FloridaMan Posted May 18, 2020 Report Share Posted May 18, 2020 (edited) I see @Cody Stallings has seen this thread already. Low RPM and mag timing were both factors in a fatal Mooney takeoff accident that was caught on video. Edited May 18, 2020 by FloridaMan Quote Link to comment Share on other sites More sharing options...
jetdriven Posted May 18, 2020 Report Share Posted May 18, 2020 I just checked my annual sheet from last fall. Static RPM is 2650. Takes a few seconds to Stabilize and get that high, when you release the brakes to get up to about 50 miles an hour, the RPM comes up. 1 Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 19, 2020 Author Report Share Posted May 19, 2020 Thanks @jetdriven Do you by any chance has Savvy link to share? I went to airport last night and the good news is, prop cable is touching the high speed stop on the governor. The bad news is, cable isn't the issue. Since my fuel servo is being flow tested, I won't actually do any other testing until I got my fuel servo back. In the the meanwhile, I'm going find some way of accurately measure the resting pitch of the prop. The spec calls for 13.9 degree, I'm hoping to find it is a bit higher than 13.9, which would explain the whole problem. 1 Quote Link to comment Share on other sites More sharing options...
jetdriven Posted May 19, 2020 Report Share Posted May 19, 2020 Do you have the McCauley c212 or C214 prop. Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 19, 2020 Author Report Share Posted May 19, 2020 That just went over my head. Here is straight copy from the Prop log book. Hub Model: B2D34C214 Blade Design: 90DHB-16E I take it I have C214? Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 19, 2020 Report Share Posted May 19, 2020 Flake, Do you have the method for measuring the blade angle when it sits on the stops? I’m going to learn something when you do it... Looks like you may have two things going on at the same time... static rpm challenge, where blade setting might be the answer... Dynamic rpm challenge, where the gov needs some help... Or a power problem... As the video of the K crashing through the fence... a graphic reminder that full power is required to get expected performance... That was a pretty short runway, and the engine/prop were not generating the expected power... For my plane... 10% less HP... results in 50% longer T/O run... 800’ vs 1200’... (real numbers) Best regards, -a- Quote Link to comment Share on other sites More sharing options...
Guest Posted May 19, 2020 Report Share Posted May 19, 2020 (edited) The ability to record engine parameters is on the first page of the Mooney inspection checklist. Clarence Edited June 5, 2020 by M20Doc Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 25, 2020 Author Report Share Posted May 25, 2020 Update on my progress. The fuel servo is now installed on the aircraft. We did a full power static run without cowl and air filter after carefully clean the run up area with a leave blower to remove all sand and debris. Surprisingly, the engine monitor shows 17.1 gph. This 1.2 gph more than before. Perhaps the flow test solvent flushed something out of the fuel servo and divider?! In any case, I now get 2525 rpm at full rich. This is almost 50 rpm improvement from 2475 rpm before the flow test. I can get rpm as high as 2555 if I lean the mixture a bit. During static run, what's really interesting is the engine rpm actually registered 2704 RPM when I first throttle up, but you can see in the screen capture below, "something", perhaps the governor *pull* the rpm back to 2515. I'm sending the the prop into the shop for a flush and depending on what the prop shop says, governor may come off the aircraft as well. I may goes with a replacement governor as @carusoam suggested. Here is the link to the engine log on Savvy. I'm trying to keep this well documented for myself as well as other that my encounter similar issue in the future. https://apps.savvyaviation.com/my-flights/21509/b7b08d3f-8796-40da-adaf-1b7059ed9770 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 25, 2020 Report Share Posted May 25, 2020 Great follow-up details, flake! Interesting ramp-up in rpm as well... Many things are going on at the same time when the throttle gets pushed in... This is called non-steady state... The blades are coming off their stops... The Governor is a bit slow to react... The power is coming up strong... Lots of things will overshoot before settling in... Including FF, OilP, and all temps... A JPI 900 typically lights up like a Christmas tree at this point.... as many red lines are temporarily exceeded... FAA redlines are important, just their rules were written long before we had digital instruments with the ability to alarm at 2701 rpm... A nice way to measure performance... collect data using CloudAhoy... T/O distance will be telling, and climb rate will confirm the power being generated... If you don’t have CloudAhoy with a WAAS source... do the best you can with runway markings and the ASI/VSI instruments... PP thoughts only, not a mechanic or CFI... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted May 25, 2020 Report Share Posted May 25, 2020 Anthony is correct. Was the prop gov already adjusted and you are not saying so? Is there some reason it has not been adjusted? Still looks like the cause of your issue to me. Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 25, 2020 Author Report Share Posted May 25, 2020 @carusoam Thanks for the suggesting on using CloudAhoy. I have always wonder how you are able to measure the take off distance. Between scanning the oil pressure, engine rpm, keeping on the center line, etc... I sure wasn't able to tell the precise moment when the wheel lift off the ground. @David Lloyd Governor was the first thing we adjusted. For good measure, we turn another full turn out before the static run. If the adjustment screw is working like the book says it should, I should have seen some change in RPM. The fact that rpm was able to reach 2700 for a second or two means governor has kicked in and the prop is no longer on the low stop. In any case, the prop is already off the airplane. It wasn't difficult to remove the prop. But, it was a two man job. Quote Link to comment Share on other sites More sharing options...
N231BN Posted May 26, 2020 Report Share Posted May 26, 2020 The fact that rpm was able to reach 2700 for a second or two means governor has kicked in and the prop is no longer on the low stop. This indicates you have a governor issue. Quote Link to comment Share on other sites More sharing options...
takair Posted May 26, 2020 Report Share Posted May 26, 2020 3 hours ago, corn_flake said: @carusoam Thanks for the suggesting on using CloudAhoy. I have always wonder how you are able to measure the take off distance. Between scanning the oil pressure, engine rpm, keeping on the center line, etc... I sure wasn't able to tell the precise moment when the wheel lift off the ground. @David Lloyd Governor was the first thing we adjusted. For good measure, we turn another full turn out before the static run. If the adjustment screw is working like the book says it should, I should have seen some change in RPM. The fact that rpm was able to reach 2700 for a second or two means governor has kicked in and the prop is no longer on the low stop. In any case, the prop is already off the airplane. It wasn't difficult to remove the prop. But, it was a two man job. Did you previously report that you can achieve 2700 in a dive? Is that 2700 sustained in the dive or is it momentary? Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 26, 2020 Author Report Share Posted May 26, 2020 Momentary only. I assumed there may be other issue with the power plant since the governor was able to reach 2700 with the help of gravity. With the latest static run, it would seem the cause may be the governor. I did one more test run after that, and the RPM never reached 2700. It is entirely possible that engine oil was been thicker at the first test run that made the governor react slower. Nevertheless, the smokeing gun is now the governor. Quote Link to comment Share on other sites More sharing options...
jetdriven Posted May 26, 2020 Report Share Posted May 26, 2020 The book says fly at full rpm for five minutes, then adjust from there. Quote Link to comment Share on other sites More sharing options...
icurnmedic Posted May 26, 2020 Report Share Posted May 26, 2020 My F only gets to 2680 rpm on Takeoff, per JPI 900. Any of you have an idea of the power lost by not having the additional 20 rpm? Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted May 26, 2020 Report Share Posted May 26, 2020 My F only gets to 2680 rpm on Takeoff, per JPI 900. Any of you have an idea of the power lost by not having the additional 20 rpm? Ditto, the difference between 2600 and 2700 is 6% so extrapolating that’s a 1.2% HP loss or 2.4HP.Tom Quote Link to comment Share on other sites More sharing options...
icurnmedic Posted May 26, 2020 Report Share Posted May 26, 2020 5 hours ago, ArtVandelay said: Ditto, the difference between 2600 and 2700 is 6% so extrapolating that’s a 1.2% HP loss or 2.4HP. Tom Wow. That seems like allot. Think it makes much performance difference? Quote Link to comment Share on other sites More sharing options...
Andy95W Posted May 26, 2020 Report Share Posted May 26, 2020 Probably about 1.2%. Sorry, couldn't resist. Quote Link to comment Share on other sites More sharing options...
ArtVandelay Posted May 27, 2020 Report Share Posted May 27, 2020 Wow. That seems like allot. Think it makes much performance difference? No, maybe you climb at 980fpm as oppose to 1000fpm. I don’t cruise at 2700, so it’s only an issue during takeoff. Have your mechanic adjust it on next annual if it bothers you. Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 27, 2020 Author Report Share Posted May 27, 2020 @carusoam There you go. A poor man's prop angle gauge. . I also have the prop shop on the field perform the same measurement. They got 13.8 and I got 13.95. The spec is 13.9. Either way, both measurement is within 0.2 tolerance. The phone was first placed on the floor above a 1-2-3 block to measure the floor angle as a baseline. The prop angle measured between 14.8 to 14.7. The number jumps every few seconds. I would call it 14.75. Subtracting the floor measure of 0.8. I have 13.95. The good news is, low stop on prop is not the problem. The only thing left now is the governor sending unwanted high pressure oil to the prop. Unfortunately, there is no way to remove the governor from the equation. My next stop is either overhaul the governor or get a PCU5000. As for PCU5000, besides lighter weight and newer design, what exact does it do that outperform the 50 years governor in my bird? 1 Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 27, 2020 Report Share Posted May 27, 2020 Sweeeet! If that is the blade angle, that set up will surely measure it... I think you get an applied mechanical engineering degree for that... The PCU is going to be a smaller more modern device... only because manufacturing technology has evolved some over the decades... the existing technology works so well... a new governor probably won’t do anything magical... Of course... with a JPI900 collecting data... you might actually see a difference on how well it controls the rpm... So you have the choice of OH what you have... or buy brand new... the OH is nearly the same as the brand new cost... then you are concerned of who is doing the OH with what parts... There may be one step in between... that would be buy a used one off the shelf and maybe get lucky... I OH’d the one on my 65C... the fly weights are on tracks and constantly moving... a few thousand hours on it.. they do wear a bit... the problem I was chasing was the seal in crankshaft.... Which, by the way... Give that a look while you have the prop off... it is at the back of the hole... a piece of aluminum that gets hammered into place... if it falls away... the prop oil pressure sneaks by it... I chased low prop oil pressure for a few days... before MS was around... the EAA gave me nearly the answer I needed... my prop was stuck on the stops, nothing but high rpm... exceedingly high rpm... I had a horrible budget to work with... PP thoughts only, not a mechanic... Best regards, -a- Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 27, 2020 Author Report Share Posted May 27, 2020 I just reviewed my log book and look like the governor was last overhauled in 2011. The big surprise is the governor doesn't match any thing the prop shop says I should have on a IO360-A3B6D engine. Mfg: Woodward Model: B210345 Does any one knows anything about Woodward governor? Quote Link to comment Share on other sites More sharing options...
carusoam Posted May 27, 2020 Report Share Posted May 27, 2020 Suddenly, a light comes on... ? How many hours since 2011? Lets see if @M20Doc knows about governors and IO360s... (See quote box below) Best regards, -a- 7 minutes ago, corn_flake said: I just reviewed my log book and look like the governor was last overhauled in 2011. The big surprise is the governor doesn't match any thing the prop shop says I should have on a IO360-A3B6D engine. Mfg: Woodward Model: B210345 Does any one knows anything about Woodward governor? Quote Link to comment Share on other sites More sharing options...
corn_flake Posted May 27, 2020 Author Report Share Posted May 27, 2020 Found more info on Google. These guys are selling the exact same Woodward governor and claim it fits M20A-G. I have a M20E, it would make sense someone would install a Woodward B210345 as a replacement. However, since my engine started its life in a M20J, the original governor should have been either C290D5/T17 or DC290D1/T5. (Ref to page B-347). I wonder if someone could have replace it with a wrong governor based on the my aircraft model, instead of the engine model. In any case, PCU5000 isn't going to since it is not STC for M20J power plant. So, overhaul may be my only option. Quote Link to comment Share on other sites More sharing options...
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