SPIT MK I/II and over boost

[41Sqn_Banks]

Originally Posted by Crumpp

Read your Hurricanes notes....

I did, it still says constant IAS to FTH and linear reduction above optimum climb.

Optimum for what???? Is that best rate or best angle???

Best rate of climb.

It is actually because of the fixed pitch propeller but lets not get ahead of ourselves and get all confused on the correct principles for climbing speeds.

This is not propeller related. There are performance tests with Rotol propellers show that the same applies to Hurricanes or Spitfires with CSP.

[Crumpp]

I did, it still says constant IAS to FTH and linear reduction above optimum climb.

It is a pretty simple concept to grasp. Climb speed changes with altitude.

That is it and all you need to know!!

If it does not change with altitude or is a simple linear then for practical pilotage it is simpified to get the pilot in the ballpark!

Again, very simple concept that does not require in depth discussion.

[41Sqn_Banks]

Originally Posted by Crumpp

It is a pretty simple concept to grasp. Climb speed changes with altitude.

That is it and all you need to know!!

Are you talking about IAS or TAS? If you mean TAS I'm absolutly with you.

If it does not change with altitude or is a simple linear then for practical pilotage it is simpified to get the pilot in the ballpark!

Again, very simple concept that does not require in depth discussion.

Of course it's an pratical approximation. In a theoretical discussion there is no direct relation between IAS and climb rate.

[Crumpp]

It is a very simple concept that does not require an indepth discussion.

Climb speeds change with altitude.

It does not matter if we are talking Indicated or True airspeed, they both change.

In fact, Indicated airspeed for Vy decreases with altitude and Indicated airspeed for Vx increases with altitude.

Where they meet is the aircraft's absolute ceiling.

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

[Crumpp]

In a theoretical discussion there is no direct relation between IAS and climb rate.

There is a definite fixed by design relationship between airspeed and climb rate based on excess power or thrust depending on whether we are talking rate or angle of climb.

[41Sqn_Banks]

Originally Posted by Crumpp

There is a definite fixed by design relationship between airspeed and climb rate based on excess power or thrust depending on whether we are talking rate or angle of climb.

Again ... you are talking about TAS and I asbolutly agree about the relation between TAS and climb rate. However IAS is influenced by installation and instrument errors and density of air. The "design relationship" cannot take these factors into account, hence there is no direct relation between IAS and rate of climb.

TAS and climb rate are in relation.
TAS and IAS are in relation.
But there is no direct relation between IAS and climb rate. For example: IAS changed becaused by a frozen pitot tube, but this will not change the climb rate.

I want to make clear that I do not want to say that IAS is mathematically constant for a theoretical maximum rate of climb. I absoluty agree with you that theory says is is decreasing. However what I want to say is that there are pratical references that indicate that for a specific aircraft the IAS for maximum rate of climb can be near constant over a certain altitude range.

[ACE-OF-ACES]

Originally Posted by 41Sqn_Banks

However what I want to say is that there are pratical references that indicate that for a specific aircraft the IAS for maximum rate of climb can be near constant over a certain altitude range.

Bingo!

Which was stated prior to crump stating it so he actully agrees with what was allready said, yet his replies thus far seem to be ingnorant of the fact that it was allready stated prior to his statement.