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galleypower
18th Mar 2009, 17:23
Hope someone can help me out on this one:

Aircraft Type A (E145) has to be flown with Approach Climb Speed during single engine go-around. The Approach Climb Speed is equals Vref.

The normal (AEO) Vref for flaps 45 is corrected for the malfunction (+10kts). This is your new Vref corrected for OEI approach flaps 22. What would be the correct Approach Climb Speed? Vref or Vref corrected? Vref for flaps22 or 45?

Thanks for your help.

Mach E Avelli
20th Mar 2009, 11:42
I am not sure if I fully understand the question, but here goes. If you are already on one engine, you should plan to land at Flap 22 approaching at Vref 22 plus whatever additive is needed for wind etc (typically plus 5 to 10 knots). In the event of a missed approach the climb speed should then be not below Vref 22 until reaching acceleration altitude. This is close enough to V2 for flap 9 (which is the flap selected during the OEI go-around) for all practical purposes.
It doesn't help that some operators don't publish Vrefs for flap 22 but expect you to remember to add 10 knots to the flap 45 Vref, then the corrections on top of that. Just to make life hard when you least need it!

Old Smokey
21st Mar 2009, 13:06
I'm also not sure of the exact nature of the question, and suspect that there are possibly two questions.

Sensible questions galleypower, I interpret the first as being in isolation to the other -

(1) Aircraft Type A (E145) has to be flown with Approach Climb Speed during single engine go-around. The Approach Climb Speed is equals Vref.

Vref (presumably Flaps 45) is 1.3 X Vs, whereas the Approach Climb is typically performed with one of the Takeoff Flap settings (presumably Flaps 22). Takeoff V2 (min) is usually 1.2 X Vs, or 1.13 X Vs in later generation aircraft. Thus, and this is fairly typical of many aircraft, the Approach Climb at the lower Flap setting is at a speed approximating V2. Therein may lie the reason why the lower Vref speed is acceptable at the Missed Approach speed at the lower Flap setting.

(2) The normal (AEO) Vref for flaps 45 is corrected for the malfunction (+10kts). This is your new Vref corrected for OEI approach flaps 22. What would be the correct Approach Climb Speed? Vref or Vref corrected? Vref for flaps22 or 45?

I THINK that the malfunction that you refer to here is a "non engine fail" malfunction, for example, a Flaps or Stabiliser problem. In such cases the higher approach speed with a Vref for Flaps 22 is to ensure aircraft CONTROL. For example, with a failed stabiliser, you may not have enough elevator authority with Flaps 45 and it's lower approach speeds). If my assumption is correct, Flaps 22 is your Maximum Flap configuration, and Vref + 10 is your Mimimum speed for all operations, AEO or OEI, and during Approach or Missed Approach.

Having said all of that, my interpretation of your question/s may be incorrect, so disregard the fore-going!

Regards,

Old Smokey

4dogs
22nd Mar 2009, 07:04
Galleypower,

The AFM usually sets out the Approach Climb performance in the AFM under a heading like Supplementary Landing Data or similar.

It will quite specifically nominate the speed.

However, (and I haven't had the pleasure of the 145) I have not experienced an aeroplane where the GA speed is less than the planned approach speed for the applicable landing configuration, ie usually Vref + 5 to 10 knots, which approximates the V2 for the reduced flap used for GA and, more often than not, is very close to the Vref for the reduced flap setting.

Having said that, does the 145 give you computed speed targets or is it a manual task?

Stay Alive....

Mach E Avelli
22nd Mar 2009, 07:52
OK, this may clear it up, then it may not! Taken verbatim from Embraer's ERJ-145 FCOM (instructions for manually setting bugs for approach and landing):

"For Vapp clb, set Vapp clb or Vapp, the greatest"

Allowing for Portuguese-English this is saying: IF your Vref plus additives is greater than approach climb speed, that's what you would fly on a missed approach. It doesn't seem very scientific to me, because what if you had used the maximum additive for a flap 22 landing (+20 knots) ? That is WAY above V2 flap 9 for any given weight. But that's what the man says, so I guess that's the way it's done.

mupepe
22nd Mar 2009, 17:57
Single engine app is VREF45+10 using F22
in case of go-around single engine, fly VAPP/CLB speed for F22 (ice or w/o ice speed accordingly).
F22 is used to permit faster acceleration meeting minimum climb gradient.

now if you approach all engine F45, vref will be VREF45 plus additive for wind.
if engine fail during go-around, use VREF 45 speed w/o additive.

the same principle apply if using F22 landing,VREF22 plus additive, and go-around use VREF22 w/o additive.

yes I know that's looking complicated, It's the way EMB designed it, and all malfunctions speed correction are related to VREF45.

It's little more complicated if you land single engine in CAT3 condition.

hope this help


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