Introduction
On November 21, 2004, a Bombardier DHC-8-402, registration JA841A, operated by Air Nippon Network Co., Ltd. as All Nippon Airways Flight 1617, experienced a serious incident upon landing at Kochi Airport. The aircraft departed Osaka International Airport at 13:51 JST and was scheduled to arrive at Kochi Airport under instrument flight rules. There were 19 occupants on board: a pilot in command, three other crewmembers, and 15 passengers. The pilot in command served as pilot flying, seated in the left seat, while the first officer acted as pilot not flying.
Flight History
According to data from the digital flight data recorder and cockpit voice recorder, as well as air traffic control communications and crew statements, the following sequence occurred. At 14:19:02, Kochi Tower cleared the aircraft to land on Runway 32, reporting wind from 020 degrees at 14 knots. At 14:23:11, the tower updated the wind to 010 degrees at 14 knots.
The aircraft crossed the runway threshold at 37 feet radio altitude and 122 knots CAS at 14:24:16. The right main wheels touched down at 112 knots CAS and 108 knots GS at 14:24:25, followed by the left main wheels at 110 knots CAS and 106 knots GS one second later. The rudder began moving slowly to the left, but the aircraft’s heading started drifting to the right. The nose wheels touched down at 93 knots CAS and 89 knots GS at 14:24:29, but became airborne again one second later. By 14:24:31, rudder deflection reached approximately 18 degrees to the left, but the heading continued to drift right. The nose wheels touched down again at 14:24:34, at which point the master caution light illuminated and an aural warning sounded. The pilot in command began moving the power lever to reverse; the aircraft speed was 70 knots CAS and 67 knots GS. The first officer applied left wheel brake at 14:24:37 at 61 knots CAS and 58 knots GS. Vertical accelerations of 1.3 to 0.7 G were recorded as the aircraft slowed. The pilot terminated propeller reverse at 14:24:43 at 30 knots GS, and the first officer stopped brake application at 14:24:44 at 25 knots GS. The right propeller speed began decreasing three seconds later, followed by the left propeller speed.
At 14:24:57, the pilot applied left wheel brake. The aircraft came to a stop at approximately 14:24:59 with a heading of about 324 degrees. At 14:25:02, the pilot requested a towing tractor due to steering trouble. The pilot announced to passengers that the aircraft had stopped due to steering trouble and would be towed; passengers were asked to remain seated with seatbelts fastened. The master caution light extinguished at 14:25:43.
Post-Landing Events
The first officer suggested recycling the nose wheel steering switch and using right engine power to return to the runway pavement. At 14:26:29, the pilot recycled the steering switch. The aircraft began advancing at 14:27:12, and the first officer reported to the tower that nose wheel steering had returned to normal and that the aircraft would taxi to the parking spot via Taxiway T-4. However, the aircraft stopped again at 14:27:23 with a heading of 305 degrees. At 14:28:50, the pilot informed the company’s operation support staff that the aircraft had run off the runway due to steering trouble and requested a towing tractor.
All passengers deplaned between 14:42 and 14:44. The runway was closed until 17:16 that day due to the incident.
Crew Statements
The pilot in command stated that he received a briefing from the dispatcher at Osaka International Airport with no mention of weather or aircraft problems, and found nothing abnormal during the walk-around inspection. The ground mechanic reported no issues. The pilot taxied without problem and flew to Kochi Airport. After the runway was in sight, he requested a visual approach and received landing clearance. He was informed of reported downdrafts on short final and decided on a target speed of 118 knots (10 knots above VREF of 108 knots for 46,000 pounds). He aligned with the runway centerline at 1,500 feet, lowered gear, set flaps 15 degrees, and placed the condition lever to MAX. With crosswind from the right, he used the crab method initially, then switched to wing-low method near the threshold. He landed on the touchdown zone markings with the right main gear first, followed by the left main and nose gear. On short final, the PAPI showed three red and one white light. After main gear touchdown, he placed the power lever in flight idle then disc position. He attempted to maintain runway centerline with rudder control, but the aircraft deviated. He applied full rudder, but the heading continued to drift right.