Finally got the proper alignment of the planets (basically
test pilot schedule) for further flight of Velocity 755V – 20B. Plane was
in the air for ˝ hour this time, basically at level cruise orbiting the airport.
OAT was about 90F and flight was at DA of about 7000’.
Since the first flight when oil temps were high, I added a
temporary ram scoop under the ‘wing root’ oil cooler inlet. Oil
temp reached near 230 during climb but later stabilized at 200 - 205F. Coolant
stabilized at 180-185F.
I have video recording of EM2 display, and this time the
pilot remembered to push the page button, so I have lots of data. For ‘%
power’ readout of 65-70%, engine rpm was 4450, prop 2050 rpm, IAS (according
to pilot) was about 145 kts. TAS readout on EM2 was 165-170 kts, but my calcs
indicate this is about 5 kts too high. Fuel burn was indicating 16-18 gph
running rich of peak.
The in-cowl radiator is handling most of the cooling load;
with the wing root rad being very ineffective. This is consistent with the
first flight results on the oil temps with the matching wing root oil cooler. The
scoop added for the OC improved the air flow, but it is still marginal, with
oil delta T of about 20F and air delta T of about 100F. It is likely the main issue
is with the exit fairings. At least now it flies stably, so I can do some
other changes and see the effects – hopefully get a differential pressure
measurement set up.
Takeoff roll of about 1500’ at 1900# weight is quite
good considering fixed pitch prop. It accelerates from rolling start to 60-65 kts
nose lift in 6-7 seconds. This with an 85” pitch prop. Something
special about Catto props.
The thing looks and sounds great, and I have to be happy
that it went up, stayed up for ˝ hr, and made a perfect landing. Main issues
right now are on-going problem with EC2 data corruption; apparently unique to
my installation, and possibly ‘noise’ related; and the need for
right aileron input in order to go straight, suggesting a need for wing
incidence adjustment.
Al