Major hazard risk indicators for monitoring of trends in the Norwegian offshore petroleum sector

Minimization of passenger takeoff and landing risk in offshore helicopter transportation: Models, approaches and analysis

“…Notice that (1) implies that at least m flights will be needed in order to pick up all p(N ) people.…”

“…The flight starts from a heliport 0, then visits installation π(1), followed by installation π (2), and so on, the last visited installation is π (h), after which the helicopter returns to the heliport. The helicopter starts with no passengers, lands at installation π(1), picks p π (1) passengers, flies to installation π (2), lands there with p π(1) passengers on board, picks additional p π (2) passengers, and so on. It can be observed that the flight takes off from installation π(k), 1 ≤ k ≤ h − 1, and lands at the next installation π(k + 1) with k j=1 p π(j) passengers on board.…”

“…If p(N ) + p(N ) ≤ Q, then we can take group N as group N . Otherwise, the total pickup demands of the remaining 2m − 2 groups is less than p(N ) − p(N ) + p(N ) ≤ (m − 1) Q, and at least one of them must have the total pickup demand of at most 1 2 Q, and that group can be taken as group N . To see that in the worst case the value of 2m − 1 cannot be reduced, take an instance of the problem with 2m − 1 installations, each of pickup demand m, so that p(N ) = m (2m − 1) and Q = 2m − 1.…”

“…For a flight schedule S SP T (m), at least one flight is capacity-feasible due to (1). Denote the number of infeasible flights by u, where 1 ≤ u ≤ m − 1.…”

“…They experience heaviness and weightlessness during takeoff and landings, heavy noise, strong vibrations, and even sometimes incidents or accidents. Vinnem et al [1] claim that the hazards associated with helicopter transportation of personnel are among the main risks experienced by offshore employees.…”