Love the video! As a new pilot and Grumman owner myself, this was informative. I have to say, I am also extremely impressed with some of the a**hole pilots/people commenting. Who knew they were professionals at overhauling props! Keep up the good work.
This is the best Grumman Pilots video I have seen so far. I got a price of 820 at a Tulsa shop for my McCaulley. Too bad this guy doesn't work there...
This video starts with my pet peeve. I've been a pilot and mechanic for decades and I've seen it time and time again. If your going to clear the prop before starting, which of course you should, then give someone time to get clear of the prop!!!!! Believe me. I'm not twenty anymore and if I'm shoved up in the wheel well or wrapped around the nose strut, it takes me more than one second to realize what is about to happen and get out of the way!!!!! I know this video may have been edited but I've seen pilots hit the starter before they finish the phrase, "clear prop." Give the old mechanic five seconds of so to move!
GOOD POINT, thumbed up. Pilots forget that phrase ACTUALLY HAS SERIOUS MEANING/implications. Kind of like liturgy, just words spoken "cause you have to".
So what, no using of ultraviolet dye penetrant to detect possible hairline cracks somewhere? Apparently sanding and polishing just somehow does not remove those. Anyway, I see you will fly and film for food? Great, as soon as I need out of sync filming work done, I'll be sure to call you right away.
In 1983-4 I for get, a company that I worked for owned several AA5B’s one Saturday evening I was at the company HQ, in Chamblee, GA. One of my co workers a student pilot had a need to deliver a Computer monitor to Augusta, Ga he asked me to fly him that night. On departure from Augusta I felt a strange vibration on take off. I returned and landed. Looking over the airplane I could not find any thing out of order. So we flew back to Kpdk with no issues. The next morning another co worker departed PDK for GSO, on board N 28820 was his wife and 5 year old Daughter. 45 minutes south of GSO the Prop broke and slung a blade. The pilot shut the engine down as parts were separating from the airframe due to the vibrations. The engine separated from the airframe at about 10 feet above the ground. No one was hurt it totaled the airplane.
Need to sync the video/audio. Great vid, otherwise. The shop noise didn't bother me, at all, that's the environment. It would be interesting to see some performance numbers from the prop before and after the fix/refurb. That little prop checking/jigging station he has set up looks really simple, effective, and versatile...well thought out and/or iterated to its present configuration. I suspect the vibration reduction is probably the largest factor, with the spanwise pitch corrections coming in second, and the trailing edge cleanup drag reduction, if it doesn't negatively effect the airfoil as the next largest. I also suspect the L/D performance numbers would show little to nothing, but I could obviously be wrong. The vibrational analysis design technique (trial and error) was interesting, but I would think good FEA and fluid dynamics sims would eliminate most of that. And he's not exaggerating, any kind of plating I've seen HATES impurities on the surface, especially oils.
At 14:03, may I suggest that when repitching that propeller one does not push only one side/arm of the torque wrench, as that is not exactly a pure twisting torque by itself, it also has a downward component which could affect the tracking of the tip. In fact, it is clearly seen that both the leading and trailing edge at the tip were deflected down. If it was a torque, then while the leading edge went down the trailing edge should have gone up. One needs to be very careful about how one gigs up for the adjusting of the pitch. Apart from that, it was a good sequenced procedure and workmanship.
Yup. Given this guy's knowledge, my guess is he just grabbed the wrong word. Unfortunately, in this case, it was the OPPOSITE meaning. You wouldn't believe how often that happens unless you do some vids where you speak. ;-) I watch some of mine, and just roll my eyes up in my head, with some of the stupid stuff I say in them. Sometimes it's so bad, I feel compelled to retake the video section. Here, this guy probably didn't have that option (then just overlaying the correct word in text "I meant work hardening" is a good fix) and wouldn't be a bad idea here, then he could also fix the video/audio sync problem, which is immense.
Actually, take a piece of copper wire and start bending it in half fast. It will heat up. It's that heating and subsiquint cooling is what Annealing is. Which in turn, through many processes of this, it makes the metal toughen and eventually if it's done enough times, it'll become brittle and break. Heating and cooling is EXACTLY what Annealing is.
@@tonym3675 No, what it will do is BREAK, and that is partially due to work hardening. You would have to bend it at about 20 Khz to heat it enough to anneal it, that doesn't happen at 120 degrees, barely within an order of magnitude of it (10X). This stuff is well known, well measured, well understood (now even at an atomic lattice level), and well documented. It is used EVERYWHERE in industry. Arguing it is TOTALLY senseless. Just go look it up or do the experiments for yourself, but you need a hardness tester of some sort to do it. Educate yourself, you are ignorant on the subject. And yes, in my engineering curriculum we had a course called "Structures and Properties of Materials" that dealt exactly with this issue, any many many others. Just go ask anyone that uses it in the industry or any knowledgeable blacksmith. You CAN'T argue against known facts, not with any intelligence.
@@MrJdsenior i CONCURE,You arguing it in the way you attempted is indeed you being senseless. Ever reloaded bullets. Well they are brass and when we want to make the case neck harder in order to hold the bullet tighter, we gently heat the case neck (not red hot but a far cooler temp. Just enough to basically see a slight color change in the brass). We do that to yes! annel; that neck. If we get it too hot it will not hold the bullet but rather as we push the bullet into the case, the case will then crack or completly break. Metal will indeed get harder even if the slighest heat hits it, the hotter the harder and more brittle it becomes.Work hardening is somthing compleatly different. but then again, over a period of time, of a piece working back and forth or up and down at a hard/solid connection point, it too will break. and that is indeed metal fatigue. A prop is spinng in the neighborhood of anywhere from 700 rotations per min on upward to 4 thousand rpms. Add to that air desinty, forward movement trough it and other calculationg factors and that prop gets hotter than you trying to use a propane torch to achieve that same thermal heat that the prop does. Yes, the prop has foward and backward deflection as it moves, but that's not what causes the prop to crack! it's in fact the anneling that causes it to get hard/brittle enough to get stress cracks and the ilk. Deny it or argue it different all you want, but you are not correct. I'm done. it's clear you don't understand metallurgy .
What surprised me was how crude the overhaul was. Take a look at surface with a x10 magnifier and it's probably rough as F*** with thousands of potential crack points. I've done some aluminium polishing on 'aircraft grade' aluminium, 6061, 7075 and various unknown 'high grade alloys The amazing thing is just how long it lasts with all of that plus all sorts of flexing/twisting as it's pushing air
My original video IS IN SYNC. I just checked it. Not sure how this version posted by GPA, with my permission, got out of sync. If it bothers you that much, see the original here: www.aviationsafetyvideos.com/wrench.html Cheers, Bob Reed
I'm curious is there not a company that can x-ray props to see if they have stress cracks in them? Just curious. That seems to be the way I would want my prop to be inspected and overhauled. Any good shop guy can use bead blasting, scotch brite, a few indicators and paint to make a prop look new again! Any good machine shop could do this!!! Just my opinion!
Readings of the Statement can Extend All Human Hopes LaAllahaAlllaho MuhammadorraSoollah Swalllahoalihywasallam Ashabehi Ajmaghin Alyhi Be Beu Beuti Beautiful work In free time... Excellentest..
Am I the only one frustrated by the talking-head. Camera on the technicians face, not on the gauges nor prop he is talking about. Through out the first seven minutes not once does the camera focus on the gaguges, or the prop. Example at 6:10 he shows a measuring stick with no explanation at all of what it is, but I know it is 60 years old. Next at 6:24 we are shown a "cross-section" gauge, again without being told what it is or does. A few seconds later we are told he is using it, but we cannot see it, the prop nor what he is doing. Just the hub of the prop is visible.
The guy is a guest in a business, it's not a full on production. Seriously how much do you expect? If you want more, go contact the company and pay for his time and I'm sure they'll cover everything in detail. But until then be thankful that they were able to share what they did.
Look it was a great honour to see what we did,skills that we never get to hear about ,you are not going to get an instructional video from a shop visit,not every company is partial to an outsider making a video of their work so lets show some thanks for the insights into propeller overhaul.
@reverse thrust Funny you mention those. I had a hive stand in a field next to some trees (partially shaded, this is a beehive stand) and long ago, the wind blew it over. It was just the stand and it was not beeing used AND I char my hive stands (burn them slightly)---get to the point, damn you! okay okay, any-hoo, it had termites just starting in it. Termites? Poison the living fuck around the hangar, in the ground. Poison, poison, poison. I don't think they climb up onto concrete (but I'm not sure on that one). That's my solution, what would you do? Perhaps a semi-perfect solution would be a titanium prop. I'd hate to pay for that one, though!
Because its probably a cold draughty shop and you loose heat from the top of your head,if you have never worn a cap then you would not have asked that question !
