Spits & Hurri's to 25,000 + feet in RL?
 

Hi All,
Having flown both the Hurri and Spit variants that are now modelled in this sim, begs me to wonder how the heck they were able to:

1. Climb fast enough to intercept incoming waves of bombers in the BOB.

2. Make it to altitudes above the mid 20k's which you often hear about in RL stories.

IMHO, it's one thing to model a speed curve, but I think it is another to model acceleration and lift. Right now, to me, both models are flying with 1,000 lbs of building blocks strapped under the wings when in climbing mode.

I know it's been said before: "This is an Alpha/Beta, but I would suggest that the flight model shortcomings are causing many pilots in my squadron to shut it down and leave the sim in disgust.

I know that the dev's are working hard to perfect the graphics and other parts of the engine, I know that the flight models are being tweaked, the pressure is one, the new theatre is being worked on but - if I can't get into an aircraft that doesn't perform, why am I even bothering to stay with the product?

Probably because I've been with it since the very first issue of IL-2 and know just what possibilities can be achieved. I guess I'm just fed up with porked adjustments that end up in public hands.

Ok, vent off.

Thanks for listening.

Spit 2a best Climb Rate was around 3000 ft per minute - to 10,000ft should be less than 4 minutes - have you timed it in game Catseye?

Spit1's was around 2500ft per minute (depending on prop fitted - csp a bit better).

Hurri had slower rate of climb but I don't know the exact figure.

I haven't timed them but I think it takes about 10 minutes to get to my preferred altitude and seemed right so never actually timed in game.

You don't see many Rotol Hurris on line any more thats for sure - mainly Spits but I still like the 1a.

I'll do some detailed timings. Trying to maintain 2500 - 3000 ft./min seems to be problematic with engine management. ie., overheat. Initially, I like to get to 10k with best climb rate and trim the aircraft accordingly. Then, to reduce rate for a climb rate of 1000 ft./min and maintain a higher speed to become less vulnerable up to 12-14k depending.

I've noticed that if the Spit is pushed right now from takeoff, and the guages run high, and then you cruise and the temps drop - if you push it again the temps rise quickly and engine damage ensues quicker than - if you hold level flight boost 4 & 2400 rpm for a bit and ease up into a climb of 2000 ft/m, when you push the throttle hard after, overheating does not seem to be a problem from that point on and gives much more extended time for combat at high settings.

What I am saying is - that it is interesting that pushing for optimum climb rate, can reduse combat performance even if the combat takes place 10-15 min later.

Interesting - I guess I'm struggling with what it was for those pilots to push a hard climb to 25k then get into combat when in our sim pushing to 10k and getting into combat results in serious engine damage in short order.

Just some thoughts.

Cheers

Try testing and post findings but try this as well - as soon as wheels up, 3000 RPM Straight and Level to 200MPH+, set PP to approx 2,700 rpm then start a full throttle climb at around 2500 feet per minute - this seems to give me optimum engine temps and best time to around 18K.

According to RL data test :

Spitfire MK1 take off weight 6,050 lbs with CSP should climb at 6 1/4 lbs 2600 RPM with 2800-2900 ft/min up to 11 000 ft then climb rate decrase

http://www.spitfireperformance.com/n3171climb.jpg

Spit Mk1 with Merlin III but 100 Octan should have even better climb rate beacuse of higher RPMs limitation - 2850 instead 2600 RPMs during climb power settings.

Spitfire MK II at 6172 lb ( so heavier then SPitfire MK1) had little better climb rate then Spitfire MK1 but with higher power settings - +9 lbs at 2850 RPMs.

http://www.spitfireperformance.com/p7280-climb.jpg

Kwiatek you are a mine of knowledge :-D

I just rather know where to find and use mine of knowledge :P

BTW i mined these subcject some time ago expecially BOB era fighters ( but not only BOB - i know something about Fw 190 and later version of 109 and SPit too :P ) when i was modding flight models for Ultr@Pack.

Also as not only armchair pilot such things interesting me a little even if i would not have a chance to fly real Spitfire or 109 :)

Hiya Cats,

As it happens, I and another ATAG member performed some time to climb tests up to 10,000ft pre-patch, and found that the 2-speed prop Spit matched the 87 octane figs quite well , but the CSP prop Spit 'MkIa' in the game had exactly the same rate of climb as the 2-speed prop version (bearing in mind the CSP on the Ia came out in a patch last year).

The Spit II and Hurri Rotol also matched published time to climb data very well too, again pre-patch.

This was all using the optimum climb speeds and rpm stated in the pilot's note etc, or available from various websites.

Obviously human error came into optimising the climb rates for all of them, as opposed to the computer programme which tests the game's flight models, but then again the real ones weren't flown by computers either.

Time to climb is a great method of testing in my opinion and together with the top speed figures at various altitudes already posted by others would give us a pretty good all round picture. ;)

Hmm, I run a 3kft/min climb all the way up to about 18 without any problems.

I would advise getting airborne from rear bases. Then you won't have to worry about getting bounced on the climb up. You should be able to take of at Gravesend or Maidstone and shoot up to 10k before you get to the coast pretty smartly.

Great information!!

I haven't pushed these rpm settings yet for extended time as I've been concerned about overheating issues.

So you hold the rpm at 2,700 - by continuing to modify pitch as altitude rises in order to hold the 2500 ft/min climb all the way to 18k?

Thanks for ino.

I want to thank everyone that has replied with this great information.

I am totally amazed sometimes when the right guys respond to a statement of frustration with clarity and logic.

Thanks for listening and for the info - I'm going to take further time and try the different settings provided including bases where distance will permit steady climb to operational height in an unchallenged manner.

Cheers.

I don't have much experience in Spits and Hurries, but i've had extensive testing done in the Blenheim of previous versions which was totally unforgiving in terms of CEM, to the point the current version Blenheim is a breeze for me to fly despite its air-cooled engines.

My experience tells me we tend to focus too much on publicised figures and not how they are achieved.

What i mean is, all these graphs tell me how a Spit climbs. They don't tell me a thing about what it entails to get that performance.

I'm lucky in the regard that i had extensive CEM training on a friend's PC running certain FSX add-ons. I could pretty much eyeball engine behaviour in CoD right from the release version and as we get corrected CEM/FM with patches it becomes all the more easier for me.
In some aspects CoD is more forgiving than the FSX add-ons i've flown and in some it's less forgiving. But overall, the practice really payed off.

What i would suggest to do is forget about the graphs for a while and learn to juggle the different engine parameters. When you are comfortable with it (and trust me, it's not if, it's when...you can learn it in an evening flying some free flight missions in QMB and trying to "ride the edge" of the CEM envelope), you'll see that the pieces of the puzzle start falling into place quite nicely.

You can also go to the A2A simulations website and download one of the manuals for their accusim aircraft. It doesn't matter which one, because they all have a preface on internal combustion engines that explains quite a bit.

Finally, one of the most important tips for efficient climbing is the angle of climb. There are aircraft in the sim where you have to actually level off, trim nose down and build some speed first before climbing and the reason is very simple: higher airspeed gives you more lift potential (hence better climb) but it also gives you more airflow over your radiators.

I've found many times that it's better to level off and build speed, trimming out the climb tendency, until i reach a good, comfortable speed. Then the speed increases further and instead of trimming it out completely, i just trim slightly to keep the vertical speed indicator where i want it.

What i'm trying to say is, you could take the same amount of time reaching 10k feet in both cases, but one could be a full power steep climb that overheats your engine, the other a rated power climb at a shallower angle that keeps everything running nice and cool.

Try it out and get used to it, then you'll see things improving considerably. I'm not much of an ace online, but i never have engine damage unless it's because of enemy action or i intentionally break it to test things out. First few days with the sim that was all i ever did, just taking one aircraft at a time on the free flight quick missions and testing its engine operation and different profiles for climb, cruise and combat power.

Trust me, it really pays off and the main reason is that it applies to all aircraft. Even if the parameters are different for each one, the "feel" of doing things and the main principles are the same.

For example, i tried the G.50 yesterday for the first time in months and while it's a bit of a handful to manage initially, during the course of a 30 minute flight i was comfortable enough keeping the engine running smooth as silk, all the way up to 3.5km and then through a high speed dive down to the circuit, approach and landing.
Then i spawned into a low alt dogfight quick mission against some AI Gladiators, i set pitch and rads once and didn't touch them for the rest of the mission. The thing run brilliantly the whole time.

Cheers ;)

At around 10/12K I ease the throttle but the PP doesn't need hardly any adjustment to maintain (or around) 2700RPM - I then continue to around 18/20K - adjusting my Climb rate for a good climb speed and more air flowing through the rads, my climb rate is changing anywhere between 1200 - 2200 fpm as airspeed drops and eng temps rise.

As others mention, Gravesend is perfect for climbing - I will be at 18K when reaching the English Point. I have never timed it though.....:grin:


Edit. I checked both the 1a and 2a while on ATAG - About 12 minutes to 18K (but the way I climb rather than the book and Rad fully open). In both cases I tended to watch my airspeed more than holding a specific rate of climb - climbing up in steps when necessary so to speak. The Spit1a was more forgiving regards full throttle and CEM and ties in with a section of Blackdogs post (which I just noticed).