Marco Ravanello's ATR 42 - IAS Hold?

[degiorgio]

Very nice rendition and an atmospheric panel.
My IAS hold refuses to adjust the throttles and hold the set airspeed on the A/P.
Does this aircraft have autothrottles in real life?
Just curious.
Also, does anyone know where I could find some good sounds for the ATR?

Thanks
John
http://www.degiorgio.homestead.com

[SSTsunami]

bump

[degiorgio]

:-jumpy BUMP!
John
http://www.degiorgio.homestead.com

[churche]

bump

[jannick]

No it does not have autothrottle, but it does have ias hold ajusted bye pitch!!

Happy new year

[Kurtvw]

Well, it must have some kind of A/T because as soon as I engage the IAS hold it decreases the throttle... too much...

Its IAS hold is broken.

http://www.crs-sonoma.org/graphics/fscsig.jpg

[degiorgio]

Jannick,

Grateful if you could explain how "IAS hold adjusted by pitch" works please.

Best wishes for the New Year to you too.

John
http://www.degiorgio.homestead.com

[rhodges]

Hello:
Auto Throttle control does not work on any turboprop that I have tried (i.e. Dash8's and BAe 31-42's). There is a try under tips on this site, but I have not been able to get that to work either. As far as I know, without a patch, there is no speed control for turboprops. Note that it is not included on the default King Air either. If you find a modification that works, I sure would like to know about it.
Thanks:
RTH

[jhender501]

On the subject of the ATR's panel (David Durst's)...has anyone
found the GPS/NAV switch? Perhaps he didn't include it, which
is fine, but I'd like to know if it's there..where is it?


(wonderful plane/panel, btw)


Jim

[Simon Evans]

IRW, IAS adjusted by pitch means that when the speed bug is set the aircraft pitches up or down to achieve the selected speed, the speed bug is NOT linked to an autothrottle system.

In climb, you use climb setting on the throttle (say 94 percent) and then click the bug to the desired climbing speed - say 160 knots. The aircraft pitches nose up until the desired airspeed is achieved, and will then adjsut pitch to maintain that speed all the way to top of climb, or until another alt hold mode is set (such as vertical speed). It is not good practice to click the speed bug to an IAS higher than the one currently achieved as the system reads that as a pitch down command, and you get a heap of bobbing and weaving while the aircraft stabilises. Commonest procedure is to reach desired climb speed, then engage the bug which was pre-set before take-off.

note that in this mode speed will be constant, but rate of climb will change, falling off with altitude.

So next, cruising at 220 knots, you set 210 knots on the bug. Nothing happens. Manually back off the throttles however, and as the speed bleeds past 210 knots the nose starts to drop as the aircraft pitches down to seek the desired velocity. Descent RATE is controlled by more or less throttle, as required.

This is commonly found on mid-range turboprops where the fancy all-singing, all-dancing autothrottle is a pricey and time-consuming option for an aircraft that spends much of its flight time in climb or descent mode.

Done right, it's a very different way of controlling Vspeed to a jet airliner.

MS don't appear to have made a good job of it yet, sigh.


Simon Evans