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View Full Version : New pilots on the 737. Watch that pitch up on go around


Tee Emm
28th Jun 2018, 07:39
https://www.gov.uk/aaib-reports/aar-3-2009-boeing-737-3q8-g-thof-23-september-2007

There has been a steady increase in recruiting of pilots by Australian Boeing 737 operators, with one operator sending its recruits overseas for abbreviated (by Australian standards) type ratings. Anecdotal evidence suggest that particular 737 type rating course has a duration of two weeks.

Overseas incidents and accidents involving the Boeing 737 series, include failure by crews to contain the marked pitch up that can occur in the 737 when high thrust is applied.as during a manually flown go-around. Autopilot controlled go-arounds are different in that the automatics are programmed to apply less than normal go-around thrust and the autopilot takes care of that quite safely.
The consequences of leaving recovery action too late from a high angle pitch up during a manual throttle full power go-around in the 737, is not often demonstrated during simulator type rating training; yet in the view of the writer, it should be.
The above link to the UK Air Accidents Investigation Board investigation of a severe pitch up by a Boeing 737 during a go-around in UK. is worth reading by all 737 operators in Australia. It should be essential study by pilots new to type.

Full report here: https://assets.publishing.service.gov.uk/media/5422eab5e5274a131700001f/3-2009_G-THOF.pdf

john_tullamarine
29th Jun 2018, 07:49
Don't folk scan any more ?

Whiskery
29th Jun 2018, 08:00
Ancient history!

john_tullamarine
29th Jun 2018, 12:44
Ancient history!

The problem lies in history's nasty little habit of repeating itself ...

sheppey
29th Jun 2018, 13:00
Ancient history!

To those of us who were flying the 737 in that era, you are right in that some like yourself consider it is ancient history and can afford to sneer. But that was never the point of the original post. . The point being the incident occurred eleven years ago in UK. It came perilously close to being a fatal accident because of mis-handling by the crew. There have been more recent examples of a similar nature where the aircraft crashed during a go-around.

Since then a considerable number (in their hundreds) of new hire GA pilots continue to be recruited by Australian airlines and are now co-pilots on the 737 series. If cadets, they would have been flying professionally in a 737 for a year and are now second in command; but with little knowledge of the past on what can bite them in the 737 or any other jet with underslung engines.

From personal knowledge in the training game, there is direct evidence that during type rating training on the 737, either in Australian or overseas simulators, the priority of type rating candidates is to pass the course asap and start earning a crust. The need to know has priority of nice to know.

Few simulator instructors have the time, inclination and professional interest in their student's professional development to pass on their own knowledge of 737 incidents or accidents. It is left to students to dig out their own information; again, if they are keen enough to do so and are previously aware of past lessons. Lawyers often refer to past cases in their judgements; yet are not derided for quoting "Ancient History".

Pprune is an invaluable repository of technical and accident investigation knowledge to those pilots determined to learn from past events. It is churlish to knock those who are interested in passing on the lessons of the past.

josephfeatherweight
29th Jun 2018, 13:27
Perhaps Whiskery was responding to John's comment:
Don't folk scan any more ?
I don't think he was down-playing the valuable info from Tee Emm...

coaldemon
30th Jun 2018, 07:22
As It has always been and always will on the Classic and NG B737 and probably the MAX. If an Airline Standards Department is not demonstrating two engine,double click TOGA go arounds in their sessions then they are do not understand the aircraft or their role.

Angle of Attack
30th Jun 2018, 11:10
It’s a fair point but remember the 300 was a pocket rocket, had far more pitch tendencies than the 400 or the NG, but still a valid point, pretty sure the only classics flying in oz are a few freighters. The NG does of course have a pitch up tendency but nothing like the 300 had.

Capt Fathom
30th Jun 2018, 11:56
Fly the aeroplane!

Centaurus
30th Jun 2018, 14:01
Fly the aeroplane!
Quite right. Most aircraft will pitch up quite strongly if you apply full power while in the landing configuration. That includes singles like the Cessna 172. Try a full throttle go around at a safe recovery height in a C172 and it will yaw as well going beyond 45 degrees nose up, unless contained by prompt intervention. Grade 3 instructors should note and demonstration of this characteristic in the landing configuration should be covered during instructor courses.

The 737 is no different; except propeller driven types will also yaw as well as pitch up during a landing configuration go-around, and that has the potential to lead to an incipient spin.

From reading a recent ATSB accident report on a night go-around in a Cirrus 22, it would seem the expected strong pitch up and yaw after a bounced landing may not have been contained quickly enough by the pilot or instructor. . As the go-around was at night, instrument flying skill may also have been a factor. See: https://www.atsb.gov.au/publications/investigation_reports/2018/aair/ao-2018-038/

Early intervention to contain a pitch up is vital; especially in IMC or dark night condition. One good reason students should not be sent solo at night until proved competent at go-arounds at the flare - not just at 200 feet.

Dora-9
30th Jun 2018, 18:54
It’s a fair point but remember the 300 was a pocket rocket, had far more pitch tendencies than the 400

AoA, you should have flown the -200! Countless times in the simulator, you'd see the guys hand-flying in cruise but with the AT engaged and eventually lose control!

Back Seat Driver
30th Jun 2018, 21:38
A -200 WITH autothrottle. Sheer bloody luxury.
When I were but a boy......

ga_trojan
1st Jul 2018, 05:38
This whole problem is aggravated by Boeing choosing not to build an Auto Throttle system in the 21st Century that can remain turned on during landing. Thus every Go Around in the 737 has to be done at full thrust until the autothrottle is turn back on during the busiest phase of flight. :ugh:

VH-ABC
1st Jul 2018, 06:19
... at full thrust? Ahh, no.

excrab
1st Jul 2018, 06:53
Why does every go around have to be flown at max thrust just because there is no auto throttle. Our SOP is to brief a sensible thrust setting for the aircraft weight. 85 to 90 % N1 will get it climbing, and then you can adjust it once you’re away from the ground.

But what I don’t understand is the comment about 21st century autothrottles. They designed it to work that way in the 20th century, select speed mode on final approach, and the A/T goes to arm
and gives you both underspeed protection and automatic go around thrust if you press TOGA. There are possible issues with uncommamded thrust lever movement in very turbulent conditions, and it is presumably because of that and possible
litigation as a result that the FCTM says that Boeing don’t recommend it. But we used to do it at the first 737 operator I worked for and I don’t remember it being a problem, but nowadays it is frowned upon.

of course the other cure for these issues is to train two engine go arounds properly in the sim, rather than just flying them at the end of a dual channel approach during LVO training.

ga_trojan
1st Jul 2018, 07:28
But what I don’t understand is the comment about 21st century autothrottles.

A/T on most other aircraft built in the last 30 years remain on and you only have to push a button or move the thrust levers in the case of Airbus to set GA Thrust. Why can't the 737 be that simple? And yes it may actually be a policy issue rather than system design.

... at full thrust? Ahh, no.

If you set some sort of 'average' N1 figure for a reduced ROC GA and something happened as a consequence I would suggest it would not look good in the subsequent safety investigation.

fox niner
1st Jul 2018, 08:13
FlyDubai at Rostov: https://www.popularmechanics.com/flight/a20530/flydubai-pilots-crash-illusion/
Tatarstan airlines at Kazan: https://fearoflanding.com/accidents/accident-reports/fatal-go-around-at-tatarstan-part-two/

And many more.

excrab
1st Jul 2018, 08:50
A/T on most other aircraft built in the last 30 years remain on and you only have to push a button or move the thrust levers in the case of Airbus to set GA Thrust. Why can't the 737 be that simple? And yes it may actually be a policy issue rather than system design.



If you set some sort of 'average' N1 figure for a reduced ROC GA and something happened as a consequence I would suggest it would not look good in the subsequent safety investigation.

I have asked around about this very issue and had a look at the technical forums on PPRUNE and I am not convinced that you can just go and set 90% and off you go. Best solution I came up with and which C &T seem to agree on is to set the bug then get the A/T back in when you can and let it do the 1000-2000fpm bit.

The 737 is that simple, once you select speed on the approach. Autothrottle goes to arm mode, you move the thrust levers manually but if you press TOGA you get go-around thrust.

And as for the findings of the subsequent safety investigation, they would be that the go around had been initiated in accordance with the company SOPs, as written in the OPS manual and as trained by the company training department in the simulator. It works, and as much as I admire PPRUNE as a source of information I am happy to fly the aircraft in accordance with company SOPs.

ga_trojan
1st Jul 2018, 10:58
The 737 is that simple, once you select speed on the approach. Autothrottle goes to arm mode, you move the thrust levers manually but if you press TOGA you get go-around thrust.


However the FCTM says in numerous places to disengage the A/T when the Autopilot is disengaged. So Boeing might well have designed the world's greatest autothrottle but they're not letting you use it during manual flying.

john_tullamarine
1st Jul 2018, 12:09
The NG does of course have a pitch up tendency but nothing like the 300 had.

Now, if you REALLY want a pitch up on the miss, try a full flap miss at minimum speed on a Super Cub ....

By George
1st Jul 2018, 22:15
The other thing is, people don't understand the difference between trimming a moving stab and an elevator. If you are pushing full forward to save the day, you don't trim a flying stab to stick position. You'll end up going 'over the hill' so to speak. That stab on the 737 is very powerful and easy to over control.

georgetw
2nd Jul 2018, 04:20
The NG does of course have a pitch up tendency but nothing like the 300 had.

Now, if you REALLY want a pitch up on the miss, try a full flap miss at minimum speed on a Super Cub ....
Better still try a Cessna 185 with full load and full flap,

Dookie on Drums
2nd Jul 2018, 06:30
Please forgive me but,

I went from a light twin to a 737 Classic.

Yes, there was a profound pitch up moment but gee it wasn't that hard. Fly the aircraft and be done with it.

Centaurus
2nd Jul 2018, 07:25
Early intervention to contain a pitch up is vital; especially in IMC or dark night condition

Yes, there was a profound pitch up moment but gee it wasn't that hard
But was the go-around on instruments at night in IMC. Different story altogether..

Dookie on Drums
2nd Jul 2018, 14:21
But was the go-around on instruments at night in IMC. Different story altogether..

Several go-arounds during type rating, limited panel etc. Only a few in real life. Proper training aligned with flying the aircraft once again.

swh
2nd Jul 2018, 14:54
The 737 is that simple, once you select speed on the approach. Autothrottle goes to arm mode, you move the thrust levers manually but if you press TOGA you get go-around thrust.

Should that not say that pressing TOGA gives go-around flight guidance however it may or may not give go-around thrust. Eg EK 777 at DXB.

excrab
2nd Jul 2018, 18:45
I canít really comment on that, as I have no knowledge of the 777 having never flown it. However that was an attempt to go around initiated after touch down, which isnít what the OP on this thread was talking about.
But ok, Iíll modify what I said. With speed mode selected pressing TOGA will, if it is working as designed, with the aircraft airborne, give you TOGA thrust. Totally nothing to do with the flight director commands which will happen whatever the A/T is doing.
Of course you should still be covering the thrust levers and do something yourself if they donít move, same as any time a power change is supposed to happen with the A/T engaged.

FGD135
5th Jul 2018, 06:59
And a couple of other things, highly relevent to this discussion:

1. How does the trim work? Please see this excellent article: https://skybrary.aero/bookshelf/books/2627.pdf

A little quote from that article, to whet your appetite:

Your speed is low, about Vapp and the thing is pitching firmly upward. You need ample forward stick/elevator to restrain it. You donít want to carry this load for long so you retrim. Question: if you run the trim forward while maintaining forward pressure on the wheel, what happens? Hands up all those who think the load reduces to zero. I see a lot of hands. My unscientific polling to date suggests that just about everyone is convinced that this is what happens, but it doesnít.

2. Be careful in the application of nose-down trim. The FlyDubai 737-800 that dived into the ground following a go-round at Rostov-On-Don in 2016 was put into that attitude by an excessive application of nose-down trim (the application lasted for 12 seconds!). Having established the aircraft in the go-round, the PF (Captain) then pressed the trim switch forward, and held it there, knowing that several seconds of application would be required. His intention, no doubt, would have been to release the switch after a few seconds, but with the high cockpit workload at the time, it appears he then became distracted - with his thumb still pressing the switch forward!

The end result was a 12 second nose-down trim application that, after sending loose objects and unrestrained passengers onto the ceiling, gave a 50 degree angle of descent!

https://en.wikipedia.org/wiki/Flydubai_Flight_981

Capn Bloggs
5th Jul 2018, 11:37
Your speed is low, about Vapp and the thing is pitching firmly upward. You need ample forward stick/elevator to restrain it. You donít want to carry this load for long so you retrim. Question: if you run the trim forward while maintaining forward pressure on the wheel, what happens?
But that isn't what pilots do (or should'nt do). You're pushing to maintain an attitude (not pushing to maintain a force), and as soon as the trim starts taking effect, the stick-load will reduce because as you're maintaining the GA attitude; you'll be reducing the pushing on the stick. Basic IF technique.

JPJP
7th Jul 2018, 04:19
But that isn't what pilots do (or should'nt do). You're pushing to maintain an attitude (not pushing to maintain a force), and as soon as the trim starts taking effect, the stick-load will reduce because as you're maintaining the GA attitude; you'll be reducing the pushing on the stick. Basic IF technique.

Mmm, you've cracked the code. Make a note ! I wonder if that deceased Captain in Russia would have typed the same paragraph from his armchair ?

Capn Bloggs
7th Jul 2018, 04:33
I was in no way commenting on what happened at Rostov. It is plainly obvious I was commenting on the quote that FDG135 made from the internet article.

framer
7th Jul 2018, 07:54
I suspect Rostov was more of a fatigue issue than a system design issue. Talk to a pilot flying similar rosters and they will tell you that it’s hard enough steering your car in a lane when that tired let alone flying a missed approach in the early hours of the morning. The pilot in question had already resigned siting fatigueing rosters as the reason.