Climb rate of Beechcraft Ducess 76

  • I have problems with the climb rate of the Beechcraft Ducess 76. The Ducess doesn't climb at all at 80 knots. It only climbs when it is accelerated to 90 knots, better 100 knots.


    This is a problem at the departure in Birrfeld, Swiss (LSZF). After taking off, you have to keep the nose down to accelerate to 100kn and then climb with at a good rate (1500ft/min). However, the hilly terrain around airfield Birrfeld does not allow this.


    The runway (727m/2385ft) seems to be too short for the Ducess. The Ducess takes off at the end of the runway.


    Is this behaviour real? Is the Birrfeld runway really too short for the Ducess? Does the Ducess needs a flat terrain after the runway?

  • LSZF is probably too short for real world Duchess 76 operations. Using the best rate of climb, 85 Kts, with the gear up as soon as you have positive climb with full power should yield your best results.


    If you just have to use LSZF in the flight sim you can always use one click of the instant up feature to add 500 m of instant altitude when climbing out. Don’t expect 1,500 fpm sustained climb rate in the Duchess.

  • try best angle of climb speed to clear obstacles.

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  • Use Best Angle of Climb speed for obstacles for sure, 71 kts, which is the same as Vr in the Duchess. But, then lower the nose and hold Best Rate when all cleaned up.


    You can check the flight review at Avsim.com for the Just Flight Duchess 76 for AFS2. There are some printable tables with V speeds in the review.

  • It has carburetted 180 horsepower engines and is low on power for a twin, it was designed to be an economical trainer and performance was not a priority, it had to have two engines that is all. It’s single engine rate of climb is a remarkable 235 fpm from sea level and the service ceiling on one engine is just 6170 feet. Add in less than 100% perfect piloting, a hot day and low pressure weather and Switzerland makes a Duchess more like a single engine plane with twice the probability of a forced landing because of engine failure.

    This makes it a more interesting FS2 plane.

  • Use Best Angle of Climb speed for obstacles for sure, 71 kts, which is the same as Vr in the Duchess. But, then lower the nose and hold Best Rate when all cleaned up.


    You can check the flight review at Avsim.com for the Just Flight Duchess 76 for AFS2. There are some printable tables with V speeds in the review.

    Nice find - thanks

    X-Plane 11.3x / DCS 2.5.4 / P3Dv4.5 / Aerofly FS 2


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  • The runway (727m/2385ft) seems to be too short for the Ducess. The Ducess takes off at the end of the runway.

    Looks like there's something seriously wrong with the flight model. Even on a grass runway at MTOW and at 40°C OAT the required takeoff roll is less than 450m IRL.

    Over the departure end from the runway you should be at almost 50ft under these conditions.

    At 71kts (flaps and gear up) she should climb very nicely. At 40°C and MTOW at 85kts the ROC should be 1100ft/min.

  • Your best bet would be to submit a support request with the developer of the Duchess 😊

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  • Thank you for all your help.


    I did several test flights with following conditions:

    No wind

    Flaps up

    Rotate at >71 kts

    Climb speed 85 kts

    Gear up when stable climb


    Results:

    Take-off distance / take-off duration / average climb rate first 1000 ft


    My Duchess ~1800 ft / 25 s / 600 ft/min

    Youtube video ??? / <= 20 s / 800 ft/min

    Diagram 1100ft / ??? / 1100ft/min


    All values can be lightly unaccurate. This values show a low perfomance of my Duchess. It seems in real the Duchess take-off earlier and climb faster as my bird. I wonder why Overloaded hasn't my "problem".


    I have checked my installation and configuration:


    Use Just Flight Ducess 76 newest version.

    Deinstalled and reisntalled Just Flight Ducess76 . No difference.

    Aerofly FS2 file check don't tell any problems.

    Fly with mouse only. No joysticks. No difference.

    Aerofly FS2 Version 2.04.05.31 (20190326)


    I haven't idea what is wrong. I will install Aerofly FS2 alpha version and test the Duchess again.


    Same problem with Alpha version.


    Several configurations changed. Same problem.


    Same configuration (wind, runway) as Overloaded. Performance is worse. See Image.


  • And with your duchess i am guessing you mean your installed just flight duchess and not a real world aircraft you could own?


    I think it's better to direct problems with add on aircraft to the developers of that aircraft. Here you probably won't see any responses from them and not from us either, since it's not our product.