HOW AIRCRAFT PERFORMANCE IS CALCULATED IN PACS
Other charter pricing software calculate rough and ready fuel burns on an "average burn per hour" basis. This can lead to very wide variances between estimated and actual fuel burns. Fuel costs today are high and often represent 15-20% of total operating cost so accuracy is very important.
To achieve the desired level of accuracy, PACS includes very precise performance calculations for each aircraft type. from engine start to engines off.
PACS uses the certified aircraft flight manual charts to calculate the maximum allowed take-off weight for a specified airport based on the runway length, airport elevation and selected temperature. This data is then used together with required payload in the calculation of sector fuel burn.
The sector fuel burn uses the aircraft operations manual data to calculate the total sector fuel burn from engines on to engines off using the permitted or required take-off weight and landing weight to calculate start-up, taxi-out, take-off, climb, cruise, descent, approach, land and taxi-in fuel burns.
This burn is accurately calculated taking into account aircraft weight, cruise flight level, and en-route winds for each sector.
The result is that pre-flight estimated fuel burns in PACS are within 1 or 2% of experienced actual burns on the day, which gives a high level of confidence to users of the system.