Inaccurate performance data of Cessna Citation Longitude (C700)

Hello guys,

I have tried to create a flightplan from Teteboro (KTEB) to Lisbon (LPPT). This route is a route the Citation Longitude is capable of according to miles and flighttime endurance. Many private jet charters including Netjets for instance are offering the Northern Atlantic crossing and even Textron Aviation is showing on their home page that this flight is within the operating range of the aircraft. I am not sure if it is allowed to post a link here but you can surely check that easily by yourself. If I now generate this flight it is telling me in the PDF that the range of the aircraft is exceeded and gives me an ETOPS warning. Could you guys please review the weights and performance data for this aircraft?

Kind regards.

It depends on the conditions of the day. What the marketing department says the range is and what the actual range is often different.

For starters, the range numbers published are for the following conditions:

  • NBAA IFR reserves, alternate 200nm away, 30 minutes hold fuel. The alternate on your flight plan was a bit farther.
  • No contingency fuel. Your flight had contingency equal to 5% of the burn. Just removing or reducing this alone would have solved the “out of range” issue on your flight.
  • Mach 80 cruise. SimBrief’s profile only supports Mach 82, which results in slightly less range.
  • 4 passengers. On your most recent flight, you planned more passengers than this. Higher payloads result in more fuel burn and less range.
  • FL450 cruise the whole way. Your flight levelled off at FL410, and had lower altitudes near departure and arrival due to airway/airspace restrictions, which reduces range even further.

When planning a flight close to max range like this, it often requires some human intervention to optimize the burn. Meaning you may need to manually set some of the flight/fuel/payload options accordingly, since SimBrief is by default more on the conservative side.

I tested the current C700 profile, under the assumed NBAA IFR conditions above, and was able to get about 3300nm of range. This is around what I would expect, given cruising at M82 instead of M80. I don’t believe the profile needs to be updated at this point.

Best regards,

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