Aircraft Performance Data

[klem]

Following the latest patch (and others!) I've been testing the Hurricane Mk I 100 octane using a data recorder script and thought it would be a good idea to gather all FM test results in one place. So I'm sticking my neck out and offering this thread with some simple tools. If it flies, it flies. If it doesn't, it doesn't.

THIS THREAD is intended for the community to post test results of CoD aircraft, particularly those in Beta patches, to determine whether they seem to be historically accurate and hopefully assist the developers in correcting any major discrepancies. It is not the intention to undermine or criticise the developers but to assist them and us in understanding the flight models we have, particularly during Beta stages.

COMMUNITY: Please do not make this a discussion Thread. Post your comments in a separate Thread such as “Aircraft Test Data – Discussion”. In those posts you can post links to results Posts in this Thread where you might feel the Aircraft Data results would be helpful.
PLEASE keep this Thread clean for easy reference by the Devs and the Community.
PLEASE do not take part in this Thread of you are not testing.

MODERATORS: If this proves useful/popular would you please sticky this and moderate it heavily to keep it solely for results.

Objective: To collect and analyse test data using a special 'Performance.mis' mission and associated script 'Performance.cs'. These are included in the attached zip file. 'Level Speed at Altitude' and 'Climb to Altitude Tests' should be made so that aircraft can be compared plus any other observations/tests as you see fit.

Method: Load and fly the test you wish to make. A data set is collected automatically in a Comma Separated Variable (.csv file). You then view and select lines of data to create an output chart and preferably save in Excel format. A guide on how to do this is included in the attached zip file.

Tools: You will need Microsoft Excel or OpenOffice or some other tool that allows you to open a .csv file save it in Excel format and create a chart. You select and Copy your results charts to paste them into your preferred image editor like MS Paint, Paint.net etc. to create 'jpg's for posting. I use OpenOffice but found it helpful to save in MS Excel Format as OO didn't keep some formulae that I was using in early tests. It also allowed me to collect more than one set of data, e.g. Level Speed and Climb tests, on separate sheets in one file.

Posting Results: Please title your post with aircraft details and version tested in the following style.:
Hurricane MkI 100 Octane - Beta Patch v.1.07.18301

Attach .jpg's of the charts using the Manage Attachments facility as this will create thumbnails and not flood the thread with full size images.
If you wish, Zip your results spreadsheet into a zip file and attach it using Manage Attachments. This may be useful for others to see. Of course you are bound to get 'feedback'

Include your sources/WWW address if you included historical data on your chart.

Summarise your conclusions such as (these are only samples!):-

Altimeter set to 1013Mb for standard Pressure Altitude readings.
(NOTE! The mission script calculates and outputs TAS and the Density Altitude to allow charting of TAS on a 'Standard day'.)
Full fuel load for all Level Speed tests.
(Recommend 100%)
For level speed tests, aircraft already flying at altitude were selected for each altitude test so starting with full fuel pre-load (or: I Climbed to height between level speed tests.)

Level Speed tests:
Conducted with Radiator fully open.
Speed approximately 7% to 12% down across altitude range.
Best speed generally achieved at 2650rpm, boost +6.25lbs

Climb to Altitude test:
Performance roughly 8% down on historical data

Other Observations:
BCO and full rpm/boost leads to early engine failre at low altitude( 30 seconds at 1000 ft)
Overheat at maximum Boost and maximum RPM after 6 minutes at 10,000 ft with Radiator fully open

.. and so on.

Its not hard, you just fly the mission and you get the data. All aircraft are included at bases but you would have to change the aircraft already at altitude in the FMB.

ATTACHMENTS
Zip file containing:
Instructions AircraftDataCollection.doc
Script file Performance.cs
Mission file Performance.mis
Script file Stability.cs
Mission file Stability.mis
Also some examples of Pre-set Mission files:
..PerformanceHurri100.mis.bak
..PerformanceHurri87.mis.bak
..PerformanceHurricaneMkI_dH5-20.mis.bak
..PerformanceSp11a.mis.bak
..PerformanceSp1a100.mis.bak
..BlackBoxPerf-HurricaneMkI_100oct.xls (sample)
..BlackBoxStab-SpitfireMkIa_oct.xls (sample)

..NOTE! The .mis.bak files are examples of how to keep a Performance file for different plane type to save you forever going into the FMB to change the aircraft type for the 'already flying' planes – rename or copy them to Performance.mis to test different a/c with the same Performance.cs script. DO NOT RUN THEM with their pre-set name as here is no script file with matching name. You can make files for other aircraft by simply changing the 'already flying' aircraft in FMB or, more simply, directly editing a copy of one in Notepad to change the aircraft type for the aircraft already flying. See instructions in zip file.

BIG CAVEAT

I've tried to get ths right and had useful exchanges with various people on these forums.

Those expert in scripting may like to look at the .cs file and tell me if they think I have chosen incorrect parameters. Please PM me.
Those expert in areodymanics/flight parameters/Flight Testing etc may like to tell me if they think my formulae are incorrect. Please PM me.

[klem]

General:

Altimeter set to 1013Mb for standard Pressure Altitude readings although 'Standard Day' is calculated into results regardless of Altimeter setting.

Fuel load 65% for both Level Speed and Climb to Height tests to match A&AEE test weight of 67850lbs.
For level speed tests, aircraft already flying at altitude were selected for each altitude test so each one started with 65% fuel.

Level Speed tests:
Conducted with Radiator fully open.
Speed approximately 5% to 10% down on A&AEE tests up to 10,000 feet.

Normal max boost speed ("6.25lbs") slightly increased on previous patch. BCO speeds down on previous patch.

Climb to Altitude test:
Time to 10,000 feet 5.8 minutes vs 4.6 minutes in A&AEE Tests, ~26% slower.
Time to 15,000 feet approx 9 minutes vs 6.85 minutes in A&AEE Tests, ~30% slower.

My flying (see ROC) appears somewhat erratic as it was hard to maintain the target climb rate or climb speed. That is why I made three separate tests and charted all three. The ROCs at the specific charted points appear to vary wildly but in fact the ROC was much more steady than appears on the chart which is probably why the Times to Height were almost identical and all well below the A&AEE tests.

Other Observations:
BCO and full rpm/boost leads to early engine failure making it hard to establish some level speed tests. Engine overheat seems to be overmodelled.

Sources:
Level Speed:
http://www.wwiiaircraftperformance.o...rricane-I.html
See
Aeroplane and Armament Experimental Establishment
Boscombe Down
12th June 1940
Hurricane L.2026
(Merlin III)
(Rotol Constant Speed Airscrew)

Hurricane I Level Speed Performance Chart (currently using figures without R.A.E. PEC correction)


Climb Test:
http://www.wwiiaircraftperformance.o...ane/l2026.html
See
CLIMBING TRIALS
Weight:- 6750 lb.

[Blackdog_kt]

I like your effort here. Good candidate for a sticky, all we need is for the thread to pick up some speed.

By the looks of it, this is a report only/specific posting format thread. So people, help Klem collect data and follow the posting format he asks. Don't turn this into a discussion thread of the collected data, neither into an FM debate thread.

To explain a bit better, if this thread starts to look similar to the 100 octane or spitfire stability threads (long debates with loads of charts, etc), the posts that create the resemblance will be deleted or moved to more relevant threads. It's not a bannable offence to go on a tangent, don't worry, but please make both Klem's and my job easier and keep this thread clean.

This is a "factory test" thread. You fly, you get the data, you post them here in the format Klem asks.

[ACE-OF-ACES]

Originally Posted by Blackdog_kt

This is a "factory test" thread. You fly, you get the data, you post them here in the format Klem asks.

As someone who has been testing 1C FMs going on 10+ years now I have learned there are two sides to the flight model testing coin

1) the in-game data
2) the real world data

Where one without the other make it pretty useless data.

And mistakes can be made in both!

For example

How many threads have you seen where someone claims there is an error in the FM because 'they' were unable to obtain such and such at such and such altitude? Only to find out later the person making that claim didn't know the difference between IAS and TAS.

How many threads have you seen where someone claims there is an error in the FM because 'they' were unable to obtain such and such at such and such altitude? Only to find out later the person making the claim was comparing the in game plane to the wrong real world data.

With that in mind..

I think before we make any claims about anything we should make an effort to agree upon the real world data we should be comparing the in game planes to. Granted in some cases you will be hard pressed to find the real world data for the exact version of the in game plane, if any. But it just does not make any since to make a claim about how right or wrong the FM is until we can at least agree upon the real world data we are using as the baseline for comparisons

With that said..

I think this thread would be a good place to submit the real world data that matches as closely as it can the in game planes, and leave the test results per test in separate threads devoted to that plane and that test. It would be nice to agree upon a min set of data that should be collected and presented in those individual test, and this thread would/could provide examples of that.

Anyway, just my two cents

[klem]

Apologies to anyone who has downloaded the zip file in the OP. There was an error in it. Please replace with the new one now in the OP.

AoA the objective is to obtain actual performance data of the various aircraft in one place and, where historical data is thought to be appropriate, compare them in the results. Sometimes there will be differences of opinion about which specific aircraft configuration is supposed to be in CoD and it would be nice if 1C would be specific but in many cases it is clear from the aircraft title. There are very few options for historical data for, say, the Hurricane MkI with Rotol CSP running 100 octane and with BCO. The aircraft test in my reference link may not have used a factory fresh aircraft but it would have been up to spec or they wouldn't have used it and it can only be regarded as representative of that aircraft. I expect there were faster and slower ones around. In any case I'm happy to take the only historical British test authority data that has been found (as far as I know). Even without historical data we will at least know for sure what the aircraft is doing in CoD.

The purpose of this post was to draw attention to the zip error. If anyone wants a discussion can they please start a new discussion thread.

[klem]

Climb Tests added to original "Hurricane MkI 100 Octane - Beta Patch v.1.07.18956" post:
http://forum.1cpublishing.eu/showpos...16&postcount=2

Performance is again down.

[klem]

Following some discussion on Spitfire Stability I thought I'd try to measure the hands off stability. I can't be certain that it is correct but we may just have the unstable Spitfire along the lines of the A&AEE (and NACA) findings. I can't vouch that it is a true representation of the condition, I just tried to fly it and see what happened.

Attached is a zip file containing an excel spreadsheet (actually created in Open Office) which is the .csv file output from the test mission but saved in excel format so I could create the chart. A jpg of it is in the attached file and also embedded in this post for easy viewing. The mission file Stability.mis and its Stability.cs script file are also in the zip so if anyone wants to try it, drop those into your My Documents/1C Soft Club/il-2 sturmovik cliffs of dover/missions/ folder.

You will see from the 9000 records of raw data and the fact that I only charted records 4000 onwards that I had a job getting it to settle. I set record 4000 as time zero and charted against time in minutes. I followed the A&AEE method of pilot controlling until steady then releasing the controls. The only adjustment I made was very light and careful aileron adjiustment as it is impossible to fly it hands-off at the A&AEE test rpm of 2580 and full boost (not BCO). Under these conditions it gradually began to oscillate longitudinally.

I charted the RPM, Manifold Pressure (cockpit reading), Altitude and, for us perhaps the most important of all, the Pitch and Speed variations. You can see from about 4.8mins I finally had it settled down and the hands off flying began creating oscillations of pitch and associated speed changes: the descending speed increased until it brought the nose up or it decayed until it brought the nose down. The oscillations are particularly noticeable in the indicated airspeed and Pitch Angles (positive = nose down). The overall progress was a gradual climb but that may be due to my elevator trimming which is quite tricky to get stable with my rotary. Perhaps a minutely lesser trimming would have kept the average altitude generally the same.

Whether or not this truly represents what we are looking for I cannot say. It could just have been bad trimming or indeed instability but I made no elevator inputs at all. Perhaps some of you would like to give it a go.

The mission is included so you can try it yourself. Be sure to edit the file path for the output file in the file Stability.cs You will find it down around line 114, where it reads:
fstring = "E:/CoD_data/BlackBox_Data/" + strfile + "-" + cur_ac.ToString() + ".CSV";

You can see I am using my E; disc. You can edit the disc and path to suit yourself. Use Notepad, Notepad+ or Microsoft Visual C# Express. Dont edit the part from + strfile onwards.

By the way I have now included Elevator trim setting in the output file which was not in my own results. It may be of use, perhaps as a marker for when you finally got it settled. Select a series of records you believe represents the settled test period and chart them.

Edits/Additions:-

EDIT 1: The title of the chart reads 2850rpm, that should read 2580rpm
EDIT 2: Files replaced. Found reason for erratic Pitch curve - wrong data column plotted
One reason why the oscillations are not as frequent as the A&AEE/NACA tests may be that the control column was not truly 'free' as it is held by the joystick springs.
EDIT 3: zip file replaced. Control deflections now included in output file.
EDIT 4: Speed at Altitude chart added. Only a few checks were necessary to tell that it is well below par.

[IvanK]

The Oracle will arrive in this thread shortly

[Crumpp]

To tell you what?

The obvious??

Standing by to be shot down in flames...........

It is a great effort Klem and shows exactly what has been said all along. The basic longitudinal stability and control is not representative of an early mark Spitfire at normal and aft CG.

[Crumpp]

Climb Tests added to original "Hurricane MkI 100 Octane - Beta Patch v.1.07.18956" post:

Hey Klem,

The test's look good.

Try running a test wih CEM turned off. An interesting point was raised in another thread about performance without CEM being improved. Maybe you can spot what is going on when the game controls the engine and what is doing compared with manual controls.