Ragsf15e

Hello - I know lots of our IO-360s leak a little oil, and mine's not too bad at 5.5 hours/quart, but I wouldn't mind a few thoughts on where to start looking based on the attached photos. It's been leaking about the same for the last 6 months (when I got it). I just got back from a long cross country this weekend and took these pictures today before cleaning it up. After any length flight, there is oil streaming back on both nose gear doors and it appears as if oil comes out from the panel just below/behind the oil cooler on the left side and streams back toward the wing root (where I also clean off oil). I only keep it between 5.5 and 6 quarts, so I know it's not overfilled. I've had a mechanic look at it during the last oil change with nothing found. Thoughts? Should I just not worry about it? Thanks! Drew

Bruce's cover came with my '68 F and it's very nice. Soft felt-like material on the inside to protect the windshield and paint. Durable canvas on the outside. Came in a nice big bag that fits nicely in the hat rack for trips. The two tiny snaps fit perfectly on the front and there's a strap that secures it under the belly just behind the wing. It fits well and it'll hold up to a good wind. Highly recommended.

Tony - Nice job with the data collection and the graph is awesome! With that much info it's usually pretty difficult to understand someone else's work, but I got it without too much study. I get a similar drop off ROP to LOP and I agree - 2500rpm and about 10 LOP at around 8-12000' is pretty good. You seem to be about 4 or 5 knots faster than me. What speed mods do you have? I only have the 201 windshield, but I do use my RAM air and I know you said you don't have that on yours. I'm wondering why else you're faster? Is your engine new? Aftermarket exhaust? Cowing? Thanks, Rags

Furledd - Just curious, why did you get the one with the internal WAAS GPS if you already had the 430W? couldn't you use the 430W as your WAAS position source?

Tony - To be honest, I'm only pulling it that far back because the speed drops off pretty rapidly with only a little change in fuel flow. That probably explains our difference in 5-6 knots vs 10-12 knots. If I pull the richest back to 40 LOP, I think I'd be about the same as you. Since I'm doing it up pretty high and the engine is at 65% or so, I'm not really worried about being close to peak. I'll be looking forward to hearing what you come up with on your trip at higher altitudes. Rags

Interesting, I've done all the speed tests and have been pretty thorough in my data collection... I'm only losing about 5-6 knots going LOP. There's probably some differences in our altitude, temperature, or technique to explain it though. I'm losing those 5-6 knots between ROP / LOP at approximately 10-12,000' Density Alt, WOT, 2500 rpm. As Bob mentioned, I try not to run LOP unless I'm below around 65%, so I'm up pretty high when I do this. I have GAMI injectors and a JPI 930. I use the lean function on the JPI and I lean it out until the richest cylinder just goes maybe 5-10 degrees LOP. The leanest one is probably 40-50 degrees LOP. That setting is about 5-6 KTAS slower than 100 ROP, but it's burning a bit over 2 GPH less fuel! It's a good trade when you consider it takes about 5 minutes longer to get where you're going on a 300 NM cross country but you saved 4+ gallons of gas. Are you guys that are losing 10-12 knots doing it any differently or at a lower altitude?

Yeah thats about the airspeed difference for the "computed tas" i got too. Pretty fast plane for ram closed!

If you haven't sold them, id be interested in the 430w. Pm me.

I only have the 201 windscreen and the LASAR cowl closure. My speeds were both about 140 KTS true at 100 ROP, 2500 RPM, RAM on, at around 10k D.A. (exact details in the first post). Bob, while the wave might be affecting your reading like you mentioned, the ASPEN is using the IAS from the pitot system to computer it's TAS, so it's not unexpected to see it wrong. The operators manual has a 3 knot correction (slower) at 140 kts, so that kind of matches up with what you saw.

Antares, that's one fast F model! That's got to be 10+ knots faster than the average bird. You're getting your money's worth out of those mods at that speed!

Tony - Just curious, why so low? You could be a lot more efficient up around 9-11,000' at full throttle, RAM on, and LOP. Your speed would be around 140 kts as the 4 pages of this forum can attest to. Rags

You guys have me laughing pretty hard... especially the part about brain surgery vs rocket science and the whole post about LOP, ROP, T&GOs, Flaps, etc. Worth reading all 4 pages of this thing just for that. Ok, I think Bob has nailed the easiest way to do this accurately that we can all agree on and do fairly simply - go fly, turn roughly into the forecast wind, fine tune your heading until GPS ground track and aircraft heading match (i.e. get pointed directly into the wind), note ground speed, turn exactly 180 degrees (perfect tailwind), stabilize and note ground speed. The average of these two numbers is a pretty accurate take on your TAS. If you don't like this method, someone can read the attached document which is the most confusing and complicated method of determining TAS that I could find, but it does handle important factors like "curvature of the earth"! Rags vol4no3_A01.pdf

Someone nailed it about 5 posts ago... the easiest way is to fly in calm air! Or maybe to fly directly into the wind... however, that pretty Aspen displayed wind value is using your pitot system because it uses IAS, temp, and pressure to figure TAS, then uses TAS, GS, HDG, and Track to figure the winds. Sorry to our mathologist, but I wasn't talking about CAS being affected by a crosswind. Here's why holding a ground track (say North) will always be slower than holding the same HEADING (North) with any crosswind... You will have to crab into the crosswind to hold your ground track. That will always increase the headwind component (if it was a headwind or direct cross) or it will decrease the tailwind component if it was a quartering tailwind. No matter what, holding a ground track crabs you into the wind and slows your forward progression.

Bob, copy, you're right, I didn't see the couple of important distinctions in your data. I'd still like to see a 3 way test to take out the pitot error. Jerry - I'm no "mathologist", but flying 4 ground tracks instead of headings is not negating the wind. In fact, you're probably going faster than indicated by the test, so that should make you feel good. If you fly a ground track you must be crabbed into the wind to hold the track - probably on all four legs unless two of them happen to be directly into/away from the wind. The greater the crab, the less your TAS down the intended track. Imagine flying with a 100kt direct crosswind. You'd be pointed something like 40 degrees into it to hold a track and you're now using 60 of your 140 knots TAS just to hold you against the wind. Get a strong enough crosswind and you have to point directly into it just to avoid being blown across your track and you won't be moving along that track at all. Unless we're talking about strong winds, I doubt there's more than a knot or two difference in the 2 or 3 methods talked about here, but I still think the 3 way test is the most accurate since the Navy Test Pilot School has some papers posted online about it with a lot of squiggly math symbols that I forgot 20 years ago. We need a mathematician on Mooneyspace! Rags

Marauder - that's one heck of a nice panel! However, I do like my "older model" engine controls and the removal of my "steam gauges"!! Rags

Yep, Bob, you posted just as I was writing... I agree, the Aspen data is only as good as the inputs whereas the ground speed test is much more accurate.

Bob - First, that's a beautiful panel on your E model! I have to say though, I don't think your Aspen displayed TAS is too accurate. First, you got a higher TAS at 9500' than you did at 8500'. 7-8000' D.A. should be right in the sweet spot for our max speeds (not for the turbo crowd). Higher should be slower according to data and the book numbers. My real problem with the Aspen TAS is that it's using your 50 year old pitot system for the IAS input. As I found on mine, it's off by about 6 knots at cruise. I'd recommend doing the GS test and verifying the accuracy of your TAS like Super Dave. Also, the pitot system error is most likely off different amounts at different speeds - so maybe 1 knot at 80 knots on final, but 6 knots at cruise. I do drool over your panel though... Rags

That's some good data and you guys have some fast airplanes! Super Dave, I'm glad you've checked the TAS on the Aspen vs TAS derived from a ground speed check because I found that TAS indicators or TAS computed on your GPS can easily be corrupted by your pitot system. The real data we have has to take the calibration error from the airspeed indicator out of the equation. The only good way to really do it is the 3 way (or maybe 4 way) test. Thanks for the feedback! Rags

Yeah, that's a good one. I read all those several times before choosing my M20F. He got pretty good speed out of that F model - around 150KTAS at 7000' with no speed mods. I think that might be a bit more than most of them are capable of (mine included) and I'd like to see some other data points too. Interestingly, my IAS was almost exactly what his was (123KTS at 10,500 and 129 KTS at 7,500) but if you use the temp and pressure to turn IAS into TAS, I find that my airspeed indicator is showing about 6KTS too fast - calibration error maybe? Anyway, the 3 way groundspeed test is very accurate. I used the pilot report above, put 3 of his directions into the 3 way test and get about 1 knot slower, so they aren't far off of each other.

Ok folks, we all fly Mooney's to go fast. My 1968 F model goes a few knots less than book (I know book was optimistic), but I'd like to get a few comparisons to see if it's about the same as others or if my 16 year old engine overhaul is starting to catch up with me. So here's what I did, I flew a speed test at 10,500 and 7,500 and I'm putting the results below. If anyone else has a chance, I'd like to know how your bird comes out on a similar test. The only speed mods I've got are the sloped windshield and the Lasar cowl closure (which cools nice, but I doubt it goes any faster) The speed check is very accurate and you only need 3 legs, 90 degree off - like North, East, South. You just write down the GPS groundspeed on each leg. It's actually more accurate than doing all 4 directions and averaging because it uses math to take out the crosswinds you'll have. The calculator is at http://www.csgnetwork.com/tasgpscalc.html. If you note the temp and altimeter setting it'll also give you the density altitude and the actual winds. I used 100' ROP for the test (although I normally run LOP which is ~6 knots slower). I used WOT, 2500 RPM, RAM air on for both runs. Weight was about 2400 lbs. My 7500' TAS was 142.6 Knots and the density altitude was 9465'. My 10,500 TAS was 139.9 Knots and the density altitude was 11,951'. Thanks for anyone that wants to use this as an excuse to go fly and report back! Rags

I checked it out on skyvector. Look on the legend, it says "minus values indicate surface up to but not including the value." Looks like exciting airspace. When i go vfr places like that, I will usually be on flight following and ask for permission to enter the class B even if there's a way to get to the destination without. That at least gets you legal even if you stay out of it. Controllers really have been good with it.

I'd also check the HSI vs the 430W "test screen" (that's not what it's called, but close). When you first turn on the 430W and it asks if you want to refuel/hit ok, you should be on the screen that says something like 1/4 deflection left, 1/2 deflection low or something like that. Look at the HSI and see if it's actually indicating as it should. I have a similar problem and my A&P and I used this as a starting point to figure out that the HSI wasn't responding to the 430... we slipped in another 430 he had laying around and it worked perfect... thus my 430 glide slope was the problem. You can also get to this calibration (maybe) page somewhere in the 430W aux menus. Good luck!

Jakl - I see the Chiefs patch, "the other squadron at Seymour"... I'm a former Rocketeer and now have an M20F (at Laughlin AFB). Like some of the others above, I'd recommend trying sitting in an M20J with your wife and see how it feels. I'm 6'3 and 170lbs. It's comfortable once I'm in, but it's a bit of "yoga" to get into the left seat. Forget about getting in the back. If you're going to take your dog(s) and/or snowboards, fold down seats will be a must. Mine don't, and I kind of wish they did. My M20F has about 635 lbs load left with full fuel (64 gal), but really, you don't need all that gas. 3 hour legs are plenty unless you plan on using piddle packs. Let me know if you want more info. I just went through the whole buying process about 4 months ago, so it's fresh. It's an awesome airplane to own and fly! Rags

Seth - You're right on all three counts... the brightness is adjusted by twisting, you can press to test them, and the F is a great airplane! Thanks for the input. Rags