Nah, it is a MBB 105. I flew them in the late '70s and early '80s. Rigid rotor, composite blades, and an extremely stable platform. Almost instant response to control inputs, unlike the articulated rotors systems of the past. When I first transitioned to the MBB 105 I initiated a zoom climb and found myself upside down, so I completed the loop and had to change my drawers later.
#7 is an example of the same effect that destroyed the Tacoma narrows bridge, affectionately known as "galloping gurdy" IIRC. It's pretty impressive, and the video of that failure has been a staple of structural engineering courses for 50+ years now. Just as much as horror stories of the great molasses flood.
It was thought to be harmonics for a long time, but has more recently (as in, about 30 years ago now) been shown to be a self-reinforcing oscillation. Basically, the bridge twists, and catches the wind to make it twist more, and jump up and down more.
Bad news, it's outside design load and stress (metal fatigue) will eventually destroy it. Need to build it more rigid, or make the decking material a grating so it doesn't catch the wind. When they rebuilt Galloping Gurdy, they decided to make it more rigid.
Not more rigid, just heavier or, make it more aerodynamic. The Whitestone Bridge in NYC had that problem when first built, the substructure was very deep and (comparatively) light. Truss girders were added to the bridge deck to stiffen it (wrong answer!) and increase the mass, thus lowering the harmonic frequency. When the bridge was renovated in the early 2000s, the trusses were removed ("Friends, throw away that truss") and fiberglass fairings were added to the sides of the bridge to allow the wind to pass over and under the structure more easily. The bridge;s weight was reduced by 6000 tons which will lead to increased lifespan for the suspension cables and suspenders.
#3. I had a laptop where the battery stopped holding a charge. When I replaced it, it was bulgy, but not that bad. I took it to the range and put a .22LR bullet through each of the cells and got some nice flare-ups.
#10. Would like to see the rest of the video. The rotor blades should have collapsed when the aircraft did the first kickover.
ReplyDeletehttps://en.m.wikipedia.org/wiki/MBB_Bo_105
DeleteNope!
Alberto
Nah. That's a BO-105. They're known for being aerobatic.
Deletehttps://youtu.be/vB1rz9EBhP8
https://www.youtube.com/watch?v=VC2E8RJE3J
DeleteSikorsky CH53A did it in 1968 except the 53 did a true loop, not a longitudinal roll.
https://stuartairshow.com/red-bull-helicopter
DeleteLots of YouTube videos available of this amazing contraption.
Look up Red Bull aerobatic helicopter.
DeleteMBB BO 105 (later Eurocopter) with a hingeless rotor. Acrobatics- YES!
DeleteNah, it is a MBB 105. I flew them in the late '70s and early '80s. Rigid rotor, composite blades, and an extremely stable platform. Almost instant response to control inputs, unlike the articulated rotors systems of the past.
DeleteWhen I first transitioned to the MBB 105 I initiated a zoom climb and found myself upside down, so I completed the loop and had to change my drawers later.
Flown on Bolkow 105s many times. If there's only one pilot you can ride in the second front seat, what a view!
DeleteWhat the hell is number 3?
ReplyDeleteStabbing and shorting out what looks like an already defective battery.
DeleteThanks, a puffed lithium cell just didn't occur to me.
DeleteRight - looked like some horrible 'pean MRE
Delete#7: https://www.youtube.com/watch?v=XggxeuFDaDU
ReplyDelete#9 Guess who won't be coming into the house anytime soon. But that dog will come out of there with the best grin on his face. It was worth it.
ReplyDelete#5 - Inflation hitting the US and crushing the Middle Class.
ReplyDelete# 4 One good hard application of the brakes coupled with a slight swerve to the right would put a stop to that kind of crap
ReplyDelete#6 The Biden Presidency
Look up Red Bull helicopter for more on the last gif.
ReplyDelete#7 I was sure someone was going to skateboard across that
ReplyDelete#7 is an example of the same effect that destroyed the Tacoma narrows bridge, affectionately known as "galloping gurdy" IIRC. It's pretty impressive, and the video of that failure has been a staple of structural engineering courses for 50+ years now. Just as much as horror stories of the great molasses flood.
ReplyDeleteIt was thought to be harmonics for a long time, but has more recently (as in, about 30 years ago now) been shown to be a self-reinforcing oscillation. Basically, the bridge twists, and catches the wind to make it twist more, and jump up and down more.
Bad news, it's outside design load and stress (metal fatigue) will eventually destroy it. Need to build it more rigid, or make the decking material a grating so it doesn't catch the wind. When they rebuilt Galloping Gurdy, they decided to make it more rigid.
Not more rigid, just heavier or, make it more aerodynamic. The Whitestone Bridge in NYC had that problem when first built, the substructure was very deep and (comparatively) light. Truss girders were added to the bridge deck to stiffen it (wrong answer!) and increase the mass, thus lowering the harmonic frequency. When the bridge was renovated in the early 2000s, the trusses were removed ("Friends, throw away that truss") and fiberglass fairings were added to the sides of the bridge to allow the wind to pass over and under the structure more easily. The bridge;s weight was reduced by 6000 tons which will lead to increased lifespan for the suspension cables and suspenders.
Delete#2 Get your fat ass on a diet and take the stairs a few thousand times so you don't die from falling over and suffocating in your fat.
DeleteThis site has some of the best commentators. Thank you.
Delete#3. I had a laptop where the battery stopped holding a charge. When I replaced it, it was bulgy, but not that bad. I took it to the range and put a .22LR bullet through each of the cells and got some nice flare-ups.
ReplyDelete[rocketride]
#4 makes my blood boil. I'd be angling just a bit to the right and stomping my brakes hard.
ReplyDeleteCyclists are CANCER and stuff like this is why I'll never think differently.
#9: Just Golden things. Usually about an hour after getting home from the groomer. "Okay, let's see if we can keep you clean for one day this time."