John Pleisse Posted January 27, 2012 Report Posted January 27, 2012 Trey Hughes from MAPA wrote a stern warning in his column some years back, suggesting repeatedly moving your airfraft by the blades could affect crankshaft weighting (my recollection). I think at the very least, if you go too far out on the blades you could affect your shimming. When you have a tow bar and a cowling, why do it? Quote
JaredDavis Posted January 27, 2012 Report Posted January 27, 2012 Just stating what is in the Prop manual. Not picking a side. pg 1-5 (37) "Never attempt to move the aircraft by pulling on the propeller." Quote
Cris Posted January 28, 2012 Report Posted January 28, 2012 Ok Now you guys have my attention. Does anyone have any documentation from any prop shop or any other place indicating that the prop had to be overhauled/repaired due to moving it by hand with the help of a tow bar? Frankly I think the "recommendation" from the mfg are more for legal reasons than enything else. We were all taught that a plane might start if you move/turn the prop ie fault ground. Having said this I try not to touch the prop & just recently thought I had a concussion from hitting the ground & then my head especially hard from a tow bar that slipped. I went back to my Robotow & holding the prop I'm a non believer Quote
PTK Posted January 28, 2012 Report Posted January 28, 2012 Quote: Shadrach If it makes you happy though, just continue moving you plane around by the convenient prop! Quote
Cris Posted January 28, 2012 Report Posted January 28, 2012 I get the point that McCauley, Hartzel and Mooney tell you don't move the airplane by the prop but what is missing is the rationale. There are any number of things in the POH and elsewhere that are there as warnings. In the instant case is the warning to prevent damage or to prevent inadvertent engine start or for some other reason. So I am asking is there anyone who has documentation from a prop or overhaul shop to show that handling a prop by hand caused actual damage? Anyone? Just sayin Quote
201er Posted January 28, 2012 Author Report Posted January 28, 2012 Good point Cris! Don't forget someone also said it could reflect on the crankshaft as well. So I am curious if actual damage to prop or engine has ever been attributed to moving it by hand. Quote
Dale Posted January 28, 2012 Report Posted January 28, 2012 When I started flying I was taught to never touch that prop to move the airplane. When I bought this mooney the MSC told me that if I was going to move the airplane by hand to only use the base area of the prop to move the plane. They said the cowling etc was not strong enough, like the prop, to do that. I questioned this with their mechanics and they insisted, said the warnings from the company and prop manufacturers were warnings to avoid prop injury should prop move. Have a good friend who I use to practice law with, has an undergrad degree from Embry-Riddle and does aviation law. I will ask and see if he knows if the warnings were for injury purposes or if they were to prevent damage to the aircraft. I resolved my concerns with the issue by purchasing a robotow to move the plane. I find this to be another thought provoking discussion. Thanks for everyone posting their thoughts on this subject. Quote
PTK Posted January 28, 2012 Report Posted January 28, 2012 Quote: N4352H Trey Hughes from MAPA wrote a stern warning in his column some years back, suggesting repeatedly moving your airfraft by the blades could affect crankshaft weighting (my recollection). I think at the very least, if you go too far out on the blades you could affect your shimming. When you have a tow bar and a cowling, why do it? Quote
sleepingsquirrel Posted January 28, 2012 Report Posted January 28, 2012 One should never hand prop an airplane because the torque applied by the "armstrong starter" is the wrong direction for what the crankshaft was designed. I guess this discussion has made me realize that I can pull by the prop hub but not "PUSH" on the prop hub because it a force in the wrong direction as designed according to the laws of physics and the engineering types. How did we get all those Cubs and Taylorcrafts started? Without damaging the crank shaft? Quote
scottfromiowa Posted January 28, 2012 Report Posted January 28, 2012 NOTHING I have read here has made me even consider changing my practice of steering with my right hand and pushing and ALSO grasping one prop blade right by spinner at hub and pushing my plane to get it up a shallow incline into my hanger...PK...chill Your response to Ross was OUT OF BOUNDS... Quote
PTK Posted January 28, 2012 Report Posted January 28, 2012 Quote: scottfromiowa NOTHING I have read here has made me even consider changing my practice of steering with my right hand and pushing and ALSO grasping one prop blade right by spinner at hub and pushing my plane to get it up a shallow incline into my hanger...PK...chill Your response to Ross was OUT OF BOUNDS... Quote
Shadrach Posted January 28, 2012 Report Posted January 28, 2012 Quote: allsmiles Both McCauley and Hartzell and Mooney I might add tell you don't do it. Quote
pjsny78 Posted January 28, 2012 Report Posted January 28, 2012 This is reminding me of my first post on mooneyspace. We are all bound together through our love of a certain type of plane (Mooney). We should all just try and get along. It’s such a simple topic, it should not garner this much frustration. I hope at the end everyone can become friends... Quote
John Pleisse Posted January 28, 2012 Report Posted January 28, 2012 Quote: Cris I'm a non believer Quote
Shadrach Posted January 28, 2012 Report Posted January 28, 2012 Quote: allsmiles You need certain prerequisites! Quote
rob Posted January 28, 2012 Report Posted January 28, 2012 Quote: Shadrach Well then tell me your credentials...so far you seem to be full of $hit and dataless proclimations. If you had just said "the mfg says don't do it, so I don't and don't think anyone else should" that would have been fine, but instead you felt the need to get pretentious about math and physics. When asked to expound on your knowledge, you infer that I lack prerequisites to understand your conplex explanations. PK, I don't really think that you're a DB; I just wish that you'd stop trying to convince me that you are... Quote
sleepingsquirrel Posted January 28, 2012 Report Posted January 28, 2012 http://www.youtube.com/watch?v=JnI7Z3qeW58 Yeah! What this guy said! You mean that if I can't understand what this guy said , I can't understand why I can't push or pull my Mooney by the propeller hub? I watch this stuff like it was porn! 1 Quote
Piloto Posted January 28, 2012 Report Posted January 28, 2012 There is nothing wrong on pulling or pushing the plane by the prop. After all thats exactly what the prop does when the engine is running. In fact I think it is a good form of pre flighting the prop. If it comes off the crankshaft when pulling the plane out of the hangar you know there is something wrong. BTW a simple fix to prevent the tow bar from coming off is to reduce the angle slightly (-5deg) between the tow tube and the insert tube. You can do this by placing the insert tube on a vice and forcing the tow tube down to reduce the angle. Recommend to apply heat at the junction while bending it. On old tow bars with a lot of use this angle tend to increase. New towbars has a slightly less than 90 deg angle. Quote
fantom Posted January 28, 2012 Report Posted January 28, 2012 Aanother tow bar simple fix is some duct tape around the insert tube.....no A&P sign off needed. Quote
gregwatts Posted January 28, 2012 Report Posted January 28, 2012 So....can we push the prop with the same hand that we pull the prop with??? Should the brakes be on or off? Quote
sleepingsquirrel Posted January 28, 2012 Report Posted January 28, 2012 Quote: gregwatts So....can we push the prop with the same hand that we pull the prop with??? Should the brakes be on or off? Quote
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