When do you NOT use flaps landing?

[rightrudder]

During calm conditions, I can't see a reason not to use full flaps (short of no-flap landing practice). Less kinetic energy on touchdown, less chance of nose wheel shimmy (for us -A guys), easier on brakes, tires, etc.

[JonJay]

Originally Posted by Bevan

Every landing is a flap landing unless the flaps are broken or training for flapless landings.

The use of flaps on an RV is no different than any other GA aircraft. If you're not sure why (and how much) flap to use on landing, maybe get with an instructor and go over some basics. Kinda hard to teach flying online but here's my take on landings...worth less that what you have paid for it....

-The ultimate goal of landing is to stop flying (safely).
-To stop flying, one must slow down and approach the ground.
-This requires more precise (maybe just different) flying skills than cruising.
-Crosswinds become more of a factor as your forward speed declines and you need to maintain track over the runway and aircraft generally aligned with direction of travel over said runway.
-The first amount of flap is to increase lift (enabling you to slow down even more), and adds some drag, and lowers the nose resulting in better visibility.
-Going to Full flap basically adds more drag which helps with speed control. In the slow speed regime, pitch now controls speed, and power now controls rate of descent.
-After touchdown, the flaps and the slower speed allows shorter roll, less energy (you want to stop afterall) with less (maybe no) use of brakes saving them for whenn you really need them.
-The above is for normal landings. Now, If you have crosswinds, it will be more challenging to control track and heading over the runway at touchdown. Reducing some flap, increases stall speed thereby reducung the crosswinds effect (a little) allowing better control but the trade off is more speed on runway, more brakes, longer (possibly much longer) stopping distance etc.
-Gusts are probably a more significant factor. Add 1/2 the gust factor to your approach speed and flaps (less than normal) to suit that higher stall speed.


Practice practice practice for consistency and variable conditions.

Bevan
Not a CFI but I...

Well stated.

[PerfTech]

Originally Posted by flyboy1963

hey, love the discussion Allan....
let's say I approach 'no flap' at 70, stall is 55, margin is thus 15.
If I approach at 70, half flap, stall is 50, margin is now 20, so I can tolerate more gust/shear without 'dropping' it in.
also would say more flap = less float, especially if you shave 5 kts off the approach speed, still have the margin, but on the ground sooner.
maybe.....
maybe not?

...I usually cross the fence at 60 mph or less, as 70 mph would require another 400 ft of runway at a minimum. Lets look at this another way, just think of the safety margin you would have if you came across the fence at 180 mph. Exaggerated statement for demonstration purposes, but you get the idea. You just need to increase your touchdown speed a bit to cover the gust possibility, potential float and drop-out. Thanks, Allan..

[Bevan]

Originally Posted by flyboy1963

hey, love the discussion Allan....
let's say I approach 'no flap' at 70, stall is 55, margin is thus 15.
If I approach at 70, half flap, stall is 50, margin is now 20, so I can tolerate more gust/shear without 'dropping' it in.
also would say more flap = less float, especially if you shave 5 kts off the approach speed, still have the margin, but on the ground sooner.
maybe.....
maybe not?

We may have two slightly different topics going on here. Crosswinds and gusty winds.

For crosswinds, generally you would reduce the flap and maintain your usual approach speed calculation (1.3-1.4x stall speed in that particular configuration).

For gusty winds, add 1/2 the gust factor to your normal approach speed for the flaps chosen as shown above.

By the way, I find the RV much easier to land in crosswinds than the Cessnas I used to fly. Probably a combination of the low wing, higher wing loading and more responsive control inputs. I used to dislike crosswinds. Not so much anymore.

Bevan

[Bevan]

Originally Posted by PerfTech

...I usually cross the fence at 60 mph or less, as 70 mph would require another 400 ft of runway at a minimum. Lets look at this another way, just think of the safety margin you would have if you came across the fence at 180 mph. Exaggerated statement for demonstration purposes, but you get the idea. You just need to increase your touchdown speed a bit to cover the gust possibility, potential float and drop-out. Thanks, Allan..

Yes but an airplane will not land gracefully until she is ready. You cannot force her to land against her will. She is designed to fly, yet you must coax her to land. Hence the dance.

Bevan

[PerfTech]

Originally Posted by Bevan

We may have two slightly different topics going on here. Crosswinds and gusty winds.

For crosswinds, generally you would reduce the flap and maintain your usual approach speed calculation (1.3-1.4x stall speed in that particular configuration).

For gusty winds, add 1/2 the gust factor to your normal approach speed for the flaps chosen as shown above.

By the way, I find the RV much easier to land in crosswinds than the Cessnas I used to fly. Probably a combination of the low wing, higher wing loading and more responsive control inputs. I used to dislike crosswinds. Not so much anymore.

Bevan

.....I think you are correct. You found the answer.

[RVbySDI]

Originally Posted by Bevan

We may have two slightly different topics going on here. Crosswinds and gusty winds.

For crosswinds, generally you would reduce the flap and maintain your usual approach speed calculation (1.3-1.4x stall speed in that particular configuration).

For gusty winds, add 1/2 the gust factor to your normal approach speed for the flaps chosen as shown above.

By the way, I find the RV much easier to land in crosswinds than the Cessnas I used to fly. Probably a combination of the low wing, higher wing loading and more responsive control inputs. I used to dislike crosswinds. Not so much anymore.

Bevan

Post #6, sentence #1 & 2!

[MarkW]

Dean,
I also fly a RV-9 tailwheel. I land most times as a wheel landing solo and half flaps. Since I am landing on a pave runway and wheel landing, I like a little higher tailwheel at touch down. Flaps bring it down. Gusty or high crosswind it is less flaps. Short field or grass it is full flaps. This thing drops like a rock with full flaps and 60 knots over the fence. To grease a wheel landing requires less sink and less loss of speed. The plane (or me) don't do three points unless CG is way aft. I use the flaps to get the pitch and decent rate I want at landing.

[JonJay]

Originally Posted by Bevan

Yes but an airplane will not land gracefully until she is ready. You cannot force her to land against her will. She is designed to fly, yet you must coax her to land. Hence the dance.

Bevan

Unless your a tailwheel airplane doing a wheelie, but even then, at some point you must put the tail down. So, I guess your right if you consider a wheel landing to be two landings. The first can be done at a very wide range of speed and flap settings to get the mains stuck to the runway. The second, getting the tail down, can only be done at or below stall speed for a given configuration lest you be flying again!
It is very difficult to have a landing technique discussion on a forum.

[MS19087]

Originally Posted by MarkW

Dean,
I also fly a RV-9 tailwheel. I land most times as a wheel landing solo and half flaps. Since I am landing on a pave runway and wheel landing, I like a little higher tailwheel at touch down. Flaps bring it down. Gusty or high crosswind it is less flaps. Short field or grass it is full flaps. This thing drops like a rock with full flaps and 60 knots over the fence. [/size]To grease a wheel landing requires less sink and less loss of speed. The plane (or me) don't do three points unless CG is way aft. I use the flaps to get the pitch and decent rate I want at landing.

In my 9A, i was taught to put in full flaps abeam the numbers (Being mindful of Vfe) I Totally agree - I'm typically never more than 65kts over the fence - otherwise the plane does drop like a rock, my touchdown ends up in the 58-62kt range. I get minimal float and can achieve a fairly short roll out. YMMV