How strong is the M20 wing?

[KSMooniac]

The picture of all the employees on the wing is a great PR photo, but in reality isn't much of a load at all.  If you had 30 200-lb people on the wing, that is only 6000 lbs.  For a 2740 lb M20J, that is only 2.2 G's.  (Negative G in this case).

 

I agree that the likelihood of passing out during a high-G pull in a Mooney is higher than breaking a Mooney.  (presuming no prior damage or corrosion of course)

[Piloto]

There are two ways of breaking a wing in-flight. One is by stress or g-loading and the other is by flutter speed. The most common cause of g-loading break up is turbulence penetration at high speed. To avoid break up slow down your Mooney to 120kts or slower. Keep in mind that heavy turbulence not only can break the wing but other components such as engine mounts and attachments to it, battery mounts, avionics racks and articulated seats. Speeds beyond Vne up to 600+kts will not break the wing as per my own GVT testing but it may get the cowling off. Maintaining 120kts or less would give you a more comfortable ride even though the stall warning may occasionally come up.  

 

José

[rbridges]

The picture of all the employees on the wing is a great PR photo, but in reality isn't much of a load at all.  If you had 30 200-lb people on the wing, that is only 6000 lbs.  For a 2740 lb M20J, that is only 2.2 G's.  (Negative G in this case).

 

I agree that the likelihood of passing out during a high-G pull in a Mooney is higher than breaking a Mooney.  (presuming no prior damage or corrosion of course)

 

I still think the people on the far edges put a lot of weight on the wing, but having the wheels down creates a shorter lever vs. at the fuselage during flight.  Not trying to argue, but how do you think other planes such as a Cessna or Piper would do with the same loads?

[chrisk]

If you have never seen flutter, it is amazing.   It will probably scare you too.   https://www.youtube.com/watch?v=pEOmCkZyXzk

[PaulB]

If you have never seen flutter, it is amazing. It will probably scare you too.

The video reminds me of my Chinese friend Ho Lee Fuc.

[KSMooniac]

I still think the people on the far edges put a lot of weight on the wing, but having the wheels down creates a shorter lever vs. at the fuselage during flight.  Not trying to argue, but how do you think other planes such as a Cessna or Piper would do with the same loads?

Making a short lever arm reduces the bending stress, so it makes the picture even less impressive from a stress analysis perspective.  

 

Other GA planes would do fine as well IMO, at least in the same class as a Mooney.  I wouldn't put a bunch of people on a Cessna 150 wing with a 1600 lb gross weight.

 

A Mooney would probably hold all of Maurader's ladies sitting side-by-side on the wing.  I wouldn't want any of them to step anywhere on the wing, though!  (much high concentration of force vs. spreading it out over the ample backside)

[HRM]

So... how strong IS the M20 wing, and how hard should one pull on the yoke if inadvertently approaching Vne in a dive?

 

Super strong. Pull hard, real hard.

[RobertGary1]

Approaching Vne isn't the problem. It's being over it. You don't have much choice but to pull up otherwise you'll just get faster. Danger goes up considerably as speed increases. So pull back as much as necessary to arrest the descent.

[pinerunner]

OK that tail flutter got my attention. Is that why my M20E is redlined at 183 mph? I've always wondered about that. Did they beef up the tail when making the M20J. Is it something about the short bodies that sets up oscillations? As I recall the M20F moves the redline up.

[carusoam]

Expect that there is a speed that you won't want to exceed in ordinary air.

Vne comes from actual testing under smooth conditions (sort of ideal).

Why they selected some off beat odd number instead of picking a nice round number like 200kias would take a more technical explanation.

Staying under Vne is a nice way to keep the wings attached and avoid flutter.

It is nice to know, nobody has experienced irrecoverable flutter in a Mooney...?

Don't be in a rush to pull back hard on the yolk to slow the plane quickly. Lower stresses, spread over time are worth thinking about.

Remove power, deploy speed brakes, slow enough to get to gear operating speed. If unable, the gear doors may be pulled off, but they are optional...

Lastly, I am only a PP, not a CFI or even close...

Best regards,

-a-

[HRM]

OK that tail flutter got my attention. Is that why my M20E is redlined at 183 mph? I've always wondered about that. Did they beef up the tail when making the M20J. Is it something about the short bodies that sets up oscillations? As I recall the M20F moves the redline up.

 

The rumor I heard was that the FAA inspector got spooked and they arbitrarily set it at 183.

 

I simply cannot imagine a Super 21 going over 200.

 

Must be extremely frightening and delightfully exhilarating at the same time.

 

I wonder what it's like 

[cnoe]

OK that tail flutter got my attention.

 

Mine too when I first saw it. That was apparently identified as the reason so many early Bo's fell from the skies from what I've read. It was also said that in the V-Tail the problem was exacerbated by full simultaneous movement of the rudder and elevator (as stated before go "wings level" before beginning the pull). Apparently many have limiters to prevent this now.

 

In my M20 if passing through Vne I'd be less concerned about tail flutter if the early speed tests were indeed legitimate. And a hearty application of elevator might not be a bad idea if anywhere in the vicinity of Terra-firma.

[kortopates]

I believe there have been 4 or 5 breakups over the years, and all from convective activity. I recall Bruce J used to discuss these in the MAPA PPP he participated in so I would expect he would recall specifics the best. The two most recent I recall was a most recent one in the Bahamas with the next previous being a much more publicized event where a K model departures into convective weather and broke up by Bakersfield CA (north of LA). That was chilling since some other Mooney pilots from the same gathering heard the chilling radio calls before they were lost.

As Robert already pointed out, it's highly unlikely one is going to find themselves in an upset attitude in IMC without turbulence and thus very important to use a spin like recovery starting with power off, rolling wings level before pulling back. Then it won't likely be the pilot pulling to many G's per se but a high G gust added from the turbulence that rips the tail off.

Sent from my iPhone using Tapatalk

[mike_elliott]

Making a short lever arm reduces the bending stress, so it makes the picture even less impressive from a stress analysis perspective.  

 

Other GA planes would do fine as well IMO, at least in the same class as a Mooney.  I wouldn't put a bunch of people on a Cessna 150 wing with a 1600 lb gross weight.

 

A Mooney would probably hold all of Maurader's ladies sitting side-by-side on the wing.  I wouldn't want any of them to step anywhere on the wing, though!  (much high concentration of force vs. spreading it out over the ample backside)

Ok Scott, go ahead and post the moment diagram here of that picture. Make reasonable assumptions for the weight of all the people and it's ok to disregard the weight of the wing. Simple freshman statics problem.... 

[AndyFromCB]

Making a short lever arm reduces the bending stress, so it makes the picture even less impressive from a stress analysis perspective.  

 

Other GA planes would do fine as well IMO, at least in the same class as a Mooney.  I wouldn't put a bunch of people on a Cessna 150 wing with a 1600 lb gross weight.

 

A Mooney would probably hold all of Maurader's ladies sitting side-by-side on the wing.  I wouldn't want any of them to step anywhere on the wing, though!  (much high concentration of force vs. spreading it out over the ample backside)

 

Actually, IIRC they didn't really have to do anything to the wing to make the Aerobat version...I don't think there has ever been an inflight break up of a 150, 152 or 172. The strutted wing bends and then unloads before there is any major damage. 

[PTK]

Expect that there is a speed that you won't want to exceed in ordinary air.

Vne comes from actual testing under smooth conditions (sort of ideal).

Why they selected some off beat odd number instead of picking a nice round number like 200kias would take a more technical explanation.

Staying under Vne is a nice way to keep the wings attached and avoid flutter.

It is nice to know, nobody has experienced irrecoverable flutter in a Mooney...?

Don't be in a rush to pull back hard on the yolk to slow the plane quickly. Lower stresses, spread over time are worth thinking about.

Remove power, deploy speed brakes, slow enough to get to gear operating speed. If unable, the gear doors may be pulled off, but they are optional...

Lastly, I am only a PP, not a CFI or even close...

Best regards,

-a-

I remember reading somewhere that Vne is set at 10 per cent less than the fastest speed the aircraft has ever flown in testing.

Problem is we as pilots don't always know why a certain Vne was arrived at. Is it for structural strength considerations or for flutter. But the beauty of certificated airplanes is that we don't have to worry. We can safely opetate up to Vne as long as we stay in the envelope. The envelope includes among otheg things a certain density altitude.

CAUTION!! This is dangerously approaching the IAS vs. TAS as it pertains Vne debate!!

Almost up there with LOP vs. ROP!!

Just an observation!!

[cnoe]

The rumor I heard was that the FAA inspector got spooked and they arbitrarily set it at 183.

 

I simply cannot imagine a Super 21 going over 200.

 

It's so hard for me to read sarcasm on the computer.

 

The Super 21 that I previously partnered in had a redline of 189 mia while my J's redline (Vne) is at 228 mia. From all I can tell there is very little (if any) difference in the airframes (other than a bit of length).

 

With that being said I didn't bust Vne in the Super 21 but it would cruise in the yellow (which I did frequently in good air).

 

In the J you have to push a bit to get it very far into the yellow, and that usually leads to uncomfortable descent rates for my passengers.

[bonal]

I can't remember if it was Bill Wheat who told me the story about the wing loading jig failure during certification but I remember it was over 10 Gs.

 

I heard that story too

[carl]

 "the super had a red line of 189...?"

 

 

 

                      I think it is 197 MPH for my 1967 E ..

[gsxrpilot]

My C cruises in the yellow easily and almost all the time. And I have to pay close attention to keep it below the 189 VNE on the descent. 

 

Mooney's LOVE to go FAST

[Hank]

"the super had a red line of 189...?"

 

 

 

                      I think it is 197 MPH for my 1967 E ..

Vne varies by model and year. For my 1970 C, Yellow starts at 175 mph, and Vne=200 mph.

[cnoe]

 "the super had a red line of 189...?"

 

 

 

                      I think it is 197 MPH for my 1967 E ..

 

That's what the POH says (shown below).

[pinerunner]

I was quoting from memory and got my Vne wrong. 

[co2bruce]

Here's the picture

[mooniac15u]

Here's an M20K that broke up due to flutter. It sounds like the folks at Mooney predicted the onset of flutter to occur at 241 knots.

http://aviation-safety.net/wikibase/wiki.php?id=36780