PPRuNe Forums - View Single Post - Reducing flaps on short finals
View Single Post
Old 14th May 2015, 13:00
  #75 (permalink)  
Kommandogerat
 
Join Date: May 2015
Location: where the crows stop to eat
Posts: 3
Likes: 0
Received 0 Likes on 0 Posts
Fair comments mostly...

I don't know who your instructor is but to preach the use of reduction of flaps to control drag under normal operations is a very risk potential practice
The situations i described definitely weren't the norm and no-ones been preaching/teaching that as the standard circuit.
Pretty much every other circuit has involved which is using power and attitude to adjust the glide path in the time honored way.

To be in a position of having to eliminate that drag means you have got it wrong and its that which needs to be addressed not the use of flaps for drag control in that manner.
Yeah, point taken - next time i'm doing a glide approach i'll hopefully judge the wind abit better and not jump the gun with the flaps.

It's the same deal with a slip on final approach, we practiced that the other week too, when we needed to lose some height, of course i know it's not a stabilized approach if you have to pull those kind of tricks.

BUT on the other hand if the engine really were to fail, the experience of having practiced these things previously, means that i'd hopefully have half a chance of pulling it off when required

The Sportstar LSA has split flaps and i'm aware that they are quite different to your average GA A/C:
1 notch is 15 deg, gives lift and abit more drag lowers the stall speed
2 notch is 30 deg, gives abit more lift again but with alot more drag.
3 notch is 40 deg, not much more lift but heaps more drag.

60kt is the "normal" approach speed with 2 stages of flap on final.

It has to said also, that there is fairly big change to the trim with and without flaps, so applying and removing SLOWLY is important to avoid ending up in at an undesired attitude.

The other side of the coin was in February this year when it was 38deg C at 9AM in the morning after a couple of heatwave days.
We did quite a few full flap landings that day as the thermal energy coming off the ground was doing it's best to stop us from coming down, at various points the VSI was showing we were getting +200-400FPM on base-final!!

Keeps life interesting through...
Kommandogerat is offline