View Full Version : Engine Warm-up Procedures
I would be interested on views cocerning engine warm-up procedures to enhance engine efficiency and increase EGT margins. Presently my company starts engines and within 10-15 minutes are setting either T/O rated thrust or Reduced thrust for departure. Engine monitoring is giving reduced EGT margins and the company is looking for ways to increase them by developing warm-up procedures. The engine manufacturer are not very helpful. Without giving to much away the engines are old PWs. Views most welcome.
woderick
9th Apr 2003, 05:55
OK I'm Avionics but I have been doing this for a while and I have never come across warm up as a method of increasing EGT margin. You don't mention which P&W but both JT8 and JT9 seem to benifit from a compressor wash. Don't remember doing them on JT3s:D
A previous company used to do regular, scheduled, washes on JT8s.
While CFM56s, V2500s, and especially CF6s all seem to benifit so it might be an idea.
Far more important to your engines would be to establish 'cool down' proceedures. 10 mins from start up to TOGA would be of no significance compared to engine shutdown after less than idle thrust. Many is the time I've heard an engine spool up to get those last few yards on stand followed by an almost instant shut down, and this will do far more damage. In my company this event is usually followed by the engineer bo**ocking the pilot.
I also agree with Wodders that comp washes are very good for restoring EGT margin.
Proper start proceedures are also very important to protect engines. Engines don't last if you continualy do hot starts and they don't last if you don't let them idle for a while to cool down. Back when I still worked in cold climates, we use to use a pre heater to warm the engine before we started it. Once it was started we would idle it a bit above normal idle speed just to get things warmed up. Most of the time the Spey wouldn't idle at it's normal idle speed unless it was warm any way. Not as much of a problem on JT8D or the Lycoming on the BAE146.