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View Full Version : Iceing go/no go decision


kuobin
14th Apr 2010, 12:14
When you check-in, got notice said your aircraft lost eng anti-ice ,It is cloudy but >+20 degrees c outside, how you make your go/no go decision, which data will you refer to? Assuming your planned altitude is >FL200?thanks.

Henry VIII
14th Apr 2010, 13:03
First, chk your MEL and any other manufacturer or company limitation(s).

Nubboy
14th Apr 2010, 13:16
Check the definition of icing conditions for your company and aircraft. For us it's less than +10deg C, in visible moisture (ie rain, cloud, or visibilty less than 1km). After the temp drops to less than -40deg C, its no longer deemed icing conditions.

If you're going to encounter any of this in flight, then it's a no brainer. Don't go.
Had exactly this discussion with an engineering manager who had been dragged out of the hangar to rectify the fault. Just because it was nice and warm and sunny at base he wanted me to take it. I had to tell him no 3 times:ugh:

Agaricus bisporus
14th Apr 2010, 13:17
Light iceing conditions are presumed to exist at all times on an IFR flight.

Also the manual almost certainly says to the effect that with anti-ice inop despatch is allowed if iceing conditions can be avoided.

That's not an assumption you can make, even in blue-sky weather.

Nogo.

A short low-level VFR transit to the maintenance facility is a different matter, buy the question gave specific wx cnditions and is clearly an airways IFR flight.

clunckdriver
14th Apr 2010, 14:10
Some of the questions I read on this forum confirm my decision to keep the 421 untill the brain/body is no longer able to fly safely, to go in a turbojet aircraft at high level without both airframe and engine anti/de ice working is bloody insane, I have seen three inches of ice in under sixty seconds on a 727 airframe in clear air letting down on the West coast, supercooled droplets being pushed up hill by an onshore/upslope wind, no forecast of same and a large dew point/temp spread on the surface{Vancouver} and nothing visible to the naked eye. and I reapeat, nothing forecast. It might be SOP for some to build aircraft with faulty pitot systems, de ice systems which allow run back ice to form, but one doesnt have to load the dice any more by going when these systems are bust!