Cracked windshield forces plane to land in Orlando

 An American Airlines flight from Miami to Boston had to make an unscheduled stop in Orlando after the aircraft's windshield cracked.

Airline spokeswoman Andrea Huguely says Flight 160 landed in Orlando late Tuesday after the pilot's double-paned windshield cracked while the plane was in flight.

Huguely says a cracked windshield "doesn't happen a lot, but it does happen on occasion." It wasn't immediately clear what caused the crack.

The Boeing 757-200 (a twin-engine jet) landed in Orlando with 156 passengers and crew members on board. No injuries were reported.

Huguely says the passengers boarded another aircraft that landed in Boston early Wednesday. The aircraft with the cracked windshield was pulled out of service for repairs.

Reports of cracked aircraft windshields are relatively rare.

In May, a Southwest Airlines flight from Newark, N.J. to Chicago's Midway airport developed a windshield crack in flight. The plane landed safely.  At the time Southwest spokeswoman Michelle Agnew told the Chicago Sun Times that the windshields are roughly an inch thick and heat up to high temperatures when flying. "When these little cracks happen, it's from heating up, but there is no structural impact and it does not impact pressurization or the aircraft," she wrote in an email.

One of the more bizarre cases of cracked aircraft windshields occurred at Denver International Airport in February 2007. In a 1.5 hour period, the windshields on 14 different aircraft cracked. Some were in flight, some were parked on the tarmac. The National Transportation Safety Board eventually concluded that FOD, or “foreign object debris" was the cause. The NTSB cited blowing sand and other debris in cold 48 mile per hour winds. But some aviation buffs have questioned that conclusion, given that most aircraft encounter much higher wind speeds in flight. Others have speculated that uneven heating of the windshields and the surrounding bolts in cold weather is a more likely cause of cracks.