Incident Overview
On August 3, 2009, at approximately 0355 eastern daylight time, Continental Airlines flight 128, a Boeing 767-224 registered as N76156, experienced severe turbulence while en route from Rio de Janeiro, Brazil (GIG) to Houston Intercontinental Airport (IAH), Houston, Texas. The aircraft was operating as a Title 14 CFR Part 121 international passenger flight with 179 passengers and crew on board. At the time of the event, the flight was at an altitude of about 36,500 feet, roughly 67 nautical miles north of Bavaro, Dominican Republic, and visual meteorological conditions prevailed.
Flight Crew Accounts
The captain reported that the aircraft had been cleared to climb from 36,000 feet to 38,000 feet. Upon reaching 36,500 feet, the airplane encountered severe turbulence lasting approximately five seconds. The climb continued to the assigned altitude of 38,000 feet with the autopilot engaged throughout. The captain noted that both weather radars were functioning normally and the seat belt sign was illuminated before, during, and after the event. The relief first officer, who was the pilot flying, stated that after entering the desired altitude in the autopilot system, the airplane initiated the climb and then the severe turbulence occurred. He observed no indications of precipitation on the weather radar display.
Cabin Crew and Passenger Experience
The lead flight attendant, stationed in the rear of the airplane, reported that the flight had been smooth despite the seat belt sign being illuminated for some time. A few minutes after 0350, he felt two to three very large jolts lasting about three seconds. After the turbulence ceased, a passenger who had been returning to her seat from the rear was found unconscious and bleeding on the deck. Another passenger, an emergency medical technician, attended to her while the lead flight attendant consulted with the captain. The captain declared a medical emergency and diverted to Miami, Florida, where the aircraft landed approximately one hour and 40 minutes later.
Injuries and Aircraft Damage
Multiple injuries were reported, and several individuals were transported to the hospital upon arrival in Miami. Following medical assessment, none of the injuries were determined to be serious. Postincident examination of the airplane revealed no evidence of substantial damage.
Flight Data Recorder Analysis
The flight data recorder (FDR) was read out at the NTSB Recorder Laboratory in Washington, DC. The data showed that as the aircraft began a climb from 36,000 feet, vertical acceleration changed from 1.0 g to 2.0 g's in one second, oscillated between 2.0 g's and 0.9 g's for seven seconds, returned to 1.0 g, and then immediately accelerated to -1.0 g in 0.5 seconds. The autopilot was engaged throughout, consistent with crew statements.
Meteorological Conditions
An NTSB meteorological specialist conducted a weather study. A tropical easterly wave with a general northwest to southeast orientation was located near the incident location. Satellite imagery indicated isolated, rapidly developing cumulus congestus to cumulonimbus clouds under the airplane’s flight path at the time. No pilot reports near the location and time of the turbulence encounter were on record. The operator’s weather document for the flight showed no predicted turbulence activity at the time of the event.