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-   -   B737 @ Aberdeen (https://www.pprune.org/rumours-news/644063-b737-aberdeen.html)

olster 4th Dec 2021 14:18

B737 @ Aberdeen
 
There has been a well documented report in the popular press of a botched B737 go around @ABZ relatively recently. Subject to an initial AAIB report and curious radio silence around here. The modern 737s have a history of go arounds that have had less than optimum outcomes. The problem lies in the integration of the automation into an old technology airframe. If you know what you are doing and have good knowledge of the autopilot / auto throttle interface coupled with config / position on approach considerations then most go around scenarios can be handled proficiently with less ‘startle’ etc. Would be interested to know what happened for the purpose of education.

Airbanda 4th Dec 2021 14:24

I too was surprised not to fond comment here sooner. The AAIB Special Bulletin stating the facts as known is here:

https://assets.publishing.service.go...8K5_G-FDZF.pdf

As a non pilot but long term observer of such things it does look a bit dicey given the altitude and rate of descent. Professional commentary will be interesting.

meleagertoo 4th Dec 2021 14:41

Penny to a pound it'll come down to "Read your FMAs!" . Do that and it's hard to get it wrong.
18 seconds from the instruction to go around and actually implementing it! Even though forewarned? Wow!

ATC Watcher 4th Dec 2021 16:06

To be fair and correct he was not instructed to "go around" but to "break the approach" at 2600 ft , or 2400ft above runway threshold, an quite some NM out, so not a very urgent maneuver. But the problem does not lies there.

Jwscud 4th Dec 2021 16:26

If you don’t need to go around immediately (ie at DA/close to the ground) taking a few seconds to confirm everything’s set correctly and how you’re going to do it with your colleague is good airmanship, particularly if you are very close to them missed approach altitude.

FlightDetent 4th Dec 2021 16:29


Above 2,000 ft radio altitude, one press of a TO/GA switch commands thrust to the full go-around N1 limit (although this is not included in the Flight Crew Operating Manual and was unexpected by the crew)
Funny that.

172_driver 4th Dec 2021 18:03


Penny to a pound it'll come down to "Read your FMAs!" . Do that and it's hard to get it wrong.
18 seconds from the instruction to go around and actually implementing it! Even though forewarned? Wow!
That's the standard quote from the training department. I respectfully disagree. Not saying the FMA:s isn't import, but much better is knowledge about pitch/power and ability to execute such in a high workload environment. Getting yourself into a dive at 3000 fpm and 280 kts means 1. You are overloaded, 2. Interpreting FMAs isn't going to happen.

The 737 is a baby to go-around in if you're one step ahead, like the one-push reduced G/A thrust. It's a nightmare if you're one step behind as you have to run the trim like crazy if you're turning, levelling off, reducing thrust simulatenously.

I feel sorry for the crew having to read about themselves in the newspaper.

Banana Joe 4th Dec 2021 18:09

There it is, 60's technology for you. I am not saying pitch and power isn't important, but the ability to keep the autopilot engaged at the beginning of the Go Around would make dealing with the workload less of an hassle.

UV 4th Dec 2021 18:23

The FO had been off flying for 11 months and had two flights with a Trainer in the previous week. This was his fourth flight in those 11 months, so I assume his second after “release”.
Unfortunately this report does not say who was the handling pilot.

His dudeness 4th Dec 2021 19:07

Being a lowlife businessjet pilot, I always wondered about our training:

ALWAYS full power etcetc. At 2000ft plus there is no need for that. Apply some power gently, bring her nose up gently, raise whatever has to be raised and go about your business....



zero/zero 4th Dec 2021 19:59

meleagertoo

Another one of those incidents that’s all too easy to criticise from the comfort of your armchair at home at 1g.

Truth is go-arounds are insufficiently practiced (I’ve done 1 real one in 5 years) and when they are, it’s generally in the sim from DA and you know it’s coming. Both Airbus and Boeing have some pitfalls with Intermediate GAs (close to MAA or above it) and the 737 adds the complexity of disconnecting the AP on TOGA selection and giving you a load of pitch/power etc etc.

As with all accidents, it can never be distilled into one cause. It’s been a crazy 1.5 years in aviation and many of us feel rusty. In this case they had a bad day in the office, but recognised and recovered the situation.

PAXboy 4th Dec 2021 21:11

As PAX I want to ask, wth some SIM sessions, do they not just get you 'depart and get to cruise' to nominated destination. THEN they throw things at you? Or do you always know what is about to happen?

zero/zero 4th Dec 2021 21:41

Sim time is very precious/limited (4hrs x 4 times/year) so there just isn’t time for a “depart and cruise”, which would honestly be a pretty wasteful use of the time. It’s generally a very hectic box ticking exercise to get all the mandatory manoeuvres ticked off - engine failure, go-around, 3d approach, 2d approach, low viz etc etc. and then training for stuff that comes around periodically - upset recovery, GPWS, depressurisation… and the list goes on.

There is an element once a year called a Line Operational Evaluation which is a small company scenario with some failures thrown in. Maybe 1hr of one of the 4hr blocks

wiggy 4th Dec 2021 22:20

PAXboy

Answering your first question first…generally these days no, you don’t know exactly, but sometimes, depending on what chunk of recurrent checking training you are doing you can make a guess…for example if you have just started the Low Visibility training part of a session you know there’s a high probability there’s a rejected take-off coming up….

Other than that as has been said given the requirement for mandatory items to be got through sim time is tight/precious…

As a result you’re probably you’ll never get a standard start up, departure and be allowed to get all the way up to 30,000 feet plus before the wings start falling off :}

You’ll either get ( thinking Long Haul sims ) a scenario where the failures are chucked in on a short sector, e.g. Bahrain/Doha or Heathrow to Manchester…that would be the Line Orientated Evaluation that zero/zero mentions…..or you (virtually) go off from London heading for the Middle East but the problems start immediately the gear is up, if not before…and you end up back in London having never got East of Dover….

If an exercise needs to be commenced at cruising level (e.g. depressurization and rapid descent..or maybe a problem that starts in the cruise such as a fuel leak) you’ll be fast forwarded to start that chunk of the lesson up there, so to speak…

ACMS 5th Dec 2021 01:20

This was the ALT-GO procedure we used and it works very well. Slows things down nicely and allows time to think.

https://cimg5.ibsrv.net/gimg/pprune....1a8ec9075.jpeg

Denti 5th Dec 2021 05:48

Yes, that is the nice difference between airbus and boeing. On the 737 there are only limited methods to get out of the approach mode: change the ILS frequency, TOGA, or disconnect the autopilot and reset the FDs. That said, in the airlines where i flew the 737 every ILS was flown dual channel, which allows for automatic go around without autopilot disconnect, which makes the whole thing a lot more relaxed.

Had an ATC advised go around this summer, since there was no urgency i took the time to do a short brief what i will do next, and then calmly did it. Quite often there is no real urgency during an intermediate go-around and a few seconds waiting helps a lot. During my career i was lucky enough to had to do roughly one go around per year on the line, and most of those were intermediate ones, not the normal training case of one engine inoperative at minimum or below minimum (balked landing training).

FlightDetent 5th Dec 2021 06:50

PAXboy

Licence revalidation checkride
- single-engine ILS
- single-engine VOR
- single-engine G/A
- EFATO w/ max x-wind
- max x/wind dual eng apch without FDs
- dual hydraulic failure
- emerg elec (backup gen only)
- emergency DES
- probably FAC1+2 with single engine
- ground evac due fire
- TCAS excercise
- WSHR recovery
- GPWS escape
Those are the pretty much the mandatory exercises. Apart from the Emerg. DES and WSHR all manual flying.

Uplinker 5th Dec 2021 09:47

Firstly my sympathy to the crew. They had probably been up at "oh-god o'clock", and doing a Palma W pattern can be a frazzling experience, especially after almost a year of not flying.

I think there are two aspects to this. First; I know that both pilots had been in the SIM, but a concert violinist would never be expected to perform a difficult musical passage well unless they had had days or even weeks to practise it at home, over and over beforehand. Unfortunately, we are not allowed to take the aircraft home to practise!
Even in the SIM, one never has the luxury of practising go-arounds say five times in a row in order to hone our responses. Usually even if it was wobbly and untidy; if the manoeuvre is flown just about within the limits then the box is ticked and the session moves on.

Secondly the 737.......There will be those shouting at the screen: "just fly the got-damned plane! Are you a pilot or an idiot?". However the limited 1950's technology of the B737 and the pitch-power couple from the engines demands a hefty push forward on the yoke and a trim forward during the go-around transition, which is opposite and counter-intuitive to what one would expect when wanting to go up. If you fly a go-around every day or every week; fine, but once a year ?

Why Boeing have still not introduced FBW or decent autopilots and auto-thrust that can handle all flight phases to the 73, baffles me. They could even have brought in FBW just in pitch, which would have made a huge difference enabling auto-trim, and things like bigger engines and MCAS would have been very easy and safe to implement.

Banana Joe 5th Dec 2021 09:57

Denti

This would work, but with one caveat: the AP must be disengaged by 350 ft RA to avoid having an aircraft severely out of trim.

Denti 5th Dec 2021 11:17

Well, true in one way. Although even in the initial type rating and line training it was specifically flown to 200ft on two, click it off and land it. Yes, one has to be aware of the (unfortunate) trim, but it is very much manageable. In normal line life it was usually disengaged well before that, except for autolands of course, which both pilots could do whenever they wished to, on CAT III capable runways.

That said, the main culprit in many ways is, outside of EBT, the fact that there is the usual litany of standard stuff one has to do every simulator which is basically box ticking but does not really help all that much on the line. Like for example intermediate all engine go arounds, which are rarely if ever practiced.


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