BAe146 Performance: Book Figures?
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I absolutely enjoy the BAe146, and always have done throughout our simulated worlds.
However, I am always questioning whether the simulated takeoff performance of the JF BAe146 follows book figures.
The takeoff roll seems OK, it’s really more about the acceleration through flap retraction speeds and to climb-out speeds.
I’ve copied to the best of my ability the various takeoff configurations (weights and atmospherics) as seen in numerous BAe136 YouTube videos, and I’ve always been unable to follow a similar flap retraction schedule.
My aircraft is invariably slower to accelerate, seemingly by several minutes.
I follow the procedures by running on APU, A/I is off…it’s all set by the book, so where am I going wrong or, for instance, is the airframe drag coefficient set too high?
Thanks. -
Like you I love the Bae146, and I had the great privilege and pleasure of working at Hatfield during its production and further development.
I created a spreadsheet to assist me with take off and landing performance, primarily for the 146 but now includes other aircraft types, which is available on Flightsim.to. Search for:
Aircraft Runway Performance SpreadsheetMy belief is that the take off and landing performance of the Just Flight aircraft is pretty accurate, although I do find the brakes to be a little weak and think the maximum application of the toe brakes should be stronger.
I find after lift off, especially at high altitude airports or with larger than 18 degree flap settings the aircraft accelerates very slowly, using the correct limiting N1 climb numbers.
The normal climb N1 limits, as a guide, are approximately:90 % N1 at 0 degrees C
Minus 1 % N1 for every 10 degrees increase in OAT
Plus 1% N1 for every 10 degrees decrease in OAT up to 95 % N1 at minus 50 degrees CSo minus 10 degrees OAT allows N1 climb of 91%
Plus 10 degrees OAT N1 limit is 89%If Engine Anti Ice is ON then the N1 figures reduce by 1%.
In order to increase climb rate N1 can be increased by 2%.Taking off at an airfield like Aspen which is over 6,000 feet up and using 30 degrees of flap in a 146-200 means a very slow initial climb while the flaps are retracted to 18 degrees before the aircraft can climb further. Aspen airlines used a 146 100 of course, which is more sprightly.
BAe published a performance document which indicated that some of their runway take off figures for the 200 and 300 series 146 were made at high weights with flap 33 selected, which would I think be difficult to achieve in the Just Flight aircraft because of the high drag.
So basically I think you might have a point, but I can't prove it.
Good luck with your flying. -
Thank you for your very detailed assessment, it’s a valuable guide.
There are many YouTube cockpit videos featuring the BAe146, and whilst they don’t cover the performance aspect of takeoff and initial climb out, as a guide they have some appeal.
I find that even with a European city to city route W&B, my BAe146 simply don’t accelerate to flap retraction speeds quickly.
However, I wouldn’t know if the JF model is right or wrong, just that it seems needlessly heavy and slow.
BTW, your performance spreadsheet is a very useful utility, thanks.
Fabio
