Page 1 of 1

Yak-40

Posted: Sun Nov 29, 2020 12:29 am
by Martinlest
A bit of a long shot, but I wonder if anyone knows about this a/c. Obviously (?) I am not flying the real thing (just as well perhaps) but there is a highly detailed rendition in X-Plane which seems to reproduce just about everything that the actual aircraft would present to the pilots.

I am new to this, but have got my head around 99% (I think) of the procedures - have had a couple of successful flights now; complex, but intriguing. One thing confuses me though: the checklists talk of ILS approach and, before landing, switching from 'route' МАРШР to 'landing' ПОСАД mode (using the switch with those options). But what does/can that do? - there seems no way actually to engage an auto ILS landing; the a/c has a very basic A/P only that will maintain the current pitch and heading. That's about it.

Thank you to anyone who is familiar with the Yak-40!

Re: Yak-40

Posted: Sun Nov 29, 2020 2:04 am
by Starlionblue
I don't know the Yak-40 but it sounds similar to activating the approach phase on Airbus. This changes the managed speed from the LRC or ECON speed to minimum clean (known as "green dot" on Airbus). Once you configure, the managed speed changes to the manoeuvring speed for the current flap setting, and once you have landing flap out to VAPP. Compared to the Cruise Phase (en route) you also get things like VDEV on the Progress page.

Then again, I don't know if the Yak-40 even has computed reference speeds. :D

Re: Yak-40

Posted: Sun Nov 29, 2020 9:32 am
by Martinlest
Thanks, that is very possible now I come to think of it. Impossible that it can be any kind of 'APPR' mode in this a/c.

Re: Yak-40

Posted: Sun Nov 29, 2020 10:24 am
by Martinlest
I found some more information. I suspect this is a Google translation from the Russian.. not 100% sure what a 'plank' is (mode?). Will have to look at this a bit more closely to see how/if it is implemented:

Switcher Route (up) / Landing (down). In route mode system works only with VOR and VOR/DME navaids and only course planks on HSIs corresponds; in landing mode – Course MP works only with landing systems ILS or SP-50 (not implemented in X-Plane). In this case will work both course and glideslope planks on HSIs, but lamps TO VOR and FROM VOR will not work...

Re: Yak-40

Posted: Sun Nov 29, 2020 11:06 am
by Starlionblue
From context, I think "plank" means "deviation bar". This makes sense as in enroute you'd be able to track VOR and VOR/DME on the HSI. And in approach you'd be able to also track the localiser on the HSI.

Looking at this cockpit picture, it does appear as if there are flight director indications on the ADI as well.

Image

To clarify on Airbus, the FMS has an approach phase that you activate. This changes speed targets and so forth in managed mode. However, to get the autopilot to actually capture the ILS, you need to arm Approach on the FCU/ACP (glareshield autopilot controls).

Re: Yak-40

Posted: Sun Nov 29, 2020 5:15 pm
by Martinlest
Yes, that sounds fair, in theory at least: in practice, I am not sure how to implement any of that in the X-Plane a/c (I am trying to use the Garmin 430), but that wasn't the point of my post of course! Thanks again for the input.