maniago

Quote: nels The prop might be bent but the spinner's look very aerodynamic.

Attached Images I would like to note two things about this picture that PK posted. 1) What Mooney model is this, because I want one! 2) The propeller on her head is bent. Someone must have been pushing and pulling by it (BTW, on reflection, my above comment is entirely out of line and un-professional. I will delete it...later)

Quote: N4352H This can happend applying power too quickly, overspeeding or other....not just a prop strike.

Quote: scottfromiowa Naw, it was the last gasp of this pathetic thread...

Quote: jetdriven Or is this another bullshit wives tale?

Quote: 201er ....I don't have the physics degrees to justify my explanation but to a layman like me it would seem that an essential/functional surface like the prop would be stronger and better supported than a mere aerodynamic/aesthetic item like the cowl?

Ok I concede. I'll tell Sean Tucker that to stop doing that aerial trick where he hangs the airplane stationary on the prop in mid air because the prop can't take all that load. The prop is going to bend in half and he'll die. After all its only 2000lbs the prop is holding up. Silly Sean.

In todays ePilot is a link to Engine and Prop short course, ASI credit. Note that inthe prop section it doesn't say anywhere that you "mustn't" pull on the prop when tugging the plane by hand. Of course lack of mention of something doesn't prove anything, but I just thought I'd note it here for argument sake. It does however have a neat pic of where stresses are on a rotating prop, ie max and min flex stresses... https://www.aopa.org/asf/osc/loginform.cfm?course=engine_prop&project_code=&WT.mc_id=120203epilot&WT.mc_sect=sap

PK, You can usually find anything on You Tube, but I struck out on crankshaft flex, which is odd since its totally cool to see. Probably have to dig into a drag racing forum. However, I then looked for camshaft flex as they do the same thing and got this: Personally I had to stop it as I began to hurl! Your mileage may vary haha

PK, They are not totally different. They are totally related. Static tests and stressors are related to dynamic tests and stressors. When we torque the bearing cap bolts on the crank, the crank is static. But we know that those torque settings will provide the correct amount of "holding power" when the crank is flinging around dynamically. So is the same with the bolts that hold your prop to the flange. A really good slide rule engineer would probably model that moving prop as just a prop that is stationary for a micro second, then is in a new stationary position a micro second later. And the two positions and stressors in those positions are interrelated and can be recreated in a much more static modulus test. Harmonic stresses are much harder to test for, and tend to be empirical (tho a nod to computers must be made these days). That said, pulling on your prop is far more akin to the static testing, for which the entire assembly (ie the whole airplane) has been modeled and tested. But I understand what you are trying to say, and it is important to approach the subject cautiously and "safety-wise", as you are. Some people use caution where its not necessary, but that's a whole lot better than throwing caution to the wind instead. Similarly, I hope you change your oil more often than 50hrs and fly every two weeks to keep the water off your cylinder walls. But its not required! haha M.

But isn't that what we are doing? Trying to dispell wives-tails and rumors? Not long ago, this would have been a heated discussion on "to lean or not to lean", having forgotten what our round motor breathren knew long long ago... But, I don't see personal attacks or name calling. That is clearly beneath us.

Quote: allsmiles I don't think so. I respectfully disagree. You know, what is really disturbing is that we have these engineers on here who should, in theory at least, have a different perspective on things. You, an engineer, can't understand the real physical issues introduced when a localized force is applied on a small area of the blade of a prop at rest? You don't see how this can potentialy "bend" the blade and at the very least throw it out of track? You don't understand that that the prop relies on centrifugal force to stay rigid? Which only happens when it is spinning and not present when not spinning? You as an engineer don't undestand that the phenolic links are not very strong in tension such as when you push on a static prop but extremely strong in compression such as when spinning? You don't see that applying a localized force on a static prop can cause misalignment of the actuating pin mechanism and upset the blades in the hub? Really??!! Let me attempt to enlighten you. A spinning prop is indeed very different than a static one. It relies on centrifugal force and draws its strength from the compression forces of this force. To make the argument that the prop withstands much greater loads in flight than can ever be applied to it by pushing on it is ludicrous. Unless ofcourse you try to push on it in flight and compare the forces. I never handle my airplane by the prop nor will I allow anyone else to do it. But each to his own. And these are my two cents.

Quote: 201er You could. We're having a New Jersey Mooney Pilots Fly in at KVAY tomorrow from 11-2. He's based there and said he'll drop in. He can have the beer but you probably can't

Quote: 201er I didn't realize this would be such a mathemetically sophisticated topic that it would stir such intellectual debate beyond mortal comprehension so now I'm curious if a majority does or does not handle plane by the prop on the ground. I couldn't add a poll to the original topic so I guess just keep discussing it there but find out where we stand on this poll.

Quote: jetdriven Do give us a proper analysis of the physics involved... please!

So lets see. The motor is connected to the frame; the prop is connected to the motor. Your hand connected to the prop to pull or push gently on the ground. Oh sure your huge-ness can do damage to the whole assembly by pulling on the prop, but no damage happens when the prop is pulling at throttle up on the runway or in descent holding you and the whole assembly back. Seriously? Give me a break. Think about it people. The critical components are called thrust bearings. You arent going to damage diddly by pushing and pulling with your fat as..es... errrrr I mean weight. Its not tin foil they are made of. You can't generate enough thrust to even rouse their knowledge of your existence.

Quote: galt1074 I don't have any experience with the Apple products, but I have an Android with an App called Navigator. It's great for moving map, and airfield information. It's only about $50 for a yearly subscription or about $5 a month. No XM weather or ADS-B at least as far as I can tell but it is a very simple App that works great for simple VFR flying and is pretty handy as an airport directory. The only to figure from there is what screen size you are looking for. Just don't count Droids out...I plan on getting one of the tablets soon. Greg

Quote: allsmiles My personal opinion is that although the iPhone is small the iPad is too big for the cockpit! I personally prefer to use the iPhone as a backup with Skycharts Pro.

Quote: jetdriven Iphone screen is too small for navigating in the plane, it works great as a preflight tool.

Ok, I know this isn't specifically mooney related, but it is IFR flying related, and I'm working on my commercial rating so I need some experienced XC fliers to help me decide (I did a search and there's nothing specific on phones since 2009). So new thread. Background: I have to get a new phone because the twins just turned 16 and I can't put them off any more, so they get our old non-smart phones. Besides its better than "Dad, can we have a car?". uh, right? That said, Foreflight or WingX are my first deciding factor, and frankly I like WingX (I think). Then its Iphone or Android OS phone (Galaxy Nexus with ice cream seems quite good). However, it also seems Android phones are trailing with regards to the two affore mentioned apps, but I'm not really Apple sold either. So what I'd like to hear from anyone who uses these is something like: "I've got X app and have Y phone and it works for me pretty good for Z missions; but, not so good when I do...etc. Sure don't want to start a phone or app bashing thread though....Thoughts anyone?

Man, this is the oddest group of forums I've ever been on - wierd animal pics, horse jerky, repeating posts, and how to measure your prop in 20 different ways. Next up: plusses and minuses of "Look-Ma!-No-hands-landings" explained - grass, tarmac and water (extra credit). I might buy in just for stories I get to tell to my FBO lounge-rats....!

Quote: rbridges We're short people in my family. I'm 5'8, wife 5'7, my folks (getting) smaller haha. Kids, damn kids, are 5'10. So if I'm in the upper left, who can fit in the rear left? And a 5'10 kid in the upper right, who in the back right, so to speak? Again, if its airline style ala American or Delta back of the bus-class or better, then its all GTG by my standards. Comments?

Hmmm odd looking beast...

Not trying to be sassy, but if this has been beaten to death numerous times, the fact that it keeps coming up means it need to be a STICKY! Or better yet, put in a FAQ file with other kinds of often asked questions....hmmm? BTW, never had horse jerky. Is it any good?

Quote: Hank Two quick notes: 1) pushing the plane around on grass is difficult; 2) with the 3-blade positioned to allow towbar access to the front wheel, there is a LOT of clearance [knee high or more].