Tom22 Posted August 19, 2016 Report Posted August 19, 2016 The NTSB report is out on the March 22, 2015 Orlando, FL R44 crash that resulted in three fatalities. Quote
Guest pokey Posted August 19, 2016 Report Posted August 19, 2016 "bolt was liberated",, never heard it quite put that way b4. We usually just say "it fell apart". Not trying to be funny, so don't jump all over me. All the helicopter experience Mr Robinson has, i cannot understand tho, how he can build helicopters without extensive use of castle nuts and cotter pins (like real helicopters) and he relies on "pal" nuts. Must save what? couple hundred bucks per helicopter and a few hours labor? Likewise on the 206 thomas coupling,, don't understand why they do these things. Quote
terminal_velo Posted August 19, 2016 Report Posted August 19, 2016 What makes you think it was a design problem? Quote
Spike Posted August 20, 2016 Report Posted August 20, 2016 (edited) https://www.youtube.com/watch?v=IKwWu2w1gGk Edited August 20, 2016 by Spike Quote
iChris Posted August 20, 2016 Report Posted August 20, 2016 (edited) These are logs and bolts you can check on pre-flight. They should be torque striped per the maintenance manual; however, on some aircraft these torque stripes have worn-off or are otherwise missing. Add it to your list of things to take a better look at. The lower swashplate had four push-pull tube attachment lugs: aft, front left, front right, and front scissor. Push-pull tubes were connected to the aft attachment lug, front right attachment lug, and front scissor attachment lug. However, the front left push-pull tube was not attached to its corresponding lug and the associated attachment bolt assembly was missing, see photo blow. According to the R44 maintenance manual, the assembly consists of a bolt, safety washer, two spacers on either side of the rod end ball bearing, washer, self-locking nut, palnut, and a torque stripe. Remnants of torque striping were observed on the aft attachment lug bolt assembly but not on the forward right or front scissor lug bolt assemblies. The forward left attachment lug was examined for any remnant of a torque stripe but none was found. Approximately 5 minutes after the pilot departed he told air traffic control that he wanted to return to the airport, but did not specify a reason. The pilot was unable to make it back to the airport and collided with trees, powerlines, and a residence. Edited August 20, 2016 by iChris Quote
iChris Posted August 20, 2016 Report Posted August 20, 2016 (edited) The fatal 2012 Bell 222 mast separation accident (NTSB# CEN10FA291) was caused by a bolt fracture as seen below; however, in the case of this R44, none of the associated attachment bolt assembly was found. Therefore, the cause of the liberation of the attachment bolt with respect the this R44 accident is currently unknown. Edited August 20, 2016 by iChris Quote
Guest pokey Posted August 20, 2016 Report Posted August 20, 2016 (edited) What makes you think it was a design problem? Show me where i said that this accident was caused by a design problem. Watch spike's video. But, since you brought it up, consider the possibilities:1) the parts were left out upon assembly2) it fell apart on its own accord 3rd ?? Edited August 20, 2016 by pokey Quote
TomPPL Posted August 20, 2016 Report Posted August 20, 2016 https://www.youtube.com/watch?v=IKwWu2w1gGkthis is one of the best videos I've seen on this subject. Frightening how easy some of them were to loosen. Quote
Guest pokey Posted August 20, 2016 Report Posted August 20, 2016 https://www.youtube.com/watch?v=IKwWu2w1gGk They mention safety wire, but did not test that one. Would like to see the results of this test done with that and also a nylon castle nut with a properly bent cotter pin. Quote
terminal_velo Posted August 20, 2016 Report Posted August 20, 2016 Show me where i said that this accident was caused by a design problem. It's a reasonable conclusion for readers to come to considering that your reply to the accident summary was a rant about Robinson's decision to use Palnuts. Quote
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