Blue on Top

Yes, fixed horizontal. NO TRIM TABS (they're counterproductive aerodynamically). Trimming was done internally Better than M20 aerodynamics on the tails (empennage). Full length rudder, top to bottom (above and below horizontal). Elevators are end=plated by the fuselage (much, much more efficient). Better spin recovery characteristics too. IOW, no "V" cutouts on the elevators for the rudder to swing. Greatly reduced drag. Bazinga!

OR...a real twin Mooney.

This truly is a GREAT thread! 1) If you're looking for these ads and others, there are currently 122 of them listed on eBay. Some are the same, some are different and some are newer. 2) Phil Corman has collected a lot of the old ads. He should publish a book ... if that's legal 3) Eventually I will find the ad again, but there is one explaining the forward swept tail. It's black and white with a lady sitting on the horizontal. 4) Libraries have all these ads in their magazine collections. For me, personally, the Wichita State Library is great. In addition, they have the collections of Ralph Harmon, the CEO and Chief Engineer of the metalized Mooney. Regretfully but also extremely interesting is that Mooney isn't just one company. It was a different company with different personnel every time it was "born again." You can see the strong differences in the ads throughout the decades. It is also during the Ralph Harmon (and son) years that Mooney took shots at the Beech "Bonanza ... which he also designed.

The last I knew about 100NL was a forum that one of the major petroleum makers gave at Sun-N-Fun 2019. They were going after a magnesium additive instead of lead. They assured all of us that there would be no cost increase, no EPA worries and no problem getting it certified ... soon. Hummmmmm. In a piston single, the only FAA-approved performance is takeoff and landing over an obstacle. Landing is not an issue (no thrust involved there ... there is drag, though . Takeoff on the other hand requires a known horsepower. If the engine automatically pulls back to protect from detonation, the consequences could be fatal ... and put the OEM out of business in the ensuing lawsuit. There HAS to be a good solution.

100 No Lead fuel will never come (in my opinion). There is a catch 22 between the lead, magnetos and high compression ratio engines. Magnetos don't have precision enough timing. Electronic ignition has the capability, but the engines we have are not designed for them. In addition, variable timing ignition does not guaranty a known horsepower output that is required for certification. I still have hopes, though.

This is a great question for Lycoming and Continental. They set the limits on their engine. I would say to look at the TCDS for the engine, but I am (educatedly) guessing that the "why" is not listed.

@jlunseth Great question! All of you are correct in your statements above. There are a lot of different things happening with the cylinders, pistons, rings, combustion cycles, lubrication, etc. The problem is that the gage can only mark so many things (very limited), but here's a few point to think about ... 1) We (the OEM and/or STC holders) are required by law to pass along all limitations. IOW, if Lycoming, Continental or Porsche has a redline or green arc as a part of their certification (14CFR33) it must be shown to the pilot ... and stated as such. 2) In this case an OEM and/or STC holder cannot put a redline on the low end because every start would be in the "red", which by FAA definition is unacceptable. (no operations in the red are acceptable). The gage could have been marked yellow below the green, but this gets into other complications. 3) Electronic gages (actually their computing and display capabilities) could remedy this situation by allowing normal operation until the temperature gets up into the green and then give a warning when the temperature goes below the green when it shouldn't. 4) We are having similar marking issues with electronic airspeed indicators. The round dials are too simple to indicate everything, but the electronic indicators have way too many possibilities ... with way, way too many failure modes. Bottom Line: Yes, CHTs in flight should be kept in the green arc for multiple reasons. Blue on Top, Ron

If they are not changing the POH through the STC process, they are not taking credit for the stall speed reduction. The Robertson STOL kit is an STC. The typical STOL people now are using experimental airplanes (with a 1-year limit), They are also using power to lower the stall speed (not allowed for certification ... at the moment ... electrics might change that ... long story ... I sit on the ASTM committee that is writing the compliance to the "new" (3 years ago) regulations). If an OEM took on the project that you are looking at, they would be required to re-calibrate the airspeed system (via 1 or 2 wing tip-mounted booms, redo all the stall testing and (my opinion) redo all the spin testing, too. How do you plan to make sure that every installation is identical? (that's conformity). For example, the stall strip adjustability (slight up and down location only) on the current airplanes is to allow for variations in wing build with production tooling. If this leading edge droop is slightly misaligned, will the airplane go over on its back. In addition, with higher leading edge camber, the odds of leading edge separation and stall are much higher. There is a business jet that has VGs on the leading edge because of this. A journey of 1000 miles starts with a single step! I want to help you.

@PT20J Yep! That's for the geometry-limited airplanes (airliners). The smoke and flames during those tests are just way freakin' cool! For me, it's been the only test I have seen a negative value on the radar altimeter with the gear in the well. Although still technically a "Blue on Top" test, it was recorded as a "Brown on Bottom" test.

@Marcopolo Bingo! You hit the nail on the head perfectly. No credit. @Petehdgs IF you are able to get an STC and claim lower stall speeds and better stall characteristics, you will also get to have your name included on all the lawsuits. On a good note, Mooney has more money and will get to pay the majority of those bills. Although I know you have a long, hard road ahead of you, I am rooting for you all the way!

@PT20J Skip: Everything you stated above is exactly correct ... just continue your thoughts along those lines. Because the wing has gotten more efficient (higher effective aspect ratio), CL will get closer to Cl. This results in a slightly lower stall speed ... and the reason Mooney aircraft are so good at floating the length of the entire runway . With today's instrumentation, a little work and 1-G stall criteria (not currently allowed in 14CFR23 airplanes), we could calculate the lower stall speed, but it has no practical value for small airplanes. We do look at it indirectly during VMU (minimum unstick velocity) takeoff tests, where the airplane, in ground effect, is made airborne at the slowest speed possible. Btw, VMU testing is very high risk, and all (FAA and Applicants) are trying to find ways to eliminate the testing). Hope this helps.

@Petehdgs I appreciate your enthusiasm and desire to make your aircraft better. I doubt that you will be able to complete a wing leading edge modification without FAA approval. If allowed, your modification will be classified by the 337 as a major modification of the wing, both structurally and aerodynamically. If it were me as a DER, the airplane will need to go into the "experimental - R&D, show compliance and/or market survey" category. This allows a year for testing and to show compliance to the regulations before it must be removed. This is why VG manufacturers don't change (and have the FAA approve) the reduced stall speeds. They are simply claims. Changing the stall speeds will require a major change to the Pilot Operating Handbook (POH), including stall speeds and performance (takeoff and landing) data. Why do you think the M20 has bad stall characteristics and landing performance?

@PT20J Skip: I was afraid my comments would come across poorly, but I know you, and know your great attention to detail which makes you a great pilot. Your technique stated above is how I fly also. The point I would like to make is the two parts of the newer AFM/POH, The AFM sections (takeoff and landing data, emergency procedures) are the best procedures to get the highest performance out of your aircraft. Those sections are also FAA-approved. All remaining data (POH) is OEM data and recommended. Your owner's manual (trying to use one title for all the different manuals over the decades) should tell the operator HOW the data in that manual was collected. For example, it might say something like: 1) Hold brakes 2) Advance throttle to full 3) Release brakes 4) Hold slight back pressure on yoke 5) Rotate at 70 knots 6) Climb at 77 knots until clear of obstacles.

I would NOT recommend this procedure, but I am also the idiot (I forget the word he used) that makes the AFM/POHs that are there to guaranty (or state the way we got those performance numbers). But, I also don't agree with Dr. Rogers all the time either (gasp!). @PT20JThere are sooooooo many factors that determine VR and the "best" way to climb out. VX is the number to fly to clear an obstacle in your path (at the exact end of the runway surface. VY is the number to fly to get to altitude in the quickest amount of time. The engine will remain below redline temperatures during a VX climb to maximum altitude; it's required by regulation. In Alaska, airplanes are allowed to fly 15% over gross weight, which is not allowed in the Lower 48. There are so many places to land in Alaska, which changes the equations a lot. Funny side note. When the Citation X was only a new prototype, we brought in a private T-38 for chase. We quickly learned that the climb schedules were significantly different (climb rates are actually close). The problem was that at Citation X climb speeds, the T-38 had to fly S-curves behind it. Then we got the brilliant idea (sarcasm is gushing out of me) to fly the formation climb at T-38 speeds. We BARELY cleared the Wal-Mart a mile off the end of the runway. I would much rather be 2,000 feet above the runway at V2 than 300 knots and 30' above Wal-Mart. But then, we both had two engines As for what to do after an engine failure on takeoff (or anywhere for that matter), plan the flight; fly the plan. Airplane or sailplane, every airport, all environmental conditions, my capabilities, etc., I plan my decision altitudes as to where I am going to put the airplane/sailplane if X happens when ... before I push the throttle up or give the take up slack signal. Bottom Line: and as @carusoam stated, DON'T STALL. Odds of survivability go up significantly.

The 3 main areas we are trying to attack are: takeoff, go-around and moose turns (low altitude maneuvering/showing off). These areas are far and away where the vast majority (more than 75%) of fatal accidents occur. Base to final turns account for roughly only 5% of loss of control fatalities. Although I am a fan of spin training, it will not help at pattern altitudes and below. It will help after demonstrating/practicing the first one, when the pilot realizes that although the nose is very low (60-70 degrees nose down), they still need to push to lower the angle of attack. Our research is showing that inadvertent stalls in the pattern (which have a large startle factor) are followed by full aft elevator control all the way to the ground, spin, spiral or straight ahead. We need to get to the pilot BEFORE the departure.

@BlueDunBoth ... and more. I am happy to know that MAPA PPP is concentrating on this maneuver. The slower the airplane is traveling, the higher the thrust will be when full power is added for the go-around (note: I am not sure how all the POHs over the decades say to preform a go-around). With the higher thrust comes higher torque, higher P-factor and higher out of trim forces ... especially if the airplane was trimmed to the lower airspeeds. If all of those items are planned for in advance, all works out very well and easily. If not ... Hope this helps.

OMG! Thanks,@takair, for the ping. Of course I have thoughts . For those on this thread that haven't read my 7 articles in "The Mooney Flyer", you need to. They only touch the tip of the iceberg on these topics, but I'm here to further expand on any of them. I'll learn from you, too. 1) Laminar flow is for wind tunnels and CFD. There is very little of it in the real world. Sailplanes are a good exception, but they scrape bugs off the leading edge that got there during the takeoff and tow to 1-2K feet. Laminar flow has little to do with stall speeds except possibly increasing stall speeds. Ask Dick Rutan about that. 2) @PetehdgsPlease do not confuse Cl with CL. Section lift coefficient (Cl) has little to nothing to do with wing lift coefficient (CL) and the associated stall characteristics. Most certificated airplanes have 2D Cl versus alpha (aoa) curves that show an abrupt stall break ... including Mooney ... and Cessna aircraft, but that is not relevant for a 3D wing design. Planform, twist, etc. are used to control stall progression. Your mention of an abrupt stall break (nose down pitching moment) is good, a goal of designers. The other (like you mentioned) is that the wings have to be kept +/- 15 degrees in roll. The last requirement can't be accomplished analytically because there are so many other factors that influence it (inertia being the largest item). 3) VGs add drag. Those that say that they don't don't have instrumentation accurate enough to measure it. 4) Yes, VGs can lower stall speeds (I have not personally tested an M20 ... except for tufting and airplane ... which are little VGs). Certification testing alone (if done with an FAA ACO that actually makes the applicant meet the regulations) will cost more than one can ever think about making on selling them ... and VGs are really, really inexpensive. 5) The Mooney TKS installation is a scab on over the base airfoil. It modifies the airfoil significantly. Airfoil designers look at 0.010" as significant; TKS is closer to 0.250". 6) Do I personally think that a modified airfoil (drooped leading edge, larger leading edge radius, etc.) would be a good idea? If your sole purpose is to lower stall speed. Yes. Plan on losing top end speed. Plan on a very, very expensive certification program ... if done properly, probably including a spin program. Is that $3M recoverable in sales? 7) Flying below 1.3 on approach will shorten the landing distance (both in air and ground roll), but it is relying on your engine to continue running and will make go-arounds significantly more difficult. BTW, that is the scenario that is the #1 fatal accident cause for the last several decades. 8) Most certificated GA airplanes do not stall at forward CGs. They will develop a significant sink rate, though. Okay, way more than my 2 cents worth. But I hope we all learn a little from this thread. Knowledgeable and proficient pilots are typically safer pilots. Blue on Top, Ron PS. Fire away.

"Flat" wingtips (the wing ends at a rib) is not as bad as people believe. Shedding a clean vortex on the wing tip is actually good. As for the aileron going all the way to the tip ... not so good. The aileron is less effective. Any tip past the end of the aileron will make the aileron more effective.

I'm just glad that someone else realized (sorry can't find your post again) that Mooney put the tail on the correct way. Putting it on the other way just slows the airplane down

PS. The VOR/LOC blade antennae are draggy by themselves. I worked with COMMANT a little while in CA, but we didn't get anything finalized. There were 2 great older gentlemen there that were awesome.

@Bob - S50 Yes, burying as many antennae as possible will reduce drag. Replacing the red rotating beacon with conformal wing tip strobes, doors that don't seat properly, excessive cooling drag (pilots note when they leave their cowling door open too long ... even in my Cessna P172D. Aft facing steps are poor ... even worse than forward facing ones (in most cases).

BTW, even blade Nav/Comm antennae are draggy, too. Interestingly, it's the base that causes drag. Very generally, what we call excrement drag (non-aircraft shape) is 30-35% of the total drag of small GA airplanes. Of course that percentage goes down as the airplane gets bigger as the same antennae are utilized on most all airplanes.

@Bob - S50 Thanks, Bob! It's great to know that someone is actually reading my monthly blurbs. I didn't get there with the Mooney tail shape for December, yet (my fault), so I think that I'll do something on wing tips, winglets and sharklets. Hint: There are no winglets or sharklets on Mooney aircraft ... that I know about.

PS 2. Yes, with Covid, engineering consulting and public speaking has, well ... , come to a halt. I've been working on aviation-related, STEM-style posters, T-shirts and maybe mouse pads. The themes are: 4 forces of flight, 6 degrees of freedom, weight & G-load, Bernoulli principle, how a wing creates lift, AOA and how a propeller creates thrust. The first two (2) can be customized with YOUR airplane ... you have to send me a photo that is nearly in the correct orientation.

Oh, man. I really, really don't want to offend anyone, but here's a little aero and engineering straight talk OMG @Hank You have peaked out with drag and ugliness, but I have to say, structurally, that thing ain't coming off. On another great note, YOU might be able to get 3.1415926 knots of speed taking it off. The aluminum work on your vertical is beautiful, too! @ArtVandelay Love the blue tail ... but I am bias. @jetdriven Love the red checker board tail. Beautiful! @PT20J wins the drag issue, though. Cat whiskers (or TV rabbit ears) wins the low drag argument. Although the Cd is high, there is little area, and that area doesn't change with AOA. In addition, due to the sweep of the antenna, the cross section is really an ovular cylinder and not a circular cylinder to the airflow. We (Mooney-Chino) actually ran all three (3) antennae in CFD to see for ourselves. PS. Why do TKS owners put up with the loss of 8-10 knots? Should I start a new thread?