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[Knochenlutscher]

To my knowledge the Brits didn't flew Komet hot (with both fuels).
I remember that, as they just managed to store small quantities of fuels and
lacked aproval for hot flights by Air Ministry. Several wartime testpilots mocked about the
flight safety issue the higher brass had, due to the severe nature of this Beast.
Brits commenced Testing the Komet cold (towed).
This would have been the cream of their career, and seeing the russians Testprogrammes,
official supplies of such, hmmm? Now hear the Story of Winkle the lucky to show us proof.
It's too great to be true.

At Me163 and Winkle Brown that's one of a few hickups that exist surrounding this Persona.
What he wrote, was whitnessed and what actually happened may be not always that way he described.
I wouldn't put my hand into fire for such claim.

Cross question, why no US Test Pilot flew a Komet hot in Merseburg in april 1945,
they frequently did, when aircraft was in flyable condition.
if you know the capture Pictures of the FE collection point,
you get a glimpse at what service state these were and simply take the Russian Testings as a base,
what it takes to get them ready, also as for a timeline of readiness. Browns story is very fantastic.
Second, Equipment, Flightsuits, Gear. You know the stage of captured AB Brandis of JG400?
Except a Munitions Bunker, Barracks that place was flattened.

A hot Komet Allied Tester was USSR/Golofastov, the Russian stockpiled masses of fuels,
even built a factory to ensure a wider testing.

[SAS~Storebror]

Similar discussion, 14 years ago: https://www.physicsforums.com/threads/characteristics-of-the-me-163-komet.426704/


Mike

[SAS~Storebror]

...and another interesting graph.
Source unknown, looks like some german trial report, but the numbers make sense.
Plot starts at 0-line for ~60 secs (takeoff, acceleration in level flight) and then proceeds with a climb at constant speed (thus varying climb angle and rate) to target altitude (12km, estimated B-29 attack altitude).
200m/s resulted in fastest climb:




Mike

[Dimlee]

To my knowledge the Brits didn't flew Komet hot (with both fuels).
I remember that, as they just managed to store small quantities of fuels and
lacked aproval for hot flights by Air Ministry. Several wartime testpilots mocked about the
flight safety issue the higher brass had, due to the severe nature of this Beast.
Brits commenced Testing the Komet cold (towed).
This would have been the cream of their career, and seeing the russians Testprogrammes,
official supplies of such, hmmm? Now hear the Story of Winkle the lucky to show us proof.
It's too great to be true.

At Me163 and Winkle Brown that's one of a few hickups that exist surrounding this Persona.
What he wrote, was whitnessed and what actually happened may be not always that way he described.
I wouldn't put my hand into fire for such claim.

Cross question, why no US Test Pilot flew a Komet hot in Merseburg in april 1945,
they frequently did, when aircraft was in flyable condition.
if you know the capture Pictures of the FE collection point,
you get a glimpse at what service state these were and simply take the Russian Testings as a base,
what it takes to get them ready, also as for a timeline of readiness. Browns story is very fantastic.
Second, Equipment, Flightsuits, Gear. You know the stage of captured AB Brandis of JG400?
Except a Munitions Bunker, Barracks that place was flattened.

A hot Komet Allied Tester was USSR/Golofastov, the Russian stockpiled masses of fuels,
even built a factory to ensure a wider testing.

About Mr.Brown. I agree that we need to be cautious with his memoirs. With all due respect to him, he made several errors in his stories. Only to be expected in the old age, happened to everyone.

About USSR. I didn't find a reliable confirmation of any "hot" flight of Me 163 by the Soviet pilots. According to the information I have, Gallai, Mosolov, Vasin, and Golofastov - they all flew being tugged by Tu-2s. The story about the factory is probably a misunderstanding caused by the memoirs of Mark Gallai. In one of his books, he mentioned that the needed amount of fuel would require to built a new factory just for the test program.

[Dimlee]

I did a quick test yesterday in UP. Take-off, accelerate to (more or less) 676 km/h at a low altitude and climb at 45 degrees. The angle is estimated visually so it's not precise. The loss of control happens over 6,000 m at TAS 150-200 km/h.
So, we have a somewhat "upgraded" Komet. No, I don't complain. 

[SAS~Storebror]

In Ultrapack we use the stock flight model where the take off mass is way too low due to the fact that the fuel mass is too low as well.
That's why the climb rate is just too good to be true.

[SAS~Storebror]

...and another interesting graph.
Source unknown, looks like some german trial report, but the numbers make sense.
Plot starts at 0-line for ~60 secs (takeoff, acceleration in level flight) and then proceeds with a climb at constant speed (thus varying climb angle and rate) to target altitude (12km, estimated B-29 attack altitude).
200m/s resulted in fastest climb

Just for reference:
Presuming this graph depicts RL german test data and the data is valid - which so far we have no reason to doubt - the values taken from the graph are:
Climb starts at about 60s @SL
Climb ends at about 210s @12km altitude
Speed is roughly 200m/s
This means:
The plane climbed for 150s through an altitude of 12km and travelled a flight path of 30km length.
This in turn means that the climb angle on average was 23.6°, which fits extraordinarily well to the graph from our math.
Which is even more interesting considering the fact that our math so far didn't include the plane's drag...


Mike

[SAS~Storebror]

Alright gents, time to conclude.

• The math makes sense. It concludes with the climb graph posted lately, apparently originating from a test report from the Luftwaffe themselves.
• The "almost vertical" climb, or "70°" as reported in almost every document, is apparently anecdotal.
  The best explanation I could come up with is that reporters misunderstood the planes capabilities when witnessing a hot start on demonstration days held for the Luftwaffe.
  During these flight performance "airshows", the pilots indeed pulled up to an almost vertical climb (while carefully avoiding negative Gs during the climb) up into the clouds (where they disappeared from spectators view).
  This - of course - works, if clouds are low enough, and it's followed by a steep dive and fast flyby during these "airshows" anyway.
  It would not have worked if it was to be a climb to combat altitude though.
• You can't betray physics, i.e. you cannot climb all the way at 70° angle with a 4-tons aircraft when you only have 1.5 tons thrust.
  That simply ain't gonna work.
• Ol Willy is right about the HWK 109-509 thrust. The Serial production version HWK 109-509A-1 produced 15.7kN max.
• Kopfdorfer is right about jettisoning the trolley.
  In fact the flight manuals advise to jettison the trolley at 5m altitude, i.e. right after getting unstuck.
• The fastest way to get to altitude is:
  * Accelerate to ~ 710 km/h. On the deck. Straight away.
  * Pull up to ~ 20° climb angle and maintain 720 km/h TAS climb speed. Yes, TAS. Yes, all the way up to 12km. Yes, your climb angle will increase...
  * At 12km altitude you should have reached a climb angle of ~ 30° while maintaining 720 km/h TAS climb speed. Throttle back to idle, level out, watch out for "Indianer"

I have supplemented the Google Spreadsheet which has been shared before, adding ingame flight test data from the upcoming Me 163 flight model as it will be found in Ultrapack 3.4 "Cassie" Patch 2 Hotfix 24.
The tab "Climb (ingame test)" shows the results:
https://docs.google.com/spreadsheets/d/1URo8UpgB6kgQ4MLuO5UkbcVvpdwnvs2IL-fa_Jk8dRc/edit#gid=467981083

Comparing this to the german test report data, I think we are almost spot on.
The difference seen in mid climb is most likely due to the different atmosphere implementation in IL-2 (we're not absolutely realistic in this regard).
I've created an overlay of the ingame test and the german report here, you get the gist:



Here are videos of the three test flights:

190m/s:


200m/s:


210m/s:


I think for the time being, we're as close as we can get to the real thing.
Thanks for all your support!


Mike

[Knochenlutscher]

Excellent, Thanks for the restoration of the precious Egg.
Nice when r/l science and ingame makes finally sense.
 Cheers
Tobi

[WxTech]

To an observer watching a 20-30 degree climb angle at a distance and where the flight path is more or less along the line of sight, the angle of ascent can give the illusion of being much steeper than it actually is. And coupled to a high airspeed, this illusion will be magnified.

One potential contribution to reports propagating down the decades of a better performance than actual...

[Dimlee]

The suspicion that Me 163 in-game was better than in real life was always in the back of my mind.
But the last graph cleared my doubts. I can continue to fly Komet without guilt of being a "cheater". 

Thanks for this research.

[SAS~Storebror]

the last graph cleared my doubts. I can continue to fly Komet without guilt of being a "cheater". 

Mind you that this graph depicts the performance of the plane in a patch that is yet to be released (UP 3.4 P2 HF 24).
The stock airplane does have several issues:

• Empty weight is slightly too low (1900kg Stock, 1905kg real life - negligible)
• Takeoff weight is way too low (3400kg Stock, 4110kg real life)
• Fuel Mass is way too low (1160kg Stock, 2018kg real life)(
• Fuel consumption is wrong. Stock 4.14.1 FM changed this, but got it wrong too. In real life the Me 163 runs ~7.5 minutes max on full power. Stock 163s can do so for 16 minutes and more.
• Mach Drag is all wrong. Not that much impact on climb performance, but even more so in level flight as the 163 is strictly mach limited in this case, especially at combat altitude.

Needless to say that the new flight model depicted here uses real life data in all aspects.


Mike