Low level Go around A320
 

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!

Assuming above FMGC acceleration altitude target speed will be green dot.

Assuming that you previously had at least Config 1 selected, SRS mode would engage when you selected TOGA. Your FMA would read “MAN TOGA / SRS / GA TRK (or NAV) / ATHR (in blue)

At CLB thrust selection your FMA would read “THR CLB / SRS / GA TRK (or NAV) / ATHR (in white)”

Approaching 2000’ your FMA would read “SPEED / ALT* / GA TRK (or NAV) / ATHR (in white)”

At ALT* your magenta target speed would jump from SRS commanded speed to Green Dot, regardless of the Acceleration Altitude programmed in the MCDU.

FCOM DSC-22-30-40 states that "If the managed speed/Mach target is set above VMAX (VFE, VMO, MMO), the FMGES automatically limits the speed to VMAX"

In theory, if the VFE was below G/D speed, the aircraft would accelerate only to VFE, but the magenta speed target would still show Green Dot. That being said in case of very quick acceleration, or environmental disturbance (turbulence, wind shift etc.), I would think it would be quite easy to exceed VFE.

For what it’s worth, this is my take on it (from experience)

In theory you are correct, the aircraft is supposed to protect you from an overspeed condition, however a go around with a low altitude level-off can turn into an overspeed very quickly, if you get behind the aircraft.

It’s because you are putting in a bootload of thrust (energy) in at low speed. It will initially go into srs, and pitch up significantly to maintain the srs speed target (hence a massive rate of climb) , followed very soon by alt* to level off.

Everything is essentially happening at once and you’re in alt* before you know it.

If you don’t bring the thrust back to climb pretty quicky (which will engage the autothrust) you will accelerate rapidly and if old mate is a bit slow getting the flaps retracted you will overspeed.


Seen it happen in the sim (and done it myself during endorsement training) :}

True - but you could always take more power off so the acceleration is more manageable and only restore TLs to Climb gate when you are happy - like you used to do on previous aircraft types.

Exactly! Nothing wrong with disengaging auto-thrust.

To start with it is not a low level GA but high energy GA. LLGA is a different ball game altogether. In high energy GA when thrust levers are brought to CLB the FG overspeed protection is available. Next speed target will be GD. It is necessary to logically understand the sequence of these activities. First you get out of approach into GA phase. TOGA does that. Second, expect SRS to change to OP CLB or ALT* in a GA. No matter what SRS changes to it is always acceleration phase and you should be anticipating to retract flaps to next setting. The first retraction is important because the VFE for next flap setting is 30kts away. Like in any aircraft always remind yourself what next. If you have to do anything else like reducing thrust etc. means you didn't anticipate the next action. It is only salvaging a bad situation and not smart flying.

don't forget to retract the gear whilst doing all that ;)

Hi vilas,
Probably easy to say with your level of experience.

From FCTM the second of the Golden Rules for pilots says:
"2. Use the appropriate level of automation at all times. ....

Determine and select the appropriate level of automation that can include manual flight
Note:
The decision to use manual flight must be agreed between both pilots and must be based on an individual assessment of the pilot. This assessment should include aircraft status (malfunctions), pilot fatigue, weather conditions, traffic situation, and if the PF is familiar with the area."

Now the OP poses the question of how to handle a TOGA climb of only 300 feet. I would suggest that full TOGA power is inappropriate as ALT* will be triggered very quickly. On previous aircraft types the manufacturer fitted a reduced level of TOGA power and the easy ability to control the applied thrust - but it's not quite so easy on Airbus.

However if the OP selected TOGA initially until the FMA confirmed the change then he reduced the power below the climb gate to say around 75%, he would have more time to reconfigure the aircraft.

So reducing the thrust while accelerating in level flight instead of keeping CLB thrust to prevent an overspeed if the PM is a second or two too late in retracting the flaps one step, raising the gear, monitoring the PF's actions and retracting the remaining flaps, probably during a go-around at a speed higher than Vapp and closer to VFE, is not smart flying?

I agree that reducing thrust below CLB is normally not required, but in case it is, there's no harm in doing so. It's called common sense and flying the airplane. You might know what's going on, but the pilot next to you might be overloaded.

New Arbii (A350, 380) have a “soft go-around mode”, which is doing pretty much the same thing. It is also an option on new A330’s, not sure if it’s available on the 320

GOLDEN and BDM
I am not against bringing thrust levers back to CLB. That will provide FG overspeed protection. Why is it required now, What do you think the protection does? It will reduce thrust to maintain VFE. Just retract the flaps that's it. As I said if you are prepared for the sequence of actions and know when and what the protection does it is very simple. If you left the thrust in TOGA till ALT* then it requires prompt actions because ATHR is only armed and not active so you can overspeed. Incidently if your GA altitude is high say 5000ft and at ACC ALT of 1500ft you forget to bring thrust levers to CLB can you tell me what will happen?

I think it's available now on A320 as an option, but I'm talking about reducing the thrust below CLB thrust to prevent excessive acceleration or overspeed after levelling off, as the level off altitude is immediately reached in the case described by Speedwinner.

Ok. Fair enough. You're right, A/THR will protect you from overspeed. But not everybody will remember this when they're in this situation where everything is happening in just a few seconds.
If I see the speed rapidly increasing and the PM doesn't retract the flaps after asking for retraction, my instinctive reaction is probably to reduce the thrust to prevent an overspeed before I have the time to realise that the A/THR will do the same.
My point was that there's nothing wrong with taking preventive actions yourself, instead of waiting for the automatics to do the same and risking ending up in an undesired state if they don't.

As others and I said before, the person next to you might not be and might be slow in retracting the flaps. Ofcourse it's manageable, but both pilots have to be fully aware of what's going on.
As for the protections, you're right, but it's not wrong to do something yourself what the automatics will do as well. The result is the same.

There are many protections, but that doesn't mean that it's not allowed to intervene before reaching the parameters that will activate that protection.

Nobody mentioned passing thru ACC ALT and leaving the levers in TOGA until ALT*. The original question was regarding a go-around initiated close to your go-around altitude and immediately bringing back the levers to CLB.
If you pass thru ACC ALT and you leave the levers in TOGA, then the LVL CLB message keeps flashing, and obviously A/THR will not become active, but I don't see what this has to do with the original question and what is being discussed here.

BDM
OP asked two simple questions. GA target speed is GD and yes protection is there. But this is usual thread discussion. Off course control of the aircraft is primary whether with automatics or manually. But instead of knowing what the aircraft does if you design a new procedure like disconnecting ATHR or reducing below climb to control speed is not smart flying. Executing a GA with AP on requires knowledge of the procedure and not skill. In Airbus, manual flying is not very demanding but it is also necessary to know it's automatics well because that's the way it is designed. What I asked next is a separate question for you to answer. with THR LVRs in TOGA will the aircraft overspeed?

No - because the elevators are controlling speed during the climb (by adjusting the pitch).

If you were flying Speedwinner's profile (post #1) in your B747, would you use TOGA, full climb thrust or something less?

GR
The answer is already given by ESCAT in post 4 and yet not many will answer this. You are out of SRS and accelerating in OP CLB the same FMGS protection will keep speed below VFE by increasing ROC till ALT* then if thrust levers are not in climb it will overspeed.

Hi vilas,

We agree on your post above and ESCAT's excellent post.

"In theory, if the VFE was below G/D speed, the aircraft would accelerate only to VFE, but the magenta speed target would still show Green Dot. That being said in case of very quick acceleration, or environmental disturbance (turbulence, wind shift etc.), I would think it would be quite easy to exceed VFE."

In order to prevent an accidental VFE speed exceedence especially when the aircraft acceleration is faster than the flaps / slats retract. VFE limit moves with the flap handle position but the overspeed warning reflects the actual flaps/slats position.
There are two options.
1) Pull speed and control the rate of acceleration.
2) Reduce thrust manually to a sensible setting.

I have used both and prefer the manual thrust method.

The problem with insisting everything must be done using the automatics doesn't help crews when the automatics fail.

I found that,

Attachment 4126

Vilas,

I see your point in explaining the overspeed protections (ALT* or ALT with A/THR or TOGA in OP CLB), although leaving the levers in TOGA during a normal go-around (where there is plenty of time to notice the LVL CLB message flashing in case you forget) seems an unlikely situation compared to the high energy go-round where you end up in ALT* almost immediately.

Goldenrivett's and my point is that disconnecting the A/THR is not something that isn't allowed. You may call it salvaging a bad situation, but it's basically doing what the A/THR will do as well, but before getting close to the VFE limit.
I agree that you shouldn't end up in this situation in the first place, in fact no situation where the protections have to kick in, but people will always make mistakes and the ability to recover from them without depending on the automation is a necessary skill that I saw was disappearing in the previous company I worked for. (GS interceptions from above messed up, GPWS warnings on a visual part of an approach or at 8NM from the runway, attempted G/A without setting the thrust, etc.)
You probably know which company I'm talking about, but a simple disconnection of the automatics and flying the plane could have prevented those situations. The pilots are the first line of defence, not the protections or automatics.

BDM
Once the pilot is in his seat if something is not happening as it should he must control the aircraft with the knowledge he has at that point of time. No argument about it. But it should be as an exception not to be converted into a procedure. If there was a need the manufacturer would have suggested that. Developing own procedures is fraught with danger in airbus FBW. Besides disconnection of automatics is not a panacea and can bring its own problems as in the case of air proximity incident between A330, A340 across the Atlantic, fatal one at Sochi. As an airbus pilot one needs to spend some time understanding the flight controls and auto flight systems. Airbus cannot be flown like a Boeing. In a flight path stable aircraft manual flying is not a great skill but one also needs to know its automatics well because that is the design philosophy. All that we are discussing high energy GA, rejected landing, interception of GS from above are routine exercises taught in a type rating syllabus and many 200hrs pilots do it satisfactorily. These are practiced procedures and not acts of acquired skill. All procedures a pilot is expected to know. Yes once in a while a human can make mistake no problem with that.

Anticipation
 

Hi vilas,
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 ......"

Is the APPR armed? ILS? RNAV?

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)

yes sure! But left flashing even after ACC ALT.

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.

Escape Path
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."

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.

vilas,
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.

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.

Golden
FCOM below:
This is in all cases whether you are Flap3 or Flap2 you retract to 1. Same is with take off. There is no Flap2.

vilas,
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."

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.

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

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

The whole premise is wrong so what follows can't be right.

It’ s a 330/340 sim ...

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?

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.

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.

From Airbus Safety First July 2011.
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.

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