Federal Investigators have launched an investigation into an incident involving an American Airlines jet last week at Charlotte Douglas International Airport.
American Airlines Flight 1851 struck several runway lights and the tail of the jet slammed into the runway while attempting to land in Charlotte.
According to the National Transportation Safety Board, the crew of the American Airlines flight reportedly encountered wind shear (sudden shifts in wind direction or speed over a small distance) shortly before touching down at the airport.
However, according to a story by the Wall Street Journal's Andy Pasztor, the weather encountered by Flight 1851 wasn't just any wind shear, but a particularly nasty weather phenomenon called a microburst.
"A microburst is a form of windshear. It's an intense, localized downburst of air from a storm front," airline pilot Patrick Smith told Business Insider in an email. "The column of cold air plummets, then moves outward in different directions — think of it like a kind of upside down mushroom cloud."
According to Smith, who is author of the book Cockpit Confidential, microbursts are particularly dangerous because they can cause unsafe fluctuations in speed and direction – making the aircraft incredibly difficult to control.
Shifting suddenly between headwinds and tailwinds, microbursts can cause planes to suddenly gain and lose altitude and speed, all within a matter of seconds. It's rare for an aircraft to fly into one anymore, thanks to modern technology used by airports and pilots, but that wasn't always the case.
As with any weather event, the severity and the amount of danger microbursts pose to airplanes can vary greatly.
"The potency of a microburst runs the range of barely noticeable to potentially deadly," Smith added. "When airplanes are taking off or landing, they operate very close to their minimum allowable speeds, and encountering a strong shear at this point is dangerous — at higher speeds it's not of such concern."
In this case, the pilots of the Airbus A321 — operated for American Airlines by US Airways — decided to abandon the initial landing attempt, but safely landed on a second try.
Fortunately, no injuries have been reported among the 159 passengers and crew onboard Flight 1851. Although the NTSB reported that the aircraft suffered "substantial damage" and — according to a statement from American Airlines — has been taken out of service.
Sadly, many others who have encountered microbursts have not been so lucky.
In 1975, Eastern Airlines Flight 66 crashed while attempting to land during a thunderstorm at New York's John F. Kennedy International Airport.
According to the NTSB report on the crash, the Boeing 727-225 struck several light towers by the runway, caught fire and came to rest on a nearby road. 112 of the 124 passengers and crew on board the plane were killed.
The crash of Flight 66 was a watershed accident that forced experts to pay more attention to the dangers of microbursts, Smith said.
However, the most infamous crash attributed to a microburst took place 10 years later.
In August 1985, Delta Air Lines Flight 191 crashed on final approach at Dallas/Fort Worth International Airport. Like Flight 66 a decade earlier, Flight 191 was also attempting to land during a massive thunderstorm.
A microburst generated by the thunderstorm caused the Delta Lockheed L-1011 Tristar to strike the ground a mile short of the runway and careen across a highway. The jet then crash into a pair of massive water tanks before bursting into flames and disintegrating. 134 of the 163 passengers and crew onboard the plane were killed along with one driver whose car was struck by the jet.
With that said, fatal run-ins with microbursts are exceedingly rare thanks to modern warning systems.
"Both airports and planes are equipped with sophisticated windshear warning systems, and pilots are well-trained in how to stay clear of microbursts, and, if need be, recover from an encounter," Smith said. "If indeed the AA flight was victimized by a microburst or other shear, this is highly unusual nowadays."
