David Lloyd

Performance charts in the old book list conditions as 2200 weight, standard conditions, best power, full fuel. That pretty much is one heavy person (210), full fuel (300), 40 pounds of headsets, oil, charts, approach books, a change of underwear and an old Mooney (1650). One point, 7500', full throttle, the chart shows 182 mph (158 knots). Under those conditions I used to see 140-144 knots. You, 145-147. That seems like ways off when we are interested in accuracy.

The owner's manual for the '65 C Model I had, the performance numbers were wishful thinking at best. The older books are on this site. Don't read with a mouthful of coffee. The increased speed claims of the "speed" mods I installed were seriously overstated. That's why I'm asking, what does work and by how much.

Filled a few pages with test data that back up theory. Memory numbers might be rounded off or depend on how much rich or lean of peak but close, I did the tests, I got the numbers. I agree that in comparing before and after speeds you need to compare at the same fuel flow. There does seem to be a lot of variation from one airplane to the next. Same model, same mods, same fuel flow, different speeds. CAS vs IAS is just a few knots but still a real thing. Anyone else test theirs? Yours high or low? One airplane to the next could be different. My IAS is 2.5 to 3.5 lower than CAS depending on the days I tested (many variables). I just use 3 and let it go from there. Groundspeed is worthless as a performance indicator. Again, does anyone have their own test numbers before and after modifications. Again, years ago I found a number of mods that did next to nothing for speed increases. What works? How much?

Fuel flow does have a big effect on TAS. My RV with everything just right will do 177 knots TAS but the flow is about 11.5 gph. Dial the rpm back to 2500 and flow about 9.5 will get me 170 knots. Bring the flow back to LOP, about 8.5 and 162 knots. 7.5 GPH, 155 knots. Yep, 4GPH will make a 20 knot difference. Blue, was there any speed difference at the same fuel flow?

Years ago I had a 1965 C. When I bought it, I remember seeing 140-143 knots depending on loading, altitude, temp, etc. In the quest for more speed I had gap seals, landing light cover, aileron seals, empennage hinge seals, empennage fairing, dorsal fairing wheel well enclosure, and brake rotation. When I sold it, I could count on...yep, 140-144 knots depending on loading, altitude, temp, etc. Quite a bit less improvement than promised before the checks were written. At the time, I don't remember anyone installing the 201 windshield or cowling. Maybe, maybe not. I did however, attempt to make a fiberglass cover to block off that big hole in front of the engine cowl. Gave up--hate fiberglass. I discussed that with someone at a fly-in. Hmm. In another thread, someone asked about the speed of the F model. Comments have speeds all over the place. Same for the E and C. Looking at Flight Aware it would appear 140 knots for the C and F and 145 knots for the E are pretty common. About the only mods where there seems to be a true benefit are the 201 windshield and cowling. I have searched but have been unable to find where anyone documented before and after testing when modifications are done. Seems faster, definitely is faster, a lot faster is not a test result. Anybody do any real before and after testing? Other vintage Mooney mods in addition to what was already mentioned are: LoPresti cowling, closure, 10:1 pistons, IO-390, Power Flow exhaust, flap and aileron hinge covers. Anyone have some hard info?

Nope, better not run for office. You admitted making a mistake!

Right now my gear is welded in place. But, after the Mooney I did 5500 hours in a F33A. Gear always came down at pattern entry or 1000 AGL on an instrument approach. Approaching either my hand went to the gear knob and would not come off until I said out loud, 3 in the green.

I've got more to check now than 40 years ago, and need more reminders. Seriously, my landing checklist is very short: Fuel selector, fuel pump on, mixture, prop. Flaps and trim take care of themselves. Takeoff is where I want the important list to keep me out of the trees. I have another checklist for departing on an IFR flight that adds autopilot stuff: heading bug, initial altitude, flight plan entered in the navigator, and the transponder code entry buttons showing on the EFIS. Things that are needed. I have seen Cherokee 140s at the runway for 20 minutes going over a checklist.

16 GPH flow seems a bit low to me but since you are climbing and max flow stays pretty constant and as manifold pressure drops with altitude less horsepower is made requiring less fuel so as you climb things pretty much correct themselves. A couple posts mentioned timing. 20 Or 25. Which is yours? Is your timing set correctly? I have found this to be equally critical to cylinder head temps as fuel flow. Being experimental I can monkey around with timing. 20 Degrees BTDC my cylinder temps are cool. I can climb at low airspeed on a hot day. 26 Degrees BTDC and I must be careful with the mixture to avoid redline CHTs in cruise. 9.5:1 Pistons put me closer to detonation than your 8.7:1 compression ratio. 23 Degrees works well for me with CHTs under control. Someone mentioned hot oil temps. Here again with hours piddling with marginal cooling I have found a direct correlation between CHTs and oil temps. No kidding, right? Wait. If cruising a full power rich of peak mixture with CHTs around 400 degrees I will have oil temps of around 203-205. Pull the mixture to lean of peak and CHTs may come down to 365-370 and after a while oil temps will ease of to about 190.

Watch the video carefully as the accident taxis out and is on the takeoff roll. Elevator neutral until part way down the runway. Then only enough elevator to raise the nose for a normal takeoff once speed is reached. No huge surprise at the end.

I was taught when on a soft surface the controls should be held back on taxi and takeoff until the nosewheel is off the ground. Unless wind dictates something else, that is what I still do. Anything else is asking for trouble especially on a soft surface.

Finally got the seat belt fastened for a big passenger, he claimed 300, in my RV. Shoulder harness, uh-uh. Could not sweep the controls. Worried there may not be enough elevator on landing. Suck it in big guy. I already am! Need bigger airplane.

Even a 15 pound dog.

But when the boss wants to sit in the back seat there needs to be a back seat.

8A6, Wilgrove Airpark. RVs are both fast and fun and comfortable for one or two. Not so much for three.