History of Flight
On May 10, 2012, at 1224 Eastern Daylight Time, an Airbus A319, registration N951FR, operated by Frontier Airlines as flight 384, encountered turbulence during descent into Fort Lauderdale-Hollywood International Airport. The flight originated from Denver International Airport at 0710 Mountain Standard Time. At the time of the encounter, the aircraft was descending through 12,400 feet, approximately 45 miles west of Fort Lauderdale, on the JINGL1 Standard Terminal Arrival Route.
The crew reported noticing typical Florida summertime buildups on initial descent and turned on the seat belt sign early. About 20 minutes before the turbulence, the captain briefed flight attendants to be seated early. As the aircraft descended through 25,000 feet, the seat belt sign was illuminated. Weather radar was set to "Weather Only" with a range of 80 nautical miles. At 1219, ATC instructed the crew to maintain 300 knots or greater for spacing. At 1224, descending through 13,000 feet near JINGL intersection, the aircraft experienced a "short moderate jolt" lasting 5–10 seconds. The cockpit voice recorder captured the first officer remarking about an isolated cloud. The crew reported they had just emerged from another cloud when they saw the large buildup. Flight data recorder showed approximately +2/-0.5 G excursion. Autopilot and autothrust were engaged; no manual inputs were made. The crew reported no weather returns on radar.
After the encounter, the crew heard a crash in the galley. The forward flight attendant, while securing the galley, was thrown to the floor and twisted her legs in the lavatory door opening. The captain requested no delay and paramedics from ATC. ATC provided priority clearance, but upon arrival at the gate, no paramedics were present. The ramp controller confirmed injuries and paramedics arrived shortly thereafter.
Injuries to Persons
One flight attendant sustained a fracture to her right fibula. Two other flight attendants reported minor injuries but continued cabin duties. No injuries occurred to the two flight crew members or the 138 passengers, including one lap child.
Damage to Aircraft
Post-flight severe turbulence inspection by Frontier Airlines maintenance found no damage to the aircraft.
Personnel Information
The captain, age 40, held an FAA Airline Transport Pilot certificate with type ratings in A320 and BE-1900, and a first-class medical certificate. He reported 7,586 total flight hours in the A319.
The first officer, age 41, held an Airline Transport Pilot certificate with type ratings in A320, BE-300, CE-500, and CE-525S, and a first-class medical certificate. He reported 4,837 total flight hours in the A319.
Aircraft Information
N951FR, serial number 4127, was an Airbus A319-112 equipped with two GE/SNECMA CFM-56 engines. The airframe had approximately 7,408 total hours. No relevant maintenance issues were recorded.
Meteorological Information
NTSB meteorological analysis using Miami WSR-88D radar (KAMX) at about 1220 EDT identified a small area of light reflectivity (<15 dBz) about 30 miles ahead of the aircraft. At the aircraft's location, the 1.51-degree sweep showed a height of about 10,000 feet. By 1226 EDT, reflectivity intensified, consistent with developing convection. A vertical cross-section at 1226 EDT indicated the highest reflectivity (~35 dBz) reached approximately 12,000 feet. No other mechanisms for significant turbulence were identified.
The Airbus weather radar system includes a turbulence detection function, which was not used. The flight crew training manual recommends specific mode, range, and tilt settings for detecting convective turbulence.
Communications
After the encounter, the flight crew could not establish communication with company dispatch or station personnel to alert emergency crews. The call to ATC for paramedics was not coordinated with tower or other personnel.
Flight Recorders
The digital flight data recorder (Honeywell SSFDR) and cockpit voice recorder (Honeywell 6022) were in good condition and data were extracted normally. The CVR recorded 2 hours of audio; the last 30 minutes of captain and first officer channels were of fair quality.
Survival Aspects
The seat belt sign was illuminated, and cabin crew were still preparing the cabin for landing at the time of the event.