Slips - How Effective?

[jetdriven]

In general I don't argue with what works but consider that long bodies have the potential to blanket the air flow over the rudder with full flaps under certain air speeds. All of the Mooney's can run out of rudder when in a forward slip when you need it most like in the final landing phase correcting for drift. Thus when I teach crosswind landings I recommend only a crab. Passengers particularly seem to appreciate this more than an aggressive forward slip.

So long bodies blank the rudder AND the elevator in a slip now? And where is the limitation in the POH or even a caution for that matter, and how many accidents were attributed to that?

How exactly does a Mooney run out of rudder in a forward slip? I have done a few hundred of them, and you use full rudder for drag, and ailerons to control bank and ground track

. Do you correct for drift in the final landing phase with a forward slip?

Do you teach to land in a crab? Do you know what that does to an airplane, or can do?

What ever happened to the wing low method and landing the airplane with the longitudan axis aligned with the centerline?

[Cris]

Byron Like I said I don't argue with what works. So if are happy with your technique stay with it. I simply am making comments on some of the points referenced within this thread. But since you seem to be quite the expert on all Mooney POH's let me point you to the following in one of the long body Airplane Flight Manual's. See Section 3, Normal Procedures M20R Ovation 2. Pg 4-16 under landing (normal)

NOTE: Crosswind landings should be accomplished by using above procedures except maintain approach speed appropriate for wind conditions. Allow aircraft to CRAB UNTILL THE LANDING FLAIR. Accomplish touchdown in a slight wing low side slip (low wing into wind) and aircraft aligned with runway. During landing roll, position flight controls to counteract crosswind.

Now as many folks know the Mooney has a 13 Kt demonstrated crosswind which is not a limitation but mearly what was demonstrated at the time of certification. This particular POH is silent in terms of a forward slip but quite specific as to how to land in a crosswind. Now it seems to me that you want to let all who read this know to strictly adhere to their POH which is great advice. So in spite of what works for you maybe you are going to have to change your tecnique to conform to the POH at least in the longbody's which is all that I was referencing.

As an aside I spent the day today with a 20 year veteran that teaches at the MAPA program and we discussed this very topic prior to me reading your response. I mentioned to him that some folks on Mooneyspace referenced a possible tail flutter with full flaps potentially leading to a tail stall. He said that there is anecdotal evidence of this and he also will not teach forward slips in longbody's. In the J and short body there does not seem to be any similar issue. Hope this helps clarify. I did not think it necessary to explain how to transition from a crab to a slip as one was landing. However if it is difficult for you may I suggest reading the POH or find an experienced Mooney instructor.

[Hank]

Cris,

Where did you read the crosswind limit? There's no mention in my Owner's Manual of things like demonstrated crosswind, ceilings, etc., and I don't recall reading them in the Type Cert.

[jetdriven]

In general I don't argue with what works but consider that long bodies have the potential to blanket the air flow over the rudder with full flaps under certain air speeds. All of the Mooney's can run out of rudder when in a forward slip when you need it most like in the final landing phase correcting for drift. Thus when I teach crosswind landings I recommend only a crab. Passengers particularly seem to appreciate this more than an aggressive forward slip.

So long bodies blank the rudder AND the elevator in a slip now? And where is the limitation in the POH or even a caution for that matter, and how many accidents were attributed to that?

How exactly does a Mooney run out of rudder in a forward slip? I have done a few hundred of them, and you use full rudder for drag, and ailerons to control bank and ground track

. Do you correct for drift in the final landing phase with a forward slip?

Do you teach to land in a crab? Do you know what that does to an airplane, or can do?

What ever happened to the wing low method and landing the airplane with the longitudan axis aligned with the centerline?

Byron Like I said I don't argue with what works. So if are happy with your technique stay with it. I simply am making comments on some of the points referenced within this thread. But since you seem to be quite the expert on all Mooney POH's let me point you to the following in one of the long body Airplane Flight Manual's. See Section 3, Normal Procedures M20R Ovation 2. Pg 4-16 under landing (normal)

NOTE: Crosswind landings should be accomplished by using above procedures except maintain approach speed appropriate for wind conditions. Allow aircraft to CRAB UNTILL THE LANDING FLAIR. Accomplish touchdown in a slight wing low side slip (low wing into wind) and aircraft aligned with runway. During landing roll, position flight controls to counteract crosswind.

Notice that POH says nothing about elevator or rudder limitations and slips. Your claim that the rudder blanks out in a slip and you "run out of rudder in a forward slip" is not supported by facts, accident statistics, or the POH. It says to land in a side slip, which is NOT the same as it seems you advocate, "crosswind landings I recommend only a crab". Or perhaps I misunderstood you.

Now as many folks know the Mooney has a 13 Kt demonstrated crosswind which is not a limitation but mearly what was demonstrated at the time of certification. This particular POH is silent in terms of a forward slip but quite specific as to how to land in a crosswind. Now it seems to me that you want to let all who read this know to strictly adhere to their POH which is great advice. So in spite of what works for you maybe you are going to have to change your tecnique to conform to the POH at least in the longbody's which is all that I was referencing.

Sounds to me like were referencing landing in a crab for passenger comfort, instead of a sideslip with one wing low which is consistent with my technique and the POH of this and every one of the airplanes I have flown, with exception to CRJ-700/900s and 747s which are landed in a crab in moderate crosswinds or greater. Perhaps you are confused between the definition of a forward slip and a sideslip?

As an aside I spent the day today with a 20 year veteran that teaches at the MAPA program and we discussed this very topic prior to me reading your response. I mentioned to him that some folks on Mooneyspace referenced a possible tail flutter with full flaps potentially leading to a tail stall. He said that there is anecdotal evidence of this and he also will not teach forward slips in longbody's. In the J and short body there does not seem to be any similar issue. Hope this helps clarify. I did not think it necessary to explain how to transition from a crab to a slip as one was landing. However if it is difficult for you may I suggest reading the POH or find an experienced Mooney instructor.

That tail burble you mention is mentioned in the Kromer article. It is NOT caused by the "flaps blanking the airflow over the rudder". It is the horizontal tail that is affected. Again, it is not an operating limitation. Kromer says in normal operations there is plenty of margin. I do agree with Kromer, that, IF you have a longbody, and IF you have a forward CG, and IF you slip the airplane at low speeds, and IF there is ice on the airplane, there is some possibility of a tail stall due to loading on it. This has never been the cause of an accident in a Mooney AFAIK, but however, I wouldnt slip a Mooney if all these factors were present, either.

[Cris]

Cris,

Where did you read the crosswind limit? There's no mention in my Owner's Manual of things like demonstrated crosswind, ceilings, etc., and I don't recall reading them in the Type Cert.

Hank The 13 kts referenced is not a limitation but rather only what was demonstrated at certification. It can be found under "Speeds for Normal Operation" -demonstrated crosswind velocity. It is also shown in the POH at the top of "crosswind component chart" in the AFM that I referenced but you may find it in many other POH's as well. The point that I was making is that not everything on Mooney's has been fully explored since the M20 certification. "There is never a problem until there is a problem" is a great quote.

Another example of what is missing or lacking is in the Ovation 3 T/O charts which use a great deal of the Ovation 1/2 data. That works fine as it is quite conservative but leaves one wondering what are the real performance numbers on T/O as opposed to climbing over a 50' object. I might like to know that at a high density airport. In other words we sometimes are left in the position of being a test pilot due to a lack of data in the POH ie no info on forward slips no MAX demonstarted corsswind and no takeoff performance number in the examples cited. You might not even have that 13 knots in your Mooney C POH but is in many others.

Byron I subscribe to the theory that there are " old pilots and bold pilots" but rarely will one find an " old bold pilot" As above, flying a long body in a forward slip is much to bold for this old pilot. But hey that's just me and if you are comfortable and proficient in your tecnique I won't' argue but I do think it important that you differentiate that you are flying a J and not a long body which is how this all got started. I too have used forward slips in a J, K or E but that is dependant on conditions In strong cross winds I will always always use a crab until the landing flare for reason I've enumerated. BTW the crab is also what is described in the 1986 J model POHnormal landings -croww wind ie "Final Approach Allow aircraft to crab" "Prior to Flare Slip Aircraft into the wind".

[fantom]

.....there are " old pilots and bold pilots" but rarely will one find an " old bold pilot"....

Hey.....I resemble that remark

While I've done lot's of forward slips in other aircraft, I've probably done less than 10 in my J in 1,500 hours. Speedbrakes, crab & kick.

[carusoam]

Results of my informal poll....

Passengers prefer speed brakes over slips.

They just don't use the built-in oversteer in their firebirds like they used to...

They've lost that lovin feeling of looking out the side window to see where they're going...

Best regards,

-a-

[FloridaMan]

Let me add that another trick you can use is to keep your airspeed up and load the hell out of the wing. I've seen guys go aggressively from downwind to final at 120mph with the plane dropping like a rock. While I don't do this in the pattern, I do use steep S-turns to get down from altitude under power.