An Avianca Boeing 787-800, registration N786AV performing flight AV-88 from Buenos Aires Ezeiza,BA (Argentina) to Bogota (Colombia), was climbing out of Ezeiza’s runway 29 when the crew reported problems with the slats, stopped the climb at FL150, dumped fuel and returned to Ezeiza for a safe landing on runway 35 at a higher than normal speed (about 170 knots over ground) about 75 minutes after departure.
Slats are aerodynamic surfaces on the leading edge of the wings of fixed-wing aircraft which, when deployed, allow the wing to operate at a higher angle of attack. A higher coefficient of lift is produced as a result of angle of attack and speed, so by deploying slats an aircraft can fly at slower speeds, or take off and land in shorter distances. They are usually used while landing or performing maneuvers which take the aircraft close to the stall, but are usually retracted in normal flight to minimize drag.
The flight was cancelled.
The aircraft remained on the ground for about 23 hours, then positioned to Bogota.