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-   -   Low level Go around A320 (https://www.pprune.org/tech-log/605110-low-level-go-around-a320.html)

Goldenrivett 9th February 2018 15:16

Anticipation
 
Hi vilas,

Developing own procedures is fraught with danger in airbus FBW
BDM and I are not developing own procedures - we are implementing Golden Rule No 4.

A GA from 1700ft to only 2,000 ft has several potential traps. They all can be avoided by generating more time to "analyze and solve the situation" by simply reducing the thrust to a sensible setting after TOGA has been selected and the FMA change has been confirmed.

"Golden Rules
4. Take action if things do not go as expected.
If the aircraft does not follow the desired vertical or lateral flight path, or the selected targets, and if the flight crew does not have sufficient time to analyze and solve the situation, the flight crew must immediately take appropriate or required actions, as follows:
The PF should change the level of automation:
- From managed guidance to selected guidance, or
- From selected guidance to manual flying.
The PM ......"

atr-drivr 9th February 2018 15:32


Originally Posted by Speedwinner (Post 10044523)
Hello guys,

simple question:

we make a go around in 1700 ft and the GA Altitude is 2000ft. So we put the thrust Levers short in TOGA and then again in the climb notch. The ATHR activates and where does the Speed bug jump to? it will protect us exceeding the placards right?

Thanks!

Is the APPR armed? ILS? RNAV?

Escape Path 10th February 2018 17:07

GR

What exactly isn't going as expected? It's a routine procedure, even if slightly abnormal because of the low level off.

I'm all for taking manual control if necessary and an advocate of manual flying skills. It isn't necessary in this case. Simple solution is to set TOGA so the FMGS switches to GA phase and then almost immediately pull the levers back to CLB. The aircraft will keep climbing, you'll get ATHR and the energy level will be easier to manage as it is lower than with TOGA thrust. I agree with vilas, manual flying on an Airbus can easily get you into trouble if you're not aware of whole scenario and how the FBW system will try to "help". In such a dynamic manoeuvre as the one discussed I don't think it's necessary or prudent to revert to manual flight, given the automation is not doing anything that requires its disconnection.

As a side note, LVR CLB will flash above THR RED alt, not ACCEL (I'm aware that they can be the same, but still)

vilas 10th February 2018 23:40


As a side note, LVR CLB will flash above THR RED alt, not ACCEL
yes sure! But left flashing even after ACC ALT.

CM1A320 11th February 2018 00:46

I know one FO that got fired from qatar for setting the thrust levers to idle at 1500 feet approaching VFE on a go around, capt was fired also just for fun.

i think it's key to train pitch and thrust, on the A320 10 deg NU and CLB is the unreliable speed config, its should always be on the back of your mind.

Goldenrivett 11th February 2018 08:53

Escape Path

What exactly isn't going as expected?
Time available and possible Flaps Slats overspeed warning.

Assume the aircraft is at max landing weight and below and consider the ALT* and level segment with TOGA thrust initially commanded then CLM thrust.
The magenta target speed would jump from SRS commanded speed to Green Dot (around 210 kts). Once the flaps have been retracted one stage to say F2, auto thrust would limit the aircraft speed to 195 kts (200 -5). As the VFE speed is approached, say around 190 kts, the flap handle is moved to 1+F and the auto thrust will continue to accelerate the aircraft to 210 kts (215 - 5). At 201 kts and above the overspeed warning sounds until the flaps are at 1+F.

In level flight with all engines operating, Autothrust can accelerate the aircraft faster than the flaps move.
"Note:
OVERSPEED alert, and VLS displayed on the PFD, are computed according to the actual flaps/slats position
VFE and VFE NEXT are displayed on the PFD according to the FLAPSlever position."

vilas 11th February 2018 13:53

Golden
OK. Let's take your example. I am actually surprised with it. If you are at ALT* with flap3 you don't retract one step but go straight to 1+F. That increases the VFE to 215kts and again Airbus the smart aircraft it is will auto retract the F part at 210kts. That makes the VFE 230Kts. There is simply no requirement to do anything extra ordinary.

Goldenrivett 11th February 2018 17:25

vilas,

I am actually surprised with it. If you are at ALT* with flap3 you don't retract one step but go straight to 1+F.
Our SOP during a GA is to retract the flaps by one step. (e.g. From 3 to 2 i.a.w. FCTM PR-NP-SOP Go-Around)

From FCTM PR-NP-SOP-120

"OVERSPEED WARNING DURING SLATS/FLAPS TRANSITION
Applicable to: ALL
During the Slats/Flaps transition, the flight crew must respect the VMAX displayed on the PFD. The VMAX value displayed on the PFD speed scale is based on the Slats/Flapscontrol lever position.
The OVERSPEED WARNING is based on the actual Slats/Flaps surface position. Therefore, during Slats/Flaps transition, the dynamic acceleration of the airplane may lead to a temporary OVERSPEED WARNING even if the current speed is out of the red and black strip displayed on the PFD. In this situation, there are no operational consequences. The flight crew must report any type of overspeed event."

I prefer to avoid the threat with a sensible dynamic acceleration rather than mitigate the event and file the paperwork.

I agree - it’s your choice - so sit back and simply watch the automatics :mad: it up.

vilas 11th February 2018 23:27

Golden
The first retraction at GA initiation is one step. That is from full to three or from 3 to 2. But at acceleration phase it is always flaps 3 to 1. You check again. It is same at take off. In over weight landing case if approach is done in three the first retraction it self is to one. I am really surprised.

vilas 12th February 2018 03:37

Golden
FCOM below:

AT GO-AROUND ACCELERATION ALTITUDE
Monitor that the target speed increases to green dot.
If the target speed does not increase to green dot:
ALT knob........................................................ ................................................CHECK and PULL
At F speed:
FLAPS 1........................................................... ............................................................ ... ORDER
FLAPS 1........................................................... ............................................................ .. SELECT
This is in all cases whether you are Flap3 or Flap2 you retract to 1. Same is with take off. There is no Flap2.

Goldenrivett 12th February 2018 12:34

vilas,

The first retraction at GA initiation is one step.
I agree - so what's your point in the rest of your posts?

I note you made no comment on my previous post regarding "OVERSPEED WARNING DURING SLATS/FLAPS TRANSITION"

Perhaps you would care to read Centaurus post in a different thread
https://www.pprune.org/10050571-post93.html

"Flight International 30 January -5 February 2018. Letter to Editor headed:
Manual flying still a necessity by Tristram Llewellyn Jones.

.....Flight International has rightly raised concerns about the degradation of manual flying skills due to over-reliance on automation."

vilas 12th February 2018 14:33

My point is same. If you do what you are supposed to do no innovation is required. When SRS changes you check speed and retract flap to 1 and that's it. If you are late then FMGC will restrict speed to VFE or you do whatever you want to. As I said this is routinely taught and executed without problem in type rating. Auto retraction is also shown. You say reduce thrust, another says disconnect ATHR, yet another may feel it's a good idea to leave the gear down to slow the acceleration and retract it later. Take your pick.

Escape Path 13th February 2018 00:08


Originally Posted by Goldenrivett (Post 10049239)
Time available and possible Flaps Slats overspeed warning.

It's going exactly as expected. It will be a dynamic manoeuvre, you know you will need to be working at a decent pace.


Originally Posted by Goldenrivett (Post 10049239)
The magenta target speed would jump from SRS commanded speed to Green Dot (around 210 kts). Once the flaps have been retracted one stage to say F2, auto thrust would limit the aircraft speed to 195 kts (200 -5). As the VFE speed is approached, say around 190 kts, the flap handle is moved to 1+F and the auto thrust will continue to accelerate the aircraft to 210 kts (215 - 5). At 201 kts and above the overspeed warning sounds until the flaps are at 1+F.

Don't wait until VFE to retract the flaps. Taking your example: F speed for an A320 @ MLW will be around 150 KTS. You can retract to 1+F as soon as you level off (SRS to ALT*). Plenty of time before overspeeding. S speed will be around 195, 20kts to go before overspeed, and even then, if both mess it up, auto retract will go to F1: auto retract kicks in at VFE-5 (210), 20 more to go to overspeed.

I just don't see any reason to do anything different and potentially get into trouble for doing something non-standard in a standard situation

vilas 13th February 2018 04:01


Once the flaps have been retracted one stage to say F2, auto thrust would limit the aircraft speed to 195 kts (200 -5). As the VFE speed is approached, say around 190 kts, the flap handle is moved to 1+F and the auto thrust will continue to accelerate the aircraft to 210 kts (215 - 5).
The whole premise is wrong so what follows can't be right.

Nick 1 13th February 2018 04:45

It’ s a 330/340 sim ...


pineteam 13th February 2018 04:57

Approach speed is quite slow compare to an A321. Nice video but I think the PF Forgot to read “A/TH Blue” and “Alt Blue” during the go around. Or will it be too much to read?

*Lancer* 13th February 2018 05:08

The two most important things to not forget are:

Get the THR LVRs into TOGA, and,
Get the THR LVRs back into CLB.

GA induced UAS events involve missing one of these steps.
If you forget everything else you are merely procedurally sloppy.

vilas 13th February 2018 06:07

pineteam
Quite a few things are strange. GA ordered by PM (may be a checker). But no GA flaps call by PF, no FMA read out by PF. FMA called only by PM, ATHR Blue was missed, +ve CLB by PF not PM, LVR CLB not called just executed and again ATHR active missed. Left side guy, the PF is just following orders then why is he on left? Not very impressive I am afraid.

vilas 13th February 2018 07:07

From Airbus Safety First July 2011.

9. Acceleration Altitude RAPID ALT* ENGAGEMENT – WITH AUTOPILOT In the event of an early capture of altitude (ALT*), for example if the Go Around is initiated close to the altitude selected on the Flight Control Unit (FCU) or in case of a high rate of climb, rapid acceleration towards a potential overspeed may occur.
As soon as ALT* engages, the autopilot lowers the aircraft pitch and the aircraft accelerates without any A/THR protections (A/THR blue). At that time, “LVR CLB” flashes on the FMA. The PF reacts by setting the thrust levers from TOGA detent to CL detent, without delay, in order to activate the A/THR, thus enabling A/THR protections. These protections include a flap overspeed protection.
That is all the manufacturer says and if you have already brought the thrust levers to climb the protection is assured. There is no need to do any thing non standard.

Goldenrivett 14th February 2018 11:11

vilas
"From Airbus Safety First July 2011.
These protections include a flap overspeed protection."

That is all the manufacturer says and if you have already brought the thrust levers to climb the protection is assured.
In 2014 Airbus recognised Manual Flying skills were being eroded and introduced a different emphasis during conversion course for A350. http://www.airbus.com/content/dam/co...agazine_18.pdf
Page 31: "In the end, the approach to training
is reversed: pilots are encouraged to
appreciate flying the aircraft manually
and consider automated systems a full
benefit, rather than considering manual
flying a degraded and potentially
challenging configuration."

From FCTM PR-NP-SOP-120 2017

"OVERSPEED WARNING DURING SLATS/FLAPS TRANSITION
Applicable to: ALL
During the Slats/Flaps transition, the flight crew must respect the VMAX displayed on the PFD. The VMAX value displayed on the PFD speed scale is based on the Slats/Flapscontrol lever position.
The OVERSPEED WARNING is based on the actual Slats/Flaps surface position. Therefore, during Slats/Flaps transition, the dynamic acceleration of the airplane may lead to a temporary OVERSPEED WARNING even if the current speed is out of the red and black strip displayed on the PFD. In this situation, there are no operational consequences. The flight crew must report any type of overspeed event.”

The FAA are concerned about degradation of manual flying skills: https://content.govdelivery.com/atta.../SAFO17007.pdf
"Discussion: Manual flight operation is defined here as managing the flight path through manual control of
pitch, bank, yaw and/or thrust.
...
5. Operations in all approved combinations of automation based on aircraft equipage, e.g.,....
• FD on, AP on, AT off."

Reading many of the above comments regarding the reluctance to even consider taking manual thrust control if the acceleration looks "too dynamic" - then I think the FAA are right to be concerned.


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