It has involved two changes to the TOLD card, 3 FSOs and a powerpoint that leaves you more confused than when you started! Once again QA of the change process has lined up all the holes the cheese has to offer. Only one person making all these changes so hopefully his "acting" days are over.
Wally, Centaurus,SMOC and clear to land, thank you very much for your answers.
Centaurus, that experience in Nauru sounded damn close to disaster, Thankfully the hauling back and firewalling saved the day. As i was reading your incident description and the Pt2 sensors I was thinking of the Potomac crash and then I saw you mentioned it as I read on.
I am aware that accel is very hard to judge as being normal or not esp at night, unless you have a basic check rule of thumb you know of in your particular acft to help you see that it seems too slow.
I was in particular thinking more of catching that basic data entry type error via some method like SMOC mentioned or a basic mental type check like Wally mentioned to catch the error long before you commence the TKOF roll.
Eg- if the TOW today is between approx X-Y tonnes then Vr/V2 should be approx A-C on an average runway etc. Just some numbers you can compare to what the FMS came up with after all the data entered to catch any gross errors, as in Emirates eg where it was 100 tonnes and the bug speeds were obviously way too low, as well as the thrust.
I met several B727 pilots yrs ago when I was riding part of a number of flights in jump seat (Pre 9/11 days) who did this exact kind of check. They had a little card with some basic wt ranges/speeds/thrust settings on it they had pulled out of the manual as a guide. Any large mismatch and it was ooops, better go back into FMS and cx everything with the load sheet to see what we did wrong.
TKOF roll, as you very well described and Emirates found out, its basically too late, very hard to detect and only a miracle along with TOGA thrust and hauling it into the air may save someone from a runway overrun / collision with obstacles and a major disaster.
This type of error ,like many any other very small ones that can go undetected can lead to major disaster if all the holes line up.
To paraphrase, " The price of safety is eternal vigilance" .
Centaurus, that experience in Nauru sounded damn close to disaster, Thankfully the hauling back and firewalling saved the day. As i was reading your incident description and the Pt2 sensors I was thinking of the Potomac crash and then I saw you mentioned it as I read on.
I am aware that accel is very hard to judge as being normal or not esp at night, unless you have a basic check rule of thumb you know of in your particular acft to help you see that it seems too slow.
I was in particular thinking more of catching that basic data entry type error via some method like SMOC mentioned or a basic mental type check like Wally mentioned to catch the error long before you commence the TKOF roll.
Eg- if the TOW today is between approx X-Y tonnes then Vr/V2 should be approx A-C on an average runway etc. Just some numbers you can compare to what the FMS came up with after all the data entered to catch any gross errors, as in Emirates eg where it was 100 tonnes and the bug speeds were obviously way too low, as well as the thrust.
I met several B727 pilots yrs ago when I was riding part of a number of flights in jump seat (Pre 9/11 days) who did this exact kind of check. They had a little card with some basic wt ranges/speeds/thrust settings on it they had pulled out of the manual as a guide. Any large mismatch and it was ooops, better go back into FMS and cx everything with the load sheet to see what we did wrong.
TKOF roll, as you very well described and Emirates found out, its basically too late, very hard to detect and only a miracle along with TOGA thrust and hauling it into the air may save someone from a runway overrun / collision with obstacles and a major disaster.
This type of error ,like many any other very small ones that can go undetected can lead to major disaster if all the holes line up.
To paraphrase, " The price of safety is eternal vigilance" .
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Flex
Flex thrust reduces wear-and-tear and increases engine life, but increases risk.
One measure of wear-and-tear is EGT drift – that is, the change of EGT compared to other parameters over time.
Benefit – I was once shown such a graph for a jet I managed. The previous pilot manager was not a fan of derate and the engineers showed me a trend-monitoring graph indicating wear-and-tear equal to six years' (derated) use in barely one year of operation.
Risk – I had a takeoff where improved climb thrust was erroneously (software design issue and human error) combined with normal speeds leading to low-thrust. I pushed the thrust up because it didn't feel right and we worked out the error later.
One measure of wear-and-tear is EGT drift – that is, the change of EGT compared to other parameters over time.
Benefit – I was once shown such a graph for a jet I managed. The previous pilot manager was not a fan of derate and the engineers showed me a trend-monitoring graph indicating wear-and-tear equal to six years' (derated) use in barely one year of operation.
Risk – I had a takeoff where improved climb thrust was erroneously (software design issue and human error) combined with normal speeds leading to low-thrust. I pushed the thrust up because it didn't feel right and we worked out the error later.
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Incorrect thrust
Framer, your assertion that taking off on the short runway with INSUFFICIENT thrust set could feel positively lively compared to taking off on the long runway with correct thrust seems to me, an old retired F/E, to be incorrect. In what way would it seem "lively"? Having had to, by company decree, not been allowed to use reduced thrust on the short runway at YSSY I can tell you a B747 Classic with only 35000 Kgs of fuel (SYD-MEL) and Max Thrust really is lively. So much so that it went up like a lift and the initial climb angle was quite steep so that the first thrust reduction and gear retraction could be completed. I would think that taking off on a short runway with insufficient thrust would be quite "hairy" rather than lively. In fact I don't see any scenario where less thrust than required on any runway would result in better acceleration than with the correct thrust setting.
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This whole episode is why as a Jetstar pilot one should subscribe to not give a fook about power by the hour lease agreements and managers KPI's more so the philosophy of TGIATW ( Thank it's a TOGA weekday) or ( Thank god it's a TOGA weekend) as opposed to TGIF.....
Hey Old Fella, I think maybe I didn't make my ponit very well. I'l try again.
I was responding to
The point I was making is that the variation in thrust (and therefore accelleration) is so great from one departure to the next that you may not get that ´odd feeling´.
For example, I could take off on Sydney´s 34L with an assumed temperature of 66 degrees and slowly lumber down the strip and struggle into the sky and there would be plenty of margin. Then two hours later I could depart from 34R with an assumed temperature of 38 degrees, the accelleration would be much greater than the departure off 34L (thats where I got the ´lively´from) yet it would be insufficient thrust for the runway and conditions because an assumed temperature of 32 degrees was required.
Does that make more sense?
I was responding to
get an odd feeling about lack of acceleration/airspeed and runway remaining, and I dunno, manually increase thrust?
For example, I could take off on Sydney´s 34L with an assumed temperature of 66 degrees and slowly lumber down the strip and struggle into the sky and there would be plenty of margin. Then two hours later I could depart from 34R with an assumed temperature of 38 degrees, the accelleration would be much greater than the departure off 34L (thats where I got the ´lively´from) yet it would be insufficient thrust for the runway and conditions because an assumed temperature of 32 degrees was required.
Does that make more sense?
Outside limits, don't go trying to muddle this skygod debate with facts! What will the experts have to discuss then?
Skygods,
Any of these "rules of thumb" been taken to your chief pilot and included in your companies SOP? Hmmmm thought not.
The Don
Skygods,
Any of these "rules of thumb" been taken to your chief pilot and included in your companies SOP? Hmmmm thought not.
The Don
Don, with the greatest respect there is nothing wrong with 'rules of thumb' they have saved me once. Having said that, sometimes even then, the holes line up. In AKL with the SQ 747 (9V-SMT, since known as the "scrape my tail") both pilots were just off the A340. When the mistake of 220t for take-off instead of 320t was made it didn't seem strange to them. With all the distractions during pre-flight, fatigue, engineering, load control, Traffic, ATC and even the well meaning FA's with the very important 'drink order' you have to somehow slow it all down and double check everything. Anybody can make a mistake, it's managing mistakes that counts.
I like rules of thumb as a broad overview, a big picture thing.
I like rules of thumb as a broad overview, a big picture thing.
By George,
I agree with you in a sense. Knowing your aircraft and a commonsense check is great. But as you described, it doesn't always work.
As mentioned by someone, one rule of thumb was to use the speed achieved at the 1500' markers as a guide. Do they brief it? And brief what actions they are going to take if its not achieved? Perhaps their rule of thumb is different from the person sitting next to them. Wouldn't be worth much if they don't actively go about using it would it?
If it was as easy as using rules of thumbs, wouldn't the manufacturer provide this guidance? What quality control is there on them?
The only consistent way of trapping and mitigating error is a robust SOP with checks built into it. If these rules of thumb were so good I am sure the airline would add them to its SOP to improve safety.
Good on the crew for making the report.
The Don
I agree with you in a sense. Knowing your aircraft and a commonsense check is great. But as you described, it doesn't always work.
As mentioned by someone, one rule of thumb was to use the speed achieved at the 1500' markers as a guide. Do they brief it? And brief what actions they are going to take if its not achieved? Perhaps their rule of thumb is different from the person sitting next to them. Wouldn't be worth much if they don't actively go about using it would it?
If it was as easy as using rules of thumbs, wouldn't the manufacturer provide this guidance? What quality control is there on them?
The only consistent way of trapping and mitigating error is a robust SOP with checks built into it. If these rules of thumb were so good I am sure the airline would add them to its SOP to improve safety.
Good on the crew for making the report.
The Don
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Any of these "rules of thumb" been taken to your chief pilot and included in your companies SOP? Hmmmm thought not.
No need to take anything to the Chief Pilot, my Boeing QRH Manoeuvres Chapter under RTO's already states:
"Prior to 80kt, the takeoff should be rejected for any of the following"
"Abnormally slow acceleration"
In the absence of Boeing Data to support their statement, I and other crew have put checks in place to gauge whether we consider acceleration is normal.
Mstr Caution,
Case in point,
You have mentioned that you use 80kts by 1000' markers (you mentioned Boeing so am guessing 737), someone else mentioned 80kts by the 1500' markers for the 737. Who is right? What happens if you fly together?
If you think its a good idea why not share it with the rest of your company so that all your company pilots can benefit from your good idea rather than just post it on an anonymous forum?
Just askin like?
The Don
Case in point,
You have mentioned that you use 80kts by 1000' markers (you mentioned Boeing so am guessing 737), someone else mentioned 80kts by the 1500' markers for the 737. Who is right? What happens if you fly together?
If you think its a good idea why not share it with the rest of your company so that all your company pilots can benefit from your good idea rather than just post it on an anonymous forum?
Just askin like?
The Don