Originally Posted by
HDQDD
This is true, but maybe not for the reason you think. RJs are primarily used for short haul flights. Short haul flights (and even larger aircraft) are more likely to get ensnared in MIT delays due to already in the air long haul flights that ATC has to fit them in between. It’s easier to hold close in flights on the ground til they have a gap.
I always thought it was based on distance to the airport. I've been on plenty of 757s flying JAX-ATL that are held on the ground until a specific time in order to route them in at a specific time even when there is no weather at ATL. It's more fuel efficient to keep the plane on the ground instead of vectoring it once airborne in order to slow it down.