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Oktas8
19th Feb 2002, 07:06
Could any line pilots of heavy aircraft (Boeing / Airbus etc) please help with the following question?

What criteria is used to retract flap in a go-around, both normal ops and assymetric? For example, is flap selection based on airspeed, AoA, rate of climb, or some combination of the above?

This is to help me better instruct my budding airline pilot students in their C172's...

Cheers,. .O8

None
19th Feb 2002, 08:17
It has been a while since I flew a 172, however I think we do the same as you do. We simultaneously apply thrust and adjust pitch and retract flaps to the initial go-around setting. Didn't the 172 manual call it a "balked landing?" After that, flap retraction is determined by airspeed limitations. What is your specific question?

Capt Claret
19th Feb 2002, 08:30
BAe 146 & DH8 - Flap retraction is based on speed, usually V2+10 for the flap setting that you have. If going around from the landing configuration, it is usual to retract to F24 (146) or F15 (DH8) then in increments as speed increases until Vfto (146) or Vfri (DH8).

The only exception I can think of to this, is a windshear encounter, where the current policy is not to reconfigure until in no longer affected by the shear.

Wino
19th Feb 2002, 09:23
Generally its a bad idea to fly one type of aircraft as if it was another. Teach your students to fly a 172 the proper way to fly a 172 (IOW don't set up 4 mile 3 degree finals etc)

I worked for an airline that had the particularly dangerous idea of trying to fly an A320 as if it was a 757 and they are very lucky they didn't kill anyone.

This will serve you well throughout your career to fly your current aircraft as the manufacturer recommends. When you do that it will actually be more like airline flying than you think.

I once reamed out an instructor for teaching people to turn the long final in a 152. Flying a 3 mile final (from 1000 feet) in a 152 at 65 knots is nothing like flying an airliner other than the than line you are tracking over the ground. (Jets have different pitch angles and the timing is all wrong) However if you went carb heat at the end of the runway 1500 rpm etc turn 1/2 mile base etc the timing and flying was actually more airline like.

Cheers. .Wino

SentryIP
19th Feb 2002, 09:46
Oktas8,

In the Boeing 707 airplane I now fly, flap retraction is initiated at a certain altitude (500 feet AGL or obstacle clearance altitude, whichever is higher) and airspeed (V2+30 knots on initial takeoff or Vref+40 knots for a go-around). It's the same procedure for four or three engines operating. Hope this helps. Take care and fly safe.

SentryIP

G.Khan
19th Feb 2002, 13:26
1st and 2nd segment climb come to mind, not a problem for a 172 I would have thought?. .You should find the answers concerning flap selection on Go Around in the notes covering performance for that aircraft, or, in more general terms,in the notes for the perf.'A' exam.

Intruder
19th Feb 2002, 22:09
In the 747-400 we retract flaps to 20 on the go-around in all cases -- flaps 25 or 30 approach/landing, 3- or 4-engine approach.

I wouldn't assume the procedures used in a 747 would be applicable to a C172. Doing so could kill somebody if they blindly retracted the flaps at the wrong time and either stalled or sunk into the ground.

I would not trust an instructor who did not follow the Flight handbook / Operator's Manual for the airplane in which he was instructing.

411A
20th Feb 2002, 02:21
WINO has the correct recommendation, IMHO. It should be done the way the MANUFACTURER recommends....period. . .Some airlines have different ideas....sadly!. .Remember years ago SQ pasted the SQ logo on the BOEING 707 QRH and stated...do it THIS way.. .Good advice!!!. .Some aircarriers NEVER ever learn... <img src="mad.gif" border="0">

Oktas8
20th Feb 2002, 05:32
Thank you for all the replies - very helpful. It seems the main idea is to retract flap based on airspeed limitations - not too different a technique from the humble 172!

Regarding the comments on the C172 - yes, the flight manual is quite specific on the balked landing, and I agree pilots should follow it for maximum safety. My question is based on my CFI's comments on teaching "for the aircraft these students will ultimately fly".

thanks again for your time,. .O8

Pegasus77
20th Feb 2002, 05:50
To achieve that, there are many other possibilities... In my flight training, during the VFR-part, we were made to take off with flaps in the first detent (PA28), just to get used to cleaning up and after-takeoff-checklists.

Max Angle
20th Feb 2002, 18:42
In Airbus a/c (only fly 320/321 but I guess all the FBW ones are the same) you retract the flap by one stage as soon as you go around and the rest in stages as speed builds once at accel. height, which is normally 1500ft agl. Seems to work very well, whatever config you have used for the approach you always put the flaps up one stage for the Go-around, even my small brain can cope with that.

Hand Solo
21st Feb 2002, 04:07
Yep in the Airbus its flap up one stage at go-around initiation then at accel altitude flap retraction is based on speed. It helps that all flap settings except Full are take off settings, so generally you're safe to wind one in.

Having learned to fly in a C172 its definitely best to fly it the way the manual says. I seem to remember you can fly the go-around in all flap settings except the maximum. To attempt that would lead to some interesting combinations of weird attitudes, high power, low airspeeds and high sink rates, along with an urgent requirement for new underwear. I learned that one the hard way!

Oktas8
21st Feb 2002, 04:57
The new 172 models (R and S) do not have the 40° flap setting, which was the one that got students into difficulties. At 30° flap, the aircraft is quite controllable at full power on most days. Bear in mind the 172 now has a 180hp engine too.

Anyhow, the manual dictates retracting one notch as soon as possible on a go around, similar to many of the airline procedures according to comments above.

The issue of "how to teach students bound for bigger aircraft" is quite interesting, but probably should occur on the Instructors' forum. I'll reply to any post there...

cheers to all,. .O8