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Whatziss (with a twist)

I’m sure you’ve all heard the military procurement horror stories -- the $500 hammer, the coffeemaker for the C-5 that was built to withstand G-forces that would turn the crew two-dimensional, the Air Defense system that showed a preference for engaging the broad side of a barn rather than an attacking aircraft, et cetera, et cetera, et cetera. Some of the tales are the result of the “investigative reporter” jiggering the figures, some are the result of imperfectly-written specifications, some are genuine cases of Waste, Fraud ‘n’ Abuse and still others are the result of what Dusty so aptly described as Pugnacious Stupidity.

The ol’ “My mind is made up -- don’t confuse me with the facts” Syndrome.

“The reg sez thus-and-such, therefore thus-and-such it is and ever shall be” -- even though the (never identified) reg may refer to something else entirely. Or the reg might just be flat-out wrong -- it was written by a human being, after all (the classic appeared in a series of changes to the OH-6A Operator's Manual, defining FARs -- Federal Aviation Regulations -- as Flying Aircraft Regulations). Or, the reg might have been correct when written, but is now hopelessly outdated.

The most expensive item in my little museum came to me courtesy of outdated specs augmented by a slavish adherence to the regs. This little beauty (*not* the needle-nosers) cost the National Guard $7,000 in 1988 dollars, as did each of its four-hundred-odd brethren.

View from the Top. Or a reasonable facsimile

What was it worth upon delivery, after its rather tortuous journey through the procurement process?

Nothing. Zip. Zilch. Nada. Nema. Rien. Nulla. Không. Nichts. ничто. For its intended application, anyway.

The reason for its transition from a shot-peen-hardened, single-block-milled, fairly expensive aircraft part to a shot-peen-hardened, single-block-milled, fairly expensive hunk of junk is visible in the pic below:

Kinda gives a whole new meaning to the term, “Military Gear,” huh?

And, for the metallurgical detectives among you, here’s the Hi-Rez.

Geez, I even impress *me* with how good I’m getting at this close-up stuff.

“Well, first off -- what is it?” you inquire. Well, since it’s kind of an esoteric part, and since you’d have to be an especially groggish grognard to know for absolute certain-sure what it is, I think I’ll be lousy, mean, rotten and spiteful and let you guess. Even Jon the Knuckle-skinner is gonna find this one a toughie.

But I can use the chuckles.

Ummmm, sorry, Miz HomefrontSix, ma’am, it’s not the gear that stows the rotor blades in flight to allow you to activate an ejection seat.

*going totally queasy at that visual…*

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35 Comments

Bill, I'm not sure what it is yet, but I'm betting the gov't would have returned the item if it hadn't been made as ordered, so either: 1) The s/n engraved on the part that's shiny ruined it, since that part of the gear is supposed act like a bearing and sit in a clamp or seat (and rotate in there). OR 2) The gear was cut properly (IAW the spec), but the teeth of one ring are cut backwards Just guessing... V/R
 
Hiya, Sanger! 1. The item was manufactured as ordered and the s/n engraving, while a tad unorthodox, is located in a noncritical area. 2. See #1. The gearing orientation is okay. As usual, hints are scattered in the rotorwash.
 
Bill, I'm guessing that the mettalurgy changes do to either heat or pressure and caused the part to go out of shape. You can see discoloration, which looks like heat bluing, on the vanes. Probably out to lunch, but that's my guess..... Respects, AW1 Tim
 
The initial runs of the gear did not get full tooth contact, so something is out of shape, I think. You can see that in the lozenge shape wear marks on the teeth, rather than full width contact.
 
Discoloration on The Vanes??? Why, I think that those polychromatic shades of patina confers an august je-ne-sai-quois to that paper weight ;) Oh - 'Tis nice to hear from you SangerM
 
AW1 Tim - The pic was shot under fluorescents, which is prolly where the burn-blue came from. Have a beer for *me* at lunch, too. SezaGeoff - The lozenge shapes are part of the finishing process rather than from wear. The part itself is brand-new; the lozenges would disappear during the first hour or so of run-time. Boq - The Prescient Puerto Rican! The Mind-Reading Moatmaster! Wait 'til you see the last pic in the dénouement--haaaaa!
 
Since you hint at outdated specs...I'm going to say that the teeth should be curved.
 
It is some kind of planet gear, possibly from the tail rotor gearbox / transmission. I'm a fixed wing guy, I stay away from that whirlybird stuff (a.k.a. a flying oil leak on its way to a crash).
 
The upper, smaller set of gear teeth have some sort of extra teeth, with an odd slope to the "tooth height" from bottom to top of the piece? Or am I seeing things? It makes a nice background for my monitor this week, I look forward to the definitive answers to both what-it-is and why-its-worng.
 
Looks a lot like the flywheel for an engine. The thing I don't get is why the grooves in the gear-looking-thingie tilt to the right on the bottom, and to the left on the top. Seems like they're working against each other. Perhaps it's for the tail blades??
 
is it cuz the cuts betwixt the smaller teeth intrude too far south into the curvy such zone?
 
It looks like a transmission gear of some sort. My theories: 1. Is the part made from the wrong metal? It appears to be some discoloration/rust on the left half of the piece. 2. Is the recess around the larger ring of teeth excessive? Given the depth of the cut there is little material left to support the outer ring.
 
MajMike... I'm not sure it's possible for teeth of any size to intrude too far south into the curvy zone. At least that's been my experience. *wink*
 
Has the wrong part number engraved on it. Confused the beddezers outta everyone...
 
Since he who flies a blender called me ou on this one, I am going to have to say that it looks like the reduction gear in a transfer case of some sort. However, since none of the vehicles I work on were like Bill's first car and designed by Henry Ford, I can not tell you specifically where it comes from. And WK, it IS possible for teeth to intrude too far. When blood is drawn, they have gone too far.
 
Since it's a double-gear and probably just rides a bearing... no keyway if it's supposed to be driven by a prop shaft?
 
does it matter that in the top view theinnercut is not so much a circle but an oblong?
 
and not centered--
 
...it's a double-gear and probably just rides a bearing... Heh. If it just rode a bearing, what rendered it worthless wouldn't have mattered. Got some rounds real close, but still not within bursting radius. Lotta techie talent appearing, too, based on observations such as the grooves in the gear-looking-thingie tilt to the right on the bottom, and to the left on the top.
 
if rides on a bearing _wouldn"t the eccentric cut of the possible bearing seat make its rotation both ingaged and disingaged 'If' the center is the bearing seat.'If'
 
I give up. Don't know where that Gear, Worm Wheel goes into. {snipped because it's too good to leave in a comment!}
 
I'm not going to be able to live the ejector seat thing down, am I? *da%n* Ah, well. Nothing ventured, nothing gained, I suppose. In my defense, I had momentarily forgotten that we were talking about helicopter parts and was focusing on fixed wing aircraft at the time. As for the gear, WHY do I always get to these things AFTER MacGyver goes to work? Grr. Time to start digging. - hfs
 
Gear teeth and hub appear discolored... improper heat treating during manufacture???
 
Gear teeth and hub appear discolored... improper heat treating during manufacture???
 
Ben - That's just the off-angle perspective. The shaft's perfectly round, but I couldn't shoot straight down without my shadow obscuring it. Hf6 - I'm not going to be able to live the ejector seat thing down, am I? *da%n*. I'll cut some slack for anyone who can keep Maggie even *halfway* out of trouble after sundown. Not much, but some...
 
It's probably just like Spinal Tap's StoneHenge. Someone screwed up the scale in the spec and it's too small.
 
I don't know that I kept Maggie out of any trouble while we were in D.C. but she sure didn't get INTO any trouble while she was with me...not sure that counts but it's worth a shot! And, no, the half-moon did NOT get her into any trouble! - hfs
 
One set of teeth are cut with the helix pointed wrong-handedly? Maggie: As I wrote, and the Chief verified in a previous thread, *sideways* ejection seats will get you out of the aircraft. You just might be all bent and twisted, afterwards.
 
JTG - Maggie is Princess Crabby, *not* HFS (HomeFrontSix). Dude, you've simply *got* to do a better job of Denizenne Recognition. Report for retraining.
 
B-b-but Sir, she *mentioned* Maggie in her last comment, and that confused me! OK, Mea maxima culpa, I dood it. (blushes)
 
And here I thought the Sgt York had a preference for shooting the ventilation fans on a field latrine instead of a helicopter. Not sure who put the latrine downrange.
 
JTG - but MAN...what a COMPLIMENT to have been confused with Miss Maggie ;) She and I do have the crabbiness in common... BillT - no more clues?? C'mon...help a girl out here! MacGyver isn't home yet!
 
Ok - MacGyver finally made it home. He says it looks like a transmission gear and that, from the top view, it's not centered. The entire shaft is off center. The other observation he had was that, in the second picture, the teeth on the top part of the gear seem to hang down and are not flush at the bottom. Not sure if this is a problem since we don't know what its purpose is.
 
Have MacGyver turn in his duct tape for recalibration and then read Ben's comment and my reply. The bottoms of the top teeth are buttressed--re-inforced at a potential trouble spot. Keeps 'em from cracking and splitting. Here's a hint: Old Helicopter. Like, from 'way before you had reached double-digits on your birthday cake--1988.
 
Mac sez: The cut into the valleys is too deep. This is evident by the machining grooves that can be seen in the buttress. ie the bevel at the bottom of the top gear. If the cut was made to the proper depth, machine marks would not be seen below the bottom of the top gear. The depth of this cut has negated any additional strength that the buttress might have provided.
 
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