Quote:
Originally Posted by camber
Hi all,
My speeds are somewhat higher than others
For example, I get around 255-260mph SL offline for Spit Ia (3000rpm, +61/2psi)
EDIT: what am I talking about? Looking back the speeds are pretty similar for the last few posts. But will leave following points in:
A few things:
The cockpit gauge is not very precise, and tool tip gives speed in 10mph increments only (the no cockpit guage is a lot better). How are people recording +/-1 mph speeds online, is it estimating from needle position? I feel like estimating within 5mph is pushing it, and above 280mph the marks are in 20mph increments so to 10mph is pushing it.
The radiator position does give small increments in speed. I found that open to 1/2 open radiator gives 5-10mph extra (1/2 open to closed gives -250mph  ). What radiator position are people using?
I also found that accelleration can be glacially slow for the final few mph. How long are people attempting to wave skim at their best 0fpm before recording a value?
Cheers, camber |
I have my trim controls assigned to two levers on my CH Quadrant which gives me pretty precise control in levelling out at the proscribed setting. That said, it sometimes took a minute or three before I was satisfied that I was flying perfectly level at the exact altitude. By that time the speed is rock stable. I'm now virtually hands off so I can easily zoom in to the airspeed gauge to get a reasonably accurate reading despite the coarse scale. I agree the speeds will be +/- a few mph, but it's not too hard to make a fair estimation -- certainly within the precision of any concern.
All my readings were taken with radiator at 50%.
I'm running about 50 feet off the waves. I use my trim axis, not my joystick axis, to make the final delicate adjustments to maintaining perfectly level flight. I found it exacting and time consuming, but the airspeed held rock steady so I felt confident in the reading I was taking -- within +/- 2 mph at the most.
Hopefully others will have data, including the LW a/c, in case others fall on the short side of the curve at various altitudes.
Other parameters, in time, will need to be looked at as well such as turn radii, dive speeds, climb rates, etc.