How do I enter a flex temperature in the Aerosoft CRJ?

In Microsoft Flight Simulator, calculate the Aerosoft CRJ flex temperature in the EFB, then enter that Celsius value on the CDU take-off thrust page under FLEX TEMP. Confirm it and check the EICAS for the reduced take-off rating and N1 target. FLEX changes the target; it does not move or hold the thrust levers.

How do I enter the Aerosoft CRJ flex temperature?

Use the EFB to calculate the temperature, then transfer the result to the CDU rather than inventing an assumed temperature yourself.

1. Complete the aircraft setup. Enter the correct weight, runway, flap setting and weather data. The EFB, CDU and engine displays must be powered; if necessary, follow our CRJ cold-and-dark power and start sequence first.
2. Calculate take-off performance. On the EFB take-off performance page, enter the actual outside air temperature, wind, pressure, runway condition and applicable aircraft configuration. Run the calculation and note the returned FLEX temperature.
3. Open the take-off thrust page. Press PERF on the CDU and select the take-off or thrust-limit page. The prompt is normally presented as THRUST LIMIT or TAKEOFF, with an assumed-temperature field labelled FLEX TEMP, SEL TEMP or similar.
4. Enter the temperature. Type the calculated Celsius number into the scratchpad and press the line-select key beside the flex-temperature field. For a calculated result of 47°C, enter 47, not 47C or the degree symbol.
5. Verify the result. Make sure the number has moved from the scratchpad into the field. With the take-off rating selected, the EICAS should indicate a flex or assumed-temperature rating and the corresponding N1 target.

Recalculate all take-off data if the runway, weather, weight, flap setting, anti-ice use or bleed configuration changes. Flex thrust and V-speeds belong to the same performance calculation; our take-off configuration and V-speed guide explains the wider departure setup.

Where should the flex temperature come from?

The flex temperature must come from a valid take-off performance calculation for the aircraft’s actual conditions. It is an assumed temperature higher than the real outside air temperature, used to command less than full-rated take-off thrust while retaining the required runway and climb performance.

A flight-plan import does not establish a safe flex temperature. Do not copy an arbitrary value from another flight, add a fixed amount to the outside temperature or combine FLEX with another derate unless the performance calculation explicitly calls for it.

Why is the FLEX TEMP entry rejected or missing?

A rejected or unavailable entry usually means the value, format or performance result does not permit flex thrust.

• Units were typed into the field: enter the bare Celsius number without C or °.
• The value is outside the accepted range: rerun the EFB calculation rather than trying progressively higher temperatures.
• The calculator returned full thrust: a result such as TO, maximum thrust or no FLEX value means reduced thrust is not available for those conditions.
• The CDU data is incomplete: confirm the take-off runway, aircraft weight and required performance entries before trying again.
• The field accepts the value but nothing changes: clear the entry, recalculate and reinsert it. If the page remains unresponsive, use our Aerosoft CRJ update procedure to check the installation.

Does FLEX set the CRJ thrust automatically?

No. The Aerosoft CRJ has no autothrottle, so entering a flex temperature establishes the reduced take-off rating and N1 reference but does not move the thrust levers.

Advance the levers as required and monitor actual N1 against the commanded target. The TOGA switches select the flight-director take-off mode; they do not advance or hold engine thrust. Our complete Aerosoft CRJ operating walkthrough covers the departure, acceleration and climb sequence.

When should I use full take-off thrust instead?

Use full-rated take-off thrust whenever the EFB does not produce a valid flex temperature or reduced thrust leaves insufficient performance margin. Short, wet or contaminated runways, high weight, hot-and-high conditions and configuration penalties can all remove the flex option.

Delete the assumed-temperature entry using the CDU’s clear or delete function, select the normal take-off rating and verify the full-thrust N1 target on the EICAS. Never force a FLEX value merely because a reduced-thrust take-off was planned.