Originally Posted by
FGD135
Run off the end of the runway due lack of performance and CASA will come after you. The proof is self evident. Outside the charts or not, you have demonstrably taken off overweight.
More likely used the wrong technique if the people that I see operating piston singles is any guide.
Well, I found that article about how to correct for the effect of short dry grass in the Sept-Oct 2002 issue of Flight Safety magazine and I was correct that the data came from the UK CAA.
The article was an analysis by “staff writers” about a takeoff accident to a Piper Lance PA-28R-300. My copy of the relevant POH has a chart to convert pressure altitude and temperature to density altitude then a takeoff distance chart presented vs density altitude only for a paved level runway. The authors focused on the importance of the correct technique per the POH and only at the end of the article did they note: “Additional factors should also be applied in the event that the performance chart does not make an allowance for variables like runway slope, runway surface, headwind component and so on (see table).” The table states a 20% increase in take-off distance for short dry grass.
Some other interesting statements in that article:
“….. It is tempting to simply say the whole episode could have been avoided if the pilot had consulted his aircraft’s take-off performance charts … However, it is unrealistic to assume that all light-aircraft pilots will calculate the exact take-off and landing distance required before every flight. ….… or the gap between the runway required and the runway available becomes marginal, the pilot refers to the performance charts and … How can we improve our decision-making skills? …….. A word of warning about aircraft performance charts. Depending on the year your aircraft was certified, its charts may or may not include built-in safety factors. ….. the production of uniquely Australian charts ceased and pilots …... calculate performance using information supplied by manufacturers. Aircraft manufacturers’ performance charts do not include built-in safety factors and in most cases reflect best-possible performance achieved with: Highly experienced test pilots …”
There was a time (two years ago) when we should’ve stopped worrying about CAO 20.7.4 – a note in the Exposure Draft of Part 91 (MOS for 91.1035 Aircraft Performance): “It is the intention that CAOs 20.7.4. …. will be subject of a project to review them and provide guidance material in the form of an AC in the future. Much of the content of the CAOs contain either certification standards or outdated information. CASA expects pilots to operate in accordance with the aircraft flight manual (AFM). All performance information in the AFM is produced and complies with the aeroplane certification standards.”