IFR in VMC with new IMC
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That is partly true, Peter, but an awful lot that is posted here is more understandable if you know about what the same people have written elsewhere and, when it comes to political debate (on FCL.008, for example) what political stance and organisations they represent.
The alternative is to expose everybody's full names, but then almost nobody will write anything frank about anything.
I have met a lot of people here but I still call them by their nicknames
Anyway, Debiassi is right in that icing tends to be vertically limited, and anyway (in stratus cloud) it has to be constrained to a band about 8000ft thick (0 to -15C), but one needs to qualify that with aircraft performance. A turbocharged engine will deliver a much better climb rate at say FL140 (say +1000fpm for a typical turbocharged/turbonormalised 250HP tourer) whereas despite flying a "pretty quick" IFR tourer I would be getting only about +300fpm up there, and that translates to a lot more exposure to icing conditions. And even with de-ice equipment it won't take a lot of airframe ice accretion (that doesn't get shifted) to eliminate that +300fpm margin altogether. That's why my options are VMC on top for the whole enroute section, or a descent option.
But one should not be scared of icing, and that is not a helpful way to teach anything.
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But one should not be scared of icing, and that is not a helpful way to teach anything.
I agree you should not be scared of icing, but you should understand the issues and respect them. You should be taught this so that you're not scared (as this can lead to panic/problems), but you should understand and respect the issues so as to not be blase about it.
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This is a good thread learning from other peoples experiences. Awareness and options is what it's all about. I would like to share an experience which has not been mentioned yet.
I was flying a PA28 Archer at FL55 just above a thin stratus layer whose tops were forecast to be about +2. The actual temperature was nearer -2 and despite being vmc started to pick up just a hint of frost on the leading edge.and round the temp probe. As I started the descent to my destination there was a sudden vibration and a line of oil began running along the top of the cowling. Power and all indications were normal and after calling a mayday we were given vectors to an uneventful ILS at our destination.
The vibration was caused by prop ice and the leak caused by the breather icing over.
The lesson learned was a tiny bit of ice in one place can mean a big bit somewhere else and don't expect the forecast to be exactly correct.
DO.
I was flying a PA28 Archer at FL55 just above a thin stratus layer whose tops were forecast to be about +2. The actual temperature was nearer -2 and despite being vmc started to pick up just a hint of frost on the leading edge.and round the temp probe. As I started the descent to my destination there was a sudden vibration and a line of oil began running along the top of the cowling. Power and all indications were normal and after calling a mayday we were given vectors to an uneventful ILS at our destination.
The vibration was caused by prop ice and the leak caused by the breather icing over.
The lesson learned was a tiny bit of ice in one place can mean a big bit somewhere else and don't expect the forecast to be exactly correct.
DO.
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That sounds either like a bodged breather pipe, or bad maintenance, DO. The crankcase breather pipe is behind the engine, in fact it should be between the bulkhead screwed to the back end of the engine, and the firewall.
The bit of the breather which sticks out into the airflow at the bottom of the plane could ice over, but the pipe itself is supposed to have a hole part-way up it (protected by the cowling) which will remain clear should the exit get blocked.
That hole also serves as a vent to prevent airflow past the exit end from creating a vacuum and sucking the oil out of the crankcase.
Sounds like that hole is missing, or was blocked up.
Prop icing is a funny one. I have a TKS prop and see no measurable speed loss with say 3-5mm of clear+rime ice on the leading edges. I therefore think that some of the stories of 10-20kt speed loss at the first hint of ice are actually caused by prop icing and resultant loss of power.
The bit of the breather which sticks out into the airflow at the bottom of the plane could ice over, but the pipe itself is supposed to have a hole part-way up it (protected by the cowling) which will remain clear should the exit get blocked.
That hole also serves as a vent to prevent airflow past the exit end from creating a vacuum and sucking the oil out of the crankcase.
Sounds like that hole is missing, or was blocked up.
Prop icing is a funny one. I have a TKS prop and see no measurable speed loss with say 3-5mm of clear+rime ice on the leading edges. I therefore think that some of the stories of 10-20kt speed loss at the first hint of ice are actually caused by prop icing and resultant loss of power.
Another aspect
Chap I knew landed having spent a worrying time in the soup in a 182 'just below' the freezing level...
Thought he had an engine problem & snagged the aircraft afterwards as he could not get more than 18" MP despite being at FL80....
My guess is that he had intake icing even though no airframe icing was apparent...
Know how the air gets to your engine and consider what would happen if you were flying in moist air close to freezing point ... I've had intake icing on more than 1 occasion caused, I suspect by local pressure (and therefore temperature) drop in the intake. Know if you have an alternate air system and keep it in mind if you get an unexpected MP drop close to icing conditions... Aircraft can do reasonably well with airframe icing present, but intake icing can be very bad news indeed...
Happy New Year
Thought he had an engine problem & snagged the aircraft afterwards as he could not get more than 18" MP despite being at FL80....
My guess is that he had intake icing even though no airframe icing was apparent...
Know how the air gets to your engine and consider what would happen if you were flying in moist air close to freezing point ... I've had intake icing on more than 1 occasion caused, I suspect by local pressure (and therefore temperature) drop in the intake. Know if you have an alternate air system and keep it in mind if you get an unexpected MP drop close to icing conditions... Aircraft can do reasonably well with airframe icing present, but intake icing can be very bad news indeed...
Happy New Year
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IFR in VMC with new IMC
A lot of newer aircraft do indeed have an elevated secondary breather escape as a lot of aircraft actually went down in cold weather operations due to that exact problem in earlier aircraft. I know a lot of ferry pilots who adapt the oil crankcase breather pipe as part of winterization techniques.
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IO540As you say it was sloppy maintenence. No "whistle slot" in the breather pipe.On a separate note. In a C172 at FL85 in spring I kissed the top of a large cumulous for perhaps 15-20 seconds and emerged with the screen frosted over and icicles streaming back from the struts. (And probably elsewhere that I could not see.)DO.
