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A full composite Mooney. Possible or not?


Cargil48

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5 hours ago, ArtVandelay said:

If you’re going to paint your Mooney, then can’t you have them use a little bondo and smooth out our wings, maybe get a few extra knots. Since this isn’t done, I assume there is a major downside; weight as you said, what about longevity? How does bondo hold up?

Tom

 

Bondo is used on many airplanes to smooth the surface.  It is heavy (use sparingly), and it will eventually crack.

There was talk at the last MooneyMax that the inboard portion of the wing has a flat spot on the top made during manufacturing.  People were talking if they should (and legally can) build that up.  I never heard the end result.

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On 12/16/2019 at 11:03 AM, Cargil48 said:

If you can afford it... 

What makes me wonder is if there is no significant weight advantage and even danger using carbon fiber when severe impacts occur, then I ask myself why are ultra-fast Formula One cars almost fully made of exactly that fiber? And boy, we do sometimes see severe hits in those races... Okay, those small parts of the front wing flip off upon the slightest impact, but... they are small and I guess with not enough "critical material" to sustain impacts. But when there are lateral impacts wheel against wheel I do admire the wonders of today's technique regarding the stiffness of those carbon fiber suspension parts! 

Back to topic. I agree that the biggest advantages of composites in aviation are lack of corrosion danger and ease of assembly (less work hours in big parts). But why then Boeing (and others) insist on that weight saving thing??? And we know this is a strange topic, since yes, the SR22 is heavy for a plane of that size... The same occured with the failed M10T project... So what explains this discrepancy?

Im pretty familiar with F1 and indycar composite structures.  Very impressive, yes.  Esp when you look at the loading of those structures, I mean you have a 1600 lb car doing 4 G's in a corner and 5.5 under braking.  The suspension motion ratio is something in the range of 4:1, so in that 4 g turn the rear push rod is seeing 16,000 lbs of compression force in that carbon fiber rod.  Then the "seat spacer" (driver) hangs it out over the curb and puts massive shock loading through the whole car over those 3" tall rumble strips.

But yeah, composites can be very stiff, very light, very strong, but are really not repairable.  I have repaired indycar bodywork but they end up not as strong and you pay a weight penalty.  They can be very safe, again ref the F1 cars.  The "tub" cockpit section of the car is all carbon and kevlar and is designed to take crashes and not crack.  The cars are actually designed to have all the rest of the parts shatter and fall off so they take energy away from the driver.  Dont really want that on a plane though, do we.  LOL

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22 minutes ago, mstephenson51 said:

  The cars are actually designed to have all the rest of the parts shatter and fall off so they take energy away from the driver.  Dont really want that on a plane though, do we.  LOL

I am not sure that would be a bad trait in an airplane depending on the forces involved. With all of the racing bodies coming out of the UK I am surprised that some industrious Brit hasn't designed a thoroughly modern airplane.  Maybe they have and I just don't know...

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5 hours ago, Blue on Top said:

Bondo is used on many airplanes to smooth the surface.  It is heavy (use sparingly), and it will eventually crack.

There was talk at the last MooneyMax that the inboard portion of the wing has a flat spot on the top made during manufacturing.  People were talking if they should (and legally can) build that up.  I never heard the end result.

I faired all of the ribs and stringer lines in the front half of the wing on my airplane. He probably used about a third of a gallon of a Epoxy and microballoons, which weighs about 5 pounds, and we sanded about 80%-90% of it off. And a gallon of Sherwin-Williams epoxy aircraft primer. So I would say there’s less than 5 pounds on the wings

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You should the 787!    I'm used to seeing airliners grow round rivets about two-thirds of the way down the fuselage, but the 787 is extremely smooth all the way back to the last few feet where the APU is.    I was surprised that it still has a lot of rivets or similar-looking fasteners, they're just very flush.   I don't know how they mix the composite and fastener stuff, but it's very nicely done.   The wing is the same.

I'm always amazed at how smooth many RV wings are...dang near as good as composite wings, probably near enough as makes no difference.
Every time I look out the window at the Mooney wing and see all the ripples and tank panels and round rivets and blind rivets I feel deprived.   
787 fuselage has co-cured stringers and mechanically fastened frames. The fasteners are countersunk titanium hi-loks. It is smooth!

Sent from my LG-US996 using Tapatalk

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Holy crap!  It wasn't even 4:30PM before I became emotionless (out of emotions?)  So, one of two things need to happen.  Either all y'all quit posting good stuff, or I get out the duct , andtap.  Keep 'em comin'!

Someone earlier in this thread mentioned going after high dollar items (I apologize for not remembering who).  One of the items many have mentioned is the avionics.  This is a nail on the head perfect example.  The engine is another.  Manufacturing techniques is another (including engineering for manufacturing.  Systems are another (landing gear comes to mind).  I say this not in the Mooney part of it, but spec'ing out the actuator is extremely expensive.

Y'all mention the high cost of new airplanes (and I agree with you), and wanting to go back to a "J" or …  A "J" with the current luxuries will cost similar to an Ovation.  A "J" like the original "J" will be significantly less.  OEMs think that everyone wants a Cadillac (which is normally true), but in this case I don't believe it is.  Can we design and build a competitive "trainer" that goes fast, too (and still look like a Mooney)?  Of course!

BTW: Cessna and Piper can't make enough trainers today. 

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I faired all of the ribs and stringer lines in the front half of the wing on my airplane. He probably used about a third of a gallon of a Epoxy and microballoons, which weighs about 5 pounds, and we sanded about 80%-90% of it off. And a gallon of Sherwin-Williams epoxy aircraft primer. So I would say there’s less than 5 pounds on the wings

And what was the improvement in speed?


Tom
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2 hours ago, ArtVandelay said:


And what was the improvement in speed?


Tom

Minimal, 1kt maybe at the most. To get all the benefit you need to wet sand the wing and knock all the dust off of it so that it flows laminar. Right now it is not laminar at all. It’s ready, I just got to do it sometime

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@jetdriven Wow!!!  Very cool. I’d like to know what you find.  Let me know if I can help in any way.  Beautiful work.

Does this include removing the rumored inboard flat spot on the top of the airfoil?

Dang you guys are good!

Edited by Blue on Top
Added comment about flat spot and compliment to @jetdriven.
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On 12/17/2019 at 3:48 AM, ArtVandelay said:

If you’re going to paint your Mooney, then can’t you have them use a little bondo and smooth out our wings, maybe get a few extra knots. Since this isn’t done, I assume there is a major downside; weight as you said, what about longevity? How does bondo hold up?

 

 

Tom

 


when you go to KOSH with Byron...   he can point out all the really smooth areas that have been bondo’d on a new Mooney...

It always helps to go to a show with other MSers to gain from their experience...

It looked like every transition from one piece to the next got smoothed over... some of those transitions were composite/aluminum...

It looked good to me.... :)

 

Some additional structure thoughts....

MS51, great explanation of Indy car technology and energy dissipation...!

 

tensile strength of composites seems strong enough to build some pretty thin and structures out of...

But, their impact resistance is terrible...

We can probably build a very light composite plane... unfortunately, it wouldn’t survive the other less defined situations such as impact with nature... birds, sleet, hail stones...

Every now and then we get a picture of a bird that has gone through the windshield...

and other pics that show the bird mangled tail structure... and leading edges...

 

I wouldn’t mind flying a new Mooney built out of composites.... I just like the Bravo models better...  :)

 

Best regards,

-a-

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Yep.  The price we would pay for a slick, light composite mooney would be that its parts are throw away if its ever cracked.  =0/

I saw a comment back there about the cost of a new Ovation...  Yeah they are retarded expensive, but remember that the FAA made them destroy like 5 of them in testing before ever getting to market.  Then all that development cost doesn't have a lot of planes to spread across; what is it 14 a year?  It sucks, but hey the FAR/AIM is written in blood so now we have to do it that way.  Cessna at least has the advantage of selling the crap out of the 172 to flight schools.  Spread all those costs out over more planes.  But have you seen how much a new 172 costs???  OMG man, I would NEVER pay that!

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5 hours ago, carusoam said:

I wouldn’t mind flying a new Mooney built out of composites.... I just like the Bravo models better...  :)

-a-

Me neither... I even took a drawing from "Scheme Desiners" and drawed carefully some changes I'd make... Let's see 

1. If you like it and 

2. If you find out the changes I did...

M20-Bravo-IIP-Freedom.png

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Well, I tell you...

1. Left side door and, to make this work, bigger windows in front and accordingly slightly smaller in the rear;

2. Bended winglets sort of "sailplane style";

3. LE slats to lower the approach and landing speeds;

4. Hinged flaps (you know what there are for so I don't need to go into details);

5. Two full wrapping ducts for the exhausts, one each side of the front LG doors. If you look carefully, there is a small opening on the front side of these ducts. Why? To get the same effect as in the fanjet engines: cool air flowing in and around the exhaust nozzles (or tubes, here), lowers the noise levels. Here, in this case, the rapidly flowing air through the ducts creates also sort of an extraction effect of the (slower) air inside the engine compartment. From cooling the cylinder heads, the turbo intercoolers and from the oil radiator. And I'd like a fully digital controlled engine from Lycoming also...

6. The antennas on the roof.

Look guys, my reasoning is the following: Complex airplanes are expensive. Just like complex cars... With today's enormous technological advance, a pilot flying IFR on any GA airplane is very close to a professional guy flying a big plane. The vast amount of information the pilot(s) get nowadays make it mandatory for them to have a huge knowledge to extract all the capabilities of the GA planes they get. Even if it's an Archer LS, it has the same panel technology as the others... Being this so, I only think of changing to a new airplane if I can afford today's technology. Otherwise I buy an used one with some 20 years on it and spend some 100/150 grand making a really deep overhaul of all systems, add some of the smaller digital instruments which fit into the holes of analog ones and get a new paint and interior at my wish. Then I'll have a good, reliable and beautiful Mooney for, say, some 400k bucks or so. If I took the care to get the plane inspected beforehand mainly for corrosion and none was found, I'd have a plane for another 20 years (if in 20 years from now they'd allow us to burn avgas or even mogas...

Let's see what you all think of it... "Babbling", of course, but... :D 

Carlos

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20 minutes ago, carusoam said:

Staying with the four cylinder IO390?

Composite prop?

:)

Best regards,

-a-

No. My "dream" Mooney would have 250 to 280hp from a turbo intercooled engine. Like the Lycoming TIO-540-C1A (250 hp) or the TIO-540-AF1B (270hp) from the Bravo TLS. Flying with turbocharged engines gives you an immense power reserve and flexibility. You need power? Boost it up. You want flying more economical? Boost down until you get the desired FF... The prop would most likely be the MT-600-Series Full Carbon Blade  one. 

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On 12/16/2019 at 12:03 PM, Cargil48 said:

If you can afford it... 

Back to topic. I agree that the biggest advantages of composites in aviation are lack of corrosion danger and ease of assembly (less work hours in big parts). But why then Boeing (and others) insist on that weight saving thing??? And we know this is a strange topic, since yes, the SR22 is heavy for a plane of that size... The same occured with the failed M10T project... So what explains this discrepancy?

Corrosion is also a problem with composites since thy embed aluminum mesh for lighting protection. You can get what looks like filiform corrosion under the paint. Carbon fiber is corrosive against metals, so it has to be electrically isolated. 

A Cirrus is "heavy for its size" due to the crashworthiness that is built it, which adds well over 100 pounds to the bare airframe. The chute alone weighs 65 pounds. Seats have crash cells embedded, along with airbag seatbelts. That's another 20 pounds. The wing assembly is stronger and therefore heavier than needed for the current gross weight. The single piece main spar goes from tip to tip and broke the test fixture the first time it was tested to destruction.

A Cirrus tends to have far more in creature comforts and avionics than the competition, adding more weight. Most have air conditioning (55 pounds).

So if you add up and strip out the extras, you will find a Cirrus is very close in basic weight to a Cessna 182 or Piper Dakota, although the cabin is much larger and far more comfortable.

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I must add here that to have a minimum of serious underlying thinking, it would be mandatory for me to use the "dream Mooney" mostly for professional reasons (for tax deduction purposes). To fly for fun just on weekends, I'd go rather the other way I described also, getting a good used one (around 150/170k) and make the steps described above as well.

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Who uses aluminum mesh in composites?  As [mention=12083]philiplane[/mention] stated, carbon and aluminum don't work well together.  Beech proved aluminum mesh didn't work back in the Starbarge days.  Personally, I believe everyone is using copper mesh today … with some trying a spray on layer.

Boeing does! On some nacelle panels there is a surfacer, aluminum mesh, fiberglass ply, and then graphite... With aluminum fittings bolted on the inside of the graphite, but there is an island of fiberglass under each fitting.

 

Sent from my LG-US996 using Tapatalk

 

 

 

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