Michael, as you allude, Carb Ice can form almost at any time, and within any regime. The cure is always the same-Carb Heat.
Good article here to remind everyone of the dangers
https://www.aopa.org/-/media/files/aopa/home/pilot-resources/asi/safety-briefs/sb09.pdf?la=en
I am guessing was aiming to recover to Lydd, but with hindsight recover to the very nearest coastline (Fairlight) which he would have made, and then see if you can get to an airport.
Michael wrote:
Hmm, now what “flight regime” would be conducive to severe carburettor icing, “at any power setting”
This refers to a BS graph in the UK safety sense leaflet on carb icing, which they also have in the report
This is, of course, engine dependent (for example, the location of the air inlet; air routing, location of the carburettor etc. all play a role).
I had some fun conversations after my engine failure in a PA28, which happened at 14 degrees with a 3 degree dew point (50% or so relative humidity), which according to the graph put me into the “Serious Icing – Descent Power” and “Moderate Icing – Cruise Power” bracket. If PA28 were that susceptible to icing, they would be virtually raining from the skies.
Mind you – in the accident case, the spread was only 1 degree, so carb icing could certainly be a factor.
Unexplained engine failures are an uncomfortable thing.
This is a good one, and is real. You get a double engine stoppage in a DA42 through this mechanism too… Alternate air (as per POH) or seemingly prop TKS seem to avoid it. But that is for fuel injected engines with the traditional narrowing air duct, and a non turbo case in the IO540 but the DA42 does have turbos…
You could get an engine stoppage in various other ways e.g. a carb failure due to a particle of debris. We have had reports posted here first-hand of these things, and in one case it kept happening and eventually they threw the engine away.
Peter wrote:
You get a double engine stoppage in a DA42 through this mechanism too…
Well, either that, or a clogged air filter. But this, from the DA42 AFM, is there for a reason:
I don’t think I was a factor in this accident but there must be more to the air filter + rain story because I have flown in the heaviest rain without alternate air. Standard Brackett foam filter.
Carb icing is something which needs experiencing to really understand it and to know what to look for. I had a lot of it in the C150, often even with full open throttle, to a lesser extent in the Mooney (mainly on ground there) but it’s a factor.
I found the best way of preventing it the installation of a carb temp gauge or indication.
I can well imagine that a relatively new pilot can get confused by a carb ice incident if he has a malfunctioning engine indication of any kind. It is totally weird however that he did not immediately head for land.
Also looks like he landed at too high speed which gave him the injuries (and probably knocked him out) before it sank. As @Peter said, he should have turned into wind at least, then applied full flaps and stalled the aircraft just above the water with the door open.
I had a rough running engine halfway across the Irish Sea a couple of years ago.
Apart from being the longest 30 seconds in my entire life, the very first thing I did was pull on the carb heat full on. The engine started running even more rough with a lot of banging and farting, but this can happen as the ice breaks free. I was able to maintain altitude during all of this, but I wasn’t far off making a mayday call.
Weather was overcast (the overcast being about 1000’ above, IIRC I was at FL055 or something like that, so the relative humidity was high).
Charlie wrote:
then applied full flaps and stalled the aircraft just above the water with the door open
I wouldn’t recommend that, as others don’t either in this recent discussion on ditching techniques.
