My understanding or mis-understanding of the S76 certification limit of -34.4 is as follows:. .They conducted the cold weather testing during the month of March and the coldest temperatures they could find (-34.4) were in Tuktyatuk where the testing was conducted. As you are aware March is the beginning of the end of winter in Canada and in order to get a lower temperature limit they would have had to wait untill the following year, and because of production deadlines ect.ect . that was not acceptable. . .The company I work for has a cold temperature limit of -32, that is because of a limitation in the allison engine manual which to paraphrase goes something like " The Allison 250 C-30 engine will run satisfatory down to a temperature of -32 while using Jet A or Jet A-1 fuel" to "operate below this temperature the aircraft must be fitted with the agro-tech fuel filter" yada yada yada. . .
Have a look at a long ranger with a C30 engine and you will notice that it has an airframe fuel filter on it, for that specific reason.
To operate the 76 down to its airframe limit of -34.4 you must use Jet B.
About the certification stuff above I'm sure Nick . .can fill us in on the exact particulars, I heard the story from one of the test pilots at Sikorsky in 96.. .p.s.. .Wind chill is not taken into account, wind chill was developped for whimpy people who live in the South to make it sound like it is colder than it really is ,they will say something like "with the wind chill it is -40" while Northerners will say its -40 because that is what the actual temperature is.
[ 28 January 2002: Message edited by: IHL ]</p>