J41 Engine Anti Ice command

[Gregg_Seipp 570]

Is there an engine ice command for the J41?

 

I tried using the standard Anti-ice and Carb-Heat commands but 1) they behave differently (seem backwards too...dropping EGT when they're on,..raising it when they're off) and 2) they don't move the Elev/Engine icing switch.

[Houghton11 12]

I have not experimented with custom offsets or LINDA or anything, but i'm not aware of a specific 'built-in' key command for the JS41's ice protection.

 

Remember, the leading edges are a "de-ice" boot type, and the engine's are "anti-ice". Kinda different operating philosophy between the two .

 

Wait till you have some ice before playing the Elev/Wing de-ice and, Engine anti-ice anytime you suspect icing. The Elev/Wing auto-timer though does make it pretty fool proof both in real life and in the sim.

[Gregg_Seipp 570]

My suspicion is that their engine-elev anti-ice is custom. When you turn it on the EGT's jump instantaneously. If you press 'H' for carb-heat, you get the same kind of jump but it's slower. So, who's to say that the 'H' command even works (most likely doesn't for the elevator). Maybe I can go fishing with the FSUIPC log when I get the chance.

[N520AT 3]

The engines on the J41 - as I'm sure you know - are tubrine engines and therefore don't require carb heat..they don't even have a carburator to heat. I have no experience with direct-drive TPE331 turbines, my only experience is with free-turbines on PW123s and PT6A's. With the free turbines, they use an initerial separater. Basically, these are "doors" that swing down into the intake so any foreign contaminates that may be sucked into the intake hit the door at are flung out the bottom of the nacelle through an opening that opens in conjunction with the anti ice door. With the Anti-Ice OFF, the door is sucked into the top part of the intake (or the bottom in the case of the PW123) and it's an obstruction free path all the way up to the turbine. Activating anti-ice causes a rise in ITT and a drop in torque. Getting to cruise altitude in the winter is always much more difficult because where I fly we are climbing through icing conditions which by use of the engine anti-ice and ice accumlating on the airframe negate the colder temperatures and we usually (with the PT6's) run into our max temperature limit way (= not being able to increase torque) before we would in the summer, with hotter than ISA temps.

 

My guess (I don't own the product) is that PMDG has this feature separately coded than anything in FSX. Does the J41 have a menu where you can assign key commands?

[Gregg_Seipp 570]

The engines on the J41 - as I'm sure you know - are tubrine engines and therefore don't require carb heat..they don't even have a carburator to heat.

 

Yeah, it's some quirks of FSX. They don't have Carb Heat, yet, if you press Carb Heat the EGTs go up. I think, behind the scenes Carb Heat is actually called Anti Ice.

 

My guess (I don't own the product) is that PMDG has this feature separately coded than anything in FSX. Does the J41 have a menu where you can assign key commands?

 

I think you're right about separately coded. No, I think most folks just provide a public API and FSUIPC includes it in some of their menus. Some items don't have an API. I think API is thought of a little during the development process but it can often be poor and difficult to use. My experience with the third party aircraft that it's fairly across the board. Some are getting better. I'm slowly learning how to write LUA to make it work with my hardware.

[Houghton11 12]

I have no experience with direct-drive TPE331 turbines, my only experience is with free-turbines on PW123s and PT6A's

 

On the Garretts High Pressure Bleed air is bled off to an ice shield (basically the lining of the compressor intake after the intake cowling) continuously, and an anti-ice valve providing the same bleed to the intake cowl and P2 probe.The warm oil of the gearbox is right above the intake so it helps as well. As one would figure, the 'robbing' of bleed air only increases EGT. It's actually a really limiting factor on the Garrets, and something that even the 331 fans admit is kind of discouraging.

 

 

The inertial separator, and the reverse flow nature of the PT6 is a much better balance between ice protection and performance...well...I would argue that.