Originally Posted by
Bell_ringer
I did some analysis from the NTSB database for the date range chose by AA above. It does make some interesting reading.
Thanks for going through that exercise, Bell_ringer, most appreciated.
My take on it is it's just trading one set of risks for another.
Robinson risks: instructional environments, low time pilots, lower capability machine with smaller safety margins.
Bell risks: more likely to be found working at more complex tasks.
And, your point about comparing Part 91, the majority of Robinson op's, to the same for Bell, is a very good one. I did that for the same time period as before (1 Jan 2015 to 1 Apr 17), and the results were:
Robinson: 70 accidents of which 6 involved fatalities
Bell: 34 accidents of which 6 involved fatalities
It's interesting that the ratio of fatalities to accidents remains approx. 2:1 with the Bell's higher, whether it be all operations or limited to only Part 91 op's.
As for the beer bet ;-), if we restrict the hours to US civil (not military) hours only, I'll take that bet. I'd be willing to bet that Robinson hours actually exceed Bell hours in US civilian operations. At least in my neck of the woods Robinsons buzz around like honey bees all day long, but you rarely see a turbine helicopter of any type. And, according to the FAA civil aircraft registry, there are almost 3.5 times as many Robinsons as Bells registered: 2846 Robinsons of all types vs. 828 Bells of all types. Given the popularity in the US of Robinson helicopters for instruction, personal and light commercial use. could it be that the Bell fleet is working 3.5 times harder than the Robinson fleet?
But...without any actual data on hours flown by helicopter types, it is admittedly difficult to come to a definitive conclusion. Nevertheless, when restricted to the US, all other data tends to suggests that the two fleets are roughly comparable, although the large number of Robinson aircraft registrations tends to tilt things a little in Robinson's favor.