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martinlest2

Nose down attitude on descent. 'Fixable'?

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I'd have thought that Mike Stone's a/c would be pretty spot on, but I find that in descent the attitude of his B1900D is very much nose down. I am, I think, at about the right speed with correct flaps, but the nose-down attitude during descend is enough to look very strange.

 

I thought I knew how to tweak the aircraft.cfg file or air file to make the a/c a little nose higher, but when I come to do it - well, seems I don't! I know that any such tweak may possibly adversely affect some other setting (?), but maybe even so, someone could remind me how it would be done?

 

(I searched the forums BTW but didn't find the answer - though I am sure it is there somewhere!).

 

Thanks

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Hi Martin.

 

During descent you should not be using flaps.  What descent speed and what altitude are you experiencing issues.

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I only have a little bit of experience in the 1900D, but the King Air 200, which is very similar, has a very nose down approach. A turboprob wont make an approach like a jet, you have to point the nose down to go down. If you are talking about just a normal descent, having anywhere between 5-10 degrees nose down is very normal on descents from altitude.

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A descent to save fuel normally has nose down until the local airport pattern with engins at flight idle. Flaps are not applied until downwind or base depending on the aircraft. It is a mix of desired vertical speed and desired IAS. One advantage of flaps besides adding drag and lift at slower IAS is that with some nose down visibilty toward the runway becomes better. Without flaps you would have to raise the nose to slow up interfering with forward vision and reducing the stall margin.

 

Study the flaps schedule for your aircraft in the airport vicinity for landing.

 

From Mike's aircraft.cfg for the 1900:
 

[Flaps.0]
type=1
span-outboard=0.300
extending-time=5.000
system_type=0
damaging-speed=250.000
blowout-speed=300.000
lift_scalar=0.500
drag_scalar=0.500
pitch_scalar=5.000
flaps-position.0=0.000, 0.000
flaps-position.1=17.000, 0.000
flaps-position.2=35.000, 0.000
[Flaps.1]
type=1
span-outboard=0.300
extending-time=5.000
system_type=0
damaging-speed=250.000
blowout-speed=300.000
lift_scalar=0.500
drag_scalar=0.500
pitch_scalar=0.500
flaps-position.0=0.000, 0.000
flaps-position.1=17.000, 0.000
flaps-position.2=35.000, 0.000

 

[Reference Speeds]
flaps_up_stall_speed=101.000
full_flaps_stall_speed=84.000
cruise_speed=280.000
max_indicated_speed=259.000000
max_mach=0.579980
 

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I think the theory of it all is OK for me... but if I compare this a/c with the PMDG B1900D, there is a noticeable difference in the pitch during descent, and I guess they can't both be right.

 

I'll check the flap settings in the aircraft.cfg file, I don't think I ever changed them though, so they should be the same as you posted. I only use flaps late on in the final approach, not during normal descent anyway. Maybe too my speed is a little on the high side - I'll double-check that as well.

 

M

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