Another Question - 109 Max ceiling ingame?

[gpang788]

Sorry guys, another question.

According to the game manual,

the 109 has a top ceiling of + - 10,000m

Ingame, the highest I could take it up to is 7,000 ++ m @ 12 prop pitch flying the E-1. The E-4, with auto prop pitch is even worse, clocking a max ceiling of only 5,000 m ++

Is this a bug or is there something I am doing wrong here?

[Blackdog_kt]

There are two problems here. First, the FMs need revision as almost no single aircraft in the sim can attain its historical performance values. According to the latest Friday update the developers are working on the FM, so a future patch will probably correct that.

Second, there is an operational error involved: you are flying at full fine pitch.

The best thing you can do is trim the aircraft to fly at about 250 kph (i think that's the best climb speed in the 109) and then add power to make it climb (the nose will rise to maintain 250kph and you will climb).

The higher you go, the lower the outside air pressure is and that means lower pressures inside the engine intake manifold as well: your Ata gauge will drop as you climb.

This means that you can add some throttle to bring it back up (i like to climb at about 1.2 Ata and loiter at 1.0 Ata to save fuel) and after a certain altitude not even full throttle will give you the full Ata you can get at ground level.

Now for the prop. Assuming you are cruise climbing like described, it's not efficient to climb at full fine pitch. 12:00 pitch is like 1st gear in a car: it pulls the car uphill with ease but it doesn't let you attain a high speed.

Similarly, full fine pitch is good for low speeds and high angles of climb (eg, at the top of a zoom climb in combat), or when you want to keep your speed under control and the engine responsive (eg, during approach and landing).

In fact, the higher you go you need to coarsen the pitch, because the outside air is thin and the propeller doesn't "bite" well at fine settings: it just turns really fast but doesn't generate much thrust.

Depending on how steeply i climb, i usually set the pitch between 10:10 and 11:00, coarsening a bit as i go to higher altitudes. Of course, if you coarsen it too much there is again a problem, because the propeller has more resistance and after a point the engine can't turn it efficiently.

It's a balancing act, you just need to play around with it and get a feel for it.

[gpang788]

What about planes like the 109 E-4? There isn't even a manual pp to play with?

[CaptainDoggles]

I have no idea what the ceiling is for the E-4 but it's much much higher than 5000 metres.

I've had the E-4 up to at least 8000.

Perhaps you are climbing too steeply.

[gpang788]

I have no idea what the ceiling is for the E-4 but it's much much higher than 5000 metres.

I've had the E-4 up to at least 8000.

Perhaps you are climbing too steeply.

What speed and angle do you climb at?

[VO101_Tom]

I can climb to 7400-7600 m, full throttle, manual PP around 2300 engine rpm. Climb speed around 200, with slow (i mean very slow) climb rate. If you pull the stick, the wing angle of attack exceed the critical value, and it WILL descend, even if the nose is pointing upwards.
The ingame ceiling is 8000m (if the altmeter set to zero properly ;) , the Spit IIa stopped climbing in this alt.

There is a promise by the devs, that this will improve.

[gpang788]

Yup 7400-7600 m is just about there for me too.

Can't clmb any higher beyond that.

[Varrattu]

Do we speak about service ceiling or absolute ceiling?

Regards Varrattu

[VO101_Tom]

Do we speak about service ceiling or absolute ceiling?

Regards Varrattu

I don't understand your question.
We speak about the ingame FM limitations.

[robtek]

I believe the absolute ceiling, the service ceiling for the 109E should be 11.000m, a bit higher then the spit mkII with 10.500, afaik.
The absolute ceiling is again a bit higher, so that some superior spit II would be able to climb above a worn out 109.

[TomcatViP]

Service ceiling = max alt where your plane still hve a certain rate of climb

Max ceiling = max alt where your plane still can fly level

[Varrattu]

Thank you for clarification.

Do you have any idea concerning the relation between iL2COD air pressure and iL2COD flight model. As far as I know it is important for discussions in connection with the ceiling.

Regards Varrattu

[SlipBall]

There are two problems here. First, the FMs need revision as almost no single aircraft in the sim can attain its historical performance values. According to the latest Friday update the developers are working on the FM, so a future patch will probably correct that.

Second, there is an operational error involved: you are flying at full fine pitch.

The best thing you can do is trim the aircraft to fly at about 250 kph (i think that's the best climb speed in the 109) and then add power to make it climb (the nose will rise to maintain 250kph and you will climb).

The higher you go, the lower the outside air pressure is and that means lower pressures inside the engine intake manifold as well: your Ata gauge will drop as you climb.

This means that you can add some throttle to bring it back up (i like to climb at about 1.2 Ata and loiter at 1.0 Ata to save fuel) and after a certain altitude not even full throttle will give you the full Ata you can get at ground level.

Now for the prop. Assuming you are cruise climbing like described, it's not efficient to climb at full fine pitch. 12:00 pitch is like 1st gear in a car: it pulls the car uphill with ease but it doesn't let you attain a high speed.

Similarly, full fine pitch is good for low speeds and high angles of climb (eg, at the top of a zoom climb in combat), or when you want to keep your speed under control and the engine responsive (eg, during approach and landing).

In fact, the higher you go you need to coarsen the pitch, because the outside air is thin and the propeller doesn't "bite" well at fine settings: it just turns really fast but doesn't generate much thrust.

Depending on how steeply i climb, i usually set the pitch between 10:10 and 11:00, coarsening a bit as i go to higher altitudes. Of course, if you coarsen it too much there is again a problem, because the propeller has more resistance and after a point the engine can't turn it efficiently.

It's a balancing act, you just need to play around with it and get a feel for it.


E-3...I was studying how the game handles pitch, by flying under the simple difficulties setting and watching the gauges. If it is modeled correctly, the pilot was very busy in rl. I don't want to pick up bad habits by watching, and then executing similar to the animation...do you know if the animation has been contested by our many experts here?:)

[Blackdog_kt]

To be honest i have never tried simplified CEM in CoD, so i don't know how it works.

In general through yes, you are busy when flying with manual pitch. If i do it often i get to a point where i can tune it well enough by the sound and only look to the gauges once in a while (this means i can look outside the cockpit for enemies, instead of bury my head in the panel).

Then real life happens, i don't fly for a week or two and i can see the plane performs worse because i'm not doing things as i should. However, once you understand how it works the first time around, it only takes 30 minutes to an hour of flying time to remember it again.

[SlipBall]

To be honest i have never tried simplified CEM in CoD, so i don't know how it works.

In general through yes, you are busy when flying with manual pitch. If i do it often i get to a point where i can tune it well enough by the sound and only look to the gauges once in a while (this means i can look outside the cockpit for enemies, instead of bury my head in the panel).

Then real life happens, i don't fly for a week or two and i can see the plane performs worse because i'm not doing things as i should. However, once you understand how it works the first time around, it only takes 30 minutes to an hour of flying time to remember it again.


Constant work load of AI pilot, can we learn from him

I may not have worded my post well, I'll try it again...My point was if AI is the perfect pilot, then by studying his use of the pitch control lever at a certain throttle position/RPM, at a certain airspeed, during a certain maneuver we can then learn through our observations of him what is the optimun settings of pitch, for the various situations we find ourselves in...in those difficulty settings, you can watch the AI's use of the pitch control lever/and clock(seeing when it is moved, why, and to what setting on the clock, how often he makes change's) for an example, you pulling the stick to climb you will notice his perfect control of the ata, its value needle never straying far, and take notice how the airspeed respond's to the use of the correct setting's of the clock, all the while the throttle position being unchanged by you the pilot...try it!...next I will observe his use of the radiator slats:-P

[TomcatViP]

The AI use a simplified FM. The engine parameters might then be different.

[ACE-OF-ACES]

The AI use a simplified FM. The engine parameters might then be different.
That was the case in IL-2.. But has that been confirmed in CoD? If so, got link? Thanks in advance!

[Blackdog_kt]

Constant work load of AI pilot, can we learn from him

I may not have worded my post well, I'll try it again...My point was if AI is the perfect pilot, then by studying his use of the pitch control lever at a certain throttle position/RPM, at a certain airspeed, during a certain maneuver we can then learn through our observations of him what is the optimun settings of pitch, for the various situations we find ourselves in...in those difficulty settings, you can watch the AI's use of the pitch control lever/and clock(seeing when it is moved, why, and to what setting on the clock, how often he makes change's) for an example, you pulling the stick to climb you will notice his perfect control of the ata, its value needle never straying far, and take notice how the airspeed respond's to the use of the correct setting's of the clock, all the while the throttle position being unchanged by you the pilot...try it!...next I will observe his use of the radiator slats:-P


I understood what you meant. What i was saying is that i never tried flying with AI-assisted engine controls, so i don't know what the AI does and i can't provide any judgement on his inputs :grin:

Also,
The AI use a simplified FM. The engine parameters might then be different.

this is correct too. The AI doesn't have the full CEM we have, it just has some artificial limits to prevent it from doing what the player can't.

An aircraft under AI control won't have the whole CEM module running. Instead, it has simpler instruction sets like for example "don't go over X amount of boost" to make sure it can't "cheat": instead of having to calculate all the parameters, it's simply told not to exceed the normal operating limits to save CPU processing load.

This was discussed early on in a development update, but i can't remember when to search for the relevant thread.

[SlipBall]

I understood what you meant. What i was saying is that i never tried flying with AI-assisted engine controls, so i don't know what the AI does and i can't provide any judgement on his inputs :grin:

Also,


this is correct too. The AI doesn't have the full CEM we have, it just has some artificial limits to prevent it from doing what the player can't.

An aircraft under AI control won't have the whole CEM module running. Instead, it has simpler instruction sets like for example "don't go over X amount of boost" to make sure it can't "cheat": instead of having to calculate all the parameters, it's simply told not to exceed the normal operating limits to save CPU processing load.

This was discussed early on in a development update, but i can't remember when to search for the relevant thread.



Thanks!...next time I'll ask Tree UK:-P

[SlipBall]

The AI use a simplified FM. The engine parameters might then be different.


I'm not sure thats the case in clod...I've been working on mastering AI's technique with the use of pitch, and have improved greatly control of speed, and engine temperature.

[Varrattu]

Sorry guys, another question.

According to the game manual,

the 109 has a top ceiling of + - 10,000m

Is this a bug or is there something I am doing wrong here?

Of course late 109's were able to reach service ceilings beyond 10,000 meter. When we speak about the iL2COD "109"we have speak about the BF109-E.

I do not know any document from Daimler Benz, Messerschmitt or Rechlin, which reports a BF109-E ceiling above 7500 meter.

Long story short, a the ceiling of 10,000 meter with a real DB601A-1 in a real BF109-E was not possible.

~S~

[Al Schlageter]

Of course late 109's were able to reach service ceilings beyond 10,000 meter. When we speak about the iL2COD "109"we have speak about the BF109-E.

I do not know any document from Daimler Benz, Messerschmitt or Rechlin, which reports a BF109-E ceiling above 7500 meter.

Long story short, a the ceiling of 10,000 meter with a real DB601A-1 in a real BF109-E was not possible.

~S~

The Bf109E could only reach 24,600ft?

[Kurfürst]

Of course late 109's were able to reach service ceilings beyond 10,000 meter. When we speak about the iL2COD "109"we have speak about the BF109-E.

I do not know any document from Daimler Benz, Messerschmitt or Rechlin, which reports a BF109-E ceiling above 7500 meter.

Long story short, a the ceiling of 10,000 meter with a real DB601A-1 in a real BF109-E was not possible.

~S~

Of course it did. I direct you to the specifications of the Bf 109E, 1939

http://www.kurfurst.org/Performance_tests/109E_Baubeschreibung/109E3_Baubeschreibung.html

"Dienstgipfelhöhe.

Die Dienstgipfelhöhe beträgt bei voller Ausrüstung 11 000 m."

Service ceiling.

The service ceiling is 11 000 meters with a fully equipped aircraft.

Note that this is service ceiling. Service ceiling is an altitude at which the aircraft could still climb at defined rate of climb, from memory it was defined by the Germans at 0,5 m/sec in other docs. So the absolute ceiling (climb = 0 m/sec) is a bit higher.

[SG1_Lud]

Some time ago I made some tests in IL2 COD, and became to the conclussion that the info that the developers used was for the engine DB601A-1 bei altem lader (VDH/FTH 4 km) (old compressor).

Those tests were made with patch version 145.50.

I never tested again in the actual patch but I reckon it remains the same.

The same engine with the new compressor (Bei neuem lader) with 13 blades,
DB601A-1 bei neuem lader** (VDH/FTH 4,5 km) gave better performance in RL.

See the graphs below, red curve is my test, fits pretty accurately with the specifications for the engine with the older compressor.

OLD COMPRESSOR
http://img580.imageshack.us/img580/4927/db601a1compresorantiguo.jpg


NEW COMPRESSOR
http://img827.imageshack.us/img827/6215/db601a1compresornuevo.jpg

[Varrattu]

I direct you to the specifications of the Bf 109E, 1939

http://www.kurfurst.org/Performance_tests/109E_Baubeschreibung/109E3_Baubeschreibung.html

Nice advertise for your Website ...

I am looking for BF109-E documents from Daimler Benz, Messerschmitt or Rechlin, not for wikipedia-like web sites. I didn't find any document on your site dealing with a whatever 11.000 m ceiling concerning a E-version.

[Kurfürst]

In that case you should firmly stick to your idea that the 109E had a sub-10km ceiling, dear 'Varratu'. :D

[Varrattu]

Thank you for your honest statement Kurfürst.

So I like to repeat:

A ceiling of 10,000 meter with a real DB601A-1 in a real BF109-E was not possible.

~S~

[Kurfürst]

Thank you for your honest statement Kurfürst.

So I like to repeat:

A ceiling of 10,000 meter with a real DB601A-1 in a real BF109-E was not possible.

~S~

On the other hand to say its a minority view is an extreme case of understatement. ;)

[Varrattu]

Who painted this nice picture?

[IvanK]

Its source is AVIA 6/9352 the original is in the UK National archives. The document is a RAE document reporting flight test of a BF109E3 and BF110C.

Here is an image of the original document taken from the file itself:

http://i40.photobucket.com/albums/e215/zulu64/AVIA109E3_Avia69352.jpg

From the same document:

http://i40.photobucket.com/albums/e215/zulu64/Avia109E32.jpg

http://i40.photobucket.com/albums/e215/zulu64/Avia109E.jpg

[Varrattu]

From memory it was a machine powered by a DB601N engine came into service after the French campaign ended ...
(Please compare boost pressures in Fig. II)

[VO101_Tom]

From memory it was a machine powered by a DB601N engine came into service after the French campaign ended ...
(Please compare boost pressures in Fig. II)

It seems to me that the boost pressure starts decrease around 4500 meters (as the A-1 engine). The /N engine would start decrease at 5500 meter.

[IvanK]

The AVIA document states clearly DB601A

The French test report (which is I believe the same aircraft used for the RAF report) only refers to DB601 and does not differentiate between engine Sub types. The jpg below from the French report lists the Max Boost as 962mm that is pretty close to 1.3ATA.

http://i40.photobucket.com/albums/e215/zulu64/FrenchE3.jpg

[Kurfürst]

Who painted this nice picture?

Oh, its by the well known absurd humorist Harri Pihl, using an exotic extract from his essay on 'Practical applications of residential waste in the agriculture'. :D