Merlin negative G cutout too quick?

Originally Posted by klem

Sternjaeger, please don't take this the wrong way, I would really like to understand this and I know you will reply on the videos but can you tell me if you actually worked on Merlins (or just study them), did you ever experience or observe the negative G effect and do you feel that an engine that misfires in level flight would ever have made it onto the Spitfire?

The vast majority of us can only use three ways to assess this: Factual official reports (hard to find), common sense (would it ever have been fitted like that) and first hand reports in biographies which, in the dozen or so I have read including Geoffrey Quill, Alex Henshaw, Al Deer, Johnny Johnson etc, only ever refer to it when pushing over into an aggressive combat dive.

Can you also explain the part about it also affecting the inlet manifold please?

I'd be truly interested to know what you think.

Klem, it's understandable and I'm well happy to explain things, so no worries!
My relatively modest knowledge of Merlins is because of my involvement with a warbirds association, I don't feel like giving too many info about it because I have had a lot of "new friends" approaching me more for my interests and luck than for anything else, so I hope you appreciate why I prefer to keep it confidential.

Anyway, I know three qualified engineers who work on pretty much any mark of Merlin ever produced, plus a pair of pilots who fly with them regularly. As you might understand, the wealth of information I have access to is pretty much blinding. Having said this, I prefer to keep things quite simple, mainly because not all of us are literate in engineering matters but still want to try and understand how things work.

Anyway, back to the topic, the videos I have seen seem show quite a jolly response, but then again if it's on full throttle they are quite spot on.

As a simple reference, the response to the negative G should be same or even less than the throttle response time.

Regarding the inlet manifolds, the answer is pretty easy: mixture, just like air or water, is a fluid, and as such is affected by gravity and G forces.

Check out this video, especially towards the end (and behold of the divine flying skills!) and see how fluids behave in the right situation.

http://www.youtube.com/watch?v=9ZBca...eature=related

now watch what happens to another kind of fluid (a more "organic" one) when under zero then negative G-load

http://www.youtube.com/watch?v=wbOU3l864H0

flying is a fun, fun thing ;0)