A320 Go-Around procedures

[Algol]

In view of the recent GF accident I was wondering how individual operator procedures vary on the G/A procedures for the A320.

Would any of you Airbus drivers care to go over the basic SOP for your company? In particular I'm interested in hearing about your views on speed control in a G/A, use of TOGA/Climb, flap retraction sequence, and your understanding of Auto Thrust operation in the G/A.

Thanks in advance.

[Diesel8]

Goaround:

At initiation of goaround apply TOGA thrust and call for flaps 3, positive rate of climb gear up. At acceleration altitude move thrust levers to climb and as speed increase reduce flap setting. If diverting to another field, flaps would obviously go to zero. If not, the pilot may choose another flap setting. Normally the FD's would be on and would provide pitch commands for speed, if not you would be looking at about 16 degrees nose up ( if memory serves me).

[ANCIENT]

The thing that makes an A320 difficult in the go-around situation following a visual or non-precision approach is the lack of FDs. The pilot must now use basic atitude flying which he most probably has not practiced since his last sim ride.

Airbus have the answer; pop up FDs and auto engagement of the auto thrust when TOGA is selected.
This is an option but not pushed by the sales people so very few operators have the feature.

I for one cannot understand why it is not mandatory.

[This message has been edited by ANCIENT (edited 07 September 2000).]

[Algol]

Diesel8, heres a question.
If you want to maintain 185kts or less in the G/A and you are at flap 3 (having moved one step up from flap full), what flap selection/speed control selection do you make next?
And, will the autothrust allow flap limit speeds to be exceeded?

[Diesel8]

Algol, I cannot believe you made me open my books on a day off, shame on you!!!

Anyway, if the A/THR is active and the FD's are off, the A/THR will be operating in the speed mode, meaning it will be controlling the speed to Vmax, which with flaps three would be 185. You could select a lower speed, say 170 by using the FCU (the speed knob)

If A/THR is not active, the levers not being in the CLimb detent with two engines or FLX/MCT with one engine, then the A/THR system would command thrust relative to the TLA, meaning that TOGA would give you TOGA thrust and then you will have to manage speed with pitch.

One scenario that often produces overspeed is Microburts/Windshear in the sim, in this case we will look at a goaround under these conditions, config full, gear down, FD's on, A/THR active, you are at 500 feet on final approach:

Either you detect/suspect windshear or the lovely synthetic voice tells you. Apply TOGA thrust and follow the FD's, once emerging from the shear, you better be quick reconfiguring, since flaps full speed is 177 knots and the increase in speed is very rapid, remember that in TOGA the TL are controlling thrust and not speed. So coming out you would select flaps three as speed dictates, gear up and flap retraction on schedule, while bringing the TL to CL which would now control A/THR to command thrust for speed.

Goaround with no FD's are not that difficult, except for the fact that Ancient mentioned, most of the time the FD's are on.

Anyway, here we go: TL to TOGA, rotate to 15 degrees of pitch while calling for flaps to three, positive rate gear comes up, at acceleration altitude, select desired speed, engage A/THR by moving the TL's to the CL detent and activating A/THR, retract flaps on schedule. Push F/A call button and ask for another coffee.

The only problem is the fact that goarounds are seldom performed, that we are used to having the FD's on and A/THR controlling speed. How many Airbus drivers have done a takeoff with FD's and A/THR off in the last three months, in there are a few Gotcha's,but again it is no big deal.

There is another thread concerning automation and degradation of flying skills, so I will only briefly state, that people who had good flying skills prior to flying these new wonders of the world, do very well when fit hits the shan, it might not always be pretty, but safety is never in doubt. I do however think, that pilots who have little experience in round dial airplanes have trouble. They get used to the automation quickly and rely on it to heavily.

The Airbus is a remarkably capable airplane, it is very automated, has many built in protection features, but like all airplanes, it does have its quirks and will bite you if you do not understand what is happening.

( This should in no way be construed as a probable cause as to the loss of Gulf Air's A-320, nor as an indication as to the skill of low time pilots)

[This message has been edited by Diesel8 (edited 07 September 2000).]

[Eecam]

Diesel,

Great explanation. I have one problem with what you said about 'Auto Thrust ON/FD Off' scenario.

As you said, this will place the aircraft in 'speed' mode - hence the speed bug will dictate what thrust is demanded. If the bug happens to be faster than the flap limit speed, then the flap limit speed will be exceeded. The only speed which the aircraft is designed to protect is VMO and MMO...and then only by applying an increase in demanded pitch - not a reduction in thrust.

In a go-around with FDs 'OFF', the trick is to nail the pitch attitude, reduce flap by one config, get the gear up, do nothing until acceleration altitude. At acceleration altitude, leave thrust at TOGA until you have selected or you have confirmed that the aircraft is scheduling a suitable speed, ie better than green dot. Then you can bring the PLs back to climb, engage FDs, AP and call the FAs for more coffee.

God, if only it went so smoothly in practise!

------------------
It's our imperfections that make us unique.

[veewunrotate]

If you are flying an A320 without the pop up flight directors and you have been doing a visual appproach using the bird, it should be killed shortly after GA commencement, it can easily cause confusion. You then switch both flight directors on, they will engage in hdg v/s, pull the thrust levers momentarily out of the TOGA gate and reengage them into the TOGA gate, hey presto you will see TOGA SRS GA TRACK!!!

[Diesel8]

Eecam,

I think we are splitting hairs, but nevertheless. If TOGA thrust is selected the A/C will only consider Vmo as the limit, and as you said will apply corrective pitch to limit the speed to Vmo+16kts. However, and I took this from FCOM 1.22.30.

"In speed/Mach mode the A/THR adjust thrust to aquire and hold the speed or mach target. The speed may be selected by the FCU or managed through the FMGC.

When in Speed/Mach mode the A/THR does not allow excursions beyond the following limits, regardless of target speed/mach number. For a selected speed target, the limits are VLS, VMax(Vmo,Mmo,VFE,VLE whichever applies)"

As you so rightly stated, better make sure you know what speed the A/THR will maintain, before you pull the TL to CL and the A/THR goes active. But on the other hand an active A/THR will prevent you from an overspeed.

[Iceman49]

Concerning the Flight Directors...we make all of our approaches with the FD's on, non-precision and visual. During a visual we tell the pilots its alright to turn off the FD's but to get them on sometime later in the approach when you should be looking outside. It makes life much easier in the event of a go-around.

[MFALK]

Iceman, what FD modes do you engage when you are in a visual approach? Can't really understand what you're doing...

[Iceman49]

If we are on a tight final, we turn off the FD's... so as not to be distracted. Sometime prior to landing we engage the FD's which come up in HDG and VS...at this point the pilot should be looking outside without any distraction from the FD. Since we started this technique, we've had no problems on the go. We hit this fairly hard in our intial tng and continuing.

[Grandad Flyer]

algol, I agree with what has been said in the previous posts, but I want to stress that the Airbus telex on the Gulf Air accident said that the aircraft remained in TOGA from the start of the go-around until it crashed. I think this may have been a key issue in the accident. The Captain was not very familiar with the Airbus philosophy and may have thought that the autothrust was active, when in fact it was armed but would not become active until the thrust levers were moved back into the climb gate.
I wonder if there was some confusion amongst the crew on this one and whether they thought that the speed was being looked after, when indeed it wasn't.

[beeswax]

veewunrotate,

Just as an aside my company are thinking of changing the F/D off G/A SOP to the one you described. I think it is considered to be a little easier to perform (or less likely to go wrong) than our present 'select green dot at accel alt and move thrust levers to CLB'.

I recently did a G/A as PNF and PF went initially to TOGA then once we were up and away straight back to CLB. It's very smooth and a total non-event as far as the pax are concerned. The cabin crew even complained that it wasn't exciting enough!