Ohhhhh yes please!!!!!!! I'm very interesting in that model!!!!! 

No problems with this, Michael.

Hi Michael,

Just wondering if you were willing to do the same for the 200 series?

James

Yes, I will probably do the same for the the 200 aircraft, since much of the work should carry over.  But it may take a while as I don't have so much time available now.

I moved both the centre of gravity and of lift.  Unfortunately we have no way to see what %MAC we have after loading the aircraft in order to properly set the trim.  Generally you should be OK in the middle of the green band. Fully loaded, you need more trim than that.

As for climb, I tested this extensively against real world climb charts. Fully loaded, you should climb intitially at a little over 3000' per minute and of course at 250 knots below 10,000 feet, but this will decline with altitude until you are down to about 500' per minute some time after 30,000 -- I don't recall the exact figures off the top of my head.  This flight model is very close to what it should be -- maybe the climb is a little low, but it's very close.  

You have to check the climb power against TAT as you climb, although once your speed is stable, EPR should rise pretty much on its own as you climb to the required amount (under standard atmospheric conditions). After 10,000 feet you should be climbing at around 280-300 IAS, using the higher value if you are heavy.  The charts I had stated 280 knots and then transitioning to mach 0.7, although other charts and guides I have seen have suggest higher figures.  I found in testing that 290 to 300 and then Mach 0.72 the best climb when fully loaded.  If you let your speed get too low, you will have to significantly reduce your climb to accelerate.  

I used the autopilot for testing as it allows very fine control of pitch.  In my experience the main trim control is too coarse to be able to climb at the optimal rate.

Finally, I believe the charts I used give climb power settings a couple of points higher than in the charts I referenced in the download -- i.e. 1.85 instead of 1.83 for example.

Be sure your gauge is showing TAT and not OAT as the two are quite different things.

Ok, I can confirm that Michael's model work very well. It follows the real 727 performance charts I have.
Finally I can fly this bird the way it should be 

Hi Michael,

New tests...  

Gross Weight: 120.000
Vr should aprox 120.

1.  What I notice is that for take-off, beside the need of at least 5 trim, it is "hard" to take off. Yoke full back and at 145 it starts to move nose up.

2. Full spoilers in flight, breaks almost nothing. Same when landed.

3. During aproach, flap 30, at 135 knots I need to trim almost full back (10) to mantain the nose straight, other wise it will dive. It should descent at 700 ft/min with nose up 4% (aprox).


Thats all I found.

Climb, cruise and descent is perfect.

Quote:


No problem at all 

Quote:


Sorry, my native language is spanish. I'll try to explain again.

In another similar plane, at 300knots if you put spoilers full extended for 5 secs, it reduce speed to aprox 270 knots. You "feel" deceleration. The VC moves a lot.

Now, in same situation with 727-100, after 5 secs it reduce speed to only 293 knots. VC moves just a bit giving sensation of not "feeling" deceleration.

Doesn't happend to you?

Quote:


Well, I use a program to read and write values to FS (because I've build some basic cockpit parts). Because of that I'm able know almost all information needed . FSUIPC has a variable for that:
Offset: 2EF8 Length 8
CG percent, as a double (FLOAT64). This is probably the position of the actual CoG as a % of MAC.

If you want this program I can point you to it. It's free for home use.

Much better flight model thanks. I notice all the leading edge slats/flaps are coming out at flap 2 though; did you need this for the dynamics?

hi micheal

I have tried your new flight model and a strange plane behaviour has occured :

on final approche, AP on, flapp 25° down, gears up, plane's weight around 130 000 lbs, catching well the GS from 5000 ft above the airport (AP altitude hold automaticaly switched off), the aircraft attitude looks impossible :
- nose pitch down 12° !
- VS around 700 ftm !
- throttle around 1.85 EPR !
- no trim applied
- KIAS 122 knots !
the aircraft has followed well the GS in that attitude  while on final, previous to touch down and gears down, I had to disconnect the AP and fly the bird by hands until on the ground. The plane landed at 86 knts at flaps 30° !!!

Previously in a clean configuration filght at FL250, I had applied 1.88 EPR to maintain 350 knots speed (plane's weight 135 000 lbs) instead the 1.63 EPR required according to DL727 charts

I have no idea why this things appened ! sorry

computer configuration : Vista 32 SP2 4Gb ram, FSX SP2, CaptainSim 727 SP 2.2 modified (fixed ERP gauge, modified aircraft.cfg and your new cs727100.air file)

I had to get back to original cs727100.air and unmodified cfg file to land with correct plane attitude (I kept the modified ERP gauge).

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Same happend to me. I use the another company-RE variant. Will try with the basic and see if it changes.

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As far as I know, the aircraft.cfg is different. Same for the .air file. Actually is not cs727100.air, it is cs727200.air.
Air file contains all the coeficients used for the flight model.

Gauges are almost all the same, besides 1 or 2.

javiercuellar wrote on Jan 18^th, 2010 at 11:04pm:

Yes Javier. You are right. The 727-100 and 727-200 do use different airfiles. But here:-

Michael2 wrote on Jan 18^th, 2010 at 6:50pm:

Michael says that it is ONLY for the 727-100 and that's what I was going by. If you are using the Mod in the 727-200 that could explain the problems.

Mark

hi micheal

thanks for your concern and the great job you've done

i'm using 727 100 model of course and i carrefuly made the modifications. But nobody's perfect so i'll try again and let you know how things goes...

Micheal,
Thanks . I think I managed the installation.
1-What will be the expectation I should looking for?
2- Will your EPR gauges replace 727-100 EPR   gauge?
3- I made a test flight, but I cant see any visual difference in the EPR gauges?

Regards
Sanal

Hi Sanal,

No, that fuel consumption is way off.  A typical high altitude cruise consumption would be about 5000 lbs per hour.  On the cruise performance charts, there is an explanation of how to calculate fuel consumption. You can cross check that with what the fuel flow gauges show (multiply one engine's consumption by three).  I calibrated the consumption to match the performance charts.

So I think something went wrong with your installation.

Do you have the following lines in your modified config file and did you remove the corresponding lines from the original?


fuel_flow_scalar= 1.05

ThrustSpecificFuelConsumption = 0.725

Did you replace the original cs727100.air file? 

As for the EPR gauges, yes you must replace the orginal file, Captain_Sim.p721.C07.CAB, in the panel folder with the replacement file of the same name.  Either take the original out, or better, just give it a different name so you can easily restore it if you need to.

http://www.fsfiles.org/imagehost/uploads/1264126344.jpg

Sorry, here is the screen picture,

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look at this post, http://www.captainsim.org/yabb2/YaBB.pl?num=1263513531 in it you can download a gauge.

David, clearly something went wrong with your installation as I would not share a flight model like that with the community.  The other possibility is that there is an error in my instructions to modify the config file, but I don't think that is the case as I have reviewed it several times and two other posters say the mod performs well.

The intent is that you should replace all of the flap sections in the original config file in their entirety only with the lines in my readme file.

Sorry about that, looking at your question I can see there is some ambiguity there.  So when you are done the only lines you should have in your config file with respect to the flaps are:

[flaps.0]
type= 1
span-outboard= 0.632
extending-time= 40.0
system_type= 1
damaging-speed= 250.0
blowout-speed= 300.0
lift_scalar= 1.000
drag_scalar= 1.000
pitch_scalar= 1.000
flaps-position.0=  0
flaps-position.1=  2
flaps-position.2=  5
flaps-position.3= 15
flaps-position.4= 25
flaps-position.5= 30
flaps-position.6= 40

[flaps.1]
type= 2
span-outboard= 0.327
extending-time= 10.0
system_type= 1
damaging-speed= 250.0
blowout-speed= 300.0
lift_scalar= 1.000
drag_scalar= 1.000
pitch_scalar= 1.000
flaps-position.0=  0
flaps-position.1=  1

[flaps.2]
type= 2
span-outboard= 0.589
extending-time= 10.0
system_type= 1
damaging-speed= 250.0
blowout-speed= 300.0
lift_scalar= 1.000
drag_scalar= 1.000
pitch_scalar= 1.000
flaps-position.0= 0
flaps-position.1= 0
flaps-position.2= 1


This produces the desired result in terms of the flight model, but unfortunately the flight model will  no longer be synchronized with the flap animation of the physical model -- all leading edge devices will now extend with the first notch of flap application.  I have found a way to correct this and will eventually post an update. I will also clarify the instructions in the download readme before then.

Ok thanks for your clarification with the aircraft.cfg edits. I fly the IGS 13A approach at kai tak, I used HDG control to capture localizer, then switched to apprch/GS auto. The aircraft flew the glideslope flawlessly. If anyone is having weird aircraft attitude issues it is probably the way you edited the flaps portion of your aircraft.cfg file.