Help needed on avro hs748 autopilot

[mapez]

Hi Maltby D
It doesn´t work
The data on aircraft.cfg file is the same as mine but I realized that in your picture, the heading index on the CDI is in the same position ( on degrees ) as in the gyrosyn compass, but isn´t for me . In fact I can´t move the course with the rigth knob of the gyrosyn compass, only works the left knob which moves the heading. is that right ????
I think not !!! Maybe that's the problem

Waiting for your help !!!!!

Warm regards.

Mapez.

[MALTBY D]

Hi Mapez

It does work.

In fact I can´t move the course with the rigth knob of the gyrosyn compass

It's the knob under the CDI that sets the correct course (circled in red) - not the knob under the compass gauge.
I don't know why, but the right knob on the compass doesn't seem to do anything. I'm sure it should rotate the compass.

Once the course is set right on the CDI, the vertical bar should be positioned near the centre and NAV lock will lock on.

Remember VOR is omni directional, different beams come out of it in all directions.
The autopilot NAV lock is only going to follow the one VOR beam that matches the course set on the CDI.
If you are nowhere near the selected beam, NAV lock may fly straight until it intercepts the beam or it may turn in an attempt to find the selected beam.

DM

[DaveB]

Hi DM

I'm between broken pc's at the moment so typically, can't find what I'm looking for There were differences between the military and civvie versions (748/780) panel layouts but having just looked through 72 pages on airliners, can find no evidence of the gyro as fitted to the model. All the shots on airliners show the UK operated 748's with a Mk4B compass as fitted to the 780. On these, the lower RH knob doesn't turn the card.. it has a white dot and a + sign which conicides with a small window (upper right) on the instrument and is used to syncronise the left and right instruments. You turn it one way or t'other depending on the indication in the window I know this doesn't help with the instrument on the 748 model but it may explain why that particular knob doesn't do anything even though the tooltip displays 'heading indicator adjust knob'. Easy answer.. ignore it I'm sure I have a 748 manual somewhere but it's not on this pc. I DO have the 780 manual so perhaps mapez would like to fly that instead The bottom RH button still doesn't work but at least he'd know what it was for

ATB
DaveB

[Fodda]

Mapez

The 748 AP is a lot older than the modern stuff and takes a little getting used to. I used to have trouble locking onto VORs, but it's not me or you, or the AP... It's the realistic way in which it's all modelled. The AP will only lock onto a VOR radial if it's already within about 10 degrees of the VOR beam to start with. Could be even closer, I've not flown the thing for a long time.

When in Beam mode, and transitioniong VORs, I find that altering the heading manually (either with the column or by adjusting Heading mode) to the new radial heading and then fine adjusting to get the needle centred pretty closely... When I then switch on Beam the AP doesn't have to work too hard to get aligned on the new VOR beam.

The problem is that the AP isn't very subtle in riding a beam... It doesn't damp out oscillations and you'll find that if it has to capture a beam at say 35 degrees to your heading it'll turn towards it (sometimes even away), overshoot by a fair way, then turn back and overshoot and so on making yourself and the pax quite airsick for about 30 mins.

Trick is to align yourself on the beam before activating the Beam follow setting on the AP. It'll become second nature after half an hour or so.

Have fun in the 748, it's a fantastic model.

[Garry Russell]

Indeed

A lot of these older AP need manual setting, or almost and then they keep you where you put them, but won't neccessarily pull you in from anything even a medium distance form the one requested.

[mapez]

Hi there : Maltby D, DaveB, Fodda, & Garry Russell !!!!
Thank you guys for all your comments
" Now I begin to see light at the end of the tunnel "
Fodda : I agree with you, the 748 it's a fantastic model.In fact I would say one of the best for me !!
Very good explanation of the operation of the A.P. just a matter of practice to master it !!
That's the way I want to fly it. " By the book ". Dave B, when you find the748 manual, can you do me a favor and send it to my e mail ? I really will appreciate it !!!. Maltby D thanks for all your patience and help
a big hug for all !!!!
keep in touch !!!!
Warm regards !!!
Mapez.