CHARLOTTE, N.C. (TheStreet) -- It is rare for a U.S. airline to lose all contact with one of its aircraft, but it does happen.
Flying from Charlotte to Rio about four years ago, US Airways Flight 800 lost contact with the carrier for about an hour and a half after heavy fog forced the airplane to divert from its destination in Rio to Viracopos International Airport in Campinas, about 300 miles away, according to four US Airways pilots, interviewed separately, who asked that their names not be used.
The airplane, a Boeing 767-200, predated the time when airplanes were equipped with satellite data links.
Neither VHF nor HF communication was available in the area, and at the time USAirways had not equipped the B-767 with a satellite phone, even though some other airlines routinely did so. As a result, the pilots had no way to quickly advise dispatch of their location.
The event occurred months after US Airways began daily Charlotte-Rio service on Dec. 15, 2009. The exact date could not be determined. Because of heavy fog, the aircraft could not land in Rio. The pilots "tried to divert to Bela Horizonte and Sao Paulo and were denied both" due to a profusion of diverted aircraft, said a US Airways pilot.
"They ended up in Campinas, which was not a part of the flight plan," the pilot said. "They could not reach the company via VHF or HF radio, so they landed and called on the ground."
The call was delayed, however, because all of the gates at Campinas airport were temporarily occupied by other planes, including many that had also diverted. The pilots could not contact the airline until they entered the airport and used a telephone.
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Concern over the disappearance of Malaysia Airlines Flight 370 prompted memories of the Rio flight, simply because it represented a rare case when a US Airways flight lost contact.
Loss of contact "is a big concern," said John Goglia, a former member of the National Transportation Safety Board who now blogs on airline safety for Forbes. "It happens occasionally. Once is too much." US Airways declined to comment for this story. Goglia said modern airplanes like the Boeing 777 are equipped with satellite transmission systems, but older 767s -- particularly the US Airways 767s, most of which flew for Piedmont Airlines -- are not.
The route from Charlotte south to Rio takes aircraft over the Amazon. While pilots typically communicated by VHF radio, coverage was spotty. In fact, US Airways pilots in the area had a list of more than a dozen VHF frequencies to try, in hopes of finding one that worked. "This was a nasty --- night" and none of the transmissions worked, a pilot said.
Another pilot added: "The weather got real foggy. The pilots diverted to a secondary diversion point. But they couldn't get to a gate and the area had no ACARS coverage and they had no satellite phones and they couldn't communicate. Dispatch was sweating bullets because they thought they had lost the airplane." ACARS is the Aircraft Communications Addressing and Reporting System, a digital system for transmitting brief messages via radio or satellite.
The incident occurred in 2010, during a period of intense conflict between the carrier and the U.S. Airline Pilots Association, which represents its pilots. At the time, the airline disputed various pilot reports regarding unsafe conditions.
Nevertheless, soon after the Brazil incident, US Airways decided to equip the 767s with satellite phones.
US Airways merged with American (AAL - Get Report) in December. In February, the carrier said it would discontinue the Charlotte-Rio flight early in 2015, the first major cutback it announced following the merger. American serves Rio from Dallas, Miami and New York Kennedy airports. Also, American will continue to operate Charlotte-Sao Paulo service, which US Airways began in June, using a Boeing 767-200.