Cool. Thank you Ed.

 

Tom K

This is looking rather promissing. When I reinstall xpx I'll try to learn where in planemaker we can set the proper values to better simulate this type of engine - free-running turbine.

 

Nice to see so many interests in common Tom, including astronomy :-) Long ago I ordered and used extensively a B&L 8'' Schimdt-Cassegrain telescope :-) Sold it to buy my first flight simulation rig :-(

 

I wish you success with your C90 mods.

 

BTW: ELITE runs in MAC too ;-)

 

Cool. Thank you Ed.

 

Tom K

Great place for PT-6 info,They're very helpful people.

http://www.pt6nation.com/en

Another C90 question. A user asked where to set "vertical speed" for the autopilot. I can't say that the reference source I used had one. I know on smaller aircraft, it is common to not have a VV selector. On the MU-2, you hold pitch then set the VV mode on the AP and it holds whatever the current VV is. To change VV, you would disable the mode...change the VV through pitch or trim input, then set the mode again. Is the C90 the same way?...some of them? optional?

I'm going to use this thread to discuss anything regarding the King Air C90 instead of the other one...whichever it was cause I can't recall.

 

Anyhow, I turned off the "FADEC" settings in PM, which affected the "twitching needles" as X-Plane tried to manage the engine. This allows you to over-torque the engine a bit...but that's probably closer to reality anyhow where you have to manage the engine a bit. Anyways, the engine needles do not twitch now and I am also seeing relatively constant fuel flow at mid-upper power settings when the prop speed is modulated between 1900-2100. There is a very small change in FF, but not enough for me to be concerned.

 

Also, I see no speed related issues as was mentioned in the other forum. The engines put out 550HP like they're supposed to...and props have plenty of thrust and I had no problem getting up to 200 kias.

 

EDIT: I also bumped up the intertia a bit...so when you do a full deflection roll (which you'd probably never do in real life)...then release the yoke, the plane will continue to roll with intertia about 30 more degrees...or so I estimate.

 

Tom Kyler

IXEG / Laminar

Anyhow, I turned off the "FADEC" settings in PM,

 

Looking fwd for your mods :-) Thx Tom!

Which C90 is supposed to be modeled?

"supposedly"...the B model....or so I hope.

Might want to check the engines... I know on the C90GTi that the engines are 550hp due to derating... but they'll actually put out a great deal more. It's the instrument red-lines that actually restrict it to 550, not the physical engine. But, that's the GTi... I don't know if it's the same for the C90B.

 

Is the 'B' even made any longer?? Why is it no one's (FSX,X-Plane, etc) doing a modern version of the King Air's??

Might want to check the engines... I know on the C90GTi that the engines are 550hp due to derating... but they'll actually put out a great deal more. It's the instrument red-lines that actually restrict it to 550, not the physical engine. But, that's the GTi... I don't know if it's the same for the C90B.

 

Is the 'B' even made any longer??

C90B has a 550SHP engine.

the B and GTi have been discontinued in production. Actually, only GTx (Pro Line 21 + 750SHP engines (PT6A-135A) + Winglets)

Actually Gustavo... that didn't really answer the first part. I know for the GTi the 550shp is a engine limits setup... as in the engine will actually produce more than 550shp if you operate it outside it's performance limits (per instrument markings).

Is the 'B' even made any longer?? Why is it no one's (FSX,X-Plane, etc) doing a modern version of the King Air's??

 

My guess is becasue you have to do the avionics with it and avionics are getting pretty specialized. They're not that easy to reproduce in that the real things have dedicated computers and huge databases to handle moving maps and such. Simulating the performance of the aircraft is very doable, but the minute you say, "it's a GTi or GTx", then everybody starts asking why the avionics aren't right. If expectations were down a bit as to the avionics, then you're right...I see no reason why not do one.

 

As far as engine capability...yes, flat /de rating is pretty common and you're right Ed, lots of turbines can put out a lot more power at sea level. The MU2 at least, is limited by it's gearbox strength. The engines are 1000HP engines per side (-10 model anyhow) but are "flat rated to 715" up to something like 25,000 feet or so (guessing). X-Plane handles this with a "critical altitude" setting that approximates a flat rated engine decently enough...guaranteeing the flat rating up to that altitude and then decreasing it beyond that...but with this method, you never get more than the flat rating HP at sea level. Another way to do it in x-plane is to just assign the engine power to it's real power ability at sea level, which is more than its flat rating..so as power decreases with altitude, you attain your "flat rating" at the guaranteed altitude. What usually happens in this case though is simmers jump on their joysticks and jam the throttle to the stops and get crazy torque roll and/or broken engines and claim it's uncontrollable. No doubt a real King Air pilot is a bit more cautious than us simmers. I've got about 40 hours of MU2 time and I can tell you we were real cautious on the takeoff roll to keep the engine within limits.....no jamming that throttle to the stops. You kept your eye on the torque and temp gauges religiously when bringing in the power.

Bit of offtopic, but is the MU2 becoming X-Plane 10 compatible in the plans?

I thought I was close a few months ago actually. Turns out the code I wrote to overcome limitations in V8/V9 is proving to just be too "legacy". I thought I could keep fixing and fixing it to keep up with xplane alterations, but it's like putting 10 layers of paint on a wall. At some point, you just have to scrape it off and start over.

 

So anyhow...just last week I decided to forgo the prop-lock feature to try and get it into V10 faster and not have to write my own prop governor and FADEC code. So definitely I have plans for it for V10, I'm just not sure when. I try and dabble with it every week. The best way I can describe it is "reverse engineering" though being that the code is over 3 years old...so it's a bit of a slow process making sure what I take out doesn't break something else. It will get to 10 though.

That's nice to know! Hope you can get that plane ready for X-Plane 10 without any major issue.