Hi All !

If you had to perform Extreme Cold and Icing Conditions Testing for a biz-jet:
- In the Northern hemishpere:
when would be the latest/warmest possible period in winter ? March, April
when would be the earliest possible period in late autumn or winter ? November, December ?
where would you go ? Iqualuit, Resolute, Narsasuaq, etc..or....Siberia, Alaska ?
- Are there suitable locations in the Southern Hemisphere ?

Thanks a lot for your inputs !

The concept of "severe cold weather testing" seems a bit odd. A business jet is presumably certified to part 23 - in all likelihood a parallel EASA CS.23 and FAA FAR-23 certification. This will cover specific cold weather and (depending upon specific clearances required) icing conditions but I wouldn't anticipate any special requirements above that.


Ability to operate in cold conditions tends to fall into three parts:

(1) startups and system operability after cold soak,
(2) ground handling in snow/ice
(3) flight in known icing conditions.

The three are quite separate, and none necessarily need you to mount an expensive detachment to some dreadful spot north of the arctic circle - although the second will probably take you to somewhere like Alaska or northern Canada for some decently contaminated runways to play on.

Part (1) can be done, cold enough for certification purposes at somewhere like Goose Bay in winter, but you'll get a lot more control taking the aircraft to a suitable test chamber - which probably means either Boscombe Down or Edwards, without the variability of waiting for exactly the right cold conditions (Sod's law say's you'll move your test team to the arctic for a month only to hit a heatwave of -15°C otherwise). Typically you're looking for around -46°C for global certification (this is from memory, I'm in the wrong office for the books on that this week.)

Part (2) isn't really about cold, it's about surface friction and surface condition. There's a really good paper on this in the 2008 SETP annual procedings called "Stopping the Raptor on Ice", which is better than anything else I've ever seen in explaining how this type of testing is done.

Part (3) Needs icing conditions, and the atmosphere being what it is, the best direction to look for that is up, rather than north or south. Pilatus have done a lot of severe icing work flying over Switzerland, but equally a business jet with reasonable altitude performance can probably fly into moderate or even severe icing conditions over the tropics - for example out of Darwin (where the Australian Met Bureau have a hugh research weather radar facility called Berrimah - probably the best in the world, conveniently close to regularly convective storms) , or into the ITCZ.

G

Iceland in may, together with a good on-board system to detect /measure ice accretion ; gives the possibility to test and verify ice shapes and accretion without the need to fly into or close to cb. A good ice certification expert is of paramount importance - then follow his instruction for staying inside the icing area and altitude - lot of ice in smooth weather !

The McKinley Climatic Lab facility at Eglin AFB. We use them for hot and cold weather testing, where we don't have a requirement to fly immediately after the soak. Running engines, APU's etc in the chamber is possible up to TOP.

If we need to carry out a cold soak followed immediately by a flight, we generally resort to the Frobisher, Resolute Bay, Iqaluit option.

http://www.aiaa.org/tc/gt/facility_database/Climatic2008.pdf

Edit: The chamber also has the capibility to generate snow and ice for accretion testing.

In Canada you can get excellent support for all the testing that has been mentioned through the Canadian Flight Test Centre in Cold Lake, AB. Jan-Mar temperatures below -30 and excellent support facilities.

I have run certification testing for anti-icing fluid out of Winnipeg Intl in January. Major airport facilities, pretty much guaranteed sub -25 temperatures, and good logistical support. In this case we needed a week or more below the fluid's LOUT of -28.

Iqaluit is also possible, although more $$$ and a bit remote.