Throttle After Flare & Cruise Power in MX7 180B

[Tomkatz]

Guys,
I just want to know what the rest of the 180-B guys are doing as far a throttle settings on landing and what cruise power is best for the 180 constant speed prop?

I've been doing all my landings power off but am going to work on low performance greasers and seeking information on technique.

Thanks in advance for any input.

[Kirk]

Do a search on landing and you'll find maybe hours of reading. Everyone has differences in preferences and technique. There's some good info in past posts.

As far as carrying power, even in my M5 which has the shortest wings of the bunch, trying to carry power to touchdown will make for lots of float. The thing just doesn't want to touch down with power on.

My best landings have been carrying a touch of power during a steep approach then taking it all off while rounding out and flaring. My worst landings have been at attempting that technique and getting the timing wrong.

Kirk

[Hogy59]

I've played with both power on and power off landings in my MX-7-180. On hard surfaces, I find it easier and much more controlled to do a power on landing. I just set my aimpoint, speed, and start slightly reducing power about 10 feet. I find that I touch about the same point, and as long as I get the power off right after I touch, the rollout isn't any longer. If coming down final at 60 or 65 (depending on weight and cg), the plane is at a 3 point attitude anyway. My worst landings on asphalt have been chopping the power and trying to stop the sink. For me, grass is no problem either way. I think the power on (with air over the rudder) helps with the crosswinds, too. Just my opinion.

[Hogy59]

As to the cruise power settings, there is a Lycoming o-360 CS prop power chart floating around somewhere on this forum. I try not to cruise at over 75% power, and usually less than that unless I'm in a hurry. But, I think I read somewhere, and you guys can chime in here, that Maule used 25 squared for their cruise data. That is a very high power setting, though.

[NZMaule]

I always hold a little power with my landings and arrest if needed quickly prior to touchdown, providing speed is on the mark then this technique does not seem to increase landing distance. I use 24/24 in the cruise which gets about 110kts at 39 litres/hr

[andy]

Mine's a MX-7-180 rather than a 180B but it's very similar except for the clipped wing. Control of airspeed and the length of the final approach are the keys to being consistent. I use 60 mph on final with full flaps and I make my base turn using a sight point on the wing, which I adjust for wind conditions and weight (closer to the touchdown point when there's a headwind or the airplane is heavy.) The power setting is around 1600 RPM but I adjust it to get the rate of descent that I want based on the sight picture of the touchdown point. When I know that I've made the runway, I reduce the power to a lower setting depending on my sink rate. I think that adjusting the pitch gradually in the flare is easier than playing with the power to get a smooth landing. Less flaps means a shallower approach with less float.

In cruise I'm usually more interested in saving fuel than getting to my destination a few minutes early so I use 21" and 2300-2350 RPM to get a fuel burn 9 - 9.5 gph leaned at around 2,500 density altitude. The Excel chart that I have on my website is taken from the Lycoming O-360 -A -C chart if you want to use the manufacturer's numbers:
http://www.wncairtours.net/data/lycomingperformance.xls

[a64pilot]

Try 1500 RPM, don't worry about manifold pressure, just 1500 RPM

[aero101]

Try glassy water technique, power will vary according to weight, but at altitude experiment with landing flaps down, put nose of acft in 3pt landing attitude, find power setting that will give you 150 to 200FPM rate of descent while holding that nose up attitude, and disregard airspeed (give sink rate enough time to stabilize). Mine usually needs 1600 to 1900RPM depending on conditions, then try it in landing - right after rotating add that power, you'll use some runway up, but if done properly you won't feel the wheels roll onto the ground. After you get a little practice, you'll develop a seat of the pants feel for your sink rate / power combo? (Very similar to Soft Field procedure in wheeled plane, but glassy water technique helps with figuring out required power.)

[Tomkatz]

Good stuff guys! Thanks for all the input!