Helicopter crash Hudson River 1

[LittleInch]

Helicopter sight seeing inner York crashed with all dead.

This video looks like it was flying at some speed, then something happens, it seems to change orientation very rapidly which causes the whole tail structure to detach, followed shortly by the main rotor blade and part of the gearbox. Horrible way to go.

https://www.reddit.com/r/CatastrophicFailure/comments/1jwfxh9/full_video_of_the_helicopter_crash_in_hudson

Six people killed after helicopter crashes into Hudson River in New York

Pilot and a family with three children who are believed to have been Spanish tourists were killed onboard aircraft

www.theguardian.com

 

[mfgenggear]

well there several modes of failure.
it is possible for boon strike , yes
was the structural integrity of the boon structure possible yes
was there possible kinetic force from the gear train and drive shafts yes

the relevance of the first video some of the rivets were tore out , and there was considerable buckling in certain areas
the second video was a review of a typical helicopter gear boxes and drive shafts, important to note some type of clutch
to disengage the engine from the gear box. I am further researching this a little more, and allow auto rotation.
I was trying find actual gear teeth attributes , such as number of gear teeth , diametral pitch, pressure angle so i could run the numbers with my
Fairfield gear analysis. so what I found and have not vetted, the rolls royce engine produces 10K rpm, 472 Hp, I calculated 247.9 ft/lbs of torque
a simple example of gear reduction of 245/45 out put is 1836,7 RPM output torque of 1344.8 torque .
attached is white paper when a clutch failed causing moment on the mass components.

 

[TugboatEng]

I have an issue with that report on the freewheel gear. They found corrosion products in the freewheel mechanism and assumed it was due to water intrusion despite no actual water being present and no sources of ingress found. Did the investigators not know of fretting corrosion? That will occur with lack of lubrication.

 

[mfgenggear]

I have an issue with that report on the freewheel gear. They found corrosion products in the freewheel mechanism and assumed it was due to water intrusion despite no actual water being present and no sources of ingress found. Did the investigators not know of fretting corrosion? That will occur with lack of lubrication.

well it may have contributed to the failure , but it is plain the evidence the clutch failed, cant get any clear then that.
I find your reluctance to look at the imperial evidence. this may not be the cause of this incident and a deep drill to audit of all components.
if there a clear evidence of not following specifications and procedure. the only wet towel, is jumping to conclusions and not following failure analysis procedures. guessing is not function of sound engineering. on the other I am not saying your wrong. but not conclusive.

 

[TugboatEng]

If there was corrosion due to water I would expect pitting on surfaces. The report makes no mention of that and oddly ommitted all images of the parts that actually failed.