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Posted

I have been hearing rumors for oleo strut conversions from the oleo donuts. This would increase the landing weight and allow for higher gross and useful load, so I have heard. Any truth to this? Possible STC from the factory if they ever get back into production? Just wondering other comments or information out there. I have an Ovation I with the 310 horse conversion which I have been informed could handle that. 

Posted

True true…

It’s in the plans…

Probably won’t find out more until it is time…

We know it is time when the first buyer claims to have bought the update for his plane, or a new plane rolls off the factory floor with it…

 

as far as it being oleo this or oleo that, or magic donuts…

Getting to full seats and full fuel will be magical no matter what mechanical method they use…

 

 

Hmmm….   What would be a good way to approach the big cheese and ask …. ‘What’s the latest update on that MGTW project?’

 

Probably a PM, showing how interested you are…. :)

PP thoughts only, not an STC sales guy…

Best regards,

-a-

Posted

@Jonny

18 minutes ago, carusoam said:

True true…

It’s in the plans…

Probably won’t find out more until it is time…

We know it is time when the first buyer claims to have bought the update for his plane, or a new plane rolls off the factory floor with it…

as far as it being oleo this or oleo that, or magic donuts…

Getting to full seats and full fuel will be magical no matter what mechanical method they use…

Hmmm….   What would be a good way to approach the big cheese and ask …. ‘What’s the latest update on that MGTW project?’

Probably a PM, showing how interested you are…. :)

PP thoughts only, not an STC sales guy…

Best regards,

-a-

 

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Posted

I would love to dump the donuts and a gross weight increase would be icing on the cake.  The difficulty with the weight increase is the increase in stall speed.  The Bravo is already at the stall speed limit. Maybe the landing gear improvement kit would include a set of vortex generators.  

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Posted
1 hour ago, FoxMike said:

I would love to dump the donuts and a gross weight increase would be icing on the cake.  The difficulty with the weight increase is the increase in stall speed.  The Bravo is already at the stall speed limit. Maybe the landing gear improvement kit would include a set of vortex generators.  

But if everyone gets vortex generators than I won’t be special anymore!

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Posted

BTW...I did find a service instruction by Mooney describing overweight operation, CG envelope and stall speeds associated with increasing the gross up to 3873 lbs. It's service instruction SIM20-133. Came out on August 30, 2018 on the Mooney website. They have looked at it. Keeping my fingers crossed!!!

Posted

Dr.  T,

You may have found the procedures to ferry a Long Body…  Ferrying over long distances of water may require a portable fuel tank…. The first lost Ovation was heavy, on a ferry flight, landed in a field, bumped into crop irrigation equipment… turned the plane into a convertible….

There is plenty known about HP vs. Lift for Mooneys…

None of it is very linear….

  • T/O lengths increase, a lot…
  • Climb rates decrease, a whole bunch…
  • Stall speeds increase, in a similar way as they do with the current weight range…
  • Options run out, a tad faster…

 

All of these are pretty acceptable until the engine stops producing power while you are still flying…

Do whatever it takes to keep the engine running…. And these weight increases will be great!


PP thoughts only, not a CFI or mechanic…

Best regards,

-a-

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Posted
On 9/20/2021 at 11:35 AM, FoxMike said:

The difficulty with the weight increase is the increase in stall speed.  The Bravo is already at the stall speed limit. Maybe the landing gear improvement kit would include a set of vortex generators.  

You hit the nail on the head, unfortunately VG’s don’t do much, some but not much. Bringing the max forward CG back can do more and usually as you load heavy, CG moves aft so often it’s achievable.

‘There are other ways, the TBM 850 doesn’t meet stall speed requirements, but got a pass for equalivent level of safety by a crashworthy seat and some other measures, I don’t know specifics.

Posted
19 minutes ago, A64Pilot said:

unfortunately VG’s don’t do much, some but not much

VGs bring the stall speed from 59 kias to 54 kias. Seems like a lot of extra margin in order to get a GWI.

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Posted (edited)
20 hours ago, Niko182 said:

VGs bring the stall speed from 59 kias to 54 kias. Seems like a lot of extra margin in order to get a GWI.

Where did that number come from? If that were true then the FAA would require the airspeed indicator to be remarked and they don’t, to say nothing of a change in the flight manual.

Flight testing that I have done on other aircraft the stall speed difference is difficult to measure, just as the loss of airspeed in cruise, it’s seems that whatever you lose in cruise you gain in stall speed, also when you do stall it’s more abrupt than without VG’s, not a whole lot, but some.

If you could get 4 kts stall speed reduction I promise you every factory STOL airplane would have VG’s from the factory and do any?  a STOL airplane manufacturer would kill for four kts lower stall speed.

The TBM 850 only misses stall speed requirement by four knots I think, if they could have made stall by adding VG’s, I’m sure they would have.

Edited by A64Pilot
Posted

IF VG’s did what many people think they do then most factory aircraft would come with them. Not that I look at any new airplanes as I can’t afford new, but I’m not aware of any GA airplanes that have VG’s? Do any PIpers, Cessna’s, Cirrus, Beechcraft models have them standard?

Posted
1 hour ago, A64Pilot said:

Where did that number come from?

It's on the MicroVG website. stall speed was reduced by 8%.

1 hour ago, A64Pilot said:

The TBM 850 only misses stall speed requirement by four knots I think, if they could have made stall by adding VG’s, I’m sure they would have.

VG have a possibility of lowering the cruise speed. The selling point of the TBM is that its the fastest SET on the market. slowing it down isn't an option, and it already has a great useful load. The Mooney does not.

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Posted
4 hours ago, A64Pilot said:

Where did that number come from? If that were true then the FAA would require the airspeed indicator to be remarked and they don’t, to say nothing of a change in the flight manual.

Flight testing that I have done on other aircraft the stall speed difference is difficult to measure, just as the loss of airspeed in cruise, it’s seems that whatever you lose in cruise you gain in stall speed, also when you do stall it’s more abrupt than without VG’s, not a whole lot, but some.

If you could get 4 kts stall speed reduction I promise you every factory STOL airplane would have VG’s from the factory and do any?  a STOL airplane manufacturer would kill for four kts lower stall speed.

The TBM 850 only misses stall speed requirement by four knots I think, if they could have made stall by adding VG’s, I’m sure they would have.

As someone who has actually installed VGs on a Mooney and checked the stall speed before and after I can assure you that they do what the manufacturer says they do.

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Posted
7 hours ago, A64Pilot said:

IF VG’s did what many people think they do then most factory aircraft would come with them. Not that I look at any new airplanes as I can’t afford new, but I’m not aware of any GA airplanes that have VG’s? Do any PIpers, Cessna’s, Cirrus, Beechcraft models have them standard?

I think they would if the manufacturer did not have to spend thousands to  recertify them. 

Posted

1) A laminar flow wing is really good at some things….  High speed flight…

2) A laminar flow wing is pretty crummy at other things…  Low speed flight…

3) I watched a fair amount of STOL racing this week…  Reno

4) I didn’t see any laminar flow wings in the competition…  plenty of high wing repurposed planes…

5) I did see an engine that turned 10krpm… with a chain drive reduction… snowmobile based…

6) I haven’t modified my wings, yet…

7) When it comes to checking stall speed….  There’s an app for that. (Low cost)

8) If you want to check stall speed with official air computer data…. There’s some lowish cost EIS equipment that records flight data…

9) Doing this with decimal point accuracy will take a bit of engineering effort… recording things like temps and weights…

10) If I lived on a short field… I would seriously consider the wing modification…

11) The cool thing about VGs on TC’d Mooneys… less drag to consider in the Flight Levels…

12) The less cool thing about VGs… they aren’t very sturdy for a low altitude level working plane…. They may get damaged by a hopper filling hose, or by getting stepped on…

 

If you can’t trust a medical doctor and a professional mathematician to report good before and after data…

What would it take to get you into a set of these VG things?

They are not very expensive…

  • to purchase
  • to install
  • to test
  • To remove when less then satisfied
  • Keep in mind… they are as visually noticeable as an AOA sensor….

PP thoughts about VGs, not a flight engineer…

Best regards,

-a-

Posted (edited)
17 hours ago, Will.iam said:

I think they would if the manufacturer did not have to spend thousands to  recertify them. 

They don’t, Annie will happily come to the plant along with her DER, use the manufacturers DMIR for conformity and get the STC issued, then the manufacturer can have the STC rolled into their TC, Annie will also sell VG kits at a very attractive price to the manufacturer.

I know this, because I’ve done it.

Of course the manufacturer doesn’t have to roll the STC into their TC, that only does two things, it allows installation prior to Airworthiness Certificate being issued and many countries don’t accept US STC’s, but do accept the aircraft and it’s TC, so being on the TC allows them to be installed.

OK, three things, if it’s on the TC the installation is a minor not major mod, so no 337.

You do something to an airplane that changes the stall speed by 8% and the FAA is going to require the Airspeed indicator to be remarked and this manual to be changed, that is a major change.

Just as they do for VG installation on some twins as they increase control and decrease single engine speed, so the AS indicator gets remarked and the manual changed.

‘On edit, I like VG’s on some airplanes, especially ones with an issue that needs fixing, I like VG’s as often they are the easiest fix. That’s why you will see them on large Commercial aircraft, used sparingly and only in places that need fixing.

My early model Maule M6 had a lack of elevator authority at low air speeds in the flare and low aileron effectiveness at very low speeds, I put VG’s on it. Wished I could only have put them in front of the ailerons and on the elevator but unfortunately you have to install the whole kit.

 

Cmon guys, if VG’s dropped the stall speed by 8% don’t you think Aviat woud put them on a Husky?

Edited by A64Pilot
Posted

I can verify the effect of VG. Flown PA-18s with and without them. On that airfoil, 8% is a conservative number. The only way I could get my PA-18-160 to stall was to go full flaps, power at least 75% then I might get the nose up high enough, but the ASI was zero. Power off it would not stall period. If I managed to stall it, I could go stop to stop on the ailerons and it would not spin. I have also flown them on a 182 and the results are equally dramatc and unless you have the King Katmai conversion, you will be hard pressed to stall it as well. Do not disbelieve unless you have flown them.

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Posted
51 minutes ago, GeeBee said:

I can verify the effect of VG. Flown PA-18s with and without them. On that airfoil, 8% is a conservative number. The only way I could get my PA-18-160 to stall was to go full flaps, power at least 75% then I might get the nose up high enough, but the ASI was zero. Power off it would not stall period. If I managed to stall it, I could go stop to stop on the ailerons and it would not spin. I have also flown them on a 182 and the results are equally dramatc and unless you have the King Katmai conversion, you will be hard pressed to stall it as well. Do not disbelieve unless you have flown them.

Completely different air foil wing on the mooney.   This is not relevant information.

Posted
1 hour ago, Yetti said:

Completely different air foil wing on the mooney.   This is not relevant information.

However, on the Mooney, my Mooney, the VGs DO lower the stall speed by about 5kts.

Posted
1 hour ago, Yetti said:

Completely different air foil wing on the mooney.   This is not relevant information.

You are correct, the Mooney does have a different airfoil. So does a Learjet. Notice what is on a Learjet wing?

It has been 45 years since I graduated with that aero engineering degree, but the effects of VGs have not changed.

Posted (edited)
45 minutes ago, GeeBee said:

You are correct, the Mooney does have a different airfoil. So does a Learjet. Notice what is on a Learjet wing?

It has been 45 years since I graduated with that aero engineering degree, but the effects of VGs have not changed.

You may have forgotten that this is an internet discussion - your extensive professional and personal experience on this exact subject is completely irrelevant. Everyone gets to express their opinion and demand to have it treated as fact.

Edited by ilovecornfields
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