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m20 performance


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I've a '66 M20C. I flight plan for 140Kts and it works out well. At altitude I burn around 8 GPH. Two weeks ago I flew from Boulder, Co to Martinsburg, WV. 1 fuel stop in Taylorsville, Il and had 18 gallons when I  landed in Martinsburg. 52 gallon tanks. Mooney's are very efficient craft. Total flight time, 8H23M.

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Numbers for my 1967 M20F:


MGTW - 2740lbs. 


Empty Weight - 1681lbs.


Useful load - 1059lbs.


Full Fuel - 64 gals or ~384lbs.


FF payload - 675lbs.


Cruise speed ranges from 153kts (GPS verified at 7K 100ROP, Ram air open) at -10.5ish GPH to ~145kts on closer to 9.5ish GPH LOP.


The above varies a bit with CG and weight. Speeds a tad conservative for light weights.


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I have a 1967 F model as well (actually one of the first four F models - airworthiness was one of the four from 1966). 


Useful Load - 1017 LBS


Full fuel - 54 gallson - bladders - 50 useable


Cruise speed - 148 knots top speed - with Ram air it breaks 150 and on a cold day even 152 knots.  10-11 gph.  If you slow it down to 142-145, it'll go that speed on 9gph.  I'm alwasy amazed after a training flight or leisure flight how little gas is burned.


The further back your CG is, the faster your cruise will be.  Once off the ground, I notch my chair back one click so I can still touch the rudder pedals but where I don't have to worry about riding the brakes on the ground - In actual testing, between weight in the back and one notch back, I've picked up a few knots.  I plan 148 when going cross country.


Best altitudes are 7000 to 9000 for me.


Take care,


-Seth

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Yeeez, my Mooney ain't that fast.Frown I must add that the cylinders were a bit glazed and I had them re-honed and installed new rings all round. I'm going to fetch it on Friday and I'm sure it will perform better. I'll also have the rigging checked at the next annual. Anyhow, my figures are as follows:


Usefull load = 1040lbs
TAS = 140kt (that's at WOT, 2500rpm and 75 deg ROP)
Fuel burn at the above power setting is normally 10gal/hr and for flight planning purposes, using 135kt seems to be more accurate than 140kt.
My Mooney doesn't have RAM air anymore and the only mod I have is the Lasar cowl closure.


All in all, it is a fantastic and very economical airplane.

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In a stock 1967 M20F with 3 blade hartzell I get systematically 143-145kts TAS at 10,000ft , leaned peak or just lean of peak at 2500 rpm on 32 litres an hour (8.5 us gal). 


A bit lower I get a couple knots more on a couple more litres, a bit higher a couple knots less on a couple litres less...! Very efficient. Just flew Britanny to central spain (about 600nm) at 13,000ft leaned to 29 litres an hour at 140kt tas.


Not bad when Avgas is over $11 a gallon here in Europe...


 


 


 

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This is what I consistently get, 145kts at 33litres I tend to fly the same route very often and always use the same settings, WOT (around 21in), ram air on, 2500rpm, leaned peak or about 10 lop, couple knots faster in winter, couple slower in high summer. So consistent that one week I was getting 139-140ktas and found out my retractable step wasn't retracting any more... simple fix , the vacuum hose was detached


At 13k last Sunday I was getting 29 litres, 19.5map and 140ish ktas.

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My C-model with 201-windshield and Hartzell 3-blade runs pretty close to 140 knots, and I'm typically 7500 and up. Fuel flow is around 9 gph based on fillups, as I don't have fuel flow.


This photo was at 10,000 msl to get out of the storms below; tops were at about 9000 that day with more turbulence that I liked. 2500 RPM, throttle was wide open then pulled back just enough to move the needle. I'm experimenting running just richer than rough instead of 50 ROP at altitude, so speed may be down just a little. Groundspeed, of course, is dependent upon wind aloft--I've maintained anywhere from 104 knots to 183 knots, pretty well centered on 140. Fuel injection and 20 additional HP make a difference with E, F and J models.


Oops--useful load is 969 lbs; 52 gallons fuel [i fill to 50 gal = 300 lbs, to leave expansion room and easy math]. Full-fuel payload is 669 lbs.


Typical departure at my 3000' home field is rotate at 70 MPH, get over the trees and climb at 900-1000fpm as I come up to 100 MPH. Heavy departures, flaps to TO, rotate at 75 MPH, the trees are still well below me; this is infrequent enough that I don't remember height or climb rates, but we're headed to the beach next week--I'll watch and report back if you are curious.


She lands well at 85 MPH final, 80 over the trees at 150 agl, pull the throttle when clear and touch down around Stripe #3. Minimal braking leads to back-taxiing from 2000-2200' to our only entrance about 1000' from the approach end.

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10,000?  iwas having trouble reading your altimeter- looked like you were 5 ft off the ground doing 130 with your gear up!


 


so in general, a c is doing 140 to 145 , and f with the extra hp is doing 145 to 153.


 


Thanks,


Rob

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