The large bore engines don’t really manage on one magneto. Apart from a very rough running engines, EGTs go through the roof, the exhaust stack melts and the turbocharger dies. Turbo engines are usually EGT limited (“TIT”) and on one magneto you are way above that limit.
That may be true for a turbo engine running at high power.
It’s not true operationally i.e. in the sense of continuing a normal flight and landing. My engine for example runs just fine on one mag.
Obviously one would not hang around up there for too long because you never know what else is about to fail…
Did the distributor gear also have a loose “finger” ?
Okay, in that setup you are certainly right. Aviation decision making is always influenced a lot by the surrounding parameters :-)
The large bore engines don’t really manage on one magneto. Apart from a very rough running engines, EGTs go through the roof, the exhaust stack melts and the turbocharger dies. Turbo engines are usually EGT limited (“TIT”) and on one magneto you are way above that limit.
achimha wrote:
For me a failed magneto is a serious emergency requiring immediately landing.
Why would that be? I had a failed magneto once around 60 Miles from my home field in FL55 and we decided to fly back home, because we could stay in glide range of at least one airport all the time. Of course, in the C172 the O-300 is far from frying at almost any cruise power setting.
WarleyAir wrote:
Is that inviting disaster?
No, it’s good for avoiding it !
No, I was referring to the fact that when you turn off one magneto in cruise, your engine will not continue to run smoothly, or at least many engines wouldn’t. The second magneto is not just a backup in case of failure, it is required to burn the mixture in those huge cylinders. With just one spark, the flame front moves too slowly. Running on one magneto can be rather unpleasant and it can quickly fry your engine, especially when you are turbocharged due to the hot exhaust. You basically have the mixture burning in your exhaust stack.
achimha wrote:
You can get a feeling of “running perfectly” by turning off a magneto in cruise setting
You mean do a magneto ‘check’ while in the cruise ?! If you have a ‘dead’ magneto, and during this ‘in flight check’ when you ‘turn-off’ the good one the engine will stop, till you get that good mag back on-line again.
Is that inviting disaster?
achimha wrote:
can get a feeling of “running perfectly” by turning off a magneto in cruise setting.
And once you do, remember to let the avgas that poured into the exhaust evaporate by reducing throttle to idle for a few moments before you go back to BOTH. Not doing so can cause the unburnt avgas to explode. (learned from some other recent thread here)
achimha wrote:
You can get a feeling of “running perfectly” by turning off a magneto in cruise setting.
Agreed, but the pilot did not report anything on the previous flight. I’ve asked to see the engine monitor log.
