Wheelchairs service at airports have caused over two-thirds of the the complaints that were recieved by the Department of Transportation last year. The report cited poor assistance, the complaints also told of incidents of damaged chairs, bad seating arrangements, long waits and difficult accessibility.

Northwest, American, Delta, and United were responsible for over 60% of the complaints. Delta has started a new program to help train employees who interact with the disabled passengers to help reduce these complaints. via Cheapflights