J airfoil vs predecessors

[201er]

I see some folks with C, E, and F's answering questions asked by J and newer pilots so I am curious about just how different the earlier planes are? I understand the body, windows, and cowling were vastly upgraded moving toward the J. But I have seen no mention of the tail, wings, and controls. Has the airfoil been altered to improve the speed of the J over the earlier models or was all that done on the body?

When someone with a pre-J plane answers a question pertaining to J's or newer, how relavent is the answer? How big or small is the difference between these planes?

[Shadrach]

Well, in terms of... Oh wait, never mind - I own a "pre-J" model...I'm standing down.  Sorry, I'm sure a J owner will be along soon to help.   You probably should have posted this in the Modern Mooney section. 

[Gone]

201er

First the wings.  Our aircraft have essentially the same wing.  There was one year where a "twisted" wing was tried on the F model ('67 or '68 I believe) but that did not last.

There was another year where the owners (Butler aviation I believe in the same era) tried saving on labour costs by not using flush skin rivets but that dissappeared to.  By the time Roy LoPresti had made the changes which we now call the J or 201, most of the cost-cutting silliness was gone and replaced with well engineered speed mods.

Next the airframe.  Your aircraft has 10 more inches in length than mine.  5" of that is forward of the firewall and 5" of it is between the rear and front seats.  Your aircraft weighs between 80 and 120 pounds more than mine depending on how much of the weightier junk we have each replaced with lighter weight versions (eg SkyTech starter).  See http://www.pilotfriend.com/aircraft%20performance/Mooney/41.htm and http://www.pilotfriend.com/aircraft%20performance/Mooney/47.htm.

We have the same engine, but you may have lower gear doors.  I do not.  Your engine intake is better designed than mine.  Mine is a real study in aerodynamic innefficiency.  I have a doghouse surrounding my engine so as to channel cooling air.  You have baffles just like the rest of the world.  My oil cooler is on the front of the cowl.  Yours is behind number 4 cylinder.  We both have one piece winshields, but yours is more sloped than mine.

As a result of these differences, and using the same engine as I use, you are 20 mph or so faster than I am.

This help?

[201er]

That's interesting. I'm kind of surprised they were able to get so much more speed out of the same wing. Is this a testament of how well the original wing was engineered or were they too lazy to change a working wing and simply found more speed increase in the fuselage improvements? Also does all this apply the same to the new long bodied Mooneys? Same wing as the C? Same pushrod connections? Did all of these awesome things carry through since the 60s till now?

[N33GG]

I have read/heard that the G wing had more washout for stall control???  Anybody know the straight scoop here?

In 1968, as stated above, a cost saving effort was made that did away with flush mounted rivets.  The result was more drag.  The J went back to the flush rivets.  My C is an early 68 model, and still has the flush rivets, or "clean wing".

As far as the actual profile of the wing (other than the rivets), I think or have heard that they are the same, with perhaps the exception of the G.  But I am not an expert, and do not claim to know for sure.  Great question.  I am looking forward to the answer from someone that knows.  I have also wondered the same.

[sleepingsquirrel]

Mooney 10 Cadet                                            NACA 43013                               NACA 43013
Mooney 18 Mite                                             NACA 64A215                              NACA 2412
Mooney 20 Mark 20                                          NACA 63-215                              NACA 64-412
Mooney 20A Mark 20A                                        NACA 63-215                              NACA 64-412
Mooney 20B Mark 21                                         NACA 63-215                              NACA 64-412
Mooney 20C Mark 21                                         NACA 63-215                              NACA 64-412
Mooney 20C Ranger                                          NACA 63-215                              NACA 64-412
Mooney 20D Master                                          NACA 63-215                              NACA 64-412
Mooney 20E Chaparral                                       NACA 63-215                              NACA 64-412
Mooney 20E Super 21                                        NACA 63-215                              NACA 64-412
Mooney 20F Executive 21                                    NACA 63-215                              NACA 64-412
Mooney 20G Statesman                                       NACA 63-215                              NACA 64-412
Mooney 20J 201                                             NACA 63-215                              NACA 64-412
Mooney 20J 201AT                                           NACA 63-215                              NACA 64-412
Mooney 20J 205                                             NACA 63-215                              NACA 64-412
Mooney 20J MSE                                             NACA 63-215                              NACA 64-412
Mooney 20K 231                                             NACA 63-215                              NACA 64-412
Mooney 20K 252TSE                                          NACA 63-215                              NACA 64-412
Mooney 20K Encore                                          NACA 63-215                              NACA 64-412
Mooney 20L PFM                                             NACA 63-215                              NACA 64-412
Mooney 20M TLS                                             NACA 63-215                              NACA 64-412
Mooney 20M TLS Bravo                                       NACA 63-215                              NACA 64-412
Mooney 20R Ovation                                         NACA 63-215                              NACA 64-412
Mooney 20S Eagle                                           NACA 63-215                              NACA 64-412
Mooney 20T Predator                                        NACA 63-215                              NACA 64-412
Mooney 22 Mustang                                          NACA 63-215                              NACA 64-412
Mooney 301                                                 NASA NLF(1)-0315                         NASA NLF(1)-0315
Mooney MT-20 (TX-1)                                        NACA 63-215                              NACA 64-412

[sleepingsquirrel]

The first column is root the second column is tip.

[201er]

So in other words, the same wing has prevailed in the entire Mooney M20 line since it was designed in wood in 1955? Did they hit the perfect wing design from the start or were they too lazy to retool and focused on improving other areas instead? Also is the span the same across all Mooneys? Despite different weights?

[carusoam]

201er,

You have come to a club that is full up with mooney enthusiasts, owners, mechanics and pilots, and you are surprised by the depth of their knowledge outside the confines of the exact machine that they currently own.

 

You must be in the early stage of your addiction.  Enjoy, there is so much to know.

 

Just remember to share what you learn....

 

Best regards,

 

-a-

[danb35]

Wing span is the same, with the exception of the fiberglass wingtips that add about a foot (the span of the wing itself remains the same, but the wingspan on newer models is listed as 36' compared to the 35' of the pre-J models due to the tips).

[Sven]

Hey, don't forget the M20D. There's only 3 of us left. Our legs don't go up but we're still faster than a 172!

-Sven

[Shadrach]

If you look at TCDS for every Mooney M20 it will be clear that they all share the same type certificate... see attachment.

 

[Hank]

So in other words, the same wing has prevailed in the entire Mooney M20 line since it was designed in wood in 1955? Did they hit the perfect wing design from the start or were they too lazy to retool and focused on improving other areas instead? Also is the span the same across all Mooneys? Despite different weights?

201er--

I prefer to think that in his many previous designs [our planes were Al Mooney's 20th type design] that Al learned a lot, and threw all of his knowledge and experience into this design. It's not perfect, and no one has been lazy--it's a pretty good wing, does many things well, and is a good compromise of cross-country speed, lift, induced drag and low-speed handling. Thus was also born our famous tail design.

As far as I have been able to tell, the only difference in wings across all models is replacing the wooden spar in the original with a nice, one-piece aluminum spar [yes, there are multiple pieces welded and riveted together, but you cannot remove the left wing like on a Slowhawk], the short-lived "twist," the temporary loss of some flush rivets, the addition of cosmetic wing tips [added to my plane--they look good, and hide the VOR antennas for less drag], fuel tank capacity increase and sealant technology improvement, the additional lower gear doors and relocation of landing lights from the cowl to the wing.

So yes, we all have the same wing. Some have more horsepower to accomodate increase weight due to longer fuselages, bigger engines, more fuel to haul around, additional insulation and leather panels, cupholders, etc., that are not on my 1970 bird. I carry 52 gallons [312 lbs] when filled to the caps, which will fly me more hours than I want to sit still for, and a whole lot further than the all-day car trips I used to make. Ovations can carry 130 gallons [780 lbs!] and fly further, but not a whole lot longer [they go a whole lot faster, at double my 9 gph]. Handling is similar across the line, except the long-bodies [your J is a mid-body] are significantly different at low speeds like takeoff and landing.

There are two huge differences between my C and your J:  you have fuel injection, which gives you 20 extra hp [more speed at a higher burn rate]; you have a longer fuselage with improved aerodynamics, which gives you extra speed from reduced drag. But I also have your sloped windshield and wingtips, just not the other aerodynamic improvements that Roy LoPresti made, some of which Mooney has never revealed.

It's all about which airplane fits your mission. Yes, 20 knots more would be nice, and you can match my burn at LOP and probably still beat me somewhere; your back seat passengers have more legroom [i don't often put anyone back there]; it costs you more to fill up; you can carry bulkier items, and more of them, with your 5" back seat stretch; your back seat may fold down for bulky cargo. My full-fuel useful load is 658 lbs, or me, the wife and over 350 lbs of "stuff". I've packed the cargo and back seat to the roof and don't think I've ever come close to 350 lbs . . . . .

[N33GG]

Very, very interesting!  Now I know the straight scoop.  Thanks everybody.

What an impressive aircraft.

[KSMooniac]

So in other words, the same wing has prevailed in the entire Mooney M20 line since it was designed in wood in 1955? Did they hit the perfect wing design from the start or were they too lazy to retool and focused on improving other areas instead? Also is the span the same across all Mooneys? Despite different weights?

I agree with just about everything written above and will add to the discussion a little bit.

Al obviously found an aerodynamic design for the wing that worked very well for the original M20 and it was state-of-the-art in the late 50's.  It has carried through to the end of the line because (a) it still works and ( the cost to re-design/re-certify and re-tool for a low-volume aircraft is enormous and wouldn't make financial sense for a possible marginal improvement.  Even in the glory years of the late 70s, I don't think it would have made financial sense to change the airfoils when they were pumping out 500-ish planes a year.  Nothing at all about being too lazy...nor is it perfect, but it is dang good!

LoPresti and the gang did a marvelous job turning the F into the J by drag reduction, especially before the days of computer analysis!  The wing was good enough, so they went after the low-hanging fruit that could be changed without incurring radical cost increases and hit a home run!  A similar effort was done in modern times going from the Acclaim to the Type S too, but it wasn't nearly the improvement that the F to J was...only because the Acclaim was so good initially.

From the airfoil data posted above, you'll notice the Mooney 301 used NLF airfoils...those are now the state-of-the-art and came from some gov't research at NASA-Langley in the 80s.  It made sense when working on a new clean-sheet airplane to use the best available airfoils before any tools were cut.  Of course the 301 got sent to France and turned into the TBM of today, which is an outstanding airplane in it's own right.  Other NLF airfoils are flying in the Corvalis 400 today, which achieves Mooney-like speeds with fixed gear.  One could imagine an M20 airframe retrofitted with a new wing sporting NLF airfoils and it might pickup an additional 5-15 knots at cruise (5-ish for non-turbo, 15-ish for turbo up high) if I had to guess...but once again it wouldn't make economic sense at all, unfortunately.

[201er]

Thanks, very interesting points. By understanding older Mooney designs, it helps me understand my own plane better. Do explain the one piece spar more. How do they haul away an off-fielded Mooney?

I still find it amazing that they could recover 20mph of speed on an already slick airplane strictly on the body. It's easy to see how a change in engine or airfoil can make a substantial difference, but this is more surprising.

A 201 + Vintage cruising in the same place/time, what kind of MP would you see on each with and withour ram air? Are they going to ultimately be the same with ram air on despite it being less effective on a J?

I used to think the reason an F can never be modified to be a J because the wing was different. But since the wing is the same, the windshield, gear doors, and cowling can be replaced with a J mod, what's left?

For people who've flown both J and vintage, aside from the speed, weight, and interior difference, any difference in feel between the planes or do they fly the same since the controls and wings are the same?

[jetdriven]

The spar is actually two halves but it is bolted together with a spar cap bridge which is about 1/3rd of the wing span. it is a huge deal to remove the wing and replace a hundred rivets to replace this piece.  Usually due to corrosion. To trailer a Mooney, you drill the rivets all along the tailcone at the rear bulkhead and separate the tailcone from the fuselage.  remove the tail from the tailcone, and place the Mooney on the trailer with the wings down the trailer.

Easier to gain speed from drag mods than horsepower.  The cowling, windshield, and things like antennas, door handles, and fairings are worth 20 MPH. It would take another 50-80 horsepower to get that.

I have flown the C, E, and J. I'd guess the MP is about the same with ram air on all 3.  The ram air off chokes down the vintage mooney's a couple inches due to the poor airbox design. the J I flew long ago woulnd only gain 1/2" or less.  on our 77 J it is deactivated.

You can mod an E, F, and even a C model with a full 201 kit if you wish. Everything goes. Maxwell doesn't recommend inner gear doors on Johnson bar airplanes due to the effort required to retract the gear with that air load.  I know someone who has the 201 windshield and cowl on his 66 C model, it even has the fuel injected engine  It is also exactly as fast as my J ~155 KTAS. Except the longer rear window it looks the same as well.

The short bodied C and E models seemed definately to get off the ground quicker and the E model when solo climbed like an empty 747 compared to a J.  Cruise flight seemed about the same, perhaps the were a little more sporty. 

For hot dogging I liked the E a lot better.  For everything else cheaply, the J is it.  The only thing better than a Mooney is a turbo Mooney!

 

 

[0TreeLemur]

This is an interesting thread from the past (12 years ago).  Bringing it up for others to experience.

[Ragsf15e]

On 6/30/2011 at 2:57 PM, N33GG said:

I have read/heard that the G wing had more washout for stall control???  Anybody know the straight scoop here?

 

In 1968, as stated above, a cost saving effort was made that did away with flush mounted rivets.  The result was more drag.  The J went back to the flush rivets.  My C is an early 68 model, and still has the flush rivets, or "clean wing".

 

 

As far as the actual profile of the wing (other than the rivets), I think or have heard that they are the same, with perhaps the exception of the G.  But I am not an expert, and do not claim to know for sure.  Great question.  I am looking forward to the answer from someone that knows.  I have also wondered the same.

 

Can you show a picture of the flush rivets on your wing?  I have a ‘68F and it has flush rivets on the forward half of the wing too.  Do others have them farther aft?

[Ragsf15e]

13 minutes ago, Ragsf15e said:

Can you show a picture of the flush rivets on your wing?  I have a ‘68F and it has flush rivets on the forward half of the wing too.  Do others have them farther aft?

Great, now I replied to a 12-year-old thread.

[201er]

17 hours ago, 0TreeLemur said:

This is an interesting thread from the past (12 years ago).  Bringing it up for others to experience.

Funny I still know and talk to all these people.

[PT20J]

Old post, but still annoying that airfoil data was presented without attribution. It appears to be friend David Lednicer's work available at https://m-selig.ae.illinois.edu/ads/aircraft.html

Skip

[KSMooniac]

Actually, the airfoil info is listed in the Type Certificate on the FAA website, but it appears that David scraped the data into a much easier format!  (I think there are errors in the Lancair entries, though.)

[PT20J]

1 hour ago, KSMooniac said:

Actually, the airfoil info is listed in the Type Certificate on the FAA website, but it appears that David scraped the data into a much easier format!  (I think there are errors in the Lancair entries, though.)

If so, let Dave know: 
dave@aeromechanical-solutions.com

 

 

[aviatoreb]

On 6/30/2011 at 10:52 AM, 201er said:

I see some folks with C, E, and F's answering questions asked by J and newer pilots so I am curious about just how different the earlier planes are? I understand the body, windows, and cowling were vastly upgraded moving toward the J. But I have seen no mention of the tail, wings, and controls. Has the airfoil been altered to improve the speed of the J over the earlier models or was all that done on the body?

 

When someone with a pre-J plane answers a question pertaining to J's or newer, how relavent is the answer? How big or small is the difference between these planes?

 

The landing gear doors went through several generations of improvements, eventually leading to full enclosure in a multipart door system.