Contract and Background
On 10 April 2017, an agreement (No. 07.04.17/55/3-07-01-50-17) was signed between Gazprom avia and the Oryol branch of Gazprom transgaz Moscow. Under this contract, on 15 May 2017, the crew of helicopter Ka-26 (registration RA-19552), consisting of a pilot-in-command and a flight engineer, flew from Kaluga Airport (Grabtsevo) to the Pleshcheyevo landing site in Oryol Region. The purpose was to perform pipeline survey flights for the Oryol branch. From 16 May 2017, three flight shifts were completed. The flight shift preceding the accident shift was performed on 23 May 2017.
Pre-Flight Activities on 24 May 2017
On 23 May 2017, a request for airspace usage on 24 May 2017 was submitted to the Moscow Regional Air Traffic Management Center, and permission was obtained for aerial work in Class C and G airspace. On 24 May 2017, at 05:00 (08:00 local time), the crew arrived at Pleshcheyevo. The pilot-in-command conducted a medical examination of the crew. At 05:30, clearance for flights was obtained by telephone from the Kaluga Approach Control. At 05:32, the pilot-in-command received meteorological information by telephone from the duty forecaster at the Kaluga Aerodrome Meteorological Station. At 05:40, the pilot-in-command delayed the start of flights (scheduled for 06:00) by telephone to Kaluga Approach because the representative from the Oryol branch (the customer) had not arrived. At 07:15, the customer's representative arrived. At 07:20, after the flight engineer reported to the pilot-in-command that the passengers (the customer and the engineer from the aerial patrol group of the Oryol branch—hereinafter referred to as the operator) had been briefed and seated in the passenger cabin, the crew took their workstations.
Flight
At 07:30, the pilot-in-command started the engines and instructed the operator via the intercom to activate the special equipment. After receiving confirmation that the equipment was ready for operation, the pilot-in-command taxied to the take-off area. At 07:40, the pilot-in-command took off and began flying along the assigned route. At 07:46, the helicopter was in contact with the Kaluga Approach Control.