Safety Warning: GASIL 11 of 2009

[idle stop]

GASIL 11-09 has an article about Magnetos on page 1. The article suggests that if the engine is running roughly and applying carb heat has no effect, you can try isolating each of the mags in turn to see if it will run more smoothly on one only. What the GASIL doesn't say is that this procedure is for piston-engined AEROPLANES only! Remember, they have that big fly-wheel thing called a propellor connected to the engine: if your first go at switching off the faulty mag results in the engine trying to stop, the prop will keep it turning while you get the mag switch back to BOTH. The engine should keep running.
DO NOT FOLLOW THE GASIL PROCEDURE IN A PISTON-ENGINE HELICOPTER: YOUR ENGINE MAY STOP COMPLETELY.

[helimutt]

Good post! :ok:

[VeeAny]

So we don't all inundate him I emailed the guy who writes the GASIL this morning to tell him and suggest they issue some kind of errata.

He's a decent bloke I'll let you know what he says.

[idle stop]

VeeAny:
I agree re the decent bloke bit. It underlines the lack of helicopter personnel in FOI (GA) now that KT has gone to PLD. As you know from my PM to you earlier, I too have emailed the CAA: so perhaps the rest of these kind folk on PPrune will leave it at that.
I had no intention of embarrassing the CAA, but how would we feel if we said nothing now: and somebody had a mag failure in a R22 or somesuch tomorrow, tried the GASIL suggestion, and ended up in hospital, or worse?

[VeeAny]

Idle

I am afraid I've only just spotted the PM, and yes agree completely.

GS

[idle stop]

The CAA have advised that they will issue a correction, as discussed above, in GASIL 12-09.

[lelebebbel]

there is a safety notice in the R44 POH that says "don't do magneto checks in flight"

I always thought that was kind of funny, because really, if you can't think that far ahead, you probably shouldn't be flying.

Then again, that SN must be in there because somebody must have done it, and probably found a faulty mag..

[VeeAny]

The CAA man has also changed the GASIL on the website this morning to make it very obvious that the advice does not apply to helicopters.

http://www.caa.co.uk/docs/33/srg_gasil11of2009.pdf

As well as that as Idle Stop says there will be a short errrata in the next GASIL.

GS