LW aircraft speed specifications

[Crumpp]

Are we really to believe that trained professional aviators and supporting aircraft technicians at the top of their game due to the intensity of war, with experience of constant life or death combat sorties, are getting IAS and TAS mixed up? I find such a thing very hard to believe.

It is a tough concept I understand to grasp the fact compressibility corrections are calculated.

It is another tough one to grasp the fact that all instruments are calibrated by machines whose scale reflects that calculation.

It is also a tough one to grasp the fact the country leading the way on compressible aerodynamics, was Germany. Of course TASGI could determine TAS from IAS but not on the same scale.

Think of it like this. The russians are calibrating their dials with a yardstick and the Germans with a meter.

1 yard = .91 meters

When the Germans reaches 300kph, the Russian instrument will show 273kph.

Using the wrong calibration equipment will slip the scale the throw off the results.

[Crumpp]

They could have used russian dials if the germans had smashed them up and or disabled/ruined the aircraft on those airfields which were over run. Crash damaged is another issue.

They would not have to change dials. It is calibrated by pressure differences.

The differences though are measured by the calibration equipment. If the calibration equipment uses a different yardstick, the results will reflect it.

[5./JG27.Farber]

You misunderstand, when retreating in Russia the Germans destryoed their equipment as best they could before it was captured. Obviously this depended on what resources and time they had left.

One way I read about was heap them all together and burn them. Smashing the dials with a hammer or submachine gun... Going to need more than calibrating after that... Crash landed aircraft may or may not be damaged. Did rounds enter the cockpit? Were the dials broken in the landing?

However I agree with you, different manufacturers use different tolerances and different methods.

[Crumpp]

I started the thread because, as I said in the first post, I did not understand the situation that was being reflected in the article;

Well you should have a better understanding of how airspeed is measured and that all nations did not have the same ability to express that speed.

Your post was a convenient opportunity to demonstrate that fact.

I still find the remarks in the article a bit of a mystery.

And they will remain a mystery. There is not enough information to make any concrete conclusions. We can only speculate.

Here are the facts:

1. Instruments require periodic maintenance and calibration. You will not see expected performance despite the fact the dials might show the correct reading if the instruments are off.

2. Not all nations expressed airspeed by the same measurements. There are different methods for determining the effects of compressibility. Some are more accurate than others and some are not very accurate depending on the realm of flight.

3. A pilots ability has a large effect on Vmax.

4. Aircraft require maintenance and will lose performance over time as engines and propellers wear.

5. Aircraft performance is a percentage range over a median. Some will be optimistic and other pessimistic. This is not only due to all the reason's listed above but manufacturing tolerances as well.

[Crumpp]

You misunderstand, when retreating in Russia the Germans destryoed their equipment as best they could before it was captured. Obviously this depended on what resources and time they had left.

One way I read about was heap them all together and burn them. Smashing the dials with a hammer or submachine gun... Going to need more than calibrating after that... Crash landed aircraft may or may not be damaged. Did rounds enter the cockpit? Were the dials broken in the landing?

However I agree with you, different manufacturers use different tolerances and different methods.

Absolutely. They did not want equipment to fall into Russian hands. It is highly unlikely that the Russians could fly any captured equipment without extensive repairs.

Even the jolt of hard landing can knock the instruments out of calibration.

If the Russian's calibrated German instruments, they would induce an error from the begining.