5-bladed OH-6A and cold weather mods for 500.
Hedski,
just saw your query re. a 5-bladed 500C. Don't know anything about a 500C, but the Snohomish Sheriff's Dept has a heli listed as an OH-6A. Reg is N13SD. It looks like an OH-6A but has two interesting features I haven't seen on any other civilian Y-tailed airframe; namely a four-bladed tail-rotor and a five-bladed main rotor. It carries a sizeable FLIR and a nitesun so, with this load, is probably fitted with a C20 unit. There are two possible explanations for this configuration;
1. Hughes developed a prototype dubbed the OH-6D (not the Japanese licence-built 500D) to compete with the Bell OH-58D for the AHIP contract in the early eighties. This was an OH-6A with a transmission and rotor system taken from the 500D and a mast-mounted sight. Maybe this is it turned over to the Police, just one of the few hundred OH-6As given away for very little to US Law Enforcement agencies in the nineties.
2. The other explanation is that it was formerly a Hughes 500P. Long story but basically the 500P was used by the CIA in Vietnam in 1972 for a special mission. Again its a Hughes prototype with a five-bladed main head and four-bladed tail rotor. Had an engine heavily insulated with sound-proofing material and a silencer fitted to the exhaust cone. With the extra blades, rotor RPMs were reduced to help make things quieter. Some of these improvements were incorporated into the 500C and lead to the 500D.
(I'd post a photo or two if I knew how.)
Finally, a question. Can anyone who flies a 500D please tell me the purpose of the semi-circular cover that fits in front of the rotormast at the front of the doghouse. Seems to be fitted to machines being used in very cold weather. Can anyone explain how it works?
Thanks.