Accident Overview
On March 5, 2014, a Cessna 172M Ram, registration JA3853, departed Nagoya Airfield at approximately 11:39 JST for an aerial photography flight toward the Omaezaki area. The aircraft struck a high-voltage power transmission tower located on a ridge in Sasahara-cho, Toyota City, Aichi Prefecture, at about 11:47. The impact destroyed the aircraft and scattered wreckage, triggering a post-crash fire. The captain and a passenger sustained fatal injuries.
Flight History
The flight plan filed with air traffic services specified visual flight rules (VFR) with a route via Okazaki, Toyohashi, Hamamatsu, and Omaezaki, and a return to Nagoya Airfield. Estimated off-block time was 11:40, cruising speed 90 knots, and total endurance 4 hours 30 minutes. The captain was advised by the flight information officer that Nagoya Airfield was under instrument meteorological conditions and the route weather was poor. The captain indicated he would depart under special VFR but did not specify en-route procedures. The aircraft actually took off under standard VFR after the airport reported visual meteorological conditions at 11:25.
GPS data showed the aircraft flew inland toward hilly terrain rather than following the filed route. Air traffic control communications recorded that at 11:33, ground control advised the captain of low clouds. The aircraft departed Runway 34 around 11:39, reported leaving the control zone at 11:43, and transmitted its final message at 11:43:35.
Witness Accounts
Several witnesses near the accident site observed the aircraft. Witness B, playing golf about 1,350 m north of the tower, saw the aircraft flying level from north to south at low altitude, then heard a collision sound as it entered cloud. The witness estimated altitude at about 60 m above trees. Witness C, also golfing, saw the aircraft nearly touching treetops at an estimated 20–30 m altitude; engine sound appeared normal. Witness D, about 870 m northeast, saw a gray aircraft with its left wing slightly down fly slowly above a hill and disappear behind trees before hearing the collision. Weather conditions were described as foggy, with low cloud, rain, and visibility under 230 m.
Aircraft and Tower Damage
The aircraft was destroyed and scattered. The power line tower sustained damage from the collision. A post-crash fire ensued.
Investigation
The Japan Transport Safety Board conducted the investigation with participation from an accredited representative of the United States as the state of design and manufacture. On-site examination, interviews, and GPS data analysis were performed. The wreckage was temporarily assembled and examined. Damaged tower parts were collated with aircraft parts.
Probable Cause
The Japan Transport Safety Board determined that it is highly probable the aircraft collided with the tower because it flew below the minimum safety altitude while operating under visual flight rules from Nagoya Airfield toward the Omaezaki area. It is somewhat likely the aircraft flew below the minimum safety altitude in an attempt to maintain visual contact with the ground due to very poor visibility and low cloud conditions that day. It is also highly probable that the captain forced the flight despite being aware of the difficulty of maintaining visual meteorological conditions, because the schedule was tight.