Flap Extension Speeds

[sailon]

Have a basic stupid question regarding flap extension speeds.  I am getting ready to fly an Ovation for the first time, and my Mooney trained CFI and I were discussing flap speeds.  I have always waited to add any flaps at Vfe which is 109 kts in my F.  My CFI mentioned that this speed in the Ovation (110kts) is the maximum extended flap speed and partial flaps can be dropped at a faster speed.  Furthermore, this quote from the POH pp 2-3 says: "Vfe, Do not exceed this speed with flaps in full down position." Elsewhere in the POH it indicates in Figure 2.2 White arc range 59-110 as the "flap operating range."  Other high performance aircraft I have flown have an approach flap setting of approximately 10 degrees.  So the question is, can I safely extend say 10 degrees at a faster airspeed than 109 or 110 kts?  If so, what speeds are commonly used for an approach flap setting?

Thanks

[Hank]

My flaps have three markings:  Up, Takeoff (15° per the Type Certificate), and Landing (33° per the TCDS). I do not operate them above Vfe, the white stripe on my ASI (125 mph for my C).

Seems like long bodies have a nice, high gear speed, something like 140 KIAS, so they can function much like a speed brake. Check the POH for the plane you will be flying, though, as my Vg = 120 mph . . . 

[Niko182]

40 minutes ago, sailon said:

Have a basic stupid question regarding flap extension speeds.  I am getting ready to fly an Ovation for the first time, and my Mooney trained CFI and I were discussing flap speeds.  I have always waited to add any flaps at Vfe which is 109 kts in my F.  My CFI mentioned that this speed in the Ovation (110kts) is the maximum extended flap speed and partial flaps can be dropped at a faster speed.  Furthermore, this quote from the POH pp 2-3 says: "Vfe, Do not exceed this speed with flaps in full down position." Elsewhere in the POH it indicates in Figure 2.2 White arc range 59-110 as the "flap operating range."  Other high performance aircraft I have flown have an approach flap setting of approximately 10 degrees.  So the question is, can I safely extend say 10 degrees at a faster airspeed than 109 or 110 kts?  If so, what speeds are commonly used for an approach flap setting?

Thanks

I saw this on my poh too and was trying to figure it out. I wonder what the speed limit for the first 10 degrees are. Just know the ovations dont really like to slow down. Good luck on your first flight.

[carusoam]

As far as I remember...

Unlike other manufacturers.... Mooney doesn’t have a different speed for the various levels of deployment...

Some planes like the C152 allowed for the first notch of deployment outside the white arc....

If you are looking for energy dissipation, The Long body is more refined than a C152....

• Speed brakes can be deployed from Vne to get you down to Gear extension speed
• once gear are deployed, you can increase speed up to gear down speed...
• Gear down speed... gets you down at maximum descent rate. Thousands of FPM....

 

• Flaps are not used until getting slowed and situated for the traffic pattern....

Expect the white arc on the ASI to apply with the details given in the limitations section of the POH.... regarding weight and everything....

Maximum descent rate is a pretty unusual feeling as is climbing out at 2kfpm.... 

TT should include these O ticket rides.  During a real E-descent you don’t want this to be your first time....

@donkaye May have some better detailed input for Long Bodies...

PP thoughts only, not a CFI....

Best regards,

-a-

[Shadrach]

I have looked for a reference to this many times. Vfe for my 67F is a dismal 100mias. Clearly the stress on the system at full flaps is a great deal more than say at takeoff flaps.  The system could obviously withstand some higher speed with the flaps partially deployed than it could with them fully deployed.  However, the factory has provided no guidance outside Vfe. Some V speeds are informational and some are limitations. Vfe is one of the latter. It may be perfectly safe to deploy some degree of partial flaps at some number higher than Vfe but unless your CFI can provide factory guidance on the subject, he’s technically flying outside the certification envelope.

[sailon]

Wish the ovation POH was clearer on topic. I agree with the consensus not to touch flaps till Vfe. 

[hypertech]

I heard from someone who bought their ovation new and had the factory training that the first notch of flaps can go in at gear extension speed. I can not find a speed for the approach flaps anywhere in my poh. I’m inclind to believe they can be extended faster but I would also really like it if there was some clarity on it in writing somewhere. 

[carusoam]

I have also seen the other side of Vne... with a m*P* CFI...  under the right conditions, not terribly amazing... under bumpy conditions, not terribly bright... 

But to get that in a POH where you want it, with the meaning that POH has...will require a whole lot of testing and documentation... that nobody has volunteered to support financially...

On the other side... over speeding with flaps extended...

There are plenty of Mooney pictures posted lately of repairs to the spar that supports the flap hinge...  it bends and cracks under the extra load... requires a brace to be added to fix...

How much extra? I don’t know...

So in a more refined plane with extra tools for slowing down and/or dissipating energy..?

Why make up new ideas to do the same thing that a documented procedure with the right tool would do better?

What more would you get by lowering the flaps too?

If hell has broken out inside your plane and three minutes of descent time is too much...  choices are limited, roll the dice, say a prayer.  Slow to Vfe to add flaps, proceed as necessary...? ( not recommended, but, nobody will fault  you...)

Know that bent and broken control surfaces are likely to become unevenly deployed... resulting in incredibly poor flying controlability?

PP thoughts only, just pointing out you have something better to use then the proposed old procedure for a prior Mooney.  If you haven’t received the training in their awesome descent power... I know a guy or several that can show you the way...

Descending with gear down and speed brakes deployed, throttle pulled, at max rpm, at gear deployed speed, is an E-ticket ride... and no fear of bent flight controls... 

The prop will be driving the engine, yes! 

But not banging on and off the thrust bearings...

when hell has broken out, it is  one way trip to the ground... the plane is expendable.  Use it in a way that preserves the lives of all on board...

throttle out, prop in, gear down, speed brakes deployed... following the procedures in the POH to not exceed the speeds that shouldn’t be exceeded. There is both slowing and speeding back up involved.

this produces much better descent rates than flying slowly with the flaps deployed safely...  really.

I have received the training using the O1 engine limited to 2500rpm... 2700 Rpm of the O3 powered planes will be an improvement in the energy dissipation scheme...

Let me know if I have overstated something, or something needs adjustment... just trying to state that there is a better way in the POH.  Get to know it. 

Best regards,

-a-

[carusoam]

Or did you mean...

What would happen if...

Approach flaps are down, on an IFR approach, at 90 knots...

And something happens to my airspeed and I accidentally exceed Vfe by a small amount?

I may have heard that in conversation... like the Vne discussion above...

Trying to find it documented seems elusive...

The laws of physics prevail, strength of materials don’t change... forces on T/O flaps are less than fully deployed flaps...So you might get away with it?

Climbing out with flaps left deployed has happened a few times in Long Bodies... have we learned anything there..?

PP thoughts only, not a CFI or aerodynamics guy.... no recommendations being made other than stow the flaps in a timely manner. Or raise the nose to slow to Vfe for flap stowage...

Best regards,

-a-

[jackn]

I wonder how many Mooney pilots have taken off or go around, and at some time, forgot to retract TO flaps without bad things happening. I wouldn't make a habit of putting in approach flaps over 110kts though.

 

[Bartman]

Once during IFR training my brain was overloaded and I forgot and left the flaps in takeoff position. After leveling off I noticed the airspeed was low. No icing was forecast and we had flown thru about a 2000 foot layer in actual IMC with temps below freezing and that was my first thought. When I looked at the leading edge it was clean, but the flaps were in takeoff position. Uuggghhhh !!!  Anyway I figure we flew about 10 minutes with flaps in takeoff position and after retraction everything was back to normal.  I told the IA after we landed and it was annual time anyway and he said he found no issues. 

That's my data point FWIW and that was nearly 10 years ago. I'm sure I am neither the first or last. 

[Shadrach]

21 hours ago, jackn said:

I wonder how many Mooney pilots have taken off or go around, and at some time, forgot to retract TO flaps without bad things happening. I wouldn't make a habit of putting in approach flaps over 110kts though.

 

My bet is...almost all of them.  I would not find it hard to believe that every Mooney from the F model back (Vfe 91kias or 105mph) have exceeded Vfe with the flaps deployed to some degree.  

I see now where an instructor might get confused if he cut his teeth in a J model.  This is the only model with a partial flap Vfe listed.  My guess is that Mooney did not publish a partial flap speed with subsequent models due to the discovery of stub spar cracks.  The problem was likely not deamed pervasive enough to revise the TCDS for the J after the fact. 

Edit:

@Bartman there's a chance you never even exceeded the TCDS's Vfe...

 

 

 

Edited November 13, 2018 by Shadrach

[LANCECASPER]

5 minutes ago, Bartman said:

Once during IFR training my brain was overloaded and I forgot and left the flaps in takeoff position. After leveling off I noticed the airspeed was low. No icing was forecast and we had flown thru about a 2000 foot layer in actual IMC with temps below freezing and that was my first thought. When I looked at the leading edge it was clean, but the flaps were in takeoff position. Uuggghhhh !!!  Anyway I figure we flew about 10 minutes with flaps in takeoff position and after retraction everything was back to normal.  I told the IA after we landed and it was annual time anyway and he said he found no issues. 

That's my data point FWIW and that was nearly 10 years ago. I'm sure I am neither the first or last. 

I think we've all done that once or twice.

A few years ago I went to look at a Mooney Ovation to possibly buy. The owner took me up for a flight and he insisted that full flaps could be put out at 140 but that you couldn't drop the gear until the white arc (110 kts). I mentioned that I thought he had those two speeds turned around and he insisted that he was correct. For a number of reasons, needless to say, I don't own that airplane. 

[skydvrboy]

53 minutes ago, Shadrach said:

I would not find it hard to believe that every Mooney from the F model back (Vfe 91kias or 105mph) have exceeded Vfe with the flaps deployed to some degree.  

For another data point, when I bought my '67 F, it had the '68 F owners manual in it.  The '68 owners manual lists Vfe as 120 mph, whereas the '67 is 105 mph.  Previous owner had placarded the ASI as such and flown it that way every time.  I have no idea if this started with him or some previous owner before that, but suffice it to say, it had a lot of operations above published Vfe.   The pre-buy and subsequent 2 annuals have not turned up any damage FWIW.

[Shadrach]

20 minutes ago, skydvrboy said:

For another data point, when I bought my '67 F, it had the '68 F owners manual in it.  The '68 owners manual lists Vfe as 120 mph, whereas the '67 is 105 mph.  Previous owner had placarded the ASI as such and flown it that way every time.  I have no idea if this started with him or some previous owner before that, but suffice it to say, it had a lot of operations above published Vfe.   The pre-buy and subsequent 2 annuals have not turned up any damage FWIW.

Good to know in case I ever get distracted during a busy departure and forget them...

[Txbyker]

19 hours ago, sailon said:

Have a basic stupid question regarding flap extension speeds.  I am getting ready to fly an Ovation for the first time, and my Mooney trained CFI and I were discussing flap speeds.  I have always waited to add any flaps at Vfe which is 109 kts in my F.  My CFI mentioned that this speed in the Ovation (110kts) is the maximum extended flap speed and partial flaps can be dropped at a faster speed.  Furthermore, this quote from the POH pp 2-3 says: "Vfe, Do not exceed this speed with flaps in full down position." Elsewhere in the POH it indicates in Figure 2.2 White arc range 59-110 as the "flap operating range."  Other high performance aircraft I have flown have an approach flap setting of approximately 10 degrees.  So the question is, can I safely extend say 10 degrees at a faster airspeed than 109 or 110 kts?  If so, what speeds are commonly used for an approach flap setting?

Thanks

This has been discussed at many a MAPA Proficiency class.  110 is for full flaps but there is no discussion about partial flaps anywhere in the POH.  I deploy first flaps at 110 regardless and use speed brakes to get there if not already.  140 is the gear down speed.  

Russ

[Andy95W]

2 hours ago, Bartman said:

 

That's my data point FWIW and that was nearly 10 years ago. I'm sure I am neither the first or last. 

If yours was 10 years ago, then I can attest to the fact that you weren't the last.  

[Chris K]

I'm reopening this thread because I was looking for the same answer about partial flap operational limits. The answer is in the POH however it is not specified as clearly as you may expect, therefore you really need to read carefully.  For my S model (air frame identical to legacy Ovation models):

1)  Section II, Limitations - Vfe specifies "maximum" flap extended speed is 110 KIAS.  It does not specify that partial flap extended speed is a limitation placed on the aircraft.  When I called Mooney a few months ago with an unrelated question, they stated my POH for my serial number aircraft is complete and no changes need to be added.

2) Section IV, Normal Procedures - Approach for Landing -  Landing Gear extend below 140 KIAS....followed shortly afterwards by Wing Flaps - T/O Position, and in parentheses (Full Down below 110 KIAS).

Before you conclude the POH sections above mean 139 KIAS is therefore the maximum safe operating speed for flaps in the T/O position for the R and S models, I want to share some more food for thought:

1)  As someone above noted, most J models set to partial flaps (about 15/16 degrees depending on your flap switch) specify a higher limitation than for full flaps.  My J model POH was odd in that it further specified max speed with full flaps and max speed for operating flaps separately (max speed to operate was 115 KIAS - my personal takeaway is that this could occur while retracting from Vfe of 110 KIAS).

2)  R/S model T/O flaps are 10 degrees (vs. 15 for medium length models) - deducing there are a few likely reasons for this design change and I'm not claiming expertise here, but weight and length of the long body models seem obvious reasons.

3)  The POH specifies a much lower negative and positive max. load factor for full flaps, but none for partial flaps, however since the flaps are only attached by hinged points, definitely not the strongest part of the wing, designed to help go downhill for approaches, and because of the airspeed and load factor limitations, it would be prudent to use the published full flap load factor limitation when using partial flaps.  Therefore I recommend extra caution if you choose to operate using partial flaps (T/O setting) in excess of 110 KIAS and below 139 KIAS.  For these reasons, I personally would not ever toy with the idea of operating above 130KIAS since turbulence could happen any time, especially if you are flying approaches at busy airports in IMC.

Thus as listed above, I have found that when flying approaches, it has been helpful to use flaps in the T/O setting on my S model for instrument approaches up to about the 120 KIAS range if there is no turbulence and maneuvering is limited to ones that do not exceed load factor limitations.  I'll see if my mechanic finds any unusual wear on my plane due to this use - on my J model he never did find an issue and I routinely flew approaches with Flaps set to T/O up to 125 KIAS.  If anyone does find something published that otherwise specifically places a limitation on the partial flap on the R/S model, please do let us know.  In the meantime - safe flying to all.

Edited January 26, 2019 by Chris K
clarification

[Niko182]

Funny enough, i do the exact same thing. The speed brakes get me to 135 KIAS. Then the gear gets me to about 120 KIAS. Then take off flaps down to 105 KIAS. And landing flaps get me to my 85KIAS long final speed. 

I routinely put the T/O flaps around around 125 KIAS at the highest. 

[carusoam]

See if I get this right...

1) You use T/O flaps for slowing down?

2) Because the extra lift they are supplying isn’t needed, you are nowhere near stall speeds on the instrument approach...

3) You have a few speed brake systems on the plane...

• Actual speed brakes from Precise Flight...
• Landing gear...
• The blue knob and its related black knob...
• Flaps..?

My take on using flaps as a speed brake... comes from E-descents... Where flaps aren’t used at all for braking...  yet the rate of descent is measured in multiple thousands of feet per minute...

it’s an emergency, why not use all the brakes you have?

The lonely flaps got left out...

I got my Transition training from Bob Cabe, a Mooney Factory trainer... (a decade ago...)

Sure... you don’t want to be in the middle zone where the prop vascilates between driving and being driven.... banging back and forth against the bearings... that isn’t braking either... and could lead to breaking... 

Never had a problem of slowing down while going down with so many braking options, where one becomes available at the ship’s red-line.

PP thoughts only, not a CFI.

Best regards,

-a-

[PT20J]

14 CFR Part 1 defines V_FE as "maximum flap extended speed".

Part 23 certification rules define requirements at full flap extension because that is the worst case for the structure. (This was before the rewrite of Part 23 in 2016 to performance-based standards).

The TCDS and Limitations section of the Airplane Flight Manual are regulatory documents that specify operating limitations.

It is clear that V_FE applies to full flaps. The manufacturer is under no obligation for certification to specify anything other than the maximum speed for full flap extension. Unless the TCDS or AFM specifies a different speed for partial extension, there is no way to know what higher speed might be acceptable for partial extension and you should treat the limitation as applicable to all extensions.

Will the flaps fall off, be damaged, or compromise the airframe  (in smooth air and unaccelerated flight) if you fly around with takeoff flaps at cruise power? Of course not - many of us have been the test pilot on that configuration. But I have always thought the flaps to be one of the weaker parts of the Mooney design. Just put them down and grab a hold of one and note the "give" in the mechanism. They are much less solid than on many other light singles. So, my point of view is, why push it when it's easy to develop techniques to operate the airplane effectively without the need to extend partial flaps above V_FE?

Skip

[Chris K]

10 hours ago, PT20J said:

14 CFR Part 1 defines V_FE as "maximum flap extended speed".

Part 23 certification rules define requirements at full flap extension because that is the worst case for the structure. (This was before the rewrite of Part 23 in 2016 to performance-based standards).

The TCDS and Limitations section of the Airplane Flight Manual are regulatory documents that specify operating limitations.

It is clear that V_FE applies to full flaps. The manufacturer is under no obligation for certification to specify anything other than the maximum speed for full flap extension. Unless the TCDS or AFM specifies a different speed for partial extension, there is no way to know what higher speed might be acceptable for partial extension and you should treat the limitation as applicable to all extensions.

Will the flaps fall off, be damaged, or compromise the airframe  (in smooth air and unaccelerated flight) if you fly around with takeoff flaps at cruise power? Of course not - many of us have been the test pilot on that configuration. But I have always thought the flaps to be one of the weaker parts of the Mooney design. Just put them down and grab a hold of one and note the "give" in the mechanism. They are much less solid than on many other light singles. So, my point of view is, why push it when it's easy to develop techniques to operate the airplane effectively without the need to extend partial flaps above V_FE?

Skip

That is a pretty good explanation - much appreciated.  Kind of the same point I was trying to make - you can use partial above the maximum flap Vfe limitation, however you must fully understand and be cognizant of the added risk and adjust your flying accordingly while in that configuration and above Vfe.   For me, I do not use that configuration to slow down per se, instead the partial extension helps to keep your descent on the glide path especially when ATC requests that you keep your speed up which is not uncommon at airports with busy jet traffic.  Though it's your perogative to tell ATC "unable", there are occasions that we can accept that request - for me personally I tell them 120 KIAS is my limit in smooth air.  The partial extension also helps with visibility over the tall panel.  Though I have speed brakes, I reserve their use for quick descents from cruise flight, not for the purpose of flying a stabilized approach - I rarely if ever see the pros flying with spoilers out once they are on the final approach course.

[ilovecornfields]

1 hour ago, Chris K said:

That is a pretty good explanation - much appreciated.  Kind of the same point I was trying to make - you can use partial above the maximum flap Vfe limitation, however you must fully understand and be cognizant of the added risk and adjust your flying accordingly while in that configuration and above Vfe.   For me, I do not use that configuration to slow down per se, instead the partial extension helps to keep your descent on the glide path especially when ATC requests that you keep your speed up which is not uncommon at airports with busy jet traffic.  Though it's your perogative to tell ATC "unable", there are occasions that we can accept that request - for me personally I tell them 120 KIAS is my limit in smooth air.  The partial extension also helps with visibility over the tall panel.  Though I have speed brakes, I reserve their use for quick descents from cruise flight, not for the purpose of flying a stabilized approach - I rarely if ever see the pros flying with spoilers out once they are on the final approach course.

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.

[Chris K]

1 hour ago, ilovecornfields said:

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!”). 

 

 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)"

Edited January 26, 2019 by Chris K
delete emoji that was not intended

[milotron]

How invasive is the inspection on the spar/hinge connection? Is this something worthwhile doing if you have not been the sole operator of the aircraft?