Rocket stall characteristics

[Stetson20]

Rocket folks,

Obviously a nose heavy plane with the big six cylinder out front. Was just curious what y’all’s thoughts and/or experiences were on Rocket stall characteristics. Any tips/tricks/concerns?

Thanks

[Fly Boomer]

1 hour ago, Stetson20 said:

Rocket folks,

Obviously a nose heavy plane with the big six cylinder out front. Was just curious what y’all’s thoughts and/or experiences were on Rocket stall characteristics. Any tips/tricks/concerns?

Thanks

I have not flown with a Rocket-specific instructor yet, but I doubt there are any WOT departure stalls or accelerated stalls in my future.  If she has any tendency to roll over on her back, I suspect full-power stalls would trigger that behavior.  Approach stalls seem a little more benign, and not significantly different to the pre-Rocket airplane.  One of the things I think about is whether the TKS installer got the stall strips where they belong.  Was there any stall testing and adjusting with them taped on like the factory did?  Or did some monkey just glue them on somewhere that looks "about right".  And what about when a stall strip starts coming loose, and is reaffixed by a mechanic?  I'm sure some effort is made to get it back where it was, but how precise can that be?

When I was taught to fly, the norm was a close-in 800 foot pattern, and you chopped power abeam the numbers.  I once asked the test pilot for the M20K (Bob Kromer) about a habit I picked up in my youth which is to conserve altitude in the pattern, and slip as I turn from downwind to final (and all the way down if necessary).  He thought about it for a minute and, while I'm sure he has put many a Mooney through the ringer, finally suggested just keeping the ball centered.

Rich Stowell, in his excellent book Stall/Spin Awareness, talked about some flight testing he contracted to do on an early version of the Mooney.  He was doing some testing a little outside the weight and balance envelope, and discovered some alarming stall characteristics.  In the book, he discusses unrecoverable spin modes that many airplanes will demonstrate under certain circumstances.

BOTTOM LINE:  I'm old and no longer as cavalier about stalls, spins, and unusual attitudes.  Most of the post-war 65 HP conventional gear airplanes are pretty predictable, but these days I'm no longer interested in testing the limits.

[A64Pilot]

I keep reading how pretty much everyone has the opinion that the big motor Mooney’s are nose heavy.

But they can’t be, not really because while I have not looked but their CG range has to be similar to a little motored Mooney, sure there is more mass out there of course but if nothing else the stall speed requirement limits the fwd CG limit. Now if you got into a spin that additional mass is going to work against you of course due to the inertia, but they can’t be much more nose heavy, yes they are heavier and they have significantly more mass on both ends which has inertia.

Another thing people get upset with me about a Mooney is me saying that a Mooney doesn’t have gentle stalls, because it has stall strips, sort of by definition any aircraft with them doesn’t act nicely in a stall, the strips are added to tame the behavior, so any airplane that has stall strips in my opinion ought to be treated with a little more respect than an airplane without them when nearing a stall.

You can be pretty sure that ANY high performance / efficient airplane gives up good slow speed handling and gentle stalls (TANSTAAFL)

I’m not saying it’s stall is evil, just that it likely requires a little more attention than a Cherokee 140.

My belief is that power off that any Mooney is going to be pretty controllable in a stall and that as long as your VMC you ought to be able to handle it.

However at high power especially the big motors are very likely to get real ugly real quick, I’m talking a real stall, not one of the training maneuvers where you break the stall before it actually occurs. I believe many don’t actually have the respect of an honest departure stall because they have never gotten into a fully developed one, which makes sense the purpose of the training is to learn to recognize the onset and correct for it.

Now I have not and will not go out and stall / spin any Mooney, I don’t do that kind of thing anymore but it is a Certified airplane (that doesn’t have an ELOS) so it’s stall should be controllable.

Very few of us actually go out and fully stall an airframe, and we shouldn’t, it’s a normal category airplane after all, sure it’s not prohibited from stalls, but if you going to go out and fully develop a stall especially under power you should be prepared for a spin. 

I am not berating a Mooney, I bought one by choice, just saying that it just might demand a little more attention in a stall than say a trainer aircraft, whether it has a big motor or not, and all of this is not from actual experience in a Mooney.

I have done an honest departure stall in a C-210, and it will roll over on its back to the left, you cannot stop it, and I’m pretty sure that if you didn’t pull power that it would spin and you also couldn’t stop it. That was in a very fwd CG too with just two people in the front seats, with the airplane fully loaded with a much further aft CG it would have been much worse.

Until then I thought the 210 was a Cessna, which frankly put meant you had to be stupid to get yourself in a situation with one, but after that it really changed my mind, but once I thought about it, the 210 is a high performance / efficient airplane and of course gave up some of the trainer handling so common on the little Cessna’s.

The reason the 210 WILL roll over on its back is that at high power and slow speed there isn’t enough rudder effectiveness to counter the engine torque, I suspect adding 100 more HP on a Mooney and keeping the small rudder if anything woukd make it worse than the 210.

[N201MKTurbo]

Rockets are nose heavy. The CG tends to run at the forward edge of the CG envelope. A friend did a one time STC to add 100 Lbs to the tail. It tamed the CG, but ate into the already small useful load. Before they did the gross weight increase, you would be over gross with full tanks and a 200 Lb pilot. This plane had long range tanks.

As far as stall characteristics is concerned, a properly rigged Mooney will stall very nicely, an improperly rigged Mooney can be very scary when it stalls. 

[Yooper Rocketman]

My "first" purchase of my Rocket, in 2001, was through Ivr Fehr, one of the first Rocket owners and very good friend of, and salesman for, Darwin Conrad, the STC holder for the Rocket Conversion.  He was a retired Marine (not sure if a military pilot) with a lot of hours in his Rocket.  He advised me during the buying process to be careful of a transition instructor wanting to perform "power on stalls".  He said there had been reports of Flat Spins when getting that higher horsepower conversion into a power on stall.  I was probably at 1600 hours (1400 M20F time) when I bought my Rocket and the only CFI I could find to sign me off for insurance had 600 hours in her logbook.  She was also the instructor my seller was using when he bounced a landing and ended up with a full engine tear down and prop repair for a prop strike (just before my purchase).

The owner, having signed docs for the sale but funds not to him yet, insisted on riding back seat with us during the transition training, and he was a good size guy.   We had a 1,500' to 2,000' ceiling, and we flew out of a small airport just southeast of Boing Field (near Seattle).   Approach power stalls were as docile as any Mooney in the Rocket, but I wasn't really comfortable doing them without more altitude.  The instructor wanted me to perform power on stalls, and I initially started the simulated climb attitude and power.  Within seconds I pulled power back and told her "I am not doing these", and explained my position on why.  She threatened me she didn't have to sign off my training, and I responded I wasn't letting her decide my odds in having a successful outcome to her request.  I simply would find someone else to complete the training.  She thought about it for a while and agreed we would move one.

The Rocket conversion has a very forward CG.  Forward enough that with full fuel and two good size adults, you would need the passenger in the back seat to meet CG.  It got better by moving the passenger seat back to the end of the seat tracks, or placing weights in the baggage compartment.  It handles like a regular Mooney now with the 4 blade MT prop.  I still taxi with the yoke in my belly, but it doesn't make the nose rise anywhere near what that procedure did with the heavy metal 3 blade before.

And a last note, the Lancair Type Group (LOBO, Lancair Owners and Builders Org) prohibits type group endorsed (FITS Approved) Training to perform stalls in the IV, IVP, and IVPT series aircraft.  There have been some pretty challenging stalls in that aircraft, including one from 12k above the ground that entered a flat spin, requiring the two pilots to crawl up onto the glare shield and recovered at 1K above the ground!  Not all high performance airplanes should be stalled, especially power on stalls.

Tom

 

[A64Pilot]

Sure it’s toward the fwd CG limit, the 210 I talk about with two good sized guys was all over tgt fwd CG limit, my Maule the same, the Maule in truth was a little out.

I would go so far as to say ANY good GA aircraft with fuel at worst CG case and two good sized guys up front should be all over the fwd limit, because everything that gets loaded after that moves the CG aft, both the 210 and my Maules absolute limit loading wise was the aft CG limit, you can overload some and not get hurt, being too far aft can hurt you.

I think the point is and no one seems to disagree is that departure stall in a high power aircraft are a whole lot different than a lower powered aircraft.

I had to take the crop duster we were Certifying and stall it at T/O power with no load and min fuel, the purpose was to determine the absolute max nose up attitude it could get it to then we had to put it in that attitude and prove the fuel system could deliver the max fuel flow the engine could consume at rated pressure, logic would seem to say I proved that in flight, but you can’t use logic, we needed a ground test.

But because it was a tail wheel aircraft and therefore had a rather large rudder it wasn’t the issue that I was afraid it could have been.

I knew I had a picture, I had to dig a hole with my backhoe in a ditch to back the tail wheel into and have the mains on top of the ramps I used to change oil on my truch to get to that attitude, it’s a lot nose higher than it looks

 

[DCarlton]

3 hours ago, Yooper Rocketman said:

My "first" purchase of my Rocket, in 2001, was through Ivr Fehr, one of the first Rocket owners and very good friend of, and salesman for, Darwin Conrad, the STC holder for the Rocket Conversion.  He was a retired Marine (not sure if a military pilot) with a lot of hours in his Rocket.  He advised me during the buying process to be careful of a transition instructor wanting to perform "power on stalls".  He said there had been reports of Flat Spins when getting that higher horsepower conversion into a power on stall.  I was probably at 1600 hours (1400 M20F time) when I bought my Rocket and the only CFI I could find to sign me off for insurance had 600 hours in her logbook.  She was also the instructor my seller was using when he bounced a landing and ended up with a full engine tear down and prop repair for a prop strike (just before my purchase).

The owner, having signed docs for the sale but funds not to him yet, insisted on riding back seat with us during the transition training, and he was a good size guy.   We had a 1,500' to 2,000' ceiling, and we flew out of a small airport just southeast of Boing Field (near Seattle).   Approach power stalls were as docile as any Mooney in the Rocket, but I wasn't really comfortable doing them without more altitude.  The instructor wanted me to perform power on stalls, and I initially started the simulated climb attitude and power.  Within seconds I pulled power back and told her "I am not doing these", and explained my position on why.  She threatened me she didn't have to sign off my training, and I responded I wasn't letting her decide my odds in having a successful outcome to her request.  I simply would find someone else to complete the training.  She thought about it for a while and agreed we would move one.

The Rocket conversion has a very forward CG.  Forward enough that with full fuel and two good size adults, you would need the passenger in the back seat to meet CG.  It got better by moving the passenger seat back to the end of the seat tracks, or placing weights in the baggage compartment.  It handles like a regular Mooney now with the 4 blade MT prop.  I still taxi with the yoke in my belly, but it doesn't make the nose rise anywhere near what that procedure did with the heavy metal 3 blade before.

And a last note, the Lancair Type Group (LOBO, Lancair Owners and Builders Org) prohibits type group endorsed (FITS Approved) Training to perform stalls in the IV, IVP, and IVPT series aircraft.  There have been some pretty challenging stalls in that aircraft, including one from 12k above the ground that entered a flat spin, requiring the two pilots to crawl up onto the glare shield and recovered at 1K above the ground!  Not all high performance airplanes should be stalled, especially power on stalls.

Tom

 

I believe I still have the Rocket/Missile documentation package from Irv Feher.  There's a slim chance I finally tossed it but will look if anyone wants it.  It should probably be scanned and uploaded to MS.  

[Stetson20]

Went up with a CFI this morning. Did slow flight, steep turns and power off stalls for proficiency.

He asked if I wanted to try a power on stall and I told him I’m not comfortable trying one. He was fine with it. We moved on.

Great feedback. Thanks all!