I did not make quite as accurate measurements as this but I plotted the IAS
against RPM for the range 90 to 130Kt on similar days and found a 5-8Kt
improvement after fitting the kit to a monowheel - I was a little
disappointed but the speed increase and improvement in fuel consumption is
permanent - in reflection worthwhile doing!
Roger Mills
141
-----Original Message-----
From: owner-europa@post.aviators.net
Subject: Flying: Interim results: Speed kit
Europa Mk 1 'Classic'. Rotax 912.
Modifications: Plenum cold air mod. & speed kit.
C of G: 62.4 inches aft.
Take off weight: approx 1120 lb (468kg)
Prop: Warp Drive fixed pitch 3 blade ground adjustable, set slightly course.
Recorded engine RPM (FLYDAT): climb 4950. static 5100. max S&L. 5700 - 5750.
Test weather conditions:
Temp: + 6 degrees celcius. Clear sky
QNH: 1038 mb
Test height: 1100 ft AGL (1400 AMSL)
Wind (1000 ft): Reported as 360 degrees, 12 mph. (Met. office)
Notes.
1/ During test, all RPM figures were 0 - 50 RPM higher than indicated.
2/ The error in each of these results must be a minimum of +- 1.5 mph !
3/ TAS has been calculated by flying a triangular course and feeding GPS
ground
speeds into an Excel spreadsheet incorporating a formula which uses trig. to
resolve TAS, test wind speed and direction.
4/ Tests performed in July produced TAS of around 5 mph lower than equiv.
winter figures.
Test results: 18/12/01
RPM TAS(mph) Wind dir(deg) Wind strength(mph)
5000 140 35 12
5100 144 33 10 (medium
cruise)
< 17 litre/hr
5300 149 20 11 (fast cruise)
5500 154 34 12 (max.
continous)
5700 161 32 14 (firewall)
My TAS run of 5500 RPM on 14/12/01 also (independently) produced 154 mph.
(Wind. 70 deg, 16mph)
Comparable figures for similar met. conditions on 15/11/01 (WITHOUT the
speed kit).
RPM TAS(mph) Difference
4700 126
5000 135 (-5)
5300 143 (-6)
5500 149 (-5)
5700 156 (-5)
My conclusion: The speed kit has improved my aircraft TAS by approx. 5mph
throughout the range.
These results may be inaccurate. Obviously, they apply only to my aircraft.
However I have some confidence that a pattern is beginning to emerge. I do
not
suggest that others will necessarily measure the same values. I hope they
are
at the very least, interesting !
Regards,
Alan
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