While "load factor" cancellations may have been common in the Islands, you don't see it so much here on the Mainland.

In Hawaii, with the high frequency of flights, it really would not matter much to the passengers. So what if they had to take another flight 30 or 45 minutes later. The only ones that it really matters to would be the crews, who have shown up for work and did not get paid for actually working a couple of flight segments that day.

Here on the Mainland, it would be safe to say that 99.9% of any "load factor" cancellations are actually caused by a mechanical problem. What happens is this....

Say you are in Hub Airport like MSP, trying to fly to Milwaukee on an A320. At that time there are about 15-20 other flights that will be departing on an A320, and it happens that the aircraft scheduled to fly to Los Angeles develops a mechanical problem that will take an hour or more to fix. Someone in the Operations Control Center makes the decision to "steal" your A320 from the MKE flight and send it to LAX instead, while the folks going to MKE will have to sit and wait for the disabled aircraft to be fixed. The decision is made based on inconveniencing the LEAST number of people, so you COULD call it a "load factor" decision. Perhaps the flight to LAX was scheduled for a short turn-around and there was a full load that needed to be brought to MSP for connecting flights. And perhaps the MKE aircraft was going to overnight there, so it did not matter what time it arrived. It makes good sense to turn mechanical delays/cancels into "load factor" delays/cancels. The folks at NW are wise to do it, and every other carrier does it also. For every time that a person is delayed by one of these, 19 or 20 times they will be helped by one, getting them where they need to be while others wait for a plane to be fixed. The problem is that you will never know about it because you were not delayed!!! But this only makes sense to do it at the Hub airports, where there are many aircraft and crew gathered at the same time. It would never make any sense at an outlying airport....if there is a delay or cancel for mechanical problems, you can believe that it IS for mechanical problems, and for no other reason!