Bulldog tech info

[dd20uk]

I've tried this on the tech forum with no luck but anyway,
Does anybody know the mean geometric pitch (at 70% chord) of the Bulldog propellor during take off and at 120kt cruise?
Also does anybody have a rough idea of the total drag (in newtons) that the Bulldog developes during the 120kt cruise.
I've tried looking everywhere, with no success, so even rough ball park figures would be appreciated.

Cheers

[Alf Aworna]

Go on- tell us why you want to know.

[Olly O'Leg]

I was happy just to GET 120 kts out of the Dog.......... ;) Magic!!!!!!!!

[Genghis the Engineer]

I'd suggest that 120kn is about Vh in the dog, so it'll be at MCP and fully coarse. If you want to confirm this, the unclassified reports held by the "information centre" (a.k.a. Science Library) at Boscombe Down will give the answer.

Try Hartzell, they should be able to give you the efficiency factor and pitch at fully coarse. The power curves of the IO-360 you can get from Janes or Lycoming. Assuming that you are at MCP, fully coarse, that should give you Cd for the aircraft (because at Vh T-D and PLF=MCP), and since you know Cl, you can work out Cdo and k.

Does that help? You could also try BAe at Prestwick, who used to be Scottish Aviation, who built the thing, or a servicing manual and check the fully coarse pitch setting.

Sound suspiciously like an undergraduate project to me. Good luck, mine was re-engining the Nimrod, in the course of which I concluded that the current aircraft couldn't possible take-off from Lossiemouth or Kinloss.

G

[ 01 September 2001: Message edited by: Genghis the Engineer ]

[dd20uk]

Thanks for the info, Genghis.
Your suspicions are correct, as part of my aero degree, I'm investigating the re-engining of the 'dog with a Continental IO 470K, whilst keeping the two blade propellor configuration.

[Blue Stuff]

[puts anorak on]

Fully coarse? I'm sure you mean fully FINE (i.e. rpm MAX) - you'd be grossly over-boosting otherwise! :eek:

[removes anorak]

Blue.

[Arkroyal]

With you on that blue.

As the thing has to demonstrate a Vne dive (185KIAS?) at full throttle without overspeeding, it will be far from coarse at 120.

Anoraksik? Me?