Stanwell (your #858),
...Re the 'unsuccessful take-off' at Winslow.
Danny42C had, earlier in this thread, suggested that, in light of his experience with PT-17s, the prop could have inadvertently, prematurely been knocked into coarse pitch...
Not the PT-17s. They had a fixed metal prop driven by a 220 hp Continental. My two-speeds were on the front of a BT-13 (Vultee Valiant) with a 450 hp P&W Wasp Junior.
...Has anybody heard anything more that would account for the claimed 300rpm drop?...
I learned a lot from Google:
<two-speed hydraulic propellors method of operation>
Select:
<AIRCRAFT PROPELLER CONTROL AND OPERATION
www.thaitechnics.com/propeller/prop_control.htmlCachedSimilar>
I clearly remember that a parked Harvard would always have the bobs "in", cylinder "back" (min rpm) = coarse pitch, although the cockpit levers were at max on shut down. When engine started and oil pressure came on, prop cyl moved forward, bobs moved out and prop turned to max rpm (fine pitch).
Can't recall how a BT-13 two-speed prop behaved, but no reason to be any different.
Question: If a two-speed were stopped dead, "shock-loaded", in an accident, with oil pressure still in the system, and cockpit lever in 'fine', would the prop still be in fine patch ?
If so, what if it were found to be in "coarse" - what then ?
............................................
India Four Two (your #860),
...Quote:
Danny42C had, earlier in this thread, suggested that, in light of his experience with PT-17s, the prop could have inadvertently, prematurely been knocked into coarse pitch
...
Not a PT-17 (as above).
Danny.