Using Autothrottle Etc..

L

lemonadedrinker

Charter Member
Hi All,
I've been using the TeamFS KBT Orions and Electras from Mike Stone, Edgar Lucariny and Libardo Guzman with various panels and would like advice about the Autothrottle which sometimes works and sometimes not! Just dies. I think what I've found is that you can't change planes mid-flight, but if you disconnect A/T and A/P and fly manually, it might recover, but it's not certain...is it something to do with FSUIPC, or just a quirk of the coding? I think I read that the A/T gauge is quite old and may be temperamental if swapped mid flight. Sometimes it won't work even when used from wheels and flaps up. Any advice would be appreciated.

Andy.
 
Hi lemonadedrinker,

can't answer your question regarding this specific issue with the KBT Electra/Orion, however to add to Bjoerns post ,I think only very few
turboprop-driven aircraft feature an autothrottle system in reality. The Short(s) Belfast being one notable exception that comes
to mind.
The reason for the absence of autothrottle system on turboprops is probably the (at least historically) technical difficulty of implementing
a system that could handle the added complexity of controlling the prop levers along/parallel to the Power Lever control.

Nowadays with FADEC turboprops, it probably is not that much of an issue anymore, but then again, when was last commercial turbo prop
was designed from scratch, without angling for a common typerating that includes earlier versions?

Long story short, if the A/T gauge occasionally drops out or doesn't work at all, that's problably quite realistic :)

Sorry, wish I could help you more,

Kind regards,

Oliver
 
Thanks for the replies. I stopped using Paul Strogen's immersive panel a while ago, but checking it just now, he states on one of the bitmaps for the panel that there is no autothrottle! This may be why I come in quite hot at 250 knots and wonder why I'm always ending up in the shrubbery. Live and Learn.
Thanks, :encouragement:

Andy.
 
Bjoern said:
Do real Electras even have autothrottles?
Click to expand...

I know the P-3 series does not, and I cannot recall any recip/turboshaft airplane that does in real life.

In a prop of either type, you set cruise power, and IAS/TAS will gradually increase in relation to weight decrease as fuel is burned. This is relatively small except over long distances in say a 4 engine type like a Connie or DC-6.

In turbojet/turbofan, weight decrease is significant over time. Small increases in IAS /IMN make a large increase in drag at high altitudes (it is a "quadratic effect" - a 10 KIAS change at 290 KIAS is considerably larger drag increase than a 10 KIAS increase at 170 KIAS). Therefore, jets typically get best fuel/range performance at a constant KIAS/IMN, and is easy to hold using autothrottle. The fussiness of setting jet engine thrust to get a precise airspeed often requires some initial, and continued throttle jockeying to hold target cruise speed..

To put it another way, jets burn a lot more fuel being off optimum speed/altitude for a given weight than a prop/turboshaft.
 
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Hi,
The Orion has been evolving over 50 years and is being outfitted to last until 2035 at least. The panels created by FS KBT and other Maestros of the craft for the different models seem to fit so neatly, it seems hard to imagine they do not have autothrottle systems! To my simple brain the throttle movement in the VC looks 'right' as it hunts back and forth. Any road up duck, it's a beauty :very_drunk:

Andy.
 
Mike71 said:
In turbojet/turbofan, weight decrease is significant over time. Small increases in IAS /IMN make a large increase in drag at high altitudes (it is a "quadratic effect" - a 10 KIAS change at 290 KIAS is considerably larger drag increase than a 10 KIAS increase at 170 KIAS). Therefore, jets typically get best fuel/range performance at a constant KIAS/IMN, and is easy to hold using autothrottle. The fussiness of setting jet engine thrust to get a precise airspeed often requires some initial, and continued throttle jockeying to hold target cruise speed..
Click to expand...

Or just set a certain initial fuel flow and let the plane do the rest. At least that's what I'm doing in cruise.
 
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