T/O FLAP SETTING FOR LANDING ?

[DCarlton]

For the aeronautical lift to drag gurus out there...  curious about something...  after years of M20F ownership but not enough recent flying, I'm bouncing a little more than I'm proud of landing.  I often use two pumps of the hydraulic flaps when landing (sometimes three; rarely max).  Two is approximately the TAKEOFF flap setting.  I'm guessing the takeoff setting provides some optimum point on a lift to drag curve which optimizes getting you off the ground.  If so, could the takeoff setting be the worst choice for a landing flap setting if you want to stick it?  

[steingar]

I fly a C.  I use full flaps for landing, unless there's a nasty crosswind, in which I make use half flaps instead.  I do use half for take off, only because the POH says to.  I haven't bounced a landing for a few years.  Land at the proper speed.

[DCarlton]

3 minutes ago, steingar said:

I fly a C.  I use full flaps for landing, unless there's a nasty crosswind, in which I make use half flaps instead.  I do use half for take off, only because the POH says to.  I haven't bounced a landing for a few years.  Land at the proper speed.

I need to work on using full flaps and I need to be more patient landing and allow the plane to settle without rushing it but I'm really curious about the takeoff setting and it's effect when landing.  I've been trying to keep my speed up a little on final too which means I need to wait for it a little longer landing.  

Edited June 7, 2022 by DCarlton

[N201MKTurbo]

I've never landed a Mooney without full flaps. Unless I wanted to. 

Why would you want to use 1/2 flaps in a cross wind? I always want to land as slow as possible.

If you are bouncing, you are landing too fast. When you flare, you should be well below 80 KTS, more like 70 with the power at idle.

[N201MKTurbo]

7 minutes ago, DCarlton said:

I need to work on using full flaps and I need to be more patient landing and allow the plane to settle without rushing it but I'm really curious about the takeoff setting and it's effect when landing.  I've been trying to keep my speed up a little on final too which means I need to wait for it a little longer landing.  

Why are you trying to keep your speed up on final? You have identified your own problem.

[RobertGary1]

Yea  Don Kaye’s video does a whole thing about the myth of partial flaps in crosswind 

[Hank]

In my C, i find using the Owners Manual recommendation of Takeoff Flaps when at or below 90 mph is good, and Flaps As Needed on final approach is good. I often land with the indicator close to the Takeoff mark.

I have several landings in a friend's F. Both planes have electric Flaps, but mine are infinitely variable while his had only three settings:  Up, Takeoff and Landing. I found Landing gave much better results. Then again, I could not select Takeoff and twitch it a little more, either.

Just a PPL, not a CFI, etc. etc.

[steingar]

5 minutes ago, N201MKTurbo said:

Why would you want to use 1/2 flaps in a cross wind? I always want to land as slow as possible.

Because you run out of control authority. Often the winds are bad enough that I run out of control authority and get blown off the runway.  The solution (for me) is to go around and come in with less flaps and faster.  Keep doing that until you can track the runway centerline without being blown clear.  The reduction in flaps allows you to maintain a higher speed until touchdown, keeping more air over the control surfaces giving you more authority to fight that crosswind.  Surprised I have to explain that in this company.

The rub is the Mooney floats, so this only works on long runways.  If the runway is short better to go find one that's better angled into the prevailing winds.

[steingar]

16 minutes ago, DCarlton said:

I've been trying to keep my speed up a little on final too which means I need to wait for it a little longer landing.  

Your problem in a nutshell.  Go a nice high altitude and stall your Mooney.  Look at the speed when it stalls, dirty it should be less than 60mph.  You should be 70-75 mph (or 65 knots) over the numbers. You won't stall the airplane. Makes landing it a lot easier.  You shouldn't need any patience in allowing your airplane to settle.

[DCarlton]

13 minutes ago, N201MKTurbo said:

Why are you trying to keep your speed up on final? You have identified your own problem.

Could be.  I had an instructor grind my ass about being too slow on final during my last BFR.  He wanted me consistently at 90 mph, then slower over the threshold.  When he demonstrated his recommended technique, his landings were outstanding, so I'm trying it.  If I were to use 1.2 VSO, that would be 1.2 (68) or 82 mph which seems way to slow on final.  I would be pulling myself out of a hole and dragging in the whole way with the stall warning chirping.  1.3 VSO seems to be about right or 88 mph.  

[steingar]

1 minute ago, DCarlton said:

Could be.  I had an instructor grind my ass about being too slow on final during my last BFR.  He wanted me consistently at 90 mph, then slower over the threshold.  When he demonstrated his recommended technique, his landings were outstanding, so I'm trying it.  If I were to use 1.2 VSO, that would be 1.2 (68) or 82 mph which seems way to slow on final.  I would be pulling myself out of a hole and dragging in the whole way with the stall warning chirping.  1.3 VSO seems to be about right or 88 mph.  

What is your stall dirty?  Mine is 57mph according to the POH, and according to me that's about what it does.  If I come in at 75 mph I'm at 1.3 VSO.  If I come in at 90 I float a long way.

[DCarlton]

12 minutes ago, steingar said:

Your problem in a nutshell.  Go a nice high altitude and stall your Mooney.  Look at the speed when it stalls, dirty it should be less than 60mph.  You should be 70-75 mph (or 65 knots) over the numbers. You won't stall the airplane. Makes landing it a lot easier.  You shouldn't need any patience in allowing your airplane to settle.

I've done this and the airplane stalled consistent with the arcs on the airspeed indicator.  Perhaps my stall indicator is coming on too soon.  The numbers that folks discuss here and the numbers recommended based on 1.2 VSO always seem too slow for my airplane.  It always feels tail heavy like your climbing out of a hole with power on.  Keep the speed up a little and the glide slope feels nice.  Wondering now what speed folks use on a long final in IFR conditions.  I use 90-100 mph.  Then slow down close to the numbers.  

Edited June 7, 2022 by DCarlton

[haymak3r]

I am still a newb with just over 40 hours in my J, so take this for what it's worth..

On a normal day, full flaps, I try to cross the threshold at 80mph. I am at 90 at short final. I pull power to idle, and let it settle down usually around 70 or less. I usually here the stall horn just before touchdown. I can be slowed down prior to the 1000 footer with this approach. Does this happen everytime? ALMOST..  But, I work on it every couple days.

[RobertGary1]

Just now, haymak3r said:

I am still a newb with just over 40 hours in my J, so take this for what it's worth..

On a normal day, full flaps, I try to cross the threshold at 80mph. I am at 90 at short final. I pull power to idle, and let it settle down usually around 70 or less. I usually here the stall horn just before touchdown. I can be slowed down prior to the 1000 footer with this approach. Does this happen everytime? ALMOST..  But, I work on it every couple days.

If you’re light take 5 mph off that. 

[Shadrach]

12 minutes ago, steingar said:

Because you run out of control authority. Often the winds are bad enough that I run out of control authority and get blown off the runway.  The solution (for me) is to go around and come in with less flaps and faster.  Keep doing that until you can track the runway centerline without being blown clear.  The reduction in flaps allows you to maintain a higher speed until touchdown, keeping more air over the control surfaces giving you more authority to fight that crosswind.  Surprised I have to explain that in this company.

The rub is the Mooney floats, so this only works on long runways.  If the runway is short better to go find one that's better angled into the prevailing winds.

Your talking about a 6mph differential in stall speed between flaps and 0 flap.  The approach speed will increase by about the same number. It offers very little in the way of additional control authority.  

[DCarlton]

8 minutes ago, steingar said:

What is your stall dirty?  Mine is 57mph according to the POH, and according to me that's about what it does.  If I come in at 75 mph I'm at 1.3 VSO.  If I come in at 90 I float a long way.

Will have to look it up when I'm at the plane.  I think it's a little higher than 57.  I can't really say my plane floats excessively.  If you're patient and let it land I always make the first turn off at my home airport.  I do have a three blade prop which might help (slow down) and it's the 67 M20 with the less common twist wing.  

Edited June 7, 2022 by DCarlton

[Ragsf15e]

6 minutes ago, DCarlton said:

Could be.  I had an instructor grind my ass about being too slow on final during my last BFR.  He wanted me consistently at 90 mph, then slower over the threshold.  When he demonstrated his recommended technique, his landings were outstanding, so I'm trying it.  If I were to use 1.2 VSO, that would be 1.2 (68) or 82 mph which seems way to slow on final.  I would be pulling myself out of a hole and dragging in the whole way with the stall warning chirping.  1.3 VSO seems to be about right or 88 mph.  

90 is way too fast.  I also have an F (and am a cfi).  80, 85, 90 (mph) are good final approaches for full flaps, t/o flaps, no flaps. If it’s gusty and you add 1/2 gust factor, that’s fine too.

Also, even if fast, you can still land ok, but it’s easier to bounce or oscillate in the flare.  You will still need to hold it off until it basically can’t fly anymore (or at least very close to that).  It’s hard to do that when trimmed for a fast final speed.  If you’re on a correct speed, pitch force is much reduced in the flare and thus feels easier to hold it off until you basically can’t anymore.

[haymak3r]

4 minutes ago, RobertGary1 said:

If you’re light take 5 mph off that. 

agreed. I usually run with more fuel than I need.

[Ragsf15e]

The stall numbers in the book are max gross weight, so even with full fuel, most of us are still “light” weight if flying alone.  You can see the effect on stall speeds if you try power off stalls at different weights and note airspeed.  I usually only adjust +\-3ish kts for weight, but it’s definitely a consideration.  
 

80mph on final, full flaps, trimmed hands off.  That’s the go to numbers in my F.

[Shadrach]

3 hours ago, DCarlton said:

Could be.  I had an instructor grind my ass about being too slow on final during my last BFR.  He wanted me consistently at 90 mph, then slower over the threshold.  When he demonstrated his recommended technique, his landings were outstanding, so I'm trying it.  If I were to use 1.2 VSO, that would be 1.2 (68) or 82 mph which seems way to slow on final.  I would be pulling myself out of a hole and dragging in the whole way with the stall warning chirping.  1.3 VSO seems to be about right or 88 mph.  

You need a new instructor.  90mph to the threshold is too fast in any Mooney.  Your 68mph is at gross weight with no flaps; with full flaps, Vso is 62mph.  At 2200lbs those numbers go to 61mph and 56mph, respectively. I too fly a 67F.  At mid weight in mild weather, I range between  65 to 70mph across the threshold. 80mph at the threshold is too fast unless I am returning to base at MGW.  Quite simply you're carrying too much energy to the threshold and trying to offset the extra energy by not using flaps.  It is the antithetical to the goal of landing the plane.  

[DCarlton]

6 minutes ago, Ragsf15e said:

90 is way too fast.  I also have an F (and am a cfi).  80, 85, 90 (mph) are good final approaches for full flaps, t/o flaps, no flaps. If it’s gusty and you add 1/2 gust factor, that’s fine too.

Also, even if fast, you can still land ok, but it’s easier to bounce or oscillate in the flare.  You will still need to hold it off until it basically can’t fly anymore (or at least very close to that).  It’s hard to do that when trimmed for a fast final speed.  If you’re on a correct speed, pitch force is much reduced in the flare and thus feels easier to hold it off until you basically can’t anymore.

Based on the responses, I think I'll try to work on reducing my numbers by 5 mph.  That's gets me back to the speeds I used to fly (although it did seem somewhat tail heavy and draggy at those speeds).  Sounds like I need to work on full flap landings too.  

[DCarlton]

6 minutes ago, Shadrach said:

You need a new instructor.  90mph to the threshold is too fast in any Mooney.  Your 68mph is at gross weight with no flaps.  with full flaps, Vso is 62mph.  At 2200lbs those numbers go to 61mph and 56mph. I too fly a 67F as well.  At mid weight in mild weather, I range between  65 to 70mph across the threshold. 80mph at the threshold is too fast unless I am returning to base at MGW.  Quite simply you're carrying too much energy to the threshold and trying to offset the extra energy by not using flaps.  It is the antithetical to the goal of landing the plane.  

At your numbers, is the stall warning horn chirping off and on the whole way and even more so when it's gusty?  

[ArtVandelay]

Don’t know why everyone still talks in units of mph…the standard in aviation (since 1969) is knots.
Does it make you feel like you’re going faster? ;-)

[Shadrach]

7 minutes ago, DCarlton said:

Based on the responses, I think I'll try to work on reducing my numbers by 5 mph.  That's gets me back to the speeds I used to fly (although it did seem somewhat tail heavy and draggy at those speeds).  Sounds like I need to work on full flap landings too.  

I put this together years ago.  You may find it useful to calculate you stall by weight and compare them to what you're flying.  In my opinion, the airplane lands better under most scenarios with full flaps. It hastens the landing transition from flying to high speed taxi. That transition is where a great deal of RLOC occurs. Probably best to minimize it.

 

[Shadrach]

1 minute ago, ArtVandelay said:

Don’t know why everyone still talks in units of mph…the standard in aviation (since 1969) is knots.
Does it make you feel like you’re going faster? ;-)

We fly vintage so we speak vintage.