Grumman Duck stalling speed.
Wed Aug 29, 2007 5:01 am
G'day,
Anyone know the stalling speed of a Grumman J2F Duck? (Any model) Feedback wanted for personal interest and glyn5's query.
TIA.
Anyone know the stalling speed of a Grumman J2F Duck? (Any model) Feedback wanted for personal interest and glyn5's query.
TIA.
Wed Aug 29, 2007 2:08 pm
The J2F-6 stalls at about 70 knots.
Walt
Walt
Wed Aug 29, 2007 8:08 pm
I think the question on the Duck is not so much how slow it stalls ,but what kind of horrendous sink rate you would see st speeds just above the stall. My guess is that stalls with the gear down, canopy open and propellor windmilling, would produce a sink rate of at least 2000 feet per minute!
Glide ratio would probably be less than the T-28's 5.4 to 1 ratio in the "dirty" configuration!
Glide ratio would probably be less than the T-28's 5.4 to 1 ratio in the "dirty" configuration!
Wed Aug 29, 2007 8:11 pm
Wow - akin to an anvil strapped to a manhole cover!
Thu Aug 30, 2007 11:22 am
I have been collecting Pilots Notes/Flight Manuals/Pilots Operating Manuals - call them what you will - for the best part of half a century. I have over 1,400 of the brutes. I even have 3 for the Duck. That should be problem solved, right? Er, wrong.
I have the manufacturers manual for the 790 hp J2F-3 (undated). The only speed mentioned is the 70% power cruise of 92 kts.
I have another manufacturers model for the 950 hp J2F-5 (also undated). The extra horses are doing some good as the cruise at 70% power has risen to 126 kts.
This manual helpfully includes take off runs under varying conditions. In a flat calm it takes 570 feet. That's pretty impressive - under 200 yards for a laden machine.
With a 15 kt wind the run reduces to 317 feet, and a 25 kt wind takes only 187 feet.
This thing takes off like a homesick angel!
For the J2F-6 model I have the Navaer Manual, dated July 1945. Hooray, that's bound to have all the information anyone could need, surely? Nope. If anything it's even more tight lipped than the manufacturers notes.
HELP !!
I have the manufacturers manual for the 790 hp J2F-3 (undated). The only speed mentioned is the 70% power cruise of 92 kts.
I have another manufacturers model for the 950 hp J2F-5 (also undated). The extra horses are doing some good as the cruise at 70% power has risen to 126 kts.
This manual helpfully includes take off runs under varying conditions. In a flat calm it takes 570 feet. That's pretty impressive - under 200 yards for a laden machine.
With a 15 kt wind the run reduces to 317 feet, and a 25 kt wind takes only 187 feet.
This thing takes off like a homesick angel!
For the J2F-6 model I have the Navaer Manual, dated July 1945. Hooray, that's bound to have all the information anyone could need, surely? Nope. If anything it's even more tight lipped than the manufacturers notes.
HELP !!