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M20F w/201 mods


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A few other things that impact speed on the F model

1.  67 and 68 models came with a cleaner wing than the later F models. They had more flush riveting.

2. The earlier 67 models had wash out on the wing that the factory said did little and did not justify the extra cost to construct. This tended to cost a knot or two but some owners felt like theirs possibly hada knot or two lower stall speed. 

3.  The early F models had the pneumatically retractable step.  The later ones had fixed steps. 

4.  A number of the F and E models have had the third fixed cowl flap mod between the two variable flaps.  This tends to reduce top speed a little but does wonders for cooling. 

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On 11/29/2017 at 6:49 PM, M20Doc said:

Isn’t the 67 F Mooney wing given “wash out” reducing the angle of incidence allowing the outer portion of the wing to stall later than the root.   “wash in” increases the angle of incidence causing the tip to stall first.

Clarence

Indeed the tips twist downward creating a lower Angle of incidence. 

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Earlier this year I posted questions on flying a C model offered to me by a local pilot who wanted his C model running. He has the problem owning Both TBM and a 1967 M20C and wanted me to keep the C flying for a season only paying for gas. It was great while it lasted! He's selling the C, but I've since found another opportunity with a similar deal structure on a 1970 M20F with the 201 windshield and a certain kind of cowling closure. Not the one I had in the C that covers the bottom engine inlet, but one that looks like a modified version of the 201 style cowl but slightly different... if that makes sense. This airplane doesn't have up to date IFR equipment but has a wing leveler and a newish Garmin panel mounted VFR gps- I'd have to check again to see what kind. My question is what to flight plan TAS for. He says the only thing different from his plane and a normal 201 is the one piece belly, so in my opinion, knocking 1-2 knots off, can I expect to plan on 152-153 KTAS? Or should I plan closer to 145-150? When I asked the question in the C, then flew the airplane on the cardinal heading test I found that 138 KTAS was better to use than the 142-144 KTAS others were telling me.
 
 
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Has a C. Trued out around 138. GREAT PLANE. Fast forward past a Bonanza A35 and an A36 to Mooney K.
Love C. K can climb without tiring. Would I trade any of above for a good C? Maybe.

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Flew the F this afternoon. It had a lot larger feel relative to the C, but I didn’t notice much of a performance increase with the 20 extra hp. One thing that I thought odd was while on final approach, the more I backed the throttle out, the more trim it needed to stay at the proper angle. I told the owner the trim felt out of line as I had the trim literally almost all the way up in order to land. He said that was normal, I disagree. I have to trim up substantially in the Ovation because the engine up front is so much larger but I never had to do that in the C, makes me wonder on the F. Does anyone have any similar experience? Other than this, I’m going to have to take it on a proper cross country to get a feel for the 201 style mods and see if it really makes any difference!


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The C trim is all the way up as well, from my experience...

The young transition trainer quipped, you can't get enough up trim in these things.

of course, it depends on WnB, for the day...

For the R, the trim goes nearly to the top, when I’m solo...

Best regards,

-a-

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2 minutes ago, carusoam said:

The C trim is all the way up as well, from my experience...

The young transition trainer quipped, you can't get enough up trim in these things.

of course, it depends on WnB, for the day...

For the R, the trim goes nearly to the top, when I’m solo...

Best regards,

-a-

In mine I am typically almost full up trim or close to it for it to be at 80 mph hands off on approach.

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Huh. My C lands with trim really close to Takeoff. But I don't use Landing Flaps unless I need to, since the Owners Manual says "FLAPS--Landing or as desired", and follows with a discussion about adjusting throttle, flaps and elevator for differences in weight, glide angle, winds, etc.

The 75 F that I have a dozen or so hours in landed much, much better with Landing flaps, but they were three positions only. In my C, flaps can be anywhere, as I use them as another tool to maintain glideslope on final; it's not unusual to be an indicator bar-width or two to either side of Takeoff when I shut down. I didn't pay attention to trim position in the F, as it doesn't matter, it is reset before takeoff anyway (to Takeoff). 

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That trim doesn't sound right, either for you or for Richard's M20C.  

Solo, with a relatively forward CG, I trim mine for 65 mph on final with full flaps, and I probably have enough up trim left to nearly stall the airplane.  And set at the Take Off indicator, I lift off with just a touch of back pressure and climb at about 80 mph before I raise the flaps.

The adjustment isn't difficult, but should be done by someone who knows what they're doing.  Rigging boards help, but not essential if they've done the job before.

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31 minutes ago, Andy95W said:

That trim doesn't sound right, either for you or for Richard's M20C.  

Solo, with a relatively forward CG, I trim mine for 65 mph on final with full flaps, and I probably have enough up trim left to nearly stall the airplane.  And set at the Take Off indicator, I lift off with just a touch of back pressure and climb at about 80 mph before I raise the flaps.

The adjustment isn't difficult, but should be done by someone who knows what they're doing.  Rigging boards help, but not essential if they've done the job before.

Interesting, I haven't thought much about it as I have read others that have almost full up trim on final.

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8 hours ago, Tx_Aggie said:

Flew the F this afternoon. It had a lot larger feel relative to the C, but I didn’t notice much of a performance increase with the 20 extra hp. One thing that I thought odd was while on final approach, the more I backed the throttle out, the more trim it needed to stay at the proper angle. I told the owner the trim felt out of line as I had the trim literally almost all the way up in order to land. He said that was normal, I disagree. I have to trim up substantially in the Ovation because the engine up front is so much larger but I never had to do that in the C, makes me wonder on the F. Does anyone have any similar experience? Other than this, I’m going to have to take it on a proper cross country to get a feel for the 201 style mods and see if it really makes any difference!


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With full flaps and back seats empty, full up trim is needed.   With take off flaps, takeoff trim is about right.  

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Thanks that helps. Seems a bit strange that trim should come up all the way with little increase in engine output relative to a C. The Ovation has an extra 100 hp so I understand the nose down attitude at slower speeds. Still Not sure I get the reasoning behind it in the mid bodies.


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Somebody in the engineering depart found it ideal, when they set the trim, in the landing configuration at max gross weight, with a forward Cg...

Since it is a setting with a set range... that is what happens...

Since it is a setting for all three body lengths, it is probably set-up the same way from the factory on each model...

 

If the range was made much larger... the trim could cause a tail stall... or some other possible issues(?)

 

Just be familiar with the go around techniques.  Max trim and max power can be a handful as the plane attempts to increase its attitude skyward...

Wether it is 180 or 310hp, it is still a lot of knowledge/practice and/or strength used to get it right....

PP thoughts only, not a CFI....

Best regards,

-a-

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First post of a new Mooney owner.

Don't mean to hijack this thread but I have a similar question that I haven't found an answer for.  My M20F was built in '66, but has a '67 SN, so I'm not sure if it has the twisted wing.  I've only flown it 25 hours and only a few  flights over 1 hr, but my fuel burn seems too low.  

My first hour fuel burn (startup, taxi, runup, takeoff, climb to 6500', cruise) was only 11.1 gallons.  That was with throttle full forward, prop at 2700 for climb, 2500 for cruise, mix 125 ROP for climb, and 50  ROP for cruise.  

My first full tank averaged 8.8 GPH for all phases of flight and my second was a whopping 8.045 GPH.  I have been throttling back to 22" MP when below 5000' for cruise or descent, but otherwise, throttle wide open and most of my flying was 7500' and up.

Is this normal?  My flight instructor is concerned with the low fuel burn that I may be running too lean and could damage the engine.  

My TAS has been around 165 mph at '9000 give or take a bit and the plane has lot's of speed mods (cowling, windshield, flap gap, aileron gap, wing root leading & trailing, tail faring, brakes rotated, and more).  The rigging is a bit out, but based on all the comments, it seems I should get a bit more speed, but also burn more fuel.  Should I be worried?

Thanks for the help.

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You should be going faster, you're making C model speed . . .

Two questions:

  1. Where did you get 125°ROP in the climb? That seems lean. I either keep Full Rich to cruising altitude, or use Target EGT. Search for it here, there is much discussion. 
  2. What does your Owners Manual say about setting power? You know, in the back under Performance Tables? 
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21 hours ago, Tx_Aggie said:

 He said that was normal, I disagree. 


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And you'd be wrong in your disagreement.  Depending on how you're loaded, it's very common to use most if not all of the nose up trim available.

Edited by Shadrach
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20 hours ago, Andy95W said:

That trim doesn't sound right, either for you or for Richard's M20C.  

Solo, with a relatively forward CG, I trim mine for 65 mph on final with full flaps, and I probably have enough up trim left to nearly stall the airplane.  And set at the Take Off indicator, I lift off with just a touch of back pressure and climb at about 80 mph before I raise the flaps.

The adjustment isn't difficult, but should be done by someone who knows what they're doing.  Rigging boards help, but not essential if they've done the job before.

This will depend on fuel load.  Also, the elevator rigging is different from C to F. 

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5 hours ago, Tx_Aggie said:

Thanks that helps. Seems a bit strange that trim should come up all the way with little increase in engine output relative to a C. The Ovation has an extra 100 hp so I understand the nose down attitude at slower speeds. Still Not sure I get the reasoning behind it in the mid bodies.


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Nose down is due to weight not HP.  The injected  4cyl angle valve is 40lbs heavier than the carburetted parallel valve.  

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I got the 125 ROP from 100 ROP being best power and trying to go a little more on the rich side.  My '67 model owners manual is in the plane at the moment, but the plane came with (only) the '68 model owners manual.  That shows cruising at 5000', 2500 RPM, 22" MP, leaned to 100 ROP, I should be burning 10.2 GPH and going 160-163 mph.  That is the speed I'm getting, but I'm not burning anywhere near that much fuel.

I don't have anything that shows fuel flow, just taking the total gallons to fill the plane divided by the hours flown.   So all phases of flight and ground ops are included.

Next time I take a longer trip I will have a full tank in one wing, switch to it after I get set at cruise, and then run it for an hour.  That will give me a better cruise burn.

I will find and study Target EGT.

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22 minutes ago, skydvrboy said:

I found the article where I got 100 ROP, and I have always waited until over 3000' to start leaning. http://www.mooneypilots.com/mapalog/powersettings.html

I certainly notice the increase in RPM and power when I start leaning during the climb.

Bob Kromer is a wise man. But study up on Target EGT for your climb to altitude. I just need to remember to do it . . . .

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Thanks for your help. I'll print that red cone chart and take it with me next time I go flying.  I'm not really concerned with economy at this point, I have economy, maybe too much economy!  I'm most concerned with not damaging my engine.  One question though, how do you determine target EGT if you don't ever fly out of sea level airports?

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SKB,

Since you don't have FF...

Do you have an engine monitor, or just the original CHT and EGT..?

These are not a requirement, but well worth the money, when able...

Leaning while climbing is often done 200 - 300 °F ROP... a combination of great power and well controlled CHTs...

Climb speeds are often 120mias - 120kias... a combination of climb speed and CHTs and ground coverage...

Controlling EGTs is a way to control CHTs.  Controlling CHTs is a way to control your maintenance expense...

Are you able to keep your CHTs under 380°F, or that hasn't come up yet?

Best regards,

-a-

 

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