Speedracer1407 From United States, joined Dec 2004, 326 posts, RR: 0 Posted (3 years 1 month 5 days 23 hours ago) and read 1429 times:
Yes, G/A questions pop up every week around here, so I feel like I've been informed from helpful posters about many elements of a go-around...except for one thing.
On a go-around in a heavy jet, it's my understanding that flaps are retracted, not fully, but to a much cleaner setting than landing configuration.
On the one and only G/A that I experienced as a passengers, the engines where spooled up and we seemed to fly straight and level for the length of the runway before retracting flaps and pulling up.
However, an in-cockpit video of an MD-11 G/A showed the pilots retracting the flaps almost simultaneously with TOGA throttle application.
So what's the schedule for retracting the flaps to a G/A setting? Although flaps don't snap to a new position, don't they move quickly enough to rapidly reduce lift if little or no extra airspeed has been gained after TOGA throttle application? Thanks for any replies.
ThirtyEcho From United States, joined Dec 2001, 1275 posts, RR: 1 Reply 1, posted (3 years 1 month 5 days 21 hours ago) and read 1409 times:
With all due respect, you seem to be a go-around worry wart.
In ANY airplane so equipped, flaps have two effects: the first effect, with flaps set at a "shallow" setting, is to greatly increase lift with not a lot of drag added. At "deeper" settings, lift is increased but drag is greatly increased.
Let's take the example of an older general aviation airplane, like the early C210, that had the max-flap setting of 40 degrees. You might use 10 or 20 degrees for a short or rough runway takeoff or a normal landing but 30 or 40 degrees would only be used for landings.
Suppose that you have flaps 40 and decide, for safety's sake, to go around. The flap setting allows the airplane to make a much slower and steeper approach but doesn't help you do a go around. In fact, the flaps work against you. You have to retract flaps to a takeoff setting but you can't do that until you reach a safe airspeed. It might even be the case that you build speed by holding a level attitude for a few seconds before you go from flaps 40 to flaps 30. As the speed builds, you can go from flaps 30 to the "takeoff" setting of flaps 20 and then to flaps 10 and, then, to no flaps for the rest of the go around or missed approach.
Big Iron is more complicated but the principles are the same as the C210A's. You are going from a regime of landing to the regime of takeoff.
By the way, Cessna eliminated to flaps 40 setting some years ago as inexperienced pilots seemed to get into trouble with all of that drag out there. To me, it sure was nice to have that when I dive bombed short runway thresholds over 50' trees back in East Texas.
Tristarsteve From Sweden, joined Nov 2005, 2822 posts, RR: 23 Reply 4, posted (3 years 1 month 5 days 21 hours ago) and read 1401 times:
Remember that the aircraft takes time to react.
From approach idle to TOGA will take 5-7secs.
From Flaps 40 to flaps 10 will take about 10secs.
So although the pilot will select TOGA and T/O flap, if you are in the pax cabin it might seem like ages until something happens.
Also, the flap quadrant in the flight deck has detents to help you. From approach flap to take off flap you just push the flap handle forward until it reaches the stop.
Quoting PhilSquares (Reply 3): Select TOGA (TOGA "paddles" on the thrust levers)
Why are the B744 paddles back to front from all other aircraft?
Speedracer1407 From United States, joined Dec 2004, 326 posts, RR: 0 Reply 6, posted (3 years 1 month 5 days 20 hours ago) and read 1382 times:
Quoting ThirtyEcho (Reply 1): With all due respect, you seem to be a go-around worry wart.
I'm not sure why you think that. Perhaps I've asked a few questions about go-arounds before. Nevertheless, I'm not "a go-around worry wart"-I've only experienced one as a passenger, and it was fun! This question was merely one of curiosity.
Quoting ThirtyEcho (Reply 1): You have to retract flaps to a takeoff setting but you can't do that until you reach a safe airspeed. It might even be the case that you build speed by holding a level attitude for a few seconds before you go from flaps 40 to flaps 30
This is why I asked my question. It's the schedule of flap retraction that i'm curious about. On the MD-11 video that I watched, the PNF selected a much lower flap setting at the same time as the pilot advanced the throttles. This made me wonder why such a quick flap retraction would NOT reduce the amount of lift available as the engines had, presumably, only just spooled up to TOGA power, and therefore, presumably not accelerated the aircraft.
Obviously, it worked, and everything was safe. So i guess I'm just curious about WHY flap retraction on G/A doesn't result in a sudden reduction of lift.
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by, the way, ThirtyEcho, thanks for your reply. I appreciate your information; perhaps I did not articulate my question in such a way as to specify the elements of my curiousity.
PhilSquares From , joined Dec 1969, posts, RR: Reply 7, posted (3 years 1 month 5 days 20 hours ago) and read 1379 times:
Quoting Speedracer1407 (Reply 6): This made me wonder why such a quick flap retraction would NOT reduce the amount of lift available as the engines had, presumably, only just spooled up to TOGA power, and therefore, presumably not accelerated the aircraft.
It does reduce the amount of lift being generated, but it also reduces the amount of drag being generated. It's a trade off. In order for the aircraft to comply with the TERPS criteria for obstacle clearance on a go around, you have to use a reduced flap setting for climb performance.
At most go around weights, TOGA is a lot of thrust. You will have a handful or aircraft to fly. In reality, once the engines start to spool up, they're already generating sufficient thrust to keep the aircraft climbing and accelerating at the same time. Not quite what you thing in your question.
Pihero From France, joined Jan 2005, 1884 posts, RR: 63 Reply 8, posted (3 years 1 month 5 days 19 hours ago) and read 1366 times:
Quoting Speedracer1407 (Thread starter): On the one and only G/A that I experienced as a passengers, the engines where spooled up and we seemed to fly straight and level for the length of the runway before retracting flaps and pulling up.
We need to know where that missed approach happened, as my feeling is that you experienced a non-precision missed approach, at which the actual go-around is not initiated until you've passed the Mapt., thence the reason for maintaining level flight.
MD11Fanatic From United States, joined Oct 2006, 81 posts, RR: 0 Reply 9, posted (3 years 1 month 5 days 13 hours ago) and read 1304 times:
Quoting Speedracer1407 (Reply 6): This is why I asked my question. It's the schedule of flap retraction that i'm curious about. On the MD-11 video that I watched, the PNF selected a much lower flap setting at the same time as the pilot advanced the throttles. This made me wonder why such a quick flap retraction would NOT reduce the amount of lift available as the engines had, presumably, only just spooled up to TOGA power, and therefore, presumably not accelerated the aircraft.
Obviously, it worked, and everything was safe. So i guess I'm just curious about WHY flap retraction on G/A doesn't result in a sudden reduction of lift.
Hi Speedracer! I'm not an MD-11 but I know a thing about the MD-11 so allow me to attempt to answer, and of course, defer to any real MD-11 pilots who may a correction to me afterwards.
If you're referring to the Finnair go-around at JFK about a year ago, I know precisely what you're talking about. A typical flap setting for the MD-11 in landing configuration is flaps 35. For go-around, the flap setting is Flaps 28 (One detent less). What you saw the PNF do was simply put the flaps to the Flaps 28 detent. As you can see, that setting is not significantly less than the landing. Also, if you notice, the PNF has his hand on the flap handle waiting to retract them and it seems to take the captain a particularly long time to call for them to be retracted.
You also get to hear my sexy MD-lady sing about stabilizer motion if we're watching the same clip. I'm desperately searching for a "Stabilizer motion" horn and annunciation for my cell phone ringtone!
CosmicCruiser From United States, joined Feb 2005, 1725 posts, RR: 17 Reply 10, posted (3 years 1 month 5 days 11 hours ago) and read 1261 times:
Quoting MD11Fanatic (Reply 9): A typical flap setting for the MD-11 in landing configuration is flaps 35. For go-around, the flap setting is Flaps 28 (One detent less).
True but it really wouldn't matter if you were at flaps 50 the go-around setting would still be 28.
Quoting Pihero (Reply 8): you experienced a non-precision missed approach, at which the actual go-around is not initiated until you've passed the Mapt., thence the reason for maintaining level flight.
Actually you can miss from any point on the app and can climb to the MAP alt however you're correct in that you may not deviate from the inbound course until the MAP.
Speedracer1407 From United States, joined Dec 2004, 326 posts, RR: 0 Reply 11, posted (3 years 1 month 4 days 21 hours ago) and read 1151 times:
Quoting Pihero (Reply 8): We need to know where that missed approach happened, as my feeling is that you experienced a non-precision missed approach, at which the actual go-around is not initiated until you've passed the Mapt., thence the reason for maintaining level flight.
It was a night flight into ORD on an AA MD-80. I donno which runway, but I seem to recall a relatively clear evening; I could see the city lights for some time before we landed.
Speedracer1407 From United States, joined Dec 2004, 326 posts, RR: 0 Reply 12, posted (3 years 1 month 4 days 21 hours ago) and read 1149 times:
Quoting MD11Fanatic (Reply 9): If you're referring to the Finnair go-around at JFK about a year ago,
Yup, that's the one. I didn't realize he had only retracted the flaps one notch. Seemed like more to my untrained eyes. Anyway, thanks for the replies, folks.
Tom775257 From United Kingdom, joined Dec 2000, 153 posts, RR: 0 Reply 13, posted (3 years 1 month 3 days 16 hours ago) and read 1027 times:
Nice and easy on the airbus (320 at least). I assume it is the same on the 330/340
At minima or wherever PF calls 'Go Around Flap.' PNF retract flaps one stage (doesn't matter which flap setting, just retract one stage). PF firewalls throttle (sorry moves the thrust levers into the TOGA gate ) and proceeds with the go around. PNF calls 'Positive Climb' PF calls 'gear up.'Then at acceleration altitude, passing F speed PF calls for 'FLAP 1' and then passing S speed PF calls 'Flap 0, after take off checklist.'
Keeps it very simple, flies it very nicely. I wouldn't worry too much about the airbus flap system, speeds etc. it is somewhat strange compared to the Boeing 757 / 737 sims that I trained on before. I remember on the 757 working out Vref30 + 20, 40, 60, 80 etc. for flap extension/retraction. I'm not sure which one I prefer, the Airbus or the Boeing way.
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) and proceeds with the go around. PNF calls 'Positive Climb' PF calls 'gear up.'Then at acceleration altitude, passing F speed PF calls for 'FLAP 1' and then passing S speed PF calls 'Flap 0, after take off checklist.' 
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