I know that this has been brought up before but seriously, this needs to be fixed. It is especially annoying on Chaos maps where there are lots of ramps and stairways. The fact that the Jump Pack can't go up a ramp or stairs is ridiculous. You have a class, that relies on this ability as a gap closer yet you can't close the gap if the ranged enemy is on a step, or a ramp, or a slight hill, sitting down on a curb etc. 

Vanguard's can zip up stairs, across gaps etc but a jet pack is essentially halted by a small elevation in the ground. It makes the class very annoying to play at times.