Spit/109 sea level speed comparisons in 1.08 beta patch

[ATAG_Dutch]

Let me guess here.

The 'math' (or 'maths' as it's referred to over here) according to Crummp, shows something adverse to the documented real life performance of the Supermarine Spitfire relative to the performance of the Bf109.

There is a distinct pattern developing here.

I find it surprising that a man who purports to concern himself with the performance of 'real aircraft', does not spend his time debating these issues on a more appropriate forum involving comparisons between 'real world' aircraft.

Why would such an expert in his field waste his time on a forum geared to the analysis of a Battle of Britain based computer game? With most of his efforts geared toward the discrediting of the Supermarine Spitfire relative to the Messerschmidt Bf109?

It's a mystery to me, but maybe a psychologist could write a thesis.

[Crumpp]

shows something adverse to the documented real life performance

It is not documented real life performance.....

It is calculated from a single data point with assumed values for CLmax.

That single data point was measured from a trailing static head.

What do you think the spreadsheet is??? Try the same the exact thing...calculated performance from data.

I just have the advantage of being able to use Mtt data, Supermarine, and NACA data that did not exist in 1940.

[Crumpp]

they had the aircraft to test the results.

And we have 70 years of data including classified documents from the people who built, designed, and flew the airplane in service.

Sorry, but we have the information advantage.

[Glider]

Originally Posted by Crumpp

And we have 70 years of data including classified documents from the people who built, designed, and flew the airplane in service.

Sorry, but we have the information advantage.

Are you saying that having the real aircraft, most up to date test facilities at the time, the only trained test pilots in the world (at the time) is not an advantage when testing theory.

There is a reason why the premier Aviation University in the UK is at Cranfield (not Cambridge who do not teach Aeronautical engineering or theory) its because they have their own test flight of aircraft often passed down from the RAF research establishments.
You should tell them they don't need the aircraft, it would save them a ton of money

[Crumpp]

the only trained test pilots in the world

That is a good point. We are talking about the test pilots who felt the Bf-109 was "embarrassed" by the slats opening in the turn.

I would not be surprised if the pilots did not operate the propeller at its most efficient point at the single data point the RAE used. That would throw off all of Gates assumption for the entire envelope.

In order to reproduce the RAE results, I have to drop the propeller efficiency to below average and assume VDM could not properly design a propeller.

[Crumpp]

classified documents from Vickers-Supermarine

It is the ones from Mtt that the RAE did not have access too. Germany was at war with England at the time so they were not exactly sharing information.

Instead, a pilot with little experience with a selectable pitch propeller had to go up and operate it to record data using a very difficult method of gathering airspeed data.

My Spitfire analysis is in agreement with the RAE's analysis.

The relative performance is not in agreement, but that has to do with Bf-109 performance and not the Spitfire's.

[SlipBall]

Originally Posted by Crumpp

It is the ones from Mtt that the RAE did not have access too. Germany was at war with England at the time so they were not exactly sharing information.

Instead, a pilot with little experience with a selectable pitch propeller had to go up and operate it to record data using a very difficult method of gathering airspeed data.

My Spitfire analysis is in agreement with the RAE's analysis.

The relative performance is not in agreement, but that has to do with Bf-109 performance and not the Spitfire's.

It's great that some of the information survived all these years, I've often wondered. Here in the States much of our early mechanical history, can be found in the library of Congress.

[Glider]

Originally Posted by Crumpp

That is a good point. We are talking about the test pilots who felt the Bf-109 was "embarrassed" by the slats opening in the turn.

I would not be surprised if the pilots did not operate the propeller at its most efficient point at the single data point the RAE used. That would throw off all of Gates assumption for the entire envelope.

In order to reproduce the RAE results, I have to drop the propeller efficiency to below average and assume VDM could not properly design a propeller.

As it happens yes they are. The UK had the first and at that time only test pilot training school in the world. As for being embarrased yes the Me109E was embarased by the way the slots opened, which no doubt was why they were redesigned for the Me109F. Unless you have a better reason for the redesign.

As for you having to drop the propeller efficiency to get the same results, working on the basis that you are not a trained test pilot then I can only assume that your model is wrong. I know you believe that the test pilots are not important but if I had to pick between their hard earned experience and training, backed up be the science of the day and access to the real aircraft, against your maths and how you read documents, I would go for the experts.

[5./JG27.Farber]

The title of the thread is:

Spit/109 sea level speed comparisons in 1.08 beta patch

So, we know that all aircraft are two slow, surely we just need a general consensus of which top speeds are correct given the fact that:

• 109 speed tests are not full throttle, 1.3 Ata is the maximum recorded/logged
• Aircraft have a gate system for more power
• speeds are slightly different on multiple tests
• Specific engines

So from this can we just agree on some numbers to submitted?