<![CDATA[Takeoff Performance - Flex (almost) always 50°C with Flaps 8]]>Hello,

I was wondering if the takeoff performance calculation was correct whenever you force Flaps 8 in the EFB. For Flaps 0, it's giving different flex temperatures, but for Flaps 8 its almost always Flex 50, even on relatively short runways. Also, when AUTO is selected in the EFB, it will give Flaps 0 almost all the time even though the flex temp is way higher.

Can you please re-check whether this is correct?

]]>https://community.justflight.com/topic/10896/takeoff-performance-flex-almost-always-50-c-with-flaps-8RSS for NodeWed, 08 Jul 2026 13:21:13 GMTTue, 07 Jul 2026 12:09:37 GMT60<![CDATA[Reply to Takeoff Performance - Flex (almost) always 50°C with Flaps 8 on Tue, 07 Jul 2026 16:49:49 GMT]]>Thanks Mark!

]]>https://community.justflight.com/post/51978https://community.justflight.com/post/51978Tue, 07 Jul 2026 16:49:49 GMT<![CDATA[Reply to Takeoff Performance - Flex (almost) always 50°C with Flaps 8 on Tue, 07 Jul 2026 15:49:36 GMT]]>The Performance Calculator uses real-world data, so I can vouch for its accuracy. The maximum FLEX in the data is 50C, so on runways where runway length is not a factor, a flex of 50C will be calculated. The F70 and F100 have a large, thick wing and have great performance at low altitudes, so flaps 0 takeoffs with a high-flex temperature are very common.

With regard to the Flaps/FLEX relationship, with AUTO flaps selected, the Performance Calculator uses the following priority for takeoff performance:

  1. Flaps 0 - FLEX
  2. Flaps 0 - TOGA
  3. Flaps 8 - TOGA

Hope that helps.

Mark - Just Flight

]]>https://community.justflight.com/post/51976https://community.justflight.com/post/51976Tue, 07 Jul 2026 15:49:36 GMT