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10 degree flap extension speed limit? can't find any speeds in the Ovation POH.


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Posted (edited)

What speed do you deploy first notch of Flaps?  10 degrees. I have been using 110knot as a limit (White Arc).

Thanks!

Edited by Jetman
Posted

All flap speeds are the same…

For all flap positions…

Mooney standard practices…

There isn’t a 10° speed limit like a Brand C may have…

LBs are blessed with Speed Brakes, and high flap operating speeds… so there isn’t much of a driving force for Mooney to go determine what that number would be vs. a full flaps number…   :)
 

If it existed… there would be steps in the white arc at the low end indicating where the flaps operate….

PP thoughts only, not a CFI or mechanic…

Best regards,

-a-

Posted

Yes and yes…

Flap extension speeds vary depending on what Mooney you fly…

The older Mooneys require slowing down a bit before deploying them…


But there isn’t a different speed for T/O flaps… vs. Full flaps… on a Mooney.  Even though the amount of stress on the spar they are mounted to increases with degrees of flap deployment….

Best regards,

-a-

 

Posted

The first time somebody asks this question…

It usually comes after an ooops moment…

 

Like… ooops, I left the T/O flaps down as I accelerated into cruise climb….  So I was at 120kias when I noticed…

What do I do next….?

 

The answer will be something like having your favorite Mooney mechanic check the spars and hinges for any signs of stress…

PP forward looking thoughts only… not a mechanic.

Best regards,

-a-

Posted

Coool!

From the link supplied by ILC above… @ilovecornfields

There is a quote from the TCDS for the M20J….

That DOES indicate different operating speeds of different degrees of flaps…

That detail supplied by Ross… @Shadrach

Looks like this…  See Ross’ red arrow….!

Best regards,

-a-

4F02C3BF-B993-44D2-B058-F2F495948845.png

Posted

Soooooo….

@Jetman are you familiar with the TCDS?

It may be a fun trip to the Ovation part of that document to see if there is a T/O flap speed listed for any of the LBs… M20R,S,M,TN….etc…

Best regards,

-a-

Posted
11 minutes ago, carusoam said:

Coool!

From the link supplied by ILC above… @ilovecornfields

There is a quote from the TCDS for the M20J….

That DOES indicate different operating speeds of different degrees of flaps…

That detail supplied by Ross… @Shadrach

Looks like this…  See Ross’ red arrow….!

Best regards,

-a-

4F02C3BF-B993-44D2-B058-F2F495948845.png

The four asterisks means it only applied to serial numbers 24-3000 to 24-3078, so only a small subset of J models.

  • Like 2
Posted
5 minutes ago, EricJ said:

The four asterisks means it only applied to serial numbers 24-3000 to 24-3078, so only a small subset of J models.

Those were the "205/205SE". Interesting that the change wasn't continued on later models.

  • Like 1
Posted

If some is really interested, they should look at that parts catalog as see if there are any differences in parts between the 205s and other J, K, and later models.

Posted

Thank you for the info!  I like to treat my airframe gentle so I will

use 110.  

We do all our Landings with only one notch of Flaps, it has eliminated the 

possibility of porpoising.   

 

Posted
3 hours ago, Jetman said:

Thank you for the info!  I like to treat my airframe gentle so I will

use 110.  

We do all our Landings with only one notch of Flaps, it has eliminated the 

possibility of porpoising.   

 

One notch may help but it definitely won't eliminate porpoising if you come in too fast.

I find my landings better with full flaps, but everyone seems to develop their own technique that works and consistently using what works well seems to yield good landings. But either way, one notch or full flaps,  a stabilized approach at 70 over the fence (depending on weight) seems to work best for me. 

Posted
3 hours ago, Jetman said:

Thank you for the info!  I like to treat my airframe gentle so I will

use 110.  

We do all our Landings with only one notch of Flaps, it has eliminated the 

possibility of porpoising.   

 

its easier to learn to land a Mooney initially with partial flaps because it helps reduce the need to fully trim for Vref so that flaring the plane is easy. But one should  continue to master trimming the aircraft for landing for Vref as well a proper speed control. Porpoising is only possible with lack of speed control and not trimming the aircraft properly. Landing as slow as possible will reduce your roll out length and reduce risk to landing mishaps. About the only time to prefer 1/2 flaps over full flaps is with a strong crosswind.

  • Like 3
Posted
26 minutes ago, kortopates said:

About the only time to prefer 1/2 flaps over full flaps is with a strong crosswind


in my M i only do full flap landings, regardless of xwind/gusts because i want to touch down as slow as possible. some people says full flaps is more difficult, but I prefer slow speed and less energy. 

I would do partial flaps with icing or (duh)  flaps inop. i don't do a lot of low-ceiling IFR, but that might be another reason not to deploy full flaps because "stable approach".

i believe the partial flaps landing in xwind/gusts comes from (high wing) airplanes whose flaps blanket the empennage and reduce rudder authority. 

Posted
31 minutes ago, rbp said:

 

i believe the partial flaps landing in xwind/gusts comes from (high wing) airplanes whose flaps blanket the empennage and reduce rudder authority. 

I believe it’s to intentionally increase landing speed, the higher speed gives you increased control response and authority. I don’t know of any high winged aircraft that the flaps blanket the rudder, be a really bad thing for a tailwheel aircraft if they did.

Some if not all Fowler flap equipped Cessna’s it seems the flaps can blanket the elevator though, but only in slips.

I know people who won’t use any flaps for takeoff and some that won’t use them for landing, me I do what the POH says unless there is some unusual condition like has been brought up like ice, but I’m chicken, I don’t do ice and only have gotten into it a couple of times, neither bad

Posted
1 minute ago, A64Pilot said:

higher speed gives you increased control response and authority

partial/no flaps means you need higher airspeed, but full flaps doesn't mean you need lower airspeed.

in any event, the M (only mooney i've flown) has more than enough rudder authority to do a low energy landing in a stiff xw with full flaps and still stay on the centerline. but then again, I have a lot of experience using my feet.

Posted
1 hour ago, rbp said:


in my M i only do full flap landings, regardless of xwind/gusts because i want to touch down as slow as possible. some people says full flaps is more difficult, but I prefer slow speed and less energy. 

I would do partial flaps with icing or (duh)  flaps inop. i don't do a lot of low-ceiling IFR, but that might be another reason not to deploy full flaps because "stable approach".

i believe the partial flaps landing in xwind/gusts comes from (high wing) airplanes whose flaps blanket the empennage and reduce rudder authority. 

Icing a great reason to not deploy any flaps.

IFR landings at minimums aren't all created at equal. If visibility is at minimums, I won't deploy flaps but continue to follow the GS to a landing at the IFR landing zone a 1000' down the runway to maintain that stable approach. But even at 200', if I have unlimited visibility, I have no issue pulling the power and putting in full flaps and slowing down from my approach speed of 100-110 kts (max Flap speed) down to Vref and landing well before the the IFR landing zone. It just depends on visibility.

The reason not to necessarily use full flaps is that in a very strong x-winds with the lots of aileron and rudder, with the plane so uncoordinated you can develop excessive vertical descent speeds as you reduce the power; especially with x-winds over 20 kts. Its doable if one is prepared for it, isn't high and doesn't just pull the power back to idle to early, but compensates by caring some power into the flare. There are other ways to do really strong cross wind landing, such even 30 kts direct crosswind, by just rolling the plane onto the runway at a higher airspeed to provide further rudder control to maintain center line; assuming you have a longer runway to accommodate. 

A gusty x-wind though is far more hazardous than and a merely a strong but stable cross wind.

  • Like 2
Posted

The problem is, the M20R AFM is less than clear with partial flaps. The following is the case:

A. In the limitations section, page 2-4, figure 2-1 it says, "Vfe--Maximum Flap Extended Speed--111/110----Do not exceed this speed with flaps in full down position."

B. Now page 1-9 under definitions describes Vfe as:

"MAXIMUM FLAP EXTENDED SPEED - The highest speed permissible with wing flaps in a prescribed extended position."

C. But wait, there is more! Next page 2-5 figure 2-2 under the table "airspeed markings" it says the "white band"----59-110 Knots----

Operating range with flaps fully extended

D. Now FAR 1.2 (definitions) describes Vfe as "Maximum flaps extended speed"

E. FAR 1.1 says "Flaps Extended Speed" as "The highest speed with the wing flaps in the prescribed position" 

F. Now Mooney in the AFM page 2-4 describes the "prescribed position" as "full down"

G. Finally the TCDS says "Flaps Extended" speed 110 knots. The Certification handbook says this description is the maximum speed with the flaps "fully extended"

So my view is the 110 knots is the maximum speed for full down and there is no speed prescribed for the T/O position. Operating conservatively,  I don't move the switch to 110 knots, but it is not by definition true because there is no prescription other than full down. IOW T/O position is "unprescribed" leaving you you to "roll your own".

 

  • Like 2
Posted
36 minutes ago, GeeBee said:

The problem is, the M20R AFM is less than clear with partial flaps. The following is the case:

So my view is the 110 knots is the maximum speed for full down and there is no speed prescribed for the T/O position. Operating conservatively,  I don't move the switch to 110 knots, but it is not by definition true because there is no prescription other than full down. IOW T/O position is "undefined" leaving you you to "roll your own".

 

I agree with this

Posted
1 hour ago, kortopates said:

The reason not to necessarily use full flaps is that in a very strong x-winds with the lots of aileron and rudder, with the plane so uncoordinated you can develop excessive vertical descent speeds as you reduce the power;

which is why i never forward slip in the mooney -- only crab to the runway. in the glider, forward slip is a required maneuver for inop dive brakes, and in planes (citabria) that don't have flaps and gliders (schwietzer 2-32) that don't have dive brakes.

 

Posted
2 hours ago, GeeBee said:

So my view is the 110 knots is the maximum speed for full down and there is no speed prescribed for the T/O position. Operating conservatively,  I don't move the switch to 110 knots, but it is not by definition true because there is no prescription other than full down. IOW T/O position is "unprescribed" leaving you you to "roll your own".

I don’t see how there is any basis to use a partial flap speed higher than 110 (except for the 205s) because the only number written down in the TCDS or AFM is 110. If you were to “roll your own” higher speed, what basis would you use to justify whatever speed you chose? 

  • Like 1
Posted
10 hours ago, PT20J said:

I don’t see how there is any basis to use a partial flap speed higher than 110 (except for the 205s) because the only number written down in the TCDS or AFM is 110. If you were to “roll your own” higher speed, what basis would you use to justify whatever speed you chose? 

Simple, it is unprescribed. Again it says 110 knots is the maximum speed with the flaps in the "prescribed position" and that position is full flaps. For instance, what is the maximum crosswind limit for the airplane? Undefined. We know what the maximum "demonstrated" crosswind is because it has been flown and analyzed at that speed. In like manner, we don't know what the maximum partial flap speed is because it has never been analyzed and prescribed. We are only told that 110 knots is the maximum speed in the fully extended position and indeed we are told that the 110 knot limit is only based upon the "prescribed position" (full) and no other. Like the crosswind limit it is undefined  unanalyzed and untested. If it said, 59-110 is the "flap operating range" then that would nail it, but they did not, they said "operating range with flaps fully extended".

Let's think about this from a certification standpoint during the CAR3 certification.

FAA: "You need to show us maximum flap speeds for each position"

Mooney: "No, we're not doing that, we only need to demonstrate the maximum speed in the fully extended position because we are not going to wire the airplane up for a partial flap analysis. (Our checkbook is dry)

We pilots want positions and conditions to be defined on an airplane. In CAR 3 airplanes we often see the manufacturer take the "Sgt Schulz" approach by only defining what they have to define and leaving the rest, undefined.

 

Posted
12 minutes ago, GeeBee said:

110 knots is the maximum speed with the flaps in the "prescribed position" and that position is full flaps.

I seem to remember that the reason for the max speed has to do with the motor and the extension of the flaps.  There is no structural or control issue with the flaps being in the extended position and you accelerate past the max speed.  Not that you should do this, but basically no safety of flight issues.  Anyone else remember this or have documentation on this?

Not that I plan to go extend the flaps and then start a descent well into the yellow arc. :D  Just trying to make sure I remember it correctly. 

  • Like 1
Posted
On 11/6/2022 at 6:52 PM, Jetman said:

What speed do you deploy first notch of Flaps?  10 degrees. I have been using 110knot as a limit (White Arc).

Thanks!

This seems to be a common question from people used to other brands. On some other brands the white band is the "full flap operating range." But you and I have read the Ovation manual 10 times and all we can find is the white band is the "flap operating range". Yes, it's different from what we're used to but everything will be just fine. White arc in the Ovation is the flap operating range. See, it's easy. Forget anything else. If you have the burning desire to drop some flaps at higher speeds maybe later in life you will get a P-51. Then you can drop the first notch of flaps at 400 indicated.

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