Power - IFR approaches and commercial manuevers

[jasong]

Hi all,

I have about 3 months and 30 or so hours in my '67 F model and I'd like to get some opinions on power settings for IFR approaches and commercial manuevers.

On the IFR side I'd like to understand what workflow and configurations you use at various stages through out the approach.  I've been flying my approaches at 16" MP, prop full forward at roughly 110-120MPH indicated.  I drop my gear, go full rich and prop full forward at the FAF, but haven't been dropping any flaps.

Since I just started my commercial, and my current instructor doesn't have much experience in Mooneys, I'd like to get the groups thoughts on entry airspeeds and power settings for all of the "standard" commercial manuevers.

Thanks all, fly safe.

Jason

[Immelman]

Jason,

I recently obtained my CFI ticket in my mooney so I had to go through all of the commercial maneuvers and get used to demonstrating them. The magic power ticket is a setting that will put you a little below Va in straight and level cruise. Of course, Va varies with weight. For my airplane that worked out to be about 125mph IAS with 2 people and full fuel.

Lazy 8: set power for approx 120mph in straight and level cruise. This happened to be somewhere between 17-18"/2500 (ROP) for me. It will vary with altitude and weight. Use an inch less power or so solo. Remember to "pitch pitch pitch bank" and let the decrease in airspeed changes drive the heading change... it may sound cliche but properly flown the airplane almost drives itself, with you 'seeding' just a smidge of initial bank and of course the pitch force... heck I would try to just get a nibble of buffet or even stall horn at the maximum pitch point (without stalling of course).

Steep turns: Same thing, just add a little power (1-2") on roll in. It doesn't take much of a power increase to hold airspeed/altitude in a 50-55 degree banked turn in our airplanes.

Chandelle: Same thing on entry, but then go to a good 65-70% power setting for the climb. (23"/2500 or so). As an editorial comment, I don't recommend going to full power for the chandelle. You can of course, but be careful. Same for power on stall work. The reason I say this is that there is uncomfortably little (if any) rudder authority left to maintain coordination at the completion of the maneuver with high power settings, at least in my 66E. Rudder size is a mooney weakness IMHO.

8's on: slightly slower, as the common practice is enter down-wind meaning you'll be descending when you start out. However, power changes are expected (and necessary in any kind of breeze) throughout the maneuver.

Steep spirals and power off 180s have the most simple power setting of all. On the steep spiral, one thing I found was that I needed to agresively lean to avoid unburnt fuel burning in the exhaust stack... put a different way with mixture rich and power to idle, the mixture is extremely rich. Also, the steep spiral can chew up a lot of altitude. One thing to experiment with to reduce the descent rate (and thus reduce the climinb you have to do to practice it) would be to go ahead and bring the prop back to course pitch which will reduce your descent rate substantially. Of course this has to be carefully managed when you 'clear' the engine once around and at the termination of the maneuver.

These maneuvers (except chandelle) can of course be flown LOP also. I did a lot of practice like that. However, I would get a stuble once in a while LOP with changing power settings and decided to use ROP mixture for the checkride and final prep just to remove that as a point of contention.

 

[eaglebkh]

For IFR work at 90 kts with the gear up, I use 16"-17" and 2500 rpm for level flight.  Once I start making decents, the gear goes down and that yields 500fpm without any changes in power setting or effect on airspeed.  For any level flight in between approach fixes, I just leave the gear down and set MP to 20"-21" with RPM still at 2500, which again yields 90 kts.

Don't typically use flaps until short final or runway is in sight.  Since I'm already at 90 kts with no help from flaps, it's not very hard to slow down to landing speed in a very short amoung of time with flaps.

This is mainly for VOR/LOC approaches where timing is important.  For GPS or precision approaches, I'm usually a bit faster, depeding on situation and/or controller needs.

Hope this helps...

[N9660M]

Jason, I tried some different configs in my 67F and settled on one similar to yours.

I configure for level flight, 1/2 flaps, 16"/2400, 90 KIAS.  I like 1/2 flaps because airplane seems a little more stable (not that it was unstable without flaps, though).  Prefer to be configured like this by the time I reach the IAF.  You have to be cautious not to overspeed the flaps (91 KIAS Vfe).  At the final approach fix, mixture/prop forward and drop the gear.  May take an inch or so power reduction to get 450 fpm decent.

I'd prefer to fly them at 105 KIAS, but couldn't get comfortable flying an ILS to minimums, and then trying to lose 14 kts, drop flaps, and continue slowing to a stabilized 70 KIAS for landing.  Too big of a configuration change for me from 200 feet AGL.

Take care - Jim  

[Hank]

For standard IFR approaches, I configure my C for 105 mph [= 90kts], generally about 17-18"/2300 RPM [low altitude, low RPMs] with Takeoff Flaps. Around here, most approaches start around 3000 msl; vary as needed. At the FAF or 1 dot high on glideslope, drop the gear, full prop, mixture rich, reduce 1-2", point the nose down and trim to hold. Throttle and flap adjustments are made only as necessary to hold slope & path, then slow for landing. I frequently land with Takeoff flaps, holding the addtional movement for calm days or if I'm high/fast, since power reduction is limited by the idle position. It also reduces the workload from breakout to runway, fewer things to mess with, and she lands nice with partial flaps.