Cold and Icing Conditions Testing

[johns7022]

So that's how it's done...everyone is sitting at the restaurant, waiting around for the bat phone to ring....'Hey we got reports of icing in Colorado...whoopee....we get to go flying today!"

In-flight testing makes sense because you need to see how the plane flies under those conditions, but I think the wind tunnel would give a much better indication of where the build ups occur, and the ability to really load up the plane safely.

But hey, if that's how it's done...waiting around for the phone call...what a great job...you could stretch that gig out for YEARS.

[Genghis the Engineer]

Originally Posted by johns7022

So that's how it's done...everyone is sitting at the restaurant, waiting around for the bat phone to ring....'Hey we got reports of icing in Colorado...whoopee....we get to go flying today!"

In-flight testing makes sense because you need to see how the plane flies under those conditions, but I think the wind tunnel would give a much better indication of where the build ups occur, and the ability to really load up the plane safely.

But hey, if that's how it's done...waiting around for the phone call...what a great job...you could stretch that gig out for YEARS.

I recall some happy days of my youth testing a training aeroplane at Boscombe Down for wind limits - it reached a rather amusing point where the values we wanted co-incided with the "no fly" limits for the fast jets (parachute dragging limits on the seats were their restriction). So, for some entertaining winter days, I and the gent who now runs most of MoD's flight testing used to trundle around the circuit doing crosswind landings in an air cadet training aeroplane whilst the Tornados and Harriers were grounded for the day.


More seriously, there are various tools - the tanker is one, there are various ice build up numerical method tools that allow engineers to predict ice formation, and then either CFD it or make up plastic models and stick them in the wind tunnel. Another, which I was privileged to play with for a while was the Boscombe Down blower tunnel...



... which will make a reasonable stab at putting calibrated icing conditions onto discrete bits of the airframe.


But all of these carry inaccuracies and difficulties, and as ICT says, ultimately you need to get the aircraft into some known icing conditions, probably with a nephelometer or similar combined suite of water phase and particle size distribution instrumentation strapped under the wing to characterise the conditions.

It is a fascinating - if specialist - branch of testing, and not as well understood as it deserves to be.

G

[leonard17F]

Again, thanks a lot !

We will use the services of the weather guy based in CO. The A/C shall be based in Nashville or Louisville, i.e. not too far but NOT WITHINE the bad icing area itself, so that we will be able to T/O and land safely, and also away from ATC congested areas. I hope to be part of the campaign. I will try to send pics later. Happy New Year everybody !