|
WRT turbocharged takeoffs (not normally aspirated as discussed in this thread)
Please be cautious about changing from manfacturer's recommendations, especially under high power, TurboCharged, TAKEOFF, extreme conditions (high temp/desnsity altitude- if u hear that on ASOS-think! ). I am pretty sure we lost a friend in 1993, who used to set up his multi-engine Duke for takeoff below the recommended specs to "save wear on the engines" and "save gas".
It is often the case that our limited gauges, enhanced as they are, may not tell us about hot spots or short term thermodynamic issues. We might be amazed at how much faster an undectected condition can cook engine parts, well below the speed, temporal, or spatial resolution and coverage of your best sensors.
Full Rich for takeoff is usually for cooling rather than for power considerations. Takeoff is one of the highest heat stress conditions: Less cooling air from zero to Vr and in climb and I suspect. the highest temperature change of the flight- it's still "warming up".
It's good to know as much as we can through these kinds of discussions, but without hard evidence and lengthy experience, our safety record indicates we should be very very careful about takeoff ops including:
-draining the sumps,
- thorough preflight,
-careful runup checks,
-try both tanks during taxi,,
-low threshold of decision to return to the ramp for a spark plug check,
-brief your aborted takeoff procedure on runway,
landing straight ahead? (1.5 x takeoff distance is a good rule of thumb for V1)
off road ops or through the fence?
or on the highway?
It's never perfect but these can always be reviewed and greatly reduce the bad odds.
Try playing a game: how close did you hit the predicted takeoff distance?
.
a. My estimte gets a little closer each time with practice. Here's my data:)
b. I did not notice or record where we lifted off
c. I did not have time to do that calculation. see 91.103(b)
d. How do you do that calculation? see 91.13
Y'all be careful out there!
Bill |