Hi all.I was at my local airport today (NZWN), and noticed the small prop planes (Beech1900)would turn into the (strong) wind whilst awaiting take-off clearance.The larger ones (Saab340) would not.Can someone tell me why the smaller planes need to do this? Obviously whatever the reason, it doesn't impact on larger propeller planes.The turns weren't small, they were at least 90degrees.CheersAllblack

most likely it is for engine cooling.

Mike is correct. Engine runups in piston engine airplanes are usually done into the wind to help cool the engines during high power prop and mag checks.Turbine powered (jet and propjet)airplanes usually park to keep a strong tailwind or crosswind from blowing up or across the tail pipe to keep the exhaust gas temp/turbine inlet temp from getting too high.Ed Weber a.k.a tallpilot

The reasons are, If they were performing a power assurance run, they want equal effects from wind on both propellers for stable engine readings,and with a crosswind, the exaust tend's to crase and deform the cabin windows.One of the reasons we cannot idle the engines with the props in feather.

Last time I worked on a Pt6 powered plane,(SD 360, Pt6-67) there were a couple of checks to be done before take-off, the autofeather check,the overspeed governor check and the low blade angle secondary stop check.In gusty wind conditions the prop is being constantly loaded and unloaded by the wind shifts, and the prop then begins to 'hunt' aroundits' selected rpm as the blades pitch up and down to try and maintain constant rpm.This can lead to the prop entering its' 'prohibited' range of rpm on the ground, as well as interfering with the checks,therefore its' best to be into wind.Basically, its' down to the operating limits for the particular engine, Saab 340's with the CT7 and Metro's/Jetstream's with the Garrett Tpe331 all have different operating limits.hope this helps:-wavePeteUK A&C

G'day Allblack(go othe Wallabies!!)If Welli is the way i remeber it it would be to stop control snatching.The 1900(like the Kingair) do great jobs of control snatching in gusty conditions.Given it can happen unexpectedly you normally can't stop it by just holding on.The last time i was in Wellington in the G4 the breeze was blowing a steady 45kts.Most smaller aircraft with non powered or non lockable surfaces prefer to park into the wind if it will be for any extended time to stop damage to control surfaces in the very gust conditioins you get at Wellington.HTHKnowing Welli's weather engine temps would not come into t as t is normally a problem to get them warm enough to actually go flying!All the best

Hi guysAnother reason could be that they don't wanna damage anyone's plane who's also waiting at the threshold, so they turn their aircraft to redirect the propwash ...DooRoohttp://www.aircraft.co.zahttp://www.eyetea.co.za

Thanks for that.Tell ya what - I won't mention the R-word if you don't!!John Mitchell and Rueben Thorne are all yours - do with them what you want!! I suggest feeding them to Cannon.CheersAllblack