Flap Extension Speeds

[carusoam]

Chris,

The emoji thing is an automatic thing related to the website software...

alternatives... (from the menu)

• one
• two
• three

Or... (manual)

a) one 

b) two

c) three

 

or...(manual)

A )

B )

C )

 

or...(extra manual) 

A)

B )

C)

 

but not... (manual with the automatic surprise)

A)

C)

 

They also have... (automatic)

1. One
2. Two
3. Three

 

It would be nice if that automated feature went away or could be turned off?... selecting emojis from the menu is pretty easy...

I sent this question over  to have a look...

Best regards,

-a-

[ilovecornfields]

9 hours ago, Chris K said:

 Look in the POH - Section IV,  Normal Procedures, Approach for Landing -  Landing Gear extend below 140 KIAS....followed shortly afterwards by Wing Flaps - T/O Position; Full Down once airspeed below 110 KIAS.   

Every pilot should know primary purpose of flaps are not to slow the airplane down - It is a question on the FAA Airman Knowledge Test:

One of the main functions of flaps during approach and landing is to A) decrease the angle of descent without increasing the airspeed.  permit a touchdown at a higher indicated airspeed. C) increase the angle of descent without increasing the airspeed

Correct answer is C.

 

PS - not sure why the emoji is appearing up there maybe a moderator can help??? when I hit enter it is "B)"

I think we’re reading the same thing and interpreting it differently. I see “don’t put the flaps full down above 110 KIAS.” I think you’re seeing “don’t put the flaps full down above 110 KIAS, but go ahead and put partial flaps down at some arbitrary number higher than that.”

You can fly and maintain your plane the way you want to and I will fly and maintain my plane the way I want to. I did enough questionable things in airplanes when I was a teenager and feel no need to continue that behavior as an adult. If there is ambiguity I will almost always take the conservative approach.

[PT20J]

Question for those who extend partial flaps above VFE: How do you determine a safe maximum speed for partial flap extension? The next higher limiting speed in smooth air is VNE. I mean, the AFM doesn’t say you can’t extend partial flaps at VNE, right?

[Ned Gravel]

No partial flap extension is provided for in my POH.  65 E model.  One speed.  100 MPH.  No flaps allowed above that speed.

1965 Mooney M20E Owner's Manual (POH) Page 24:  "Flap speed is 100 mph."  

[Hank]

@Ned Gravel, the Owners Manual for my 1970 C is similar:

So there is only one Gear Speed and only one Flap Speed. Makes it easy to remember! The Flap Speed = 125 mph also matches the white stripe on the Airspeed Indicator. 

[Chris K]

10 hours ago, PT20J said:

Question for those who extend partial flaps above VFE: How do you determine a safe maximum speed for partial flap extension? The next higher limiting speed in smooth air is VNE. I mean, the AFM doesn’t say you can’t extend partial flaps at VNE, right?

Skip - this is a great conversation and really appreciate the brainstorming here to find an answer that is not obvious.  I definitely agree that doing something just because an AFM / POH does not expressly say you can't could potentially be unsafe.  Further, sage advice is that if you do something outside of what the AFM / POH states the aircraft is certified to perform, not only could you possibly bust Regs. but you are also acting as your own test pilot and risk not only your own life but others as well.  That being said, for my S model specifically, the approach checklist expressly states gear down below 140 KIAS followed by Flaps set to T/O.  I've spent some years as a technical writer and if it was not Mooney's intent for pilots to follow along and set Flaps to T/O after gear is down, then that is a huge blunder on the part of Mooney and the FAA that approved the AFM.  As I noted above, I called Mooney directly to ensure that the AFM for my serial number has not been revised to which they affirmatively stated that my AFM is current.

For us owners that are not privy to the flight tests that Mooney may have completed for partial Flap use, what speed is safe is a very good question.  As you noted in your prior post, it appears that Mooney is not obligated to publish limitations for partial flap extension for type certification, yet the AFM / POH for my model states partial below 140 KIAS is a normal procedure.  Since we don't know unless someone privy to Mooney's test flights could chime in here, seemingly good advice is to use caution if you choose to operate in that range.  Personally, though 139 KIAS is inferred to be a safe and normal operation according to the AFM, I set my personal limit to 1) Not do it often (certain instrument approach only); 2) Limit to smooth air only; 3) Limit to no abrupt maneuvers (no g loading as per full flap load limits); and 4) Max 120 KIAS.  As others also noted, the parts on our planes do wear and are costly to replace and maintain, therefore operating moving parts at higher loads should factor into your decision making - just because the AFM says we could fly in an emergency with speed brakes and landing gear extended at the top of the yellow arc does not mean you should do it routinely.

Obviously if we are to receive information that the AFM as published and approved for this specific model was an error regarding the normal procedures then that would be very welcome information. 

[Marauder]

I don’t see where that says “you can use partial above the maximum flap Vfe limitation.” I get where it says the limitation is for full flap extension, but in the R/S there is NOTHING that tells you what is allowable for partial flap extension or discusses this. (My son uses this logic - “You didn’t tell me I can’t do this, so that means I can!”). 

Sure, it’s unlikely that one of the flaps will break off if you use partial flaps above Vfe, but it certainly not “allowed” anywhere and I can’t understand why you would need to put the added wear and stress on your airframe parts and motors.

If you’re really having trouble slowing down, maybe it would be worth getting some time with an experienced Mooney CFI. When I bought my Ovation the spedbrakes broke and I practiced a lot of slips in my transition training. I’ve never had a problem with using power and speedbrakes to get below gear speed and with the gear and speedbrakes out it slows pretty quickly. 

Just my thoughts but I’d rather fly (or buy) an airplane that was kept comfortably within the limitations than one routinely flown just a little bit outside the envelope.

 

The V speeds that are provided in the various POHs do vary. In older Mooneys the POH will call out a VFo and VFe. Newer Mooney POHs will call out a VFe only.

 

VFe is the limitation in IAS where either full flaps or what they will called a “prescribed” position can be used. You will find that these speeds will vary In the various and same models. Mooneys built prior to the J models had a VFo and VFe speed which I believe are the same.

 

What should dictate what flaps speeds should be used is what is dictated in YOUR POH.

 

What I think precipitated some of this flap over flaps was the attachment issues. I know that older Mooneys had issues with damaged caused by operating the flaps at higher speeds. They most likely beefed this area up in later Mooneys. Even with that, you will see there is still some uncertainty of what is an acceptable speed limitation for full versus partial flap deployment.

 

Here is a POH segment for 2 J models.

 

Older J (POH revision date 1984). This one calls out a limitation for full flap but doesn’t clearly say it is okay to deploy above VFe. Although the word “given” may mean the range of flaps you can deploy.

 

 

 

Newer J (POH revision date 1986). Two years later a revision that comes out that says it is okay to use partial flaps above VFe and clearly tells you the speed.

 

 

 

Fast forward to 2007. An Ovation POH, doesn’t mention anything about partial flaps. But the tone makes it sound like you can deploy partial above that. But no indication what that speed limit is.

 

 

 

For guys with newer Mooneys, the higher gear speeds and those with speed brakes should make this a moot point. For those of us stuck with low gear speeds and no speed brakes, we need to plan.

 

 

 

Sent from my iPad using Tapatalk Pro

[Robert C.]

So, I can confess I'm one of the many who in the press of things has forgotten to raise T/O flaps when climbing out. As a matter of fact, on at least one occasion I didn't remember until I was already leveling of for cruise and accelerating past 150kts. During the panel scan I noticed the flap button in the "T/O down" position. Lump of ice in the stomach I looked over my shoulder and saw the flaps aligned with the wing. For sure, i thought I had busted something....but they came out fine on the way down. 

After the flight I checked in with my A&P who said....nah....you're fine. The newer Mooneys have a mechanism (forget his exact words) where the air pressure just pushes the flaps in/up from the T/O position when above Vfe.

I haven't had any problems with my flaps or attachment points and feel reassured that the aircraft can easily handle a distracted pilot forgetting to raise (T/O) flaps.

Robert

[PT20J]

3 hours ago, Robert C. said:

After the flight I checked in with my A&P who said....nah....you're fine. The newer Mooneys have a mechanism (forget his exact words) where the air pressure just pushes the flaps in/up from the T/O position when above Vfe.

That's really interesting. Most of my experience is with Js, so I don't know many details about Ovations. I found a Oct-94 M20R service manual online (http://www.softoutfit.com/static/refs/smm-wiring.pdf) and section 27-50-00 doesn't mention this feature -- it shows essentially the same flap mechanism that's been used ever since they went electric. Likewise the Rev G 03-2000 M20R POH (http://www.softoutfit.com/static/refs/poh.pdf) system description doesn't mention this feature (though all the system descriptions in the POH are pretty lean on details). Does anyone know if this is the latest service manual or have one for a 2006 or later Ovation? I'd really like to know if Mooney added this feature (The DC-3 had this). Of course, if Mooney was to mess around with the flap actuating design, my vote would be to add an up lock so you didn't have to step over the darn thing (and worry about your passengers stepping on it - I leave mine down after shutdown to avoid that).

Skip

[carusoam]

Great documented document research, @Marauder! 

It is interesting how the company documented some things, and completely left things out in later years...

We would like to get a copy of an Ultra POH to see how they document this same challenge in the modern Mooney World...  See if @mike_elliott would be familiar with the partial flap speed challenge...

Expect there is some fuzziness when it comes to giving speed limitations on some things... where smooth air vs turbulence can become a big factor...

Thanks for sharing those details.

Best regards,

-a-

[mike_elliott]

From the M20V manual pg 2-4, KCAS/KIAS

VFE Maximum Flap Extended
Speed
111/110 Do not exceed this
speed with flaps in
all extended positions

[Hank]

So no change from my 1970 Owners Manual other than higher speed. (Hah! Just did the math--Ultra Flap speed is 110 KIAS [ = 126.5 mph]; electric C Flap speed is 125 mph, so not much change at all. Just easy-to-see speeds.)

Thanks for the clarification, Mike!

[ilovecornfields]

41 minutes ago, mike_elliott said:

From the M20V manual pg 2-4, KCAS/KIAS

VFE Maximum Flap Extended
Speed
111/110 Do not exceed this
speed with flaps in
all extended positions

Mike,

I think we’ve already definitively established that what Mooney INTENDED to say was that you can do partial flaps at 139 kts (see posts above). You may want to inform them of the error in this latest POH. Disappointing for an $800k airplane.

[mooniac15u]

16 minutes ago, ilovecornfields said:

Mike,

I think we’ve already definitively established that what Mooney INTENDED to say was that you can do partial flaps at 139 kts (see posts above). You may want to inform them of the error in this latest POH. Disappointing for an $800k airplane.

Trying to extract airspeed limitations from text in the POH is an interesting approach but all of the limitations are described in the TCDS.  If it doesn't have a partial flaps limitation in the TCDS then the Vfe applies to any amount of flaps.

[mike_elliott]

1 hour ago, ilovecornfields said:

Mike,

I think we’ve already definitively established that what Mooney INTENDED to say was that you can do partial flaps at 139 kts (see posts above). You may want to inform them of the error in this latest POH. Disappointing for an $800k airplane.

Where have you definitively established what Mooney INTENDED to say for partial flaps at 139 kts on a M20V? 

If you know, you might reach out to Kevin Kammer kkammer@mooney.com and advise him of the error.

[ilovecornfields]

2 minutes ago, mike_elliott said:

Where have you definitively established what Mooney INTENDED to say for partial flaps at 139 kts on a M20V? 

If you know, you might reach out to Kevin Kammer kkammer@mooney.com and advise him of the error.

Sorry. I don’t know how to do the green font thing so my sarcasm doesn’t come through very well sometimes.

I’ve been trying to make the point all along that if Mooney intended for partial flaps to be lowered above Vfe they would have said so. Others have argued that by not explicitly prohibiting it, they are allowing it.

Thank you for clarifying that in the latest POH they explicitly prohibit it.

[jaylw314]

It sort of makes sense that Vfe would specifically only apply to full flaps, since it's presumably based on data about structural limitations.  If it's based on data, there's no way any company would publish similar speeds for partial flaps, especially with aircraft that have an infinite number of flap settings, since they couldn't possibly have data for all the various settings. 

For example, if they actually had structural data about a higher maximum speed for "half-flaps", what will they or the FAA do if someone goes a smidge over half-flaps?  or if someone gives it a smidge under full flaps and says "well, it was under full flaps so the half-flaps speed should apply?"  Obviously, reality dictates that 1 degree of flaps probably does not require flying at Vfe.

The only exception might be the mechanical flaps in Cherokee's, where the mechanism limits you to only 3 flap settings.

TLDR: I think Vfe is intended to refer to full flaps only, and if you fly a little faster with partial flaps you're probably ok but in a test pilot situation.  Does anyone know if there is an actually regulatory definition of what Vfe means?

[N201MKTurbo]

40 minutes ago, jaylw314 said:

It sort of makes sense that Vfe would specifically only apply to full flaps, since it's presumably based on data about structural limitations.  If it's based on data, there's no way any company would publish similar speeds for partial flaps, especially with aircraft that have an infinite number of flap settings, since they couldn't possibly have data for all the various settings. 

For example, if they actually had structural data about a higher maximum speed for "half-flaps", what will they or the FAA do if someone goes a smidge over half-flaps?  or if someone gives it a smidge under full flaps and says "well, it was under full flaps so the half-flaps speed should apply?"  Obviously, reality dictates that 1 degree of flaps probably does not require flying at Vfe.

The only exception might be the mechanical flaps in Cherokee's, where the mechanism limits you to only 3 flap settings.

TLDR: I think Vfe is intended to refer to full flaps only, and if you fly a little faster with partial flaps you're probably ok but in a test pilot situation.  Does anyone know if there is an actually regulatory definition of what Vfe means?

One thing you are overlooking, there is a big difference between up and down any amount. 

When the flaps are up they are being supported by the stop screw. If you put them down at all you transfer the support from the stop screw to the actuator. The actuator and linkage linkage mounts are where the cracks form.

[mike_elliott]

4 hours ago, ilovecornfields said:

 

APPROACH FOR LANDING
The airplane must be within allowable weight and balance envelope for landing (REF.
SECTION VI). It will require a minimum of one hour of flight before a permissible landing
weight is attained when takeoffs are made at maximum gross weight. If landing at a
weight exceeding maximum landing weight (3200 Lbs.) (1452 Kgs.) is required, see
OVERWEIGHT LANDING PROCEDURE, SECTION III.
-CAUTIONSeats,
Seat Belts/Shoulder Harness . . . . . . . . . . . . . . . . . . . . . . . . . . . ADJUST AND SECURE
Internal/External lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AS DESIRED
Landing Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EXTEND below 140 KIAS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (Check Gear Down light ON- Check visual indicator)
Mixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FULL RICH (on final)
Propeller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HIGH RPM (on final)
Fuel Boost Pump Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF
Fuel Selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FULLEST TANK
Wing Flaps (below 110 KIAS in all extended positions) . . . . . . . . . . . . . . . . . . . T/O POSITION
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (FULL DOWN)
To minimize control wheel forces when entering landing configuration, timely nose-up
trimming is recommended to counteract nose down pitching moment caused by reduction
of power and/or extension of flaps.
-CAUTIONElevator
Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AS DESIRED
Rudder Trim . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AS DESIRED
Parking Brake . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VERIFY OFF
-NOTEThe
parking brake should be rechecked to preclude partially applied brakes during
touchdown.

 

Here it is again referred to on pg 4-16 of the M20V POH under Normal Procedures.

21 hours ago, Robert C. said:

After the flight I checked in with my A&P who said....nah....you're fine. The newer Mooneys have a mechanism (forget his exact words) where the air pressure just pushes the flaps in/up from the T/O position when above Vfe.

They make no mention of an actuator or mechanism that will allow the flaps to be extended to TO position above 110 KIAS and compensate for the excess speed by having the wind force keep them up, and I sure haven't heard this until reading it on this thread, and would darn sure make certain of this claim before I relied on the wisdom of the A&P here. This mechanism that allows this might be a cracked flap actuator mount  

The Nov 2007 edition of the M20R AFM says it a little differently, and is suggestive without specifically authorizing it, the use of flaps above the white arc less than full down. I still would not do it as there is no real purpose for it as stated earlier

VFE Maximum Flap Extended
Speed
111/110 Do not exceed this
speed with flaps in
full down position.
 

AND
Seats, Seat Belts/Shoulder Harness . . . . . . . . . . . . . . . . . . . . . . . . . . . ADJUST AND SECURE
Internal/External lights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AS DESIRED
Landing Gear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . EXTEND below 140 KIAS
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (Check Gear Down light ON--Check visual indicator)
Mixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FULL RICH (on final)
Propeller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HIGH RPM (on final)
Fuel Boost Pump Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFF
Fuel Selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . FULLEST TANK
Wing Flaps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T/O POSITION
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (FULL DOWN below 110 KIAS)

[Marauder]

And to another point, who is to say that the 1986 version of the POH was correct. The original certification documents as mooniac pointed out is where the truth should be found.

Anyone have a link for our TCDS documents? I’ll research it later today.


Sent from my iPhone using Tapatalk Pro

[mike_elliott]

5 minutes ago, Marauder said:

And to another point, who is to say that the 1986 version of the POH was correct. The original certification documents as mooniac pointed out is where the truth should be found.

Anyone have a link for our TCDS documents? I’ll research it later today.


Sent from my iPhone using Tapatalk Pro

Here ya go...

http://www.airweb.faa.gov/Regulatory_and_Guidance_library/rgMakeModel.nsf/0/60107bc8954c93a686256c24005b5075/$FILE/2A3.pdf

[Vance Harral]

4 minutes ago, Marauder said:

Anyone have a link for our TCDS documents? I’ll research it later today.

Type Certificate 2A3 for the Mooney M20 series: http://www.airweb.faa.gov/Regulatory_and_Guidance_library/rgMakeModel.nsf/0/60107bc8954c93a686256c24005b5075/$FILE/2A3.pdf

[carusoam]

Mike,

Great documented documentation support!

Looks like the Ultra’s POH got a few words extra to really clear things up.

 

Starting to look more like a legal document, than a pilot’s guide...

 

Any guidance on how often some people review their ships’s POH?  Is there a recommendation like annually?

 

They can be difficult to read... you immediately get reminded how much detail you forgot...

PP thoughts only, not a CFI...

Best regards,

-a-

[m20kmooney]

Is anyone else disturbed by this thread or is it just me? Are folks actually using flaps to slow down? And is there really so much confusion about Vfe?

Vfe IS THE HIGHEST PERMISSIBLE SPEED WITH FLAPS IN A PRESCRIBED EXTENDED POSITION. This speed is going to be higher for T/O flaps and lower for any setting beyond T/O. It’s spelled out in the POH. For example my POH says this speed is 132 KIAS for T/O setting and 115 KIAS for ANY SETTING BEYOND T/O, i.e. 15° to full down. 

Edited January 29, 2019 by m20kmooney

[Hank]

10 minutes ago, m20kmooney said:

Is anyone else disturbed by this thread or is it just me? Are folks actually using flaps to slow down? And is there really so much confusion about Vfe?

Vfe IS THE HIGHEST PERMISSIBLE SPEED WITH FLAPS IN A PRESCRIBED EXTENDED POSITION. This speed is going to be higher for T/O flaps and lower for any setting beyond T/O. It’s spelled out in the POH. For example my POH says this speed is 132 KIAS for T/O setting and 115 KIAS for ANY SETTING BEYOND T/O, i.e. 15° to full down. 

Many of our Owners Manuals / POHs only list a single Flap Speed. It seems some pilots try to justify a higher speed than listed for partial flap extension. Until this thread, I had nomidea . . . . Until I'm below the (only) Flap speed mentioned in my Owners Manual, I don't touch the flap switch.