Bobby Kirbos
Scrounger of Cellulose Based BTUs
Commercial airliners fly at 30k to 40k. The peak of Mt Everest is 29029ft. I don’t think you can push a piston aircraft much above 14k. I would think your only easy options are battery or hand powered core cutter. Both would have serious working drawbacks at high altitude. You could also try to modify an existing chainsaw to run on compressed air but l don’t know how well or long they would cut on a say a SCUBA tank of air.
Here's one that is not a piston engine....
https://www.dailymail.co.uk/news/ar...ngineers-create-chainsaw-runs-JET-engine.html
It's a concept saw. However, it may be worth it to contact Stihl and talk to them about your application requirements. They may be able to offer you a solution. I don't expect that it will come cheap though, so make sure you are sitting when you look at the price quote.