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DirectAnywhere
8th Feb 2012, 02:59
Fortunately no LOC antenna or runway lights involved this time. Take care out there boys and girls. This is one those 'can kill ya' type things if you get it wrong.

Investigation: AO-2012-022 - Pre-flight planning event - Airbus A320, VH-JQX, Sydney Airport, 6 February 2012 (http://www.atsb.gov.au/publications/investigation_reports/2012/aair/ao-2012-022.aspx)

Jetstar takeoff error at Sydney causes ATSB investigation | Plane Talking (http://blogs.crikey.com.au/planetalking/2012/02/08/jetstar-sydney-takeoff-incident-causes-atsb-inquiry/)

gobbledock
8th Feb 2012, 03:46
TICK TOCK TICK TOCK TICK TOCK

Typhoon650
8th Feb 2012, 04:14
I only fly lighties, but wouldn't you get to a certain distance down the runway, get an odd feeling about lack of acceleration/airspeed and runway remaining, and I dunno, manually increase thrust?

Roger Greendeck
8th Feb 2012, 04:19
I've said it before, and I'll say it again. A timed acceleration check will stop this type of error ending up in an accident instead of an incident.

Mr Leslie Chow
8th Feb 2012, 04:24
Yep 'phoon most would or reject if this is the case here.

Why ASA and CASA do not put J* in the same basket as Tiger has got me buggered. Surely there must be some heat put onto someone about the inconsistencies in the way they pick and choose who they investigate, ultimately the traveling public are involved.

Let's just hope one day someone like BB is held accountable properly....

You get what you pay for I guess.

ejectx3
8th Feb 2012, 04:28
Yes , it's called experience and that feeling in the seat of your pants. In 737 if you haven't hit 80 knots by 1500 foot markers something's wrong.

Mstr Caution
8th Feb 2012, 04:29
Typhoon.

I can only speak from the environment I operate in.

There are multiple opportunities to ensure the thrust is correct.

1. Is the thrust setting reasonable for the runway in use & aircraft weight. That comes with experience.

2. All pilots independently calculate the required thrust for takeoff.

3. When the PF briefs the thrust required for takeoff, actually check that this is the thrust that is set.

4. After engine start. My own experience has led me to check the thrust is correctly set. Electrical spikes after engine start on the aircraft I fly has caused the thrust setting to default back to maximum takeoff thrust.

5. Check the thrust setting prior to entering the runway. This is a company requirement. In case there is a runway change or departing from an intersection other than that planned.

6. Normal takeoff acceleration will see the 80kt call around about the 1000 foot markers (in the aircraft I fly) if the takeoff commenced at full length. Other than full length, it takes the same time to set takeoff thrust, check engine parameters & get out the 80 kts call.

MC

inandout
8th Feb 2012, 04:39
Also as the thrust is set based on runway takeoff data, one needs to make sure the wts used for this data is correct. With 30min turn arounds mistakes can and do happen. The old swiss cheese.

Kharon
8th Feb 2012, 05:25
We have it covered - trust us.

We know how to do this (http://youtu.be/QuxSl_4yLz4)

:D

aussie027
8th Feb 2012, 05:40
inandout said-- Also as the thrust is set based on runway takeoff data, one needs to make sure the wts used for this data is correct. With 30min turn arounds mistakes can and do happen. The old swiss cheese. Exactly, wieghts need to be triple checked too, as Emirates found out in their very narrow escape from a major disaster in MEL a few yrs back!!!

I think, from memory it was an entry error of 100 tonnes lighter than actual as the 1st and 2nd digits of the weight were swapped on entry??

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???
1 person makes an error and the SOP check fails and 2 others confirm the error as correct???
I'm sorry, I know anything is possible under the right mix of circumstances but I am still at a loss to understand how this actually happened without being detected until it was very nearly too late in the take off.

Wally Mk2
8th Feb 2012, 06:21
These types of errors happen more than we would know I suspect. Most get picked up b4 power up. Humans make mistakes & we all know that fatigue (not saying it is the case here), high levels of automation & the saving of $$$ all adds up to a risk level that's getting higher.
Flex temp T/Off (reduced T/off thrust) is purely to save the engines with less wear & tear as we operate out of Rwy's longer than actually needed but that comes at a cost as we have seen here in this latest J* event.
The basic fix for this scenario is go max thrust on every T/off but that costs $$$$, something that aviation now revolves round more than safety!

I do a gross error check on the weights of the 'bus' in my head b4 I/we launch, old school I guess. Eg. 43 tonne Op Wt machine (Fleet average rounded up). 8 tonnes gas (typical 2 hr sector). 180 seats (A320) I round that up to 16 tonnes for a full ship(allows for average bags under floor also).That's 67 Tonnes as we trundle out to the black stuff (Rwy). The actual current GW of the 'Bus' is always displayed on the bottom R/H side of the SD screen when the plane is 'alive' so I compare that to what I worked out in my head, it's always within a tonne or so often a few 100 Kg's, not enuf diff to effect the T/Off drastically. Obviously the exact figures have been worked & entered but there in lies the possible error as is the subject of this discussion.

It will happen again you can count on it !


Wmk2

Jack Ranga
8th Feb 2012, 06:22
I only fly lighties, but wouldn't you get to a certain distance down the runway, get an odd feeling about lack of acceleration/airspeed and runway remaining, and I dunno, manually increase thrust?


Smart man :ok:

(your type is not wanted on Jetstar flight deks)

Capt Kremin
8th Feb 2012, 06:36
I wonder if cumulative fatigue will be found to be a factor?

Wasn't it about about 6-7 years ago that Joyce famously told a forum that Jetstar would be burning out it's pilots in 6-7 years with its rostering practices?

http://www.pprune.org/dg-p-reporting-points/230445-jetstar-pilot-life-expectancy.html

clear to land
8th Feb 2012, 06:44
Aussie-the augment crew, by SOP, were required to report tired and ready to rest. They are not involved in the performance data-it is a 2 man operation (in actuality the SOP at the time specified that that they not be involved in the pre-departure process -including maybe doing walkaround or similar-due to having to report ready to rest). Self preservation is another issue, but the bottom line is the only reason augment crew are physically in the cockpit for departure is that you can't occupy the CRC for T/O and Landing, and are not allocated a pax seat. It is a 2 pilot cockpit and 2 pilot op.

framer
8th Feb 2012, 07:02
I only fly lighties, but wouldn't you get to a certain distance down the runway, get an odd feeling about lack of acceleration/airspeed and runway remaining, and I dunno, manually increase thrust?

Not neccesarily. If they were going off the short runway in YSSY then the aircraft could have had insuffcient thrust set while at the same time feeling positively lively compared to if they had gone off the long runway.
So....insuffcient thrust can provide quite brisk accelleration compared to the correct amount of thrust on a different runway. Hope that helps explain how it can happen Typhoon.

sheppey
8th Feb 2012, 11:03
In 737 if you haven't hit 80 knots by 1500 foot markers something's wrong.

Due you count intersection departures in that statement:E

neville_nobody
8th Feb 2012, 11:51
Interesting to note that in the Emirates incident in MEL none of the crew noticed a slow rate of acceleration and that was in a heavy aeroplane with a huge error in the thrust calculation.

Can't comment on the A320 but does the Flex Temp setting change the rate of acceleration in that thing?

Centaurus
8th Feb 2012, 12:06
I'm sorry, I know anything is possible under the right mix of circumstances but I am still at a loss to understand how this actually happened without being detected until it was very nearly too late in the take off.

I can assure readers from personal experience that the detection of slower than expected acceleration is difficult particularly at night. It is only until almost at the end of the runway when you realise something is wrong. Rather like overtaking a vehicle going 10 kms slower than you on a freeway. While a long way behind the vehicle the rate of closure seems very slow then as you draw alongside you are now conscious of almost speeding past the vehicle.

Nearly 30 years ago, an Air Nauru 737-200 lined up for a night take off from the 5600 ft length runway on Nauru. No overun area - just boulders and a 20 feet drop into the water. Max bleeds off take off due runway performance limited. Planned EPR 2.18 which is full power.

80 knot call made by the captain who was PNF. Passing 110 knots the 737 would normally be passing abeam the control tower which is close to the runway. Very black hole take off over water. It was only when about five runway lights were left to go when the penny dropped that the 737 was well below V1 and never going to get airborne in the remaining runway length. An abort was now out of the question so the captain took control and fire-walled both thrust levers against the mechanical stops at the same time hauling back on the control wheel. The jet blast lifted concrete from the perimeter road back along the runway.

Later investigation revealed that at no point during the take off roll did the engines develop full thrust - although both EPR gauges indicated full 2.18 EPR thrust was achieved. In fact, it was calculated later the EPR gauges had over-read by nearly ten percent which resulted in significantly reduced thrust. The trouble was caused by the engines inlet sensors called Pt2 tubes which were later found to be blocked by a combination of phosphate dust and insects because engine covers were not in place overnight.

Close inspection of the N1 compressor gauges on the instrument panel would have revealed the lower than expected N1 readings during take off but for various reasons none of the three crew members in the cockpit that night double checked the N1 readings against the indicated EPR digital read-outs.

It was an almost identical situation to that of the 737-200 that crashed into the Washington Potomac River due to iced up Pt2 sensors on both engines that resulted in faulty EPR readings. In that case the F/O as PF was aware that `something was not quite right`during the take off roll but was unable to pin-point the problem which was lack of expected acceleration.

The captain failed to fire-wall the engines and the 737 clipped a bridge and crashed into the river killing most on board. Fortunately the captain of the Air Nauru aircraft did fire-wall the engines at the last few seconds of the take off roll and that saved the day.

Putting aside the blame-game that later ensued where the Air Nauru captain was hung out to dry by management, it was clear to this writer (I was in the jump seat) that the slower than normal full power acceleration during the take off roll at Nauru was never enough to alert the crew to an impending serious accident because the sensation was so subtle. The dark night scene didn't help. It was only in the last few seconds of the take off roll that a positive picture of the true situation became apparent. All three crew members were fooled.

The same take off thrust actually achieved that night during the majority of the take off roll at Nauru, was identical to the reduced thrust settings used on longer runways such as Guam or Hong Kong when calculated by the Assumed Temperature method. That was around 2.10 EPR. The difference of throttle angle between 2.18 EPR and 2.10 EPR is quite small. The clue was in the readings of the N1 compressor where the instrument dial is quite small and N1 needle readings small scale and hard to see at night.

Ironically if one only engine Pt2 sensor had been blocked at the time of the incident, the subsequent split throttle position needed to set equal EPR needle readings would have alerted the crew early enough in the initial take off roll to safely reject the take off. In fact this had happened to another crew on Nauru a few weeks earlier. It was an unfortunate quirk of fate that both engine Pt2 sensors suffered similar blockages leaving both EPR gauges giving identical readings as expected during a normal take off.

J52
8th Feb 2012, 12:25
One trick this SLF learnt years ago in the RNZAF days (from an aborted takeoff). Set your stop watch at start of takeoff roll. If you have still not rotated after 45 seconds get ready for the worst and make sure you have the nearest exit mapped in your mind. Pretty much works for most a/c types flying out there. When I put my life in some junior jocks hands, I want to know that I still have a little bit of control over a stuff up. Shabu Shabu anyone?

Mstr Caution
8th Feb 2012, 12:36
The ATSB report states the time was close to midday.

Could have been dark, was there an eclipse this week? :suspect:

SMOC
8th Feb 2012, 13:04
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???

Our ACARS RTOW requires us to enter the ZFW & the TOW it will reject any entries where the TOW and the ZFW are too close for the intended flight or are obviously inverted.

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.

slamer.
8th Feb 2012, 18:56
I'd commend the crew for reporting this.

Centaurus .. someone who knows what he's talking about.

framer
8th Feb 2012, 20:21
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¨

Turbine Overheat
8th Feb 2012, 20:26
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.

trashie
9th Feb 2012, 04:04
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

Bula
9th Feb 2012, 04:54
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.

Mstr Caution
9th Feb 2012, 05:16
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

Lookleft
9th Feb 2012, 05:41
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.

aussie027
9th Feb 2012, 07:21
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.:ok:
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" .:ok:

FlareArmed
9th Feb 2012, 07:52
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.

Old Fella
9th Feb 2012, 10:28
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.

SteaminDivet
9th Feb 2012, 10:37
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.....:E

framer
10th Feb 2012, 03:55
Hey Old Fella, I think maybe I didn't make my ponit very well. I'l try again.
I was responding to get an odd feeling about lack of acceleration/airspeed and runway remaining, and I dunno, manually increase thrust?
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?

outside limits
10th Feb 2012, 04:17
Has anyone actually heard what happened? IE, was a TKOF 34R done with 34L v speeds/thrust ETC

Artificial Horizon
10th Feb 2012, 05:36
From the description could it be as simple as a planned TOGA takeoff being completed with a flex set?? It doesn't say anything about incorrect wieghts.

donpizmeov
10th Feb 2012, 06:57
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

By George
10th Feb 2012, 08:25
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.

donpizmeov
10th Feb 2012, 09:38
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

Mstr Caution
10th Feb 2012, 09:58
Any of these "rules of thumb" been taken to your chief pilot and included in your companies SOP? Hmmmm thought not.

Don

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.

donpizmeov
10th Feb 2012, 11:35
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

Old Fella
10th Feb 2012, 11:46
Framer, coming from the "steam driven" era I have not had any experience of all these modern techniques. In my day we determined Take-off data from the charts, used the thrust available for the barometric conditions (Flat rated up to 29 degrees C) and from that base determined what our limiting take-off weight would be for the runway to be used. We would de-rate if conditions and runway permitted, otherwise we used max available EPR for the take-off. In any event we had only three levels of de-rate. From what I read, given sufficient runway length the thrust set these days can be greatly below what is available. Also, the FE would compile the take-off data from the charts and the non-handling pilot would check the data. As I said, steam driven and, generally, less likely to allow gross errors to occur. I understand where you are coming from with your explanation and being unfamiliar as I am with modern practice I accept what you say. It seems to me that the old adage about computerised data stands i.e. "Garbage in - Garbage out"

Normasars
10th Feb 2012, 12:33
Old Fella
:ok:

Metro man
10th Feb 2012, 14:13
Similar incident reported here:

Report: Arik B737 at Southend on Nov 21st 2010, takeoff with too low a thrust (http://avherald.com/h?article=44471741)

Report: Arik B737 at Southend on Nov 21st 2010, takeoff with too low a thrust
By Simon Hradecky, created Thursday, Oct 13th 2011 18:53Z, last updated Thursday, Oct 13th 2011 18:53Z

An Arik Air Boeing 737-700, registration 5N-MJI performing positioning flight W3-6656 from Southend,EN (UK) to Lagos (Nigeria) with 2 crew, was taxiing out for departure from runway 24, when ATC changed the runway to 06 requiring the crew to reprogram the FMC with some urgency. The aircraft was subsequently configured for flaps 5, engine anti ice off and bleed air on. The aircraft backtracked runway 06 and began the takeoff run with the first officer being pilot flying. The captain thought acceleration was slow while the aircraft accelerated through 100 KIAS and called for maximum thrust. The aircraft rotated at 133 KIAS, became airborne before the runway end and continued to Lagos for a safe landing without further incident.

The AAIB released their bulletin reporting that during reprogramming the FMC after the runway change the FMC lost its performance data requiring to re-enter them. In the hurry the first officer entered an assumed temperature in the range of about 50 degrees C which was appropriate for most of the longer runways in his home country. However, with a takeoff distance available of 4785 feet for Southend's runway 06 the temperature was too high, an assumed temperature of 29 degrees C would have been correct.

The flight data recorder showed, that the engines had accelerated to about 80.9-81.9% N1 before the brakes were released for the takeoff run. The engines subsequently accelerated to 86.0/86.1% N1 within the first 500 feet of takeoff roll. The rotation was initiated at 133 KIAS and the aircraft became airborne at 140 KIAS and climbed through 35 feet about 4317 feet from the point of brake release. The aircraft crossed the runway end at 150 feet AGL.

A review of the aircraft performance using the assumed temperature of 50 degrees C showed, that had the crew elected to reject takeoff at V1, insufficient runway distance would have been available to stop the aircraft within the runway. The aircraft would needed 656 feet additional stop distance and therefore would have gone into the arrestor bed past the end of the runway overruning the end of the runway at about 60 knots.

Equally, had the aircraft suffered an engine failure at V1 and had the takeoff been continued insufficient runway distance would have been available to become airborne before the end of the runway.

The AAIB anaylsed that although the captain recollected calling for maximum takeoff thrust the FDR did not support that maximum takeoff thrust had been applied.

The AAIB analysed that both pilots were qualified aircraft commanders making it appear likely that mutual confidence into each other's abilities may have caused a break down in the monitoring of each other's tasks. Although the first officer called out the data he was programming into the FMC the captain did not notice the wrong assumed temperature.

ejectx3
10th Feb 2012, 20:46
Tested the 80 knots by 1500 foot vs 80 knots by 1000' yesterday on 737. 80 knots occurred about half way between the two from a standing start , brakes release at toga button.....

Hence my assertion 80 knots by 1500.

Mstr Caution
10th Feb 2012, 22:40
Don.

I appreciate where your coming from.

I don't fly the 737.

I wouldn't necessarily reject a takeoff if 80kts wasn't achieved by my own reference point. It's just a cue to consider my options if there was a significant difference.

Have you ever tried putting changes thru a flight technical department. In a lot of instances I've made submissions. The response is generally unless the data can be backed up from the manufacturer. Then a change or additional information in a training manual wont happen.

MC

-438
10th Feb 2012, 23:46
Rules of thumb may give you a sense you are trying to do the right thing, however they will never cover all cases.
5 sec between 80kts & 100kts, if you are half a second out, that is a 10% error.
80kts by 1500' markers, thats fine if you don't have a displaced threshold or an intersection departure or a 4000m runway etc.
An accelerometer programmed for individual runway configs could be of use, but I don't know if these exists.

The only way is to ensure your data input is correct and independently verified.
Check your ATIS independently.
Calculate your take off weights independently, close your performance book (reset your EFB) after calculating your figures.
Write your figures on separate pieces of paper.
Then come together to check your differences.

TOLD cards can be an issue when pilots source data from them to calculate TO data as both pilots end up using the same incorrect data.

Finally, don't have pilots covering for other departments due to cost savings (load control etc) with the resulting time constraints affecting their ability to concentrate on the things that can kill people.

Mstr Caution
11th Feb 2012, 02:34
438 -

http://www.onderzoeksraad.nl/docs/rapporten/2008027e_2006086_N516MC_Schiphol.pdf

The week before this incident.
On a takeoff from Miami, the Captain rejected the takeoff for unusually slow acceleration. I'm sure on the day in question data was independently checked, verified, briefed. ATIS independently checked, correct runway & weights used.

In this case the B747 was dragging the body gear brakes.

One can do everything correct in the flight deck, but unless there is an expectation of what acceleration is normal & what is not. There is no protection afforded against other subtleties like incorrect tyre pressure or dragging brakes.

A google search will highlight cases where a dragging brake & slower acceleration, coupled with gear retraction & wheel well fire has lead to a hull loss.

That expectation (what is normal & what is not) comes with experience. An experience in which Airline Executives & Training providers believe can be substituted by ensuring crew just comply with procedures.

MC

waren9
11th Feb 2012, 04:26
Finally, don't have pilots covering for other departments due to cost savings (load control etc) with the resulting time constraints affecting their ability to concentrate on the things that can kill people.

And that is exactly the crux of the problem at Jetstar.

FSO's and INTAPs issued daily which are often changes and revisons to recent FSO's that shift responsibilty from the departments whose job (it used to be) to make sure those FSO's werent issued in the first place.

-438
11th Feb 2012, 21:01
I completely agree MC, I was just pointing out that little rules of thumb may not be the answer, otherwise they would probably be included in FCTM's. You always need to be prepared to firewall (TOGA) or reject if things don't feel right. The Jetstar AC came away unscathed so we don't know what rules of thumb they did or did not use.
My point being, do all you can to mitigate these events prior to rolling down the runway.
It can very easily happen to any one of us on any given day.

HF3000
12th Feb 2012, 15:20
I think any pilot who has been doing it long enough would agree that good SOP's are important, but not nearly enough to ensure a safe outcome.

Rules of thumb help, as do "personal" SOP's that cover many potential traps that the manufacturer's SOP's and the airline's SOP's don't cover.

These personal SOP's come from experience.

An example is how to ensure all required actions and data entry is correct and complete following a late runway change prior to landing or takeoff.

Another example is how to pick up a gross error in ZFW. Do you know the basic weight of your aircraft? How often do you do a quick mental calculation of basic weight plus pax times 100kg plus freight to estimate the ZFW and compare it to the load sheet weight presented? I was taught that years ago by an ol-skool trainer and have never seen anyone do it since.

The quote above stating reasons for rejecting prior to 80kts including abnormal acceleration is all very well but it gives no guidance for detecting abnormal acceleration. That can only come from experience and vigilance.

But I'm told experience doesn't count any more as these new beaut machines pretty much fly themselves.

framer
12th Feb 2012, 19:36
I think any pilot who has been doing it long enough would agree that good SOP's are important, but not nearly enough to ensure a safe outcome.

Rules of thumb help, as do "personal" SOP's that cover many potential traps that the manufacturer's SOP's and the airline's SOP's don't cover.


I agree with everything HF 3000 has said but feel like something is missing from this conversation. Discipline. It may not solve every problem but it can solve a lot of them.
I imagine that greater discipline would prevent many of these incorrect thrust events because it would mean that SOP's were followed exactly.
Crews are under pressure from many different angles to achieve things in a certain time frame and strong discipline is needed to maintain healthy priorities.For example, if you have pushed back and started and an ATIS change requires new calculations but you are holding up someone elses taxi clearance what do you do?
A/ Hold them up while re calculating?
B/ Ask for a clear spot to do it in?
C/Get the F/O to do it on the taxi?
D/Not worry about it because you know the EFB only uses half the headwind anyway?
There are many different ways to deal with common situations like this but I imagine that often the independant calculation element of the SOP's is sacrificed, or there is significant distraction during the process as the crew try to do two things at once.
The same sorts of choices about priorities happen for different reasons throughout the pre-flight and taxi. A strong drive (discipline) to adhere to the SOP proceedure for performance calculations will keep you safe in these circumstances. Discipline can be built up, it can be lost, it can come and go depending on your state of mind, but if you practice it regularly it can also become habit.

Old but not bold
13th Feb 2012, 01:12
Interesting lot of technical stuff but what about the basics, CRM and monitoring each other, Why do we bother with two pilots up front in a critical phase of the flight and they both just sit there with puzled looks on their faces, this is all about disciplne and training, seems to an old stager like me that we are missing the point here????????:ugh:

Ejector
13th Feb 2012, 04:45
Is 13 months normal for an investigation like this?

Mstr Caution
13th Feb 2012, 05:03
Ejector.

13months sounds about right.

Its been nearly 2 years & still no final report regarding the Singapore go around. :suspect:

HF3000
13th Feb 2012, 13:18
framer, absolutely.