Flight Details
On 3 June 2012, at approximately 1545 hours, a Boeing MD-83 registered as 5N-RAM, operated by Dana Airlines (Nig.) Limited as Flight 0992 (DANACO 0992), crashed into a densely populated area of Iju-Ishaga, a suburb of Lagos, Nigeria. The domestic scheduled commercial flight originated from Abuja (ABV) and was destined for Lagos (LOS). All 153 persons on board, including six crew, were fatally injured, and six ground fatalities were confirmed. The aircraft was destroyed by impact and post-crash fire.
Sequence of Events
The flight was the fourth segment of the day, consisting of two round trips between Lagos and Abuja. It arrived in Abuja as Dana Air Flight 0993 at approximately 1350 hours. After routine turnaround, engine start was initiated at 1436 hours. The aircraft was cleared to taxi and subsequently took off from Runway 04 at 1458 hours, reporting a fuel endurance of 3 hours 30 minutes. At 1518 hours, the crew contacted Lagos Area Control Centre and reported an estimated arrival time of 1545 hours at cruising altitude of 26,000 ft.
The Cockpit Voice Recorder (CVR) captured about 30 minutes 53 seconds of the flight, beginning at 1513:44 hours. At that time, the captain and first officer were discussing a non-normal condition regarding correlation between engine throttle setting and power indication. They did not voice immediate concerns. As the flight descended from cruise at 1522 hours, concerns grew. At 1527:30 hours, the first officer suggested landing on Runway 18R, which was approved by radar control at 1531:49 hours. At 1531:12 hours, the crew confirmed no throttle response on the left engine, and the captain assumed control as pilot flying. The flight continued without declaring a distress message. Power indication issues persisted, and at 1532:05 hours, thrust loss on the No. 1 engine was observed.
During final approach, the crew deployed slats, flaps, and landing gear. At 1541:46 hours, the first officer asked, "both engines coming up?" The captain replied "negative." The crew then agreed to declare an emergency. At 1542:10 hours, a Mayday call was made: "dual engine failure ... negative response from throttle." The crew attempted to continue the approach, retracting flaps and landing gear at the captain's instruction. At 1543:27 hours, the captain stated, "we just lost everything, we lost an engine. I lost both engines." Over the next 25 seconds, they attempted to recover engine power without reference to any checklist. The aircraft crashed approximately 5.8 miles north of Lagos airport, impacting an uncompleted building, two trees, and three other buildings. The wreckage was concentrated at coordinates N 06° 40.310' E 003° 18.837' at an elevation of 177 ft.
Probable Cause
The official investigation identified probable causal factors: 1. Engine number 1 lost power seventeen minutes into the flight, and engine number 2 lost power on final approach, failing to respond to throttle movement for increased power. 2. Inappropriate omission of the use of the checklist, and the crew’s inability to appreciate the severity of the power-related problem, followed by failure to land at the nearest suitable airfield. 3. Lack of situation awareness, inappropriate decision making, and poor airmanship. Tear-down of the engines revealed that the No. 1 engine, overhauled in the U.S. in August 2011, was not in compliance with Service Bulletin SB 6452. Both engines had fractured, cracked, bent, twisted, or pinched primary and secondary fuel manifold assemblies, leading to fuel leaks, fuel discharge to the bypass duct, loss of engine thrust, and failure to respond to throttle movements.