SPIT MK I/II and over boost

[JtD]

Neither his point nor mine.

Regarding acceleration in a climb, that's TAS you need to look at, the energy of a plane going 600 in vacuum and going 600 in sea level atmosphere is the same, even if IAS in one case is 0 and in the other 600. That energy needs to be accounted for. Flying the plane a a constant IAS will not give you an acceleration free climb.

As an example, the acceleration during a climb at a constant IAS of 360 km/h to 6000m in standard atmosphere will cost you about 400m in altitude, or 7% in average climb rate. At lower speeds, closer to the typical climbing speeds of WW2 aircraft, the loss is less, around 3-4%.

[TomcatViP]

Well AoA I won't make any comments on the SPit in IL2. It's way out of topic and CoD does not deserve that with all the efforts they hve made to make it credible

But I figure you never attempted to B&Z a spit in Il2. My personal safety minimal margin was 500 meters to regain after each pass to find myself still above the free ballooning alt of the beast

[ACE-OF-ACES]

Originally Posted by TomcatViP

Well AoA I won't make any comments on the SPit in IL2. It's way out of topic and CoD does not deserve that with all the efforts they have made to make it credible

I only brought it up because you were saying the IL-2 Spit and the CoD Spit have the same problem..

Or did I misunderstand you when you said the following?

Originally Posted by TomcatViP

The prob with the Spit in old Il2 was not so much with the numbers but with its relaxed "E-liability".

Somehow the very same happen here for now.

Originally Posted by TomcatViP

But I figure you never attempted to B&Z a spit in Il2

You figured wrong

Originally Posted by TomcatViP

My personal safety minimal margin was 500 meters to regain after each pass to find myself still above the free ballooning alt of the beast

Which IMHO says more about the relative pilot skills than the FM and thus is not proof that the Spit is ignoring the laws of physics

[ACE-OF-ACES]

Originally Posted by JtD

Regarding acceleration in a climb

I think I found the source of our miscommunication?

I am talking about a ROC test

Where there is no acceleration!

The speed (BCS) is kept as constant as it can be kept (humanly possible) during a WWII style ROC test

[JtD]

Originally Posted by ACE-OF-ACES

...The speed (BCS) is kept as constant as it can be kept (humanly possible) during a WWII style ROC test...

As an example of WW2 climb tests, look at table I in this Spitfire IX test, you can see a constant IAS up to FTH and a constant TAS above FTH. Il-2 compare will always give you constant TAS, which will give you the somewhat higher climb performance below FTH, about 100 fpm in this case. Less than 5% obviously, and all I wanted to say.

[ACE-OF-ACES]

Originally Posted by JtD

As an example of WW2 climb tests, look at table I in this Spitfire IX test, you can see a constant IAS up to FTH and a constant TAS above FTH. Il-2 compare will always give you constant TAS, which will give you the somewhat higher climb performance below FTH, about 100 fpm in this case. Less than 5% obviously, and all I wanted to say.

Ah good so both you and that report agree with what I allready said, i.e.

Originally Posted by ACE-OF-ACES

Some if not most planes ROC performance required the BCS to be adjusted as altitude increased

S!

[Crumpp]

Historical performance data for climb typically comes with a climb speed information. This climb speed hardly ever is constant.

Climb speed will never be constant with altitude. Any pilot or first year aeronautical science students knows this....

Climb rate without speed is useless information. All aircraft performance occurs at a specific point on Power required curve and is fixed by the design of the aircraft.

If speed is held constant, the aircraft is not maintaining the best performance point on the Pr curve.

http://home.pcisys.net/~aghorash/Why...h_Altitude.pdf

http://aerosrv.cls.calpoly.edu/dbiez...20and%20Vy.pdf

http://www.pprune.org/tech-log/343259-vx-vy.html

http://williams.best.vwh.net/smxgigpdf/mfly2.pdf

[JtD]

Originally Posted by Crumpp

Climb speed will never be constant with altitude. Any pilot or first year aeronautical science students knows this....

Yes, and in second year they learn that there always are exceptions to the rule, and thus it's "hardly ever" and not "never". An example for an exception has already been given in this topic, so feel free to educate yourself.

[Crumpp]

Yes, and in second year they learn that there always are exceptions to the rule, and thus it's "hardly ever" and not "never". An example for an exception has already been given in this topic, so feel free to educate yourself.

Baloney. To achieve Vx or Vy, velocity must change with altitude. There are no exceptions to that no matter how much you tap dance.

[camber]

Gentlemen!

So many of these arguments seem to based on interpreting an slightly ambiguous statement to make it wrong.

Originally Posted by JtD

As an example of WW2 climb tests, look at table I in this Spitfire IX test, you can see a constant IAS up to FTH and a constant TAS above FTH. Il-2 compare will always give you constant TAS, which will give you the somewhat higher climb performance below FTH, about 100 fpm in this case. Less than 5% obviously, and all I wanted to say.

Well this is pretty clear and supported by the reference. the Spittie pilots doing that test climbed at constant IAS mostly and recorded climb rate.

Originally Posted by Crumpp

Climb speed will never be constant with altitude. Any pilot or first year aeronautical science students knows this....

Obviously the pilot can choose to climb at constant IAS if aircraft capability permits. I take it, this statement should be:

Vx (IAS for best climb angle) and Vy (IAS for best rate of climb) will never be constant with altitude."

This is true enough but I know a flight instructor that had it a bit confused . So climb tests at constant IAS (such as that Spittie one) may not be capturing optimum rate of climb at each altitude? Interesting.

Originally Posted by JtD

Yes, and in second year they learn that there always are exceptions to the rule, and thus it's "hardly ever" and not "never". An example for an exception has already been given in this topic, so feel free to educate yourself.

There seems no real disagreement at this point, just an imaginary one

Originally Posted by Crumpp

Baloney. To achieve Vx or Vy, velocity must change with altitude. There are no exceptions to that no matter how much you tap dance.

A clearer statement now it is expanded from just "climb speed".

It is quite hard to write unambiguously in technical detail, and anyone's forum posts are likely to fall down on this now and again regardless of their aviation knowledge. But instead of jumping on it as evidence of moron, why not have a lovely big glass of wine? Of course that is what I am doing AND writing this post, so maybe you can do both if you really want to

2007 Reisling, camber