Does anybody know why Air Canada continues to fly its A220 at a max altitude of 29000'? I understand the AD in place and the restrictions placed upon the N1 speed above that flight level, but AC and Swiss seem to limit their aircraft, whereas Delta, AirBaltic, Korean and Egyptian all cruise at up to FL410. Everybody's using the same engine (Pratt & Whitney's PW1500G).

Is it a case of differing levels of tolerance at different airlines? I wondered if it was conservatism with a new product, but the most-experienced (LX) and the least-experienced (AC) A220 operators are opting to keep low, whereas the others are flying higher. What are Airbus' recommendations? And do the fuel burn differences influence differing decisions made by different operators?

Stooging along at 28-29000' on a 4+ hour transcon doesn't seem all that appealing if you can't outclimb much of the weather, and I can't imagine that the manufacturer's' claim of 15% less costs per seat over the E190 can be realized in the lower to mid-flight levels.