Help with fast climb - can't break 15 minutes to 20,000 ft

[Killratio]

So you're saying that the engines were kept warm somewhat during the day back then? I guess that makes sense since one doesn't really have time to let the engine warm up when the enemy is approaching.

Presactly!! Early morning is, obviously, the most crucial time, temperature wise.

[Piper_EEWL]

Understood! Thanks for the additional information.

I did another run yesterday with the constant speed prop. I followed the correct warmup procedure and was off the ground with about 100C. It's a different scenario then I have to admit One has to be a lot more careful with the temperature management.

Also with 12psi that Spit is a real beast

This scramble is really a lot of fu to get right. Still have to do the comparison with the P-51 though this is not a fair fight since I only have the civilian model.

Happy flying

[Killratio]

Yes, 12 is damned impressive!! The temps are a problem, both Rad and oil with the 3000rpm 12 start and then drop back to 2850/9. You need to monitor oil temp because whilst you can be a little cavalier on the rad temp, the oil temp will start damaging your engine pretty smartly after it exceeds 90C and it is metal on metal type damage. Also be aware that with the Rotol set full fine and the throttle full, you will bust 3000rpm during takeoff. Another fairly quick way to hurt the engine.

Now we start to see the real meat of the Scramble skills!


I didn't do the detailed performance testing on the P 51 but I seem to recall that the Civ has about the same horsepower at normal throttle as the early Spitfire at 12lbs/sq in vis about 1200/1300hp. So with the higher weight, I reckon it will be a close call....but the Spit needs to drop back after 5 minutes, so my guess is that the Mustang will just do better. Of course carry on to 30k and it will be all Mustang!



Best regards

Darryl

[Piper_EEWL]

So I did some testing with the Spitfire vs the civilian P-51D.

To make it a even fight I filled the tanks on both planes and let the engines warm up. I started the time on the runway once the aircraft started rolling.

The Spitfire MkIIa with the constant speed propeller following the procedure with full throttle takeoff and climbout at 2850rpm and 9psi at 160mph got a time of 6min40s.

The Mustang with a full throttle takeoff and a climb at 55 inHg and 2800rpm at 150kts got 7min23s.

Rather surprising in my opinion. The problem is that I couldn't find any information for a max climb to 20kft in the Mustang. Not with a rather quick search anyways.

[alan CXA651]

Hi.
I have just tried this challenge , had issues that distracted me , DONT park the spit near a refuel point , i thought i had a problem , every time i opened the canopy on my mk11b, it immediately shut , restarted sim , thinking it had not initalised properly , same problem , only when i took aircraft from that parking slot , did things work as they should , that was my distraction , started aircraft , taxiied to active , started the clock just prior to startup , took off operated my saitek landing gear switch , concentrated on trying to climb , aircraft not picking up speed as it normally does , it was not till i got to 9000ft , i realised my stupid mistake , i assumed the saitek gear switch had put the gear up , it had not , once gear up , and the damage to my time , and eng temps , i carried on , got to 20000ft in 18.5 min and had managed to get temps back to normal operating temps by then.
Must try this again some time , BUT WITH GEAR UP.
regards alan.

[Killratio]

Hehehe!

At least if the gear came up at 9,000, you know that you kept around the best climbing speed of 160 and not much over

Don't feel too bad. A little while ago a RW Spitfire pilot had a mental lapse whilst taxiing in and pulled up the gear instead of the flaps!! He knew immediately, of course, as it took full; power to taxi after that

[Killratio]

So I did some testing with the Spitfire vs the civilian P-51D.

The Mustang with a full throttle takeoff and a climb at 55 inHg and 2800rpm at 150kts got 7min23s.

Rather surprising in my opinion. The problem is that I couldn't find any information for a max climb to 20kft in the Mustang. Not with a rather quick search anyways.

Much heavier aircraft... But in any case, have a look at this... :

[Piper_EEWL]

... DONT park the spit near a refuel point , i thought i had a problem , every time i opened the canopy on my mk11b, it immediately shut , restarted sim , thinking it had not initalised properly , same problem , only when i took aircraft from that parking slot , did things work as they should , that was my distraction...

Hi Alan,

This is a rather well known bug in FSX that affects all aircraft. So nothing specific to the Spitfire or that scenery. If you're at a refueling spot the doors/canopy won't stay open. Move the aircraft away from the refueling spot and you're fine.

Much heavier aircraft... But in any case, have a look at this... :

Thanks for that chart! That's what I was looking for! So if I read this correctly I should still be able to make it to 20kft in just under seven minutes correct? But the climb power used here is 67" and 3000rpm? That seems rather aggressive on the engine no?

Thanks for sharing the information!

[Killratio]

So if I read this correctly I should still be able to make it to 20kft in just under seven minutes correct? But the climb power used here is 67" and 3000rpm? That seems rather aggressive on the engine no?
!

Yes, about 6.30 or thereabouts.

But remember you are talking about absolute best climb on the charts, from a combat perspective. And you are flying a Civ version, and conservatively at that.


D

[gulredrel]

My best showing was 9 minutes 16 seconds with the Spitfire I, DeH 20PCP Airscrew. I say "best" not fastest because I have climbed faster in the Spit II but not relative to the real aircraft time to height.

I came up with MkIa and DeH two position airscrew in 11 min 32 sec but I'm not sure if done correctly. I didn't use the boost override.
How to manage the 2-position airscrew, do you leave it in fine pitch or coarse or fiddle around to get in between?

Thanks
Jens

[Killratio]

Jens,

Yes, that is where some of the skill comes in. Whether or not you use the 12lbs/sq in , you will climb better if you manipulate the Bike Pump airscrew control to maintain your max climbing RPM (in the Spitfire I, that is 2600). The closer you keep your speed to ideal and your rpm to 2600, the better you will climb. In effect, the pilot becomes the CSU. Basically, having managed the Spitfire I, you will see why, despite the worse optimal climb rate, the ROTOL or CS DH were considered worth it.

Climbing speeds for the Spitfire I:

0-12,000 - 185mph
To 15,000 - 179mph
to 20,000-169mph

(all IAS)

Regards

Darryl

[gulredrel]

Thanks, I will try your suggestions in the Spit I before changing over to the Mk II with the ROTOL.

[Killratio]

Interested to hear how you go!

D

[alan CXA651]

Hi.
Just had a second attempt at this challenge , parked just off the active runway at duxford , started stopwatch , started engine .
Once warmed , taxiied onto runway and took off , hdg east , rad set to the red triangle , gear up , this time i made sure it was up, pitched for 2000ft min at 2600rpm watching speed and temps , as speed got to 100knts i pitched for 1000ft min once speed increased i then pitched for 2000ft min again , kept doing this till 20000ft , did it in 14 min dead , temps good at top of climb , i had ASN giving weather , i got thunderstorms and it was going dark on landing .
regards alan.

[Killratio]

Alan,

With the greatest respect and in the immortal words of my first girlfriend.. "No, no, no...you're doing it all wrong!!"

Pitch + power = performance. Therefore maximum achievable Pitch + maximum achievable power = maximum performance (sustained climb).

Best climb is achieved by setting your power and RPM , then pitching to give you the 160 mph IAS (assuming you're flying the II) . Flying performance is always A + B = C
Here you are looking for Climb Performance as "C". That is the Resultant.

If you plot airspeed against climb rate you will get, say, 1000fpm at 300mph, AND 1000ft per minute at 100mph (different sustainable angle of climb). Then maybe 2000fpm at 200mph AND 2000fpm at 130mph, then 3000fpm at 170 mph AND 3000fpm at 160mph and finally, let's say 3500fpm at 165 mph h ie...the top of the pyramid. It is THAT figure that gives maximum performance.
The graph will actually be bell shaped and uneven..but you get the idea.

If we said, you have exactly 15 minutes and 20,000ft, let's see who can get the FURTHEST in that time and height, then it would be a whole new ballgame and playing with the forward speed and varying climb rate would be the way to go... THAT is the the new Resultant. Some people may choose to climb slower and go faster. Some may try to stay at 1000ft and go flat out then climb as fast as possible to 20,000 when there are 7 minutes left. Some may climb as fast as possible to 20,000 then go flat out level for what remains of the 15 minutes (which would be my guess) yet others may aim for a 1333fpm climb rate and full power.

Looking forward to seeing more times!

regards

Darryl