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Stall warning during go around

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Old 4th Aug 2011, 20:22
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Stall warning during go around

Hi

Is it acceptable to reach the short-time stall warning during automatic go around with one engine inoperative? Should I disengage AP and proceed manual go around?

Thanks
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Old 4th Aug 2011, 20:45
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Not knowing which kind of aircraft you are flying, that's a tough question for anyone to answer.

That said, if you are flying, do what you need to do not to stall. The warning is intended to cue you to do something to reduce (or at least not increase any further) your Angle of Attack.
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Old 4th Aug 2011, 21:22
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No it isn't.
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Old 4th Aug 2011, 21:31
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If you get stall warning, shaker, pusher then I would seriously suggest you reduce the AOA
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Old 4th Aug 2011, 22:10
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Gents

I think ImbracableCrunk was answering the OP's question
Is it acceptable to reach the short-time stall warning
by posting
No it isn't.
rather than contradicting Lonewolf's accurate description of the purpose of stall warning.

I'll just add that its generally considered a non-certifiable behaviour if stall warning sounds during any recommended procedure, especially something like a go-around. It's telling you the GA speed (or approach speed) is too slow to permit the GA to be conducted with an acceptable margin to the stall.
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Old 4th Aug 2011, 22:16
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its generally considered a non-certifiable behaviour if stall warning sounds during any recommended procedure

If I recall correctly, an operator for which I was doing some 732 sim training work years ago, had a problem with the 744 on departure cleanup with intermittent on schedule warnings at low flap settings ? As I recall the problem presented itself on several runways where a turn was required at the point where the relevant flap setting was taken.
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Old 4th Aug 2011, 22:18
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Fair point, Mad Scientist.
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Old 4th Aug 2011, 22:31
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Is it acceptable to reach the short-time stall warning during automatic go around with one engine inoperative? Should I disengage AP and proceed manual go around?
Please explain this a bit further...as you stated you are on an automatic go-around...you mean a coded procedure? What is the aircraft type?

As this is not a typical scenario, am I to assume this is a sim?

Here is the issue with a coded procedure...

The procedure is based on many factors, typically a combination of many factors. EO performance is very, very limited on a twin...while the procedure may work in design, in the sim, depending on the settings, it may disco...on the flight val, there are many issues that come into play.

The flaps settings may not change as fast as the procedure design required, for the most part, it is the initiation of the EO missed approach...

The EO missed, assumes the worst case, EO at the MAPt...in reality, if you are EO, at the MAPt (you better be going in) if we look past the worst case, initiating the missed before the MAPt, with some energy other that the final approach speed, then this is much more of a real time situation.

Aside from that, your individual aircraft, and the particular box, from Honeywell, Smiths, or others, will have their own particular settings. Some boxes will give you a prox warning on the missed, assuming a 400' ROC...others will not...

If you were to provide more details on the aircraft, box, altitude, sim, etc, it would be easier to determine...

(stall warnings are never good, no matter who makes the box, but it happens in low speed transitions) what to do is another matter.
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Old 4th Aug 2011, 23:43
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I think ImbracableCrunk was answering the OP's question


The message you have entered is too short. Please lengthen your message to at least 10 characters.
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Old 5th Aug 2011, 00:47
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It's telling you the GA speed (or approach speed) is too slow to permit the GA to be conducted with an acceptable margin to the stall.
This would be true on almost any procedure if you tried to do an EO missed at the MAPt...

That is what no one wants to hear, but alas...it is true.

You pilots thinks about this...you are at flaps 30 or 40 on final, near 140kts...and you lose an engine....

while you are trying to turn this bird upwards,
retract flaps, feather throttle, and retract gear...

now...think about all of the things you have to do...

and build that into an automated procedure...
assuming weights, temperatures, and engine performance...
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Old 5th Aug 2011, 01:26
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I would far rather lose an engine at the MAP that just after V1 on takeoff.

Thankfully, both are extremely remote.

In any case, at the MAP I am, at most, at MLW. At just after V1 I may be at MGTOW.
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Old 5th Aug 2011, 04:51
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We have thought about it, its practiced in the Sim:--

If you have an Engine failure during a Go Around when the thrust increased ( the worst time, but it does happen ) then the calls for the Go Around remain the same. ie for the 777 "Go around Set Thrust Flap 20…." It then becomes the same as a V1 Cut situation. Climb out one Engine Flap 20 at Vef to Vref + 15 to reach acceleration height and clean up…………It wont take long as you are at TOGA thrust and at or below MLW.

Obviously during the initial climb after gear up and above 400' you should run the applicable Eng Fail/Fire/damage proceedures

I've seen people get ahead of themselves and call "Go Around Set Thrust Flap 5" by mistake
Then they most likely will hear the Stall warning!!
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Old 5th Aug 2011, 05:03
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Not on my Checkride....

Not acceptable. Ultimately, who is flying the airplane? If the automation isn't doing the right thing, then disconnect and correct the situation.
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Old 5th Aug 2011, 07:35
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JT to answer your post ref the 744. At maximum take-off weights (395 ton or above) any early turn on the SID can be very speed critical, especially if cleaning up from flap 1 to Up. (The yellow and red bricks almost coming together). Throw in turbulence, some care is required especially if hand flying. For this reason it's standard procedure to manoeuvre with flap 5 or at least 1 until pointing in the right direction. As to the original question you should never, in my opinion trip a stall warning/stick shaker on a GA. Something wrong with the pitch or speed there.
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Old 5th Aug 2011, 09:46
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Originally Posted by FlightPathOBN
You pilots thinks about this...you are at flaps 30 or 40 on final, near 140kts...and you lose an engine...

while you are trying to turn this bird upwards,
retract flaps, feather throttle, and retract gear...

now...think about all of the things you have to do...
Why would we be going around from final because of an engine failure?

Land. It makes life much easier.
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Old 5th Aug 2011, 10:18
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Hi 777AV8R,

I agree. Disconnect automatics, reduce the pitch slightly until stall warning stops and when in the hold investigate the problem. Either your bugs were set for the wrong weight - or the instructor had loaded the incorrect TO weight / Zero Fuel Weight into the simulator. (e.g. TOW inserted into ZFW box on sim).
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Old 5th Aug 2011, 10:30
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Why would we be going around from final because of an engine failure?
- not stabilized
- runway incursion
- etc.
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Old 5th Aug 2011, 14:49
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Some confusion here (could be mine entirely

are we talking about an engine failure precipating a procedure of a go-around? or are we talking about a go around procedure for any reason and while engaged in that procedure an engine fialure occurs resulting in a stall warning.

It make a difference in any claims about the aircraft being outside its design certification intent.

At any rate the previous responses have already covered how to deal with it while flying.
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Old 6th Aug 2011, 21:00
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Angel Stall warning during go around

Question;

Is it acceptable to reach the short-time stall warning during automatic go around with one engine inoperative? Should I disengage AP and proceed manual go around?

My answer;

Having flown in turbulent and thermal conditions close to the ground, my
experience tells me that,for a given acceptable IAS and attitude (AOA),the stall warning will trigger when airflow direction changes occur through the start of thermals or the gusting and rolling effects of turbulence close to the ground.
I would think, though,that stall sensors are different from one aircraft type to another and,although I fly low performance power planes,high performance aircraft on auto pilot (or auto anything), may react differently.
Another thing is that with multiengine aircraft, there is a possibility that
differential thrust, causing slipping or skidding, may trigger occasional airflow changes (turbulence) over one wing etc.
IF Airspeed and Attitude are within limits,occasional and intermittend stall warning sounds should be nothing to worry about.
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