Just Flight VC10 Question.

[Nigel H-J]

For those who have the Just Flight VC10 I am hoping that you may be able to answer my question, when reducing speed and selecting the first stage flaps and slats i.e. 20 deg I have found that the aircraft flies with quite a bit of nose down attitude as though it is on approach, only when I select 35 deg of flap does the aircraft resume a straight attitude.

Has any-one else noticed this and if so is this the normal flight characteristics of the VC10? Somehow it just feels a bit strange, but then again, I have never noticed it until recently when going for an outside view.

As far as I can remember when flying DMs' VC10 I don't think it showed this kind of flight characteristic, though it must be at least 4 years ago since I last flew the DM version.

if anyone can shed any light on this it would be helpful.

Regards
Nigel.

[delta558]

Hi Nigel,

According to the VC10 pilot on our testing team, the initial pitching is upwards followed by a downwards pitching towards the end of travel of the first stage of flaps. Further flap selection should then give progressively more nose-down.

Within the limitations of FS, the only way to create the pitching in opposite directions was to have the slats pitching up and the flaps pitching down. From memory, the slats are set to take about 10 seconds and first stage of flap roughly 15 seconds. That, combined with the reduction in speed, should see you pitching down towards the end of that first flap movement.

It probably isn't perfect, but our Ten pilot was happy enough with it.
Cheers,
Paul.

[Nigel H-J]

Hi Paul, many thanks for the explanation, so as I understand from what you have written is that after I have selected 20 deg of flap and the slats come down and I fly the a/c at say 190kts then it is normal for the nose to point downwards? that is until I reduce speed then select 35 deg flap where the nose comes up and the a/c resumes near normal level flight.


Hopefully I am correct in the above after reading your reply.

Again, many thanks.

Regards
Nigel.

[delta558]

I'll have a dig through my notes when I get off shift later, Nigel - should be able to give you a better response then.

[delta558]

Hi Nigel,

Right then - I've gone through my notes, the manuals and conversations with our Ten pilot. Also flown a quick circuit to have a look at the situation again.

The pitching down is more than I expected when viewed from the outside (see note after). However, 190kts is close to the top end of the speed range for the first stage of flap (229kts max). It is possible that it's too much at that end of the speed range if speed is maintained, but from all conversations the extension of flaps would coincide with an expected reduction in speed. The flap drag accounts for this, and the reduction brings you below the limiting speed for the next stage of flap (177 kts). At that point you should be flying more or less level, the 2nd stage of flap then giving slightly more nose-down pitching which will need to be trimmed out.

(note): the RW lift from the flaps is quite excessive - the difference in stall speed clean and full flap is huge (in the region of 50kts for full flap, 25kts for just the first stage). To fly around at near max flap speed in FS is going to give you that nose-down attitude unfortunately. I'm not saying it's right and I will bear it in mind when we start looking at the Pro version (along with Dutch Roll, which I really need to spend some time on). The flap lift is set at sea level, close as poss to empty weight - as it is currently set it hits the figures there, but the further you head away from it the more likely you are to find discrepancies.

To finish, I'll give you some relevant quotes from our VC10 pilot:

I flew the '10 as a pilot for 3.5 years, with about 1100 hrs on the jet
Flaps: The pitching moments are interesting and not all the same way. Moving from T/O to App or Land is similar to many other jets (certainly the 707!) and gives quite a strong nose down pitch (ie requiring nose up trimming), exacerbated by the decelleration. From Up to T/O, and vice versa might be more difficult to simulate; as I've already mentioned the flap movement from T/O to Up (and vice versa) is quite slow, probably about 15 seconds or so. In that you'd be trimming both ways! Up to T/O would be nose down trim initially before trimming nose up as they approach the T/O position.
Flying controls - they've got a good balance. Elevator effectiveness is just about right as is the roll control
I think the pitching with flap and slat is just about spot on.

I hope that is all useful for you,
Paul.

[Nigel H-J]

Hi Paul, very many thanks for your reply. It has been most helpful, I have pm'd you as well.

Regards
Nigel.

[adysmith]

Been looking at the specs for this aircraft.

For a fairly detailed sim why didn't they include the super ten as well?

Additionally it looks like a VC only model, I am not a great fan of virtual cockpits.

Ady

[blanston12]

I think they are planing the super as an expansion pack