DiverDriver.com Turbocharged Engines
I have had a lot of requests for information on best ways to operate turbocharged engines in skydiving operations. The greatest fear it seems is from rapid cooling and breaking the turbocharger. What I will provide next is a summation of information gained from personal experience, many current DiverDrivers flying jumpers in turbocharged piston engines, and a series of articles by John Deakin called the Pelican’s Perch. This section should not run contrary to any manufacturer’s information. You must take the time to research information you use in your operation.
Turbocharged engines in skydiving ops:
- Go over the engine manufacturer’s guidance thoroughly. If you don’t have it CALL THEM.
- Follow the warm up and cool down guidance. In general, you want at least 2 minutes at idle after landing to let the turbocharger cool before shutdown to prevent damage. Normal taxi time from runway to parking can accomplish this. Don’t think you have to get to your parking spot and THEN start a 2 minute wait. You may very well be heating your turbo back up!
- Do not exceed 380˚F CHT in the climb. Use mixture and airspeed to control CHT.
- Look to be level about 2 miles before drop so a power reduction for level flight will begin the cooling process of the turbocharger and cylinders. Close cowl flaps.
- Last jumper out, close door, ensure cowl flaps are closed, reduce to bottom of the green MP and this should keep the engine from cooling too quickly. If you observe a maximum of 380-400˚F CHT during climb you will not “shock cool” the cylinders. You can only shock cool that which has overheated to begin with.
- Do NOT push mixture full rich on descent. This will cool your cylinders too fast. Use a slightly ROP (rich of peak) setting. Remember, richer is cooler.
- All cylinder engine monitoring system HIGHLY recommended with a CHT alarm that can be set to 400˚F while you monitor your TIT (turbine inlet temperature).
Read John Deakin’s articles here on turbochargers. Part 1 and 2 are how turbochargers are constructed and the theory on how they work. Part 3 begins the nuts and bolts of what to do. However, it comes with a warning to make sure you read part 1 and 2! Best power comes at about 100˚F rich of peak (ROP) exhaust gas temperature (EGT). John recommends to not allow your CHT go over 380˚F (buffer for a limit of 400˚F)
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