Will be interesting to see what happens Next The FAA and Boeing cooperation has been so so at times " Like dogs watching television "
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Just out of curiosity - Airplane Guys
- Thread starter Downeaster
- Start date
Will be interesting to see what happens Next The FAA and Boeing cooperation has been so so at times " Like dogs watching television "
HH had many lady friends, they say, and when I was 19 I listened to pillow talk about him. She was at that time "49" and well worth knowing. OTT my lips are sealed!
My recollection is slightly different, though only in detail... from reading - this is that the rivet holes were punched, not drilled, such that incipient cracks exceeding a critical growth size were thus formed. One of the fix changes (in addition to oval) was to drill the rivet holes. I have punched lots of aluminum and steel and stainless in sheet metal fab...with the observation that punch dies are almost always "non-ideal", as in phuched up. .................. A GE engineer I worked under in the 1980s, over pizza and beers at the completion of a steam turbine overhaul, said that the alloys developed for the recip engine airframes were not fatigue-compatible with the gas turbine vibration spectrum, at least in his days in that department...circa 1950's..so he said. He told some stuff about the bomb, too...which I have kept to myself, but it was interesting. He must be dead by now... Nice guy. I took his stories as sincere, but a with a grain of salt.
Nope.
On second thought, and after a quick look under rubric "comet airliner crack propagation punched holes"
https://www.thinkreliability.com/case_studies/comet-accidents/
https://www.sciencedirect.com/topics/engineering/de-havilland-comets
"In this case, rivet holes that punctured the skin, which were used to attach the aircraft windows, acted as the “flaw” where cracking could begin. Fatigue cracking caused the crack to grow, and there was nothing to stop the crack from propagating,"
I guess my old pal was telling a true... It made sense at the time...
https://www.thinkreliability.com/case_studies/comet-accidents/
https://www.sciencedirect.com/topics/engineering/de-havilland-comets
"In this case, rivet holes that punctured the skin, which were used to attach the aircraft windows, acted as the “flaw” where cracking could begin. Fatigue cracking caused the crack to grow, and there was nothing to stop the crack from propagating,"
I guess my old pal was telling a true... It made sense at the time...
Kinda hard to cite a negative, no?
Have I ever "punched" rivet holes? Yes I have, but rarely, and only on non-structural type stuff. Interior panels and such... stuff that doesn't affect structural integrity. Wing/fuselage skins... ribs, stringers and formers... all drilled with precision. That was all well understood back in the comets day also.
That Max has been very good for Airbus. I used to say “If it’s not Boeing, I’m not going!” Not anymore. More like the opposite where the Max is concerned.
From your links:
"Rivet holes that punctured the skin" A drill bit "punctures" the skin. there's nothing there to say it was "punched" instead of drilled.
"Rivet holes that punctured the skin" A drill bit "punctures" the skin. there's nothing there to say it was "punched" instead of drilled.
Countersunk holes are precision holes. Depth of the countersink is critical to a smooth skin. Kinda hard to believe they'd "punch" a hole then use precision tooling to countersink it.
AUTOMAN
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That needle nose put me in mind of the Douglas X-3, first flight October 20, 1952 and featured in an old 1955 Eagle Book of Modern Wonders I've had since I were a kid.
I know, the resemblance is only superficial, some people eh?
Thrust and AOA works every time...
Nine year old me was so impressed by that X-3. I mean, WOW.
But looking at Wikipedia, it seems the thing was designed as a Mach 2 plane but never able to achieve Mach 1 in level flight, due to the specified power unit not being available, so they fitted much lower thrust engine instead. But apparently, it gave useful data used later for the Starfighter?
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If you've got 15 minutes and are interested in the aircraft business, curl up with a good cuppa and watch this:
During a routine maintenance to service a fuel line, someone left a handheld flashlight inside the engine compartment and then test fired the engine. The resulting damage is said to have totaled the engine. I’d hate to be the guy that left the flashlight in there! 
https://www.newsbreakapp.com/n/0qqD2eQb?pd=04dsPR4T&lang=en_US&s=i16&send_time=1705681284
https://www.newsbreakapp.com/n/0qqD2eQb?pd=04dsPR4T&lang=en_US&s=i16&send_time=1705681284
