Detonation, etc.
 

Hi guys,

Just finishing the ATPLs and it's occurred to me that I've never experienced or come across Detonation or Pre-Ignition.

Do any of you learned folks know of any web-site or DVD / Video that demonstrates this? Obviously, it's not something you would want to do purposely so I wondered if anyone knows of a source of info.

The nearest I've come is inadvertently switching the Mags to 'Off' during power checks then back on quickly which resulted in a great big 'bang!' and cloud of smoke, along with a group of onlookers diving for cover. As a matter of interest, what was that?

Cheers,

2close

The 'great big bang' was the unburnt fuel in the exhaust suddenly igniting after the mags were turned back on (very hot gases through the exhaust valve). Very spectacular, I agree, especially on a large radial engine!
Anyone interested in detonation and pre-ignition will find this article useful:
http://www.douglasdc3.com/sohn/7.htm

Thanks for the info Steve.

Much appreciated.