Stability and Control characteristics of the Early Mark Spitfires

[winny]

I have another question, the RAE refer to the bf-109 as being " too stable for a fighter".

So is instability a good or bad thing?

[Al Schlageter]

Originally Posted by winny

I have another question, the RAE refer to the bf-109 as being " too stable for a fighter".

So is instability a good or bad thing?

It depends if one is BLUE or RED.

[CaptainDoggles]

Originally Posted by winny

I have another question, the RAE refer to the bf-109 as being " too stable for a fighter".

So is instability a good or bad thing?

I've read that quote, but Mike Williams seems to have sort of picked it out without including a lot of context from the original source, so it's hard to know exactly what they were referring to.

Here's the quote for people unfamiliar:

Longitudinally the aeroplane is too stable for a fighter. There is a large change of directional trim with speed. No rudder trimmer is fitted; lack of this is severely felt at high speeds, and limits a pilot's ability to turn left when diving.

Now, the way I interpret it is that they're referring to the trim problem. I could be wrong. There could be a truncated sentence or two preceding the quote that makes it more clear, but that's how I interpret it.

Edit: I think in this case that they're correct. You don't want the pilot's attention on trimming the aircraft every five seconds; you want the pilot's attention devoted to situational awareness.

[winny]

Originally Posted by CaptainDoggles

I've read that quote, but Mike Williams seems to have sort of picked it out without including a lot of context from the original source, so it's hard to know exactly what they were referring to.

For your reference, the quote, in context.



Apologies for the quality, it's an iPad screen grab.

[lane]

Originally Posted by winny

For your reference, the quote, in context.

Thanks for the context winny! Here is some more "context":

[ACE-OF-ACES]

Originally Posted by lane

Longitudinally the aeroplane is too stable for a fighter

Bingo!

Just as I was saying.. Fighters, than and now, intentionally design an alittle instability to make them more maneuverable!

So I can understand how some modern civ pilots..

Who are already blinded by their agenda

Could fool themselves into thinking a fighter that does not have the same stability attributes of their putt-putt cessna is a failure.

[winny]

For anyone who would like to read the full RAE evaluation of the 109 it's here in PDF.

It's 14 Mb and should open in your browser, you can then save it if you wish.

[taildraggernut]

Originally Posted by winny

For anyone who would like to read the full RAE evaluation of the 109 it's here in PDF.

It's 14 Mb and should open in your browser, you can then save it if you wish.

I hope an RAE evaluation is admissable, don't forget the British had no concept of stability and control

[CaptainDoggles]

Originally Posted by ACE-OF-ACES

Just as I was saying.. Fighters, than and now, intentionally design an alittle instability to make them more maneuverable!

I just want to point something out here: Adding instability does not necessarily make the aircraft more maneuverable.

Perfect example is the B-2 Spirit. Extremely unstable, but not particularly maneuverable.

[Crumpp]

Originally Posted by CaptainDoggles

I just want to point something out here: Adding instability does not necessarily make the aircraft more maneuverable.

Perfect example is the B-2 Spirit. Extremely unstable, but not particularly maneuverable.

Exactly. Instability does not do anything except make the aircraft harder to control.

It is a myth that instability has positive effects on maneuverability. In fact, it narrows the maneuvering envelope because the pilot cannot precisely control the aircraft.