Introduction
On 25 August 2011, Chinook HC Mk 3 ZH898, callsign Pegasus 2, departed RAF Odiham at 1335 hours as part of a two-aircraft formation. The aircraft was crewed by two student pilots, two student crewmen, a Qualified Helicopter Instructor (QHI), a Qualified Helicopter Crewman Instructor (QHCI), and a service passenger. The sortie was a programmed training mission for the Operational Conversion Flight (OCF) syllabus, aimed at introducing student crews to tactical formation at low level, including descents to 50 feet above ground level (AGL).
Crew Details
The QHI, who served as captain of ZH898, had 1,792 total flying hours, with 166 instructional hours. The QHCI had 2,340 total flying hours, with 22 hours of instructional time. The student handling pilot at the time of the incident had 3,600 total flying hours, including 78 hours on Chinooks. The non-operating student pilot had 329 total flying hours, with 81 on Chinooks. The No. 1 student crewman had 188 total flying hours, and the No. 2 student crewman had 193 total flying hours.
Sortie Background
The formation planned to fly to Abingdon airfield via a training field, conduct a crew change, and reverse the route back to RAF Odiham. The outbound leg was flown without incident. After the student crew change at Abingdon, Pegasus 1 led the formation on the return leg. The weather was clear, with visibility greater than 10 kilometers and cloud base above 3,000 feet. The formation operated at heights between 80 and 100 feet AGL, with ZH898 offset to the left of the lead aircraft.
Incident Sequence
At approximately 1455 hours, near Uffington (Grid SU296892), the formation transited in a southwesterly direction. Two horse riders were on a minor road; one rider wore a high-visibility jacket. The riders heard the first aircraft pass north of them, then heard a second aircraft approaching but could not see it due to a tall hedgerow. ZH898 directly overflew the riders' position. The non-operating student pilot, seated in the forward starboard door, observed a rider fall from a horse and suffer serious injuries.
Post-Incident Actions
The aircraft captain immediately directed the handling pilot to climb to 1,000 feet AGL and advised Pegasus 1 to climb to 500 feet. He stored the approximate grid location using the Control Display Navigation Unit and requested the No. 2 crewman plot it. ZH898 returned to the site at 1,000 feet to confirm. Seeing the fallen rider being attended to, the captain transmitted a radio message to Benson Approach requesting emergency services. He then terminated the sortie and led the formation back to RAF Odiham at 1,000 feet. The crew made hot statements, and the sortie authorization sheets and charts were impounded.