C-27J Spartan

Hi Jeff..I'm
currently working to get a copy of the 1.2 fde. As soon as i have it, i'll be going over it with a fine tooth comb. Some things appear to be caused by gauges and there isnt much i can do in an fde to change that, but other things are definitely in my ability to change.. Bear with me. I'll do everything I legally can..
oh, and sorry but i'm afraid there isnt much i can do about lighting. the lights are 3D models and part of the original mesh.. They have been noted before and its been recommended to set the plane up with A2A's 3D lights..

Talk soon

Pam
 
RCAF_Gunner said:
I don't know if this'll help narrow down the max speed issue but what I observed during a run @ 22,500' this morning is the critical N1 setting is 92%. At or below 92% the aircraft appears to flying as expected but as soon as it hits 93% it behaves like the engines are cut or a speed brake is suddenly deployed. Power/speed drops like a rock. FF was showing @ 161 @ the N1 92% setting ~ just wondering if fuel flow get starved at 93% or something like that? Note: I was testing with an aircraft.cfg file which had the changes to thrust and throttle limit listed in this thread.

Rick
Click to expand...
Rick..
Thanks for the feedback. I've allso noticed the speed issue where when you get above a certain speed the throttles get momentarily chopped and the plane starts bucking.. I dont know what causes that to be totally honest, and i dont know if theres a way i can program around it, but i'm gonna do my best..
Talk soon
Pam
 
I did fictional skin to trip over Antarctica X.

British Antarctic Survey (BAS)


spartanbas3t.jpg


spartanbas6.jpg


spartanbas4.jpg


spartanbas1.jpg


spartanbas8.jpg


spartanbas5.jpg
 
Thanks Pam. I'll be patiently waiting.

Bummer that some anomolies aren't being fixed proper from IRIS directly.

Cheers,
Jeff
 
ST0RM said:
Thanks Pam. I'll be patiently waiting.

Bummer that some anomolies aren't being fixed proper from IRIS directly.

Cheers,
Jeff
Click to expand...

Well, to be honest, i feel that since my name was associated with this plane from the beginning, that to do anything less than take ownership of the mistakes and fix them, would be less than cowardly.

I could use a little help here from ya'll though.. What i need is for those of you that have both the 1.0 and 1.2 flight models, to put the 1.0 aircraft.cfg file in with the 1.2 air file, and after turning off bitchin betty, check your acars and tell me if your also seeing oil pressure warnings for both engines.. Ive gotten her where she accepts the fact that shes got 900 sq ft less wing area than she thought, and weights 17000 pounds more when empty. She'll easily cruise at 324 knots ( 350 mph ) and takes off in the proscribed 1900 ft without flaps.. i just havent figured out the oil pressure warning yet, and its bugging me..
Pam

PS.. Never mind.. found the problem and fixed it.. oil pressure may not be exact, but at least the warnings are off.. will keep working on it..
 
Got it. Thank you and currently in 45 minutes testing.
x
The ITT rate is hovering around 720 with a indicated speed 320 no engine blow outs or fires. That is a major plus improvement on 1.2. Handleing is excellent in touch and go's in Canada's Arctic short strips ie Hall CYUX and CYGT with AS2012 throwing a snow fest lol. Able to do high degree angle rapid turns and sharp landings. Brakes need a adjusting for tightening so far Ive detected. Next up a a feisty high speed rapid stop low Cat 3 landing YFB. no crazy s-turns with wx engine AS2012 and REX.
 
excellent..
ok then, heres the plan.. I will make this available to those that ask for it ( 1.3 fde ). It is not perfect, it is not final, it's not a lot of things. But it is better than whats come previously. Then, as you folks let us know about problems your seeing, I will go in and fix those problems and keep it updated until Iris releases the 1.2.2 update..
Admittedly, with less than 24 hours invested in creating it, this is not my greatest masterpiece.. But it will help...
If anyone wants it, pm me with your email addy and i'll send it right out..
Pam
 
warchild said:
...the lights are 3D models and part of the original mesh.. They have been noted before and its been recommended to set the plane up with A2A's 3D lights...
Click to expand...

Might you have the parameters for the landing and taxi lights? I guess the location on the model so I can set mine up.

Thanks again!

-Jeff
 
I dont at this time. I suspect that since the lights are all part of the opriginal mesh, that theyve been modeled into their correct positions, but, if your considering adding 3D lights Redux I'll dig out the schematics and be able to give you at least ball park locations within a couple days..
 
Thanks for continuing to work on this Pam. I'd like to try your latest FDE files so I'll send you a PM.

While "googling" around for performance specs on the C-27J I've come across two sets of maximum speed numbers:

- max cruise speed: 325 KTAS (602 km/h)
- max cruise speed: 315 KTAS @ MTOW (which I'm presuming to mean "maximum take-off weight")

but I haven't been able to find an associated altitude reference for either of those figures. (I'm used to seeing a related altitude for a given spec such as "at sea level" or "at XX,XXX ft ASL".)

So I have a couple of questions:

- when the reference is "cruise speed" does that mean at some specific/reduced throttle setting (such as N1 @ 90%) as opposed to using full throttle (which you'd think would have a time limitation on use)? I'm more of a piston prop person so not that familiar with turbo prop management. For instance, I find it really odd N2 is generally above 100% once you have gained some altitude in the C-27.

- what altitude should those speeds be achieved at? (I've been testing against 25,000 and 30,000 which are both listed as ceilings depending on the source.)

Thanks,
Rick
 
Hi Gunner...
Yes, cruise speed is a reduced speed wherein you are able to achieve the greatest amount of range. On the C-27J that speed is 350 mph or 324 knots. For a plane with this weight and power with a cieling of 35000 feet, a good "working" altitude is around 19000 feet, although the plane will cruise at sea level just as well as it does above 15000.

As too why N2 is always at 100%, I dont really have an answer, however, there are some good discussions of jet turbine operation and theory on the web, specifically

http://www.airliners.net/aviation-forums/tech_ops/read.main/166437/

and

http://www.b737.org.uk/powerplant.htm

As you will see in these conversations, 100% rpm is defined as the designed rpm. Quite freaquently a spool can rotate faster than 100% which is usually reserved for emergency use or in the case of the space shuttle for take off ( at 109% ).

The biggest thing here is remembering that you have a jet engine thats driving the propeller instead of a piston engine. The Jets thrust is used to turn a shaft which connects to the reduction gear, which in turn connects to the propeller. The constant speed of the propeller is maintained by a set of gears and clutches that constantly change as the power output of the plane changes, and adjust the pitch of the prop accordingly. ( i hope ive got that right. its a very confusing area ).
The other big thing to remember, is that flight simulator has "never" modeled turbo props correctly. There are others here with far more knowledge than I that could tell you why much better than i can.
 
ok.. I've gotten some requests for the 1.3 fde fulfilled now and have gotten some feedback on them.. As I said earlier, 1.3 is a stepping stone. More of a beginning point actually. It will allow you to enjoy the aircraft while I make repairs based on your feedback.

Two things to keep in mind when flying the bird at this moment..
she only has 880 sq feet of wing space. and gods only know which profile is being used in there to define lift, so presently she will climb more slowly than she did previously, and moreso than she will in the not too distant future ( hopefully by the end of this week: heh, new years, new bird. I like that idea ).
The second thing is altitude. As you all know quite well, above 14000 feet or so, air pressure begins to drop dramatically. By the time you reach 20000 theres not enough air outside to even breathe. Old superchared and turbocharged engines made up for this using the supercharger to compress what air was available before feeding it to the engines intake so that the manifold pressure always remained correct to sea level values.
Modern jets dont have a supercharger, in a sense, they're one giant one all on their own. This makes them susceptible to the same issues that a normal gas engine would have. The trick is to change the N1 rate to allow for a greater volume of air to be delivered to the engine. Normally, the FADEC handles that without anyones intervention, but the fact that the c-27 currently is not doing that leads me to suspect that something else is wrong and I think i know where to start looking, so i'll be working on that as well..
Stay tuned..
Pam

PPS.. I litterally just woke up and havent had coffee yet, so if i dont make snse its because i'm still too goofy brained to do so.. please bear with me..
 
You must log in or register to reply here.
Back
Top