|Date||August 24, 2001|
|Type||Fuel exhaustion in flight, fuel leak|
|Site||Lajes Air Force Base, Terceira Island, Azores, Portugal|
|Aircraft type||Airbus A330-243|
|Flight origin||Toronto Pearson International Airport, Toronto, Ontario, Canada|
|Destination||Portela Airport, Lisbon, Portugal|
Unknown to the pilots, the aircraft had developed a fuel leak in a fuel line to its right engine. During the course of the flight, the pilots had noticed a fuel imbalance between the fuel tanks in the left and right wings of the aircraft and had attempted to remedy this by opening a cross-feed valve between the tanks. This caused fuel from the operational tank to be wasted through the leak in the engine on the other side.
Without fuel, an aircraft’s engines cannot provide thrust or electrical power. On the Airbus A330, an emergency ram air turbine is deployed automatically to provide essential power for sensors and instruments to fly the aircraft.
When the engines suffered a flame out important systems became unavailable. Specifically, the aircraft lost its main hydraulic power which operates the flaps, brakes, and spoilers. Additionally, an aircraft without operating engines cannot use its thrust reversers to slow the plane after touchdown.
The pilots of the Airbus A330 were able to glide the aircraft to a landing at Lajes Air Base, Terceira Island in the Azores. The reported landing speed was about 200 knots Indicated airspeed(or IAS), which is higher than the normal speed of 130 to 145 knots IAS. There were no fatalities, but there were minor injuries. The favorable outcome was also due to the flight being rerouted on a more southerly route across the Atlantic to prevent congestion, bringing them closer to the Azores.
Sequence of events
Flight TS 236 took off from Toronto at 0:52 (UTC) on Friday August 24, 2001 (local time: 8:52 p.m. (EST) on Thursday August 23 2001). It made an emergency landing at 6:46 a.m. (UTC) on August 24 2001, at Lajes Airport, Terceira, Azores, Portugal.
There were 293 passengers and thirteen crew members on board. The aircraft was an Airbus A330 manufactured in 1999, configured with 362 seats and placed in service by Air Transat in April 1999. Leaving the gate in Toronto, the aircraft had 47.9 tonnes of fuel on board, 5.5 tonnes more than required by regulations.
At 04:38 UTC (estimated), a fuel leak started in the area of engine no. 2 (right engine).
At 05:16 UTC, a cockpit warning systems chimed and told of low oil temperature and high oil pressure on engine no. 2. There is no obvious connection between an oil temperature or pressure problem and a fuel leak. At first, Captain Piché and co-pilot DeJager suspected these warnings were computer bugs and communicated with their Maintenance control center.
At 05:36 UTC, the pilots received a warning of fuel imbalance and diverted fuel from the port (left side) wing tanks to the starboard tanks, which were showing close to empty. Because the fuel leak in the starboard engine had still not been diagnosed, this diversion had the effect of sending fuel to the leak and causing further loss.
At 05:48 UTC, an Emergency was declared with Santa Maria Oceanic air traffic control because of fuel shortage.
At 06:13 UTC, 28 minutes after the emergency declaration, engine no. 2 on the right wing flamed out, exhausted of jet fuel. Captain Piché then ordered full thrust from engine no. 1 on the left wing, and the plane descended to 30,000 feet (9,150 metres), unable to stay at cruising altitude with one engine.
At 06:23 UTC, Mayday was declared with Santa Maria Oceanic air traffic control.
At 06:26 UTC, engine no. 1 flamed out.
Without engine power, control of the aircraft depended on the last backup, a ram air turbine, which supplied limited power to hydraulic and electrical systems. While Piché flew the plane, DeJager monitored its descent rate — around 2000 feet (600 metres) per minute — and calculated that the plane had about 15 to 20 minutes left before they had to ditch the plane in the water.
The crew flew the plane a few more minutes, until sighting the air base. Piché then had to execute a series of 360 degree turns to lose altitude. Although they successfully lined up with Runway 33, they faced a new danger. The plane was on a final descent, going faster than normal. Although they had unlocked the slats and deployed the landing gear, the airspeed was 200 knots, compared to the preferable 130-140 knots.
At 06:45 UTC, or 02:45 EST, after 19 minutes without engine power, the plane touched down hard 1,030 feet down Runway 33 with about 200 knots (370 km/h). The aircraft bounced back into the air but touched down again 2,800 feet from the approach end of the runway and came to a stop 7,600 feet from the approach end of the 10,000 foot runway. With the operation of the emergency brakes, several tires burst. Fourteen passengers and two crew members suffered minor injuries during the evacuation of the aircraft. Two passengers suffered serious, but not life-threatening injuries.