Flight directors request extremely high pitch angle on take off
-
I've noticed that on take if you were to follow the flight directors (hand flying), your pitch angle is excessive - up to 20 degrees, and you risk stalling. I've ended up pitching to what I thought was best - which is often 5-8 degrees lower than the flight directors.
Not an issue exactly but behaviour I wouldn't expect.
(This is on the RJ 100)
-
During takeoff and initial climb, the flight directors should indicate the pitch required to climb at the V2+10 speed.
We did come across situations in testing where spiking in the user's throttle axis can cause the flight directors to indicate too great a pitch angle during takeoff and initial climb, but we worked around this by adding the "A/T THROTTLE LOCK" option on the EFB which disconnects the users throttles from the aircraft whenever the A/T is active (A/T green on the PFD).
Something I would recommend trying is to load into the aircraft on the runway. Ensure the "A/T THROTTLE LOCK" is enabled on the Aircraft page's Configuration Menu. Advance your physical throttles to 100% (fully forward), then trigger TOGA in the aircraft (click the hidden click spot on the bottom left screw on the captain's VHF NAV radios). Release the parking brakes and takeoff. With the A/T THROTTLE LOCK active, and your throttles in the fully forward position, this should negate any spiking in your throttles axis and allow the flight directors to display the correct pitch angle.
Hope that helps.
Mark - Just Flight
-
Hi Mark, same issue here although I've tried all suggestions as stated by you above.
The F/D is simply directing the wrong pitch attitude.
Best regards
-
The only cause I recall of the Flight Director indicating too great a pitch during takeoff/climb was a throttle axis spiking issue. That's covered in my previous response in this thread, along with a potential workaround for that.
Another way of working out if it is throttle axis spiking related, will be to temporarily unplug any external hardware with a throttle axis assignment from your PC (joystick, throttle quadrant, etc.) and then load a flight in the RJ on the runway. With a flight loaded on the runway, enter a flight plan in the FMS takeoff as normal. If the flight director bars indicate 8 degrees pitch up for the takeoff roll, and then indicate the pitch required to maintain V2+10 during the initial climb, then they are behaving as expected and the cause will likely be related to a spiking issue in the throttle axis.
If the issue persists with no throttle axis assignment in play, the could I kindly ask you to raise a ticket with Just Flight Support via the following link: https://www.justflight.com/support
In the support ticket, if you could supply a video of the behaviour, then our support team will have the best chance of either reproducing that behaviour and be in the best position to assist with further troubleshooting.
Mark - Just Flight
