I was taught to do both the accumulator test and isolation test at ground idle before I knew anything about squirrels.
Our company has both B2 and Super D single engine variants. The pre take off checks in the company SOPs for both aircraft have both tests being carried out BEFORE advancing the FFL to flight idle.
Think about what the tests are proving... the accumulator test is simply proving that the accumulators will discharge within the few seconds that they should and that this discharge should be fairly uniform across all 3 of them. The isolation test simply proves that the hydraulics can be cut off in case of a hydraulics failure so as they don't come back unexpectedly and bite you on the arse as you run on.
Both checks can be proven whether at ground idle or flight idle.
Not making sure the collective is locked when it should be? That's a Darwinian issue methinks.
GP
