Originally Posted by
andrewr
Density altitude was part of the PPL theory. You can in fact predict the effects with reasonable accuracy.
doing it right per AC23-8 and noting the appropriate use of fudge factors for conservatism - notes in Appendix 2 partly explains the reasons.
Originally Posted by
andrewr
The letter from CASA is actually claiming that the ranges specified in the performance charts forms part of the aircraft limitations. Which also suggests that the aircraft must be grounded below 0C.
Yes indeed, and their general statement: "This means that a pilot must not operate an aircraft outside the limits set out in the AFM, including limits set out by the ranges of the parameters on the performance charts." has broader implications, not just the temperature range - take the PA-28-161 for example:
- pressure altitude - lower end of the range is sea level so if the QNH is higher than 1015 at an airfield close to SL then we're outside the range of the performance chart. Today is 1024 at YMMB so all Warriors must be grounded all day.
- maximum headwind on the chart is 15 kts so if the wind is straight down the runway at 17 kts then they can't fly but 17 kts across the runway is fine.
Perhaps everyone should write to CASA asking these related questions?
Meanwhile Kaz and I shall continue to fly undisturbed - my airplane's AFM has no performance information at all.