In one case, the Federal Aviation Administration has assessed a fine of $687,500, CNN reported. It involves a Boeing 737 with chips in the nose cone in the area where radar and navigational equipment are housed.
The damage was originally pointed out by an FAA inspector. When the plane's captain reported it to a maintenance center, he was told it was within acceptable limits.
In another case, a Delta Airbus 320 allegedly made almost 900 trips in seven months in 2010 and 2011 with a broken floodlight socket in the cockpit, the FAA said. FAA regulations allow one of four lights to be inoperable but require repairs within 10 days.
The fine in the second case has been proposed at $300,000.