Run up, take off, and cruise questions for M20C

[Andy95W]

Oh good, does this mean we are going to re-open the discussion about whether or not to use flaps for takeoff?

What about for touch and goes?

[Hank]

Oh good, does this mean we are going to re-open the discussion about whether or not to use flaps for takeoff?

What about for touch and goes?

Naw, those horses are dead, Dead, DEAD!! Please use the Search box for LOP/ROP, Flap usage, touch and goes, Camguard, grass fields, electric gear vs J-bar, etc. Sly Monkey asked for advice on flying his C; as his CFI seems to have some strange ideas, I posted how I fly my C for him to compare against how others do, so that he can experiment safely and make better choices. He just won't have the snazzy electric gear and flaps that I do . . .

Mr. Rhesus, if you want to know about these hot button topics, study only one per day and pour a TALL cold drink before typing into the search box. Then take a day or two off before starting your next Search, or longer with more cold drinks if you're still feeling ill.

[lahso]

Mag check at 1700, Prop check at 1800.

 

For takeoff it's 15 deg flaps, gear up before 80 MPH. Flaps up at top of white arc. Climb to pattern (or higher depending on the situation) altitude with no adjustment to throttle/RPM. Then FT/2600 RPM to cruise altitude.

 

For cruise I used to do FT/2400 RPM no matter what trip I was taking. Lately I've been experimenting with the Key number system that MAPA uses. I encourage you to check it out.

[lahso]

+1 (except I think you meant "flaps up BEFORE top of the white arc?")

I now use the 20/23 descent profile ... and the approach profiles too ...

 

Yes, the same for me on descent and approach profiles.  

[Oscar Avalle]

My field is 5000 feet and density altitude higher than that most of time. So here is my take on the issue:

 

Run up:

1800 RPM, mag check (drop) and LASAR ignition light on (should go off after three minutes

Cycle Prop

Carb heat (I sometimes forget carb heat, but you should not...)

Cowl flaps open

15 degrees of flap.

I expect around 2700 RPM during the take off run

 

After take off, I retract the gear once I run out of usable runway and retract flaps.

Due to consideration related to high CHTs I climb with 2550 RPM and WOT

 

Landing:

Full flaps

[bonal]

Checking carb heat is a habit I learned from training in my Cessna you see a drop similar to mag check. If not and you get carb icing well nuf said and when I chop power in the pattern it's always applied but you must be ready to push it in on the go.

[Hector]

Yes, the same for me on descent and approach profiles.

+1 for me also with a slight modification. I have an engine monitor so I keep a close eye on my cylinder temperatures. When OAT is really hot climbing at FT/2600 will produce temps of 400 even at 120 IAS. I have noticed that pulling back to 26/2600 gets me back to 380 while climbing at 120 IAS. When OAT is below 80 then FT/2600 works well. Cruise setting for me is typically 22/2400, and I descend at 20/2300.

[Hank]

Hector, do you have any temperature data for WOT/2700 climbs? It has been asserted that the higher RPMs push more air through the cowling and provide improved cooling. I don't have a monitor, I just try to keep the gage in the green. This results in slower summer climbs, but that happens to all of us.

[jetdriven]

+1 (except I think you meant "flaps up BEFORE top of the white arc?")

I now use the 20/23 descent profile ... and the approach profiles too ...

I use the "don't touch a thing from cruise until at pattern altitude 3 miles from the airport" profile. It can't get any easier than not touching anything.

[jetdriven]

Hector, do you have any temperature data for WOT/2700 climbs? It has been asserted that the higher RPMs push more air through the cowling and provide improved cooling. I don't have a monitor, I just try to keep the gage in the green. This results in slower summer climbs, but that happens to all of us.

Pulling the prop back to 2600 RPM also increases cylinder pressure, and all other things equal will increase CHT. Say you leave the throttle full open. You lose HP at the crank at 2600 RPM so you must either give up climb rate or IAS durning climb. Then the BMEP in the cylinders is higher so the CHT will increase over the same full throttle at 2700 RPM.

[bonal]

I am climbing at 2700 WOT and between 120 and 130 my head temp is right at 400 and oil is around 180 to 190 depending on OAT but that's just coming off the original cluster gauge in warmer weather. When it's cool outside it stays under 400 but I don't know how accurate those gauges are. My engine temps and performance are very consistent in all phases of flight. David what were your temps on those different climbs. When in cruise I pull 1 inch off MP lean to just rich of rough at 2500 and trail my cowl flaps slightly and that will leave me at 380 degrees head and oil at 160 to 180.

[jetdriven]

Andrew's M20G runs at 400F in cruise and it did so for 1700 hours. It was overhauled for a suspected problem of overheating, that turned of to be two brand new slick mags. anyways, I'm thinking that 400 CHT in a parallel valve Lycoming is OK. They have less fin area than an angle-valve, run hotter, yet still love longer than an IO-360

[schule]

The 25 squared thing is a carry over from Cessna flying. At any thing above 25 squared a Cessna actually flies fast enough to kill bugs with the windscreen and wing leading edge which makes a mess for flight schools that don't have time to learn better technique/science let alone clean off the bugs.

[carusoam]

Typical method that the carb heat fails...

There is a piece of wire that actuates a throttle valve. To open CH, the wire is pushed. To turn it off, the wire is pulled...

The one in my C failed by wearing out the valve's axle, and the wire bent in response to the added mechanical load.

Good idea to check this safety of flight issue.

Who woulda thunk this...,

-a-

[Hank]

When the butterfly fails in the half-open position, takeoffs become "interesting." Especially when departing with wife, dog and several days' luggage. Made me happy to be at a 5000' field with open approaches at each end, as I crossed the end of the pavement at about 200 agl.

With my quadrant, the carb heat lever goes up for Off and down for On. Contrary to my thoughts looking inside the left cheek, Up = Off = arm Back (seems like Off would be arm forward . . . ).

Climbs are abysmal, and ATC will query you re: aircraft make, with tones of disbelief . . .

EDIT: if your climb rate is abysmal at your normal settings, check the Carb Temp gage. If it read 30-40°C, check your carb heat. Mine was turned off, OAT was in the 50's F, and carb temp was in the 40's C. A&P to the rescue!

[carusoam]

65C is a push pull knob...

Out to actuate...

Power is noticeably restrained while CH is on. Good to have the carb heat indicator for this.

As usual this is an old fuzzy memory,

-a-

[Hector]

Hector, do you have any temperature data for WOT/2700 climbs? It has been asserted that the higher RPMs push more air through the cowling and provide improved cooling. I don't have a monitor, I just try to keep the gage in the green. This results in slower summer climbs, but that happens to all of us.

Hank, in the Summer months WOT/2700 can get me over 400 at 120 IAS. I can get it below 400 by climbing at 130. I have not documented the exact difference between WOT/2700 and WOT/2600 but I know both will be at or over 400. If I pull back to 26/2600 it will stay under 400. I guess what I need to do next is figure out the difference in rate of climb between 26/2600 at 120 IAS and WOT/2700 at 130. Will give that a try next weekend.