C-27J Spartan

The N2 (or the gas generator section, also called Ng) will operate at 100% in a turbo prop (or close to it, depending on the make and model) even with a reduced torque setting, so power will be instantly available when you increase the torque setting. Turbo props are known for having almost instant power increases, and they do it by virtue of little or no spool up time in the N2/Ng section....because it's already spooled up, some at 100% and some not.

Each engine type has it's own parameters on this theme. I have 6288 hours on turbo prop equipment, spread between the EMB-110 Bandeirante, EMB-120 Brasilia, and ATR-72, and each type operated differently.
 
I'm thoroughly enjoying this model, but somehow I ended up with the Single Pilot version. Lol.


2011-12-28_14-3-51-56.jpg
 
Bone.. left cick on the gust brake in front of the throttle levers. that'll bring up an option kneeboard that allows you to add or remove seve3ral things including crew,, to close it right click on the gust brake..
 
Ok guys, here's what i did..
In the aircraft.cfg file, under the turbine engine section, i changed the air intake size from 1.0 to 4.4. 1.0 is about the size of a human head so it was way too small..
Next, i took the plane for a spin at 20700 feet and ran it through afsd ( image below ).
The speeds everyone is seeing at 20000 feet are correct and normal..
As you cimb up to 20000 feet, the FADEC is purposely decreasing the N1 ( LP spool ) rpm to allow for there being less air. As you can see in the pic, N2 ( hp spool ) remains at 100%. The speed you are seeing in the EADI is derived from the air pressure as it hits the pitot tube. since there is less air at 20000 feet than sea level, its not getting enough air pressure to read the true air speed of the plane. as you can see below, the true airspeed is still above 350 knots. This is working as it should be..
If you folks would make that littler change in the aircraft.cfg file using notepad or win-vi, you should be fine..
The change will also be reflected in the next update on the flight model, but my intentions are to get you folks up and flying and having fun as quickly as possible without having to wait for me. so what i'm gonna do is let you all know what changes i'm making in the aircraft.cfg file so that you can change them too, and be flying better, that much quicker..

Pam

View attachment 55255
 
ok, more good news. my partner Paul frimston ( delta558 ) has agreed to focus on this project with me. Paul is my eyes and ears when it comes to flight testing, and one of the best in the business. between your feedback, and his input we should be able to give you a superior flight model in no time at all..
Pam
 
Just a quick update for you folks. nothing but good news i hope..
I was able to locate the FAA certification sheets for the aircraft, engine and propellers, and paul was able to latch onto some official alenia documentation. After a quick glance over of the design methods used, we decided to go ahead and re-write the entire fde, but dont fret. We have it rotating at 97 mph without trim or flaps, and stalling at 110. It flies quite nicely (at 350 knots and below ) at this moment, but its not JFTC quality yet. It has a few little gotcha's in it that i know would not be tolerated by alenia in the real plane, so, we wont tolerate them either.. As with all JFTC flight models, we demand smoothness and predictability in all out big twins. This one isnt any different.. As to whether it will be good or not?? Well, I'll let you folks be the final judge of that.. It wont be too long and we'll have this out too you.. You wont need the entirety of Antarctica to land or take off from.. I promise you that..
Talk soon
Pam
 
Just to throw my opinion in here, I got it yesterday and have given it workout.
In my opinion the best thing that could happen here is to figure out how to shorten the turbine lag. I know turbo props have some lag but I timed from throttle advance to when the power actually starts to increase. 8 seconds.
DA's Cheyenne has about a second if I remember correctly and that seems much more realistic.

As it is, changing the static thrust error and min throttle made an enormous difference in the approach speed and landing distance. With full fuel I can land in 2000 feet which is ok by me. With less turbine lag this would be even better. I do wish the spoilers had an armed mode.

I think the spoilers are much too effective in flight. It is possible to do a Khe Sanh approach without flaps which doesn't seem right at all.
I don't think you should be able to hop in an aircraft with full fuel and fly a demo profile like a test pilot in an aircraft with minimum fuel. I am much more interested in real world operations that the demo. Looking at some videos of operations in the field I am not sure 2000 feet is that far off.
One of the things I notice is the takeoff and landing speeds in the manual are very conservative.
I find rotating at 90-95 knots with flaps 2 to be no problem at all.

I haven't messed with cruise speed much but at 25,000 I had 300 knots TRUE airspeed at 85% N1.
It is supposed to cruise at what 315 kts or so?
I am really looking forward to seeing this sorted out, at the same time I wouldn't want it to be a rocket ship where no effort or technique is required to reach the Paris airshow type performance.

Thanks for doing this Warchild and to anyone who is on the fence like I was after reading about some of the issues, Get it, it is a great add on that is getting even better.
 
I need some help please. I am trying to get the CS C130 engine smoke to work on the C-27

I added the following lines to the config but no smoke???

[SMOKESYSTEM]
SMOKE.0 = -7.80, -15.00, 0.90, cs130_smoke
SMOKE.1 = -7.80, 15.00, 0.90, cs130_smoke

Do I need to add something to my panel config also and if so, What? :kilroy:

Looking forward to Pam's final Version :applause:
 
doublecool said:
I need some help please. I am trying to get the CS C130 engine smoke to work on the C-27

I added the following lines to the config but no smoke???

[SMOKESYSTEM]
SMOKE.0 = -7.80, -15.00, 0.90, cs130_smoke
SMOKE.1 = -7.80, 15.00, 0.90, cs130_smoke

Do I need to add something to my panel config also and if so, What? :kilroy:

Looking forward to Pam's final Version :applause:
Click to expand...

Hi DC :) ..

If you can be patient, I'll work on that problem with you personally making sure it works on my machine ( as i also have the c-130 ), but, the best i can suggest right now, is, dont waste your time on this flight model. Here's why..
Although my name and my companies name appear in the credits in the manual as creators of the flight model ( which we were ), We realized that the final released version of that flight model had been majorly modified to the point of it no longer really being our flight model, but rather, just a shadow of it.. So, we tried modifying what existed and that was version 1.3, but it isnt good enough. SO, I decided to completely reconstruct the flight model based on faa and Alenia documentation. this places the reference datum position back on the nose ( alenia used 600 mm in front of the nose but i cant get that tight with nothing but an architects scale ). thats going to take anything you do now, and force you to change it later on because of the changes in the way things are distanced from the reference datum position. However, i can guarantee your going to want the fde update. We set the numbers in today, and its flying better, faster and with more stability than 1.3 or anything previous. We just have to polish some rough edges and we'll have it out too you asap.. I guarantee that this update will be a full blown, un-modified, 100% JFTC flight model, of the same quality that is seen in the P-61, the A-10, the A-7, Pasped, Pl-4 and many others..
bear with us, and stay tuned..
Pam
 
joe bob said:
Just to throw my opinion in here, I got it yesterday and have given it workout.
In my opinion the best thing that could happen here is to figure out how to shorten the turbine lag. I know turbo props have some lag but I timed from throttle advance to when the power actually starts to increase. 8 seconds.
DA's Cheyenne has about a second if I remember correctly and that seems much more realistic.

As it is, changing the static thrust error and min throttle made an enormous difference in the approach speed and landing distance. With full fuel I can land in 2000 feet which is ok by me. With less turbine lag this would be even better. I do wish the spoilers had an armed mode.

I think the spoilers are much too effective in flight. It is possible to do a Khe Sanh approach without flaps which doesn't seem right at all.
I don't think you should be able to hop in an aircraft with full fuel and fly a demo profile like a test pilot in an aircraft with minimum fuel. I am much more interested in real world operations that the demo. Looking at some videos of operations in the field I am not sure 2000 feet is that far off.
One of the things I notice is the takeoff and landing speeds in the manual are very conservative.
I find rotating at 90-95 knots with flaps 2 to be no problem at all.

I haven't messed with cruise speed much but at 25,000 I had 300 knots TRUE airspeed at 85% N1.
It is supposed to cruise at what 315 kts or so?
I am really looking forward to seeing this sorted out, at the same time I wouldn't want it to be a rocket ship where no effort or technique is required to reach the Paris airshow type performance.

Thanks for doing this Warchild and to anyone who is on the fence like I was after reading about some of the issues, Get it, it is a great add on that is getting even better.
Click to expand...

Hi Joe bob..

Not sure what a Khe Sahn approach is, i was in Nha Trang.. Sorry..
We'll be setting the spoilers to factory/FAA specs so they should be correct in the update coming up.. mind you, this is not the official Iris update, but rather the JFTC flight model update that i'm talking about.
Official cruising speed on the Spartan is 350 mph or 324 knots, and Vne is 374 mph or 350 knots..
Minimum maneuvering speed is 120 knots, so you can take off with flaps at 97, but you really dont want to do anything but gain speed till you get to 120.. ( thats gonna be in the update )Landing and braking distance we havent gotten too yet because at this exact moment, the pitch rate at near stall speeds ( 110 knots clean config ) is wishy washy and i demand surgical accuracy and smoothness.
Now, its true that turbines have a slow spool up time, but, once spooled up, N2 ( hp spool ) runs at or near 100% at all times so that there is immediate power available to the props.. Ask any airborne grunt thats been in a c-130 when it hit the throttles.. Damn thing almost dumps you out the back of it from the force those props exert.. The mini 130 ( spartan ) is no different. We've changed the prop minimum and maximum to faa requirements of -17 degrees minimum on ground beta and a maximum of 89 degrees.. I think your going to like the results :)..
Pam
 
For those "Ice Pilots" that are having the IAS go to zero in icing conditions, I did some testing.
I added my 2D cheater window that has all the necessary switches on it.
Unfortunately, cycling the OH panel Pitot or Anti-Ice buttons had no effect.
Using my cheater switches I could turn on the Pitot Heat, get my airspeed back, and with my structural de-ice switch on, recover from what seemed to be ice adding weight to the plane.
As it flew, on AP, it gradually added power and trim when my anti-ice was off.
I have a little freebie Icing indicator(icev10.zip at avsim) that verified my findings.
I have yet to figure out what the L:variables IRIS used to turn on the Pitot and Airframe heaters are.
When and if I do, I might be able to create a fix...Don
 
Ok, I cheated last night.. went completely against my own principals, but i felt i had too.. It seems that FSX doesnt like the idea of having 3000 gallons of jet fuel sitting 5 feet above the CG and located away from the centerline of the plane. Was giving me no end of headaches. Fool plane kept acting like a fish outta water. So i cheated.. Although FSX doesnt for all appearances like having so much weight so high, it doesnt mind split level weighting. So i placed the main fuel cells down close to the centerline below the CG and moved the auxiliary fuel cells into the wing closest to the fuselage.. I'm really sorry that i had to do this, but i hope you all will understand.. perhaps if i had months, i could find a way, but i dont want you to have to wait any longer, so i fudged it.. Please dont think too badly of me..
Pam
 
warchild said:
Hi DC :) ..

If you can be patient, I'll work on that problem with you personally making sure it works on my machine ( as i also have the c-130 ), but, the best i can suggest right now, is, dont waste your time on this flight model. Here's why..
Although my name and my companies name appear in the credits in the manual as creators of the flight model ( which we were ), We realized that the final released version of that flight model had been majorly modified to the point of it no longer really being our flight model, but rather, just a shadow of it.. So, we tried modifying what existed and that was version 1.3, but it isnt good enough. SO, I decided to completely reconstruct the flight model based on faa and Alenia documentation. this places the reference datum position back on the nose ( alenia used 600 mm in front of the nose but i cant get that tight with nothing but an architects scale ). thats going to take anything you do now, and force you to change it later on because of the changes in the way things are distanced from the reference datum position. However, i can guarantee your going to want the fde update. We set the numbers in today, and its flying better, faster and with more stability than 1.3 or anything previous. We just have to polish some rough edges and we'll have it out too you asap.. I guarantee that this update will be a full blown, un-modified, 100% JFTC flight model, of the same quality that is seen in the P-61, the A-10, the A-7, Pasped, Pl-4 and many others..
bear with us, and stay tuned..
Pam
Click to expand...

Excellent news!! The only other thing I'd like to add and no doubt this will be solved with the rest of the updated FDE but for those of us that like to do short field ops I noticed the take off distance was quite a bit longer than advertised by Alenia, especially at or near gross weight. Version 1.0 was off and 1.2 was even further off.

Looking forward to the new dynamics, thanks for the continued improvements on this model.

-Bob
 
Not sure how close we are at the moment.. Alenia advertises 1900 feet. We're somewhere in that ballpark, but not sure where yet, and i'm experiencing this phenomena that most people dont realize is there.. the close i bring all of the dimensions and variables to their real life counterpart, the more impossible it is for me to make changes.. its much like over stressing a piece of tempered glass.. you can place a lot of stress on it, but at some point, you will stress it just too much, and it will shatter.,. Doesnt matter where you place the stress, it breaks the entire thing.. Lift is in one of those stress area.. the wings shape, area and MAC are all set in stone.. typically, all the other numbers in the fde should be the result of calculations based on those three things. But we can fudge it a tiny bit, however fudging too much and you can get some really super bizarre things happening.. Will do my best though..
Pam
 
doublecool said:
I need some help please. I am trying to get the CS C130 engine smoke to work on the C-27

I added the following lines to the config but no smoke???

[SMOKESYSTEM]
SMOKE.0 = -7.80, -15.00, 0.90, cs130_smoke
SMOKE.1 = -7.80, 15.00, 0.90, cs130_smoke

Do I need to add something to my panel config also and if so, What? :kilroy:

Looking forward to Pam's final Version :applause:
Click to expand...
I might have found a reason for our no smoke issue. Problem is, I can't find the root cause. Somewhere in the model's coding, or one of the gauges, "KEY_SMOKE_OFF" is constantly firing. It is supposed to be enabled when N2 reaches 80%. Ain't happening.

It isn't the only looping event though. Those could be interfering with other variables. I posted a list in the IRIS forum for their code guru and hopefully they will get them/it ironed out...Don

BTW, You are doing a great job, Pam. :applause: Thank You...
 
A very simple xml gauge should be able to turn on the smoke when N2 reaches 80%.

I know a guy that might give it a shot. He does variable smoke gauges for helicopters and flap & wing tip vortex gauges.

I will let you know what he says.

VCN-1
 
You must log in or register to reply here.
Back
Top