Hi all, Do not know the exact circumstances but the DP/T spread suggests a cloud base of app 4000 ft. A descent from say 3000 ft would be right in the sweet spot for icing at least according to the french diagram..
I think life is too short to be flying planes with carbs, but unfortunately most of the smaller types don't come with a fuel injection option.
I would never go back to carbs again, ever.
Although engine-related icing can be an issue with injected engines, as well.
"The accident was caused because the engine failed due to ice formation in the fuel injector unit and because of the subsequent forced landing. Ice formed in the fuel injector unit when the flight was continued into a rain shower during the final simulated approach where the conditions for icing were favourable."
Although engine-related icing can be an issue with injected engines, as well.
True but which do you think is more likely (by an order of magnitude)? And while I have had it at -40, it leads to rough running not complete engine failure.
Although engine-related icing can be an issue with injected engines, as well.
Extremely unlikely to happen.
Reading that text, I wonder how they determined that it was ice.
In most (all?) fuel injected installations, the air passes through a filter and one would expect supercooled water droplets to be freezing up when they hit that, not passing through it untouched and then freezing inside the fuel servo.
Carb ice mechanism is totally different and is caused by the venturi temp drop causing the RH to go up, and the droplets then freezing if the air is below 0C.
I have heard pilots saying that one should fly (at altitude) with the alternate air OPEN but I think that's wrong, because any SLDs will then freeze inside the fuel servo.
I'll be honest, I cant picture those charts in my head..
Well, it basically means there is a chance ice will form under pretty much most atmospheric conditions. The exception might be when it's below approx -15C, where one may conclude ice will not form.
However, in the event you experience a rough running engine below -15C which isn't due to ice , applying carb heat will put you right back in the most favourable conditions for ice to form sigh
In an industry which prides itself on "safety", I have never understood why in this day and age carbs are still used.
In an industry which prides itself on "safety", I have never understood why in this day and age carbs are still used.
Me neither. Fair enough there are a lot of old aircraft out there (mine included), but surely no modern aircraft (even the cheapest in a line) are using carbs and carb heat are they?
My preference is to use the diagram as an indication of the climate that's fit for human habitation :-)
(I had carb ice in 2011 once, on the ground. Another time in around 1978, with my dad flying)
I think life is too short to be flying planes with carbs
Well, not if you're flying antiques. Most of the vintage small aircraft will have them.
Having said that the propensity for carb icing varies enormously. I've never had it on C172s with Lycoming engines, nor in our Lycoming-engined Auster (despite living somewhere where we are ALWAYS in the "severe carb icing zone" on any chart). Nor in the Cessna 140 I was part owner of when I lived in the US (despite living somewhere humid and the C85 engine having a reputation for being a bit of an icemaker).
However, the Piper Apache that I did my FAA multiengine rating in, even the slightest possibility of moisture and it made masses of ice even if the carb temperature gauges suggested otherwise. Basically the slightest wisp of visible moisture and you needed full carb heat.
Icing can cause stoppages in fuel injected engines, a friend of mine had to ditch in the Irish Sea after such a stoppage. The AAIB's best guess at the probable cause of the engine failure was "It is possible that ice formed on the impact tubes of the throttle servo valve and this reduced fuel flow to the engine and thereby limited power regardless of the throttle position." (I say best guess because in the report they do indicate it was difficult to prove what the fault(s) were given the aircraft had sat on the bottom of the Irish Sea for 5 months).
rough running engine below -15C which isn't due to ice , applying carb heat will put you right back in the most favourable conditions for ice to form sigh>
Can carb heat ever increase the risk of carb ice, given that the maximum water content of the air is determined by the OAT - and heating it will not change that.
