Given how few airline accidents have occurred over the past 20 years, people rarely give a second thought to whether or not the aircraft they are boarding is mechanically reliable. If they did look into the matter, they would likely be surprised to see how much work goes into making sure the aircraft is in working order. Maintenance of an airliner is both time and manpower intensive, and results in each aircraft being unavailable for revenue generation for an extended period of time. As a result, any technology that can reduce either the amount of personnel or the amount of time needed to inspect an aircraft can have a big impact on the bottom line.
By way of example, an “A Check” inspection is performed on aircraft roughly every 400-600 flight hours or 200–300 takeoffs and landings, takes between 50 and 70 man-hours, and takes the plane out of service for a minimum of 10 hours. The more thorough “B Check” is performed every 6-8 months, requires 160-180 man-hours, and can take 1-3 days.
Even before the first Section 333 Exemptions were granted, people were experimenting with the idea of using unmanned aircraft to speed up inspections. Since most work of this type occurs in a large hangar, it is outside the National Airspace System, providing more flexibility and freedom in performing this work.