According to CAT.POL.H.110-Obstacle accountability:

(a) For the purpose of obstacle clearance requirements, an obstacle located beyond the FATO, in the take-off flight path, or the missed approach flight path shall be considered if its lateral distance from the nearest point on the surface below the intended flight path is not further than the following:

(1) For operations under VFR:

(i) half of the minimum width defined in the AFM — or, when no width is defined, ‘0,75 × D’, where D is the largest dimension of the helicopter when the rotors are turning;

(ii) plus, the greater of ‘0,25 × D’ or ‘3 m’;

(iii) plus:

(A) 0,10 × distance DR for operations under VFR by day; or

(B) 0,15 × distance DR for operations under VFR at night.

(2) For operations under IFR:

(i) ‘1,5 D’ or 30 m, whichever is greater, plus:

(A) 0,10 × distance DR, for operations under IFR with accurate course guidance;

(B) 0,15 × distance DR, for operations under IFR with standard course guidance; or

(C) 0,30 × distance DR for operations under IFR without course guidance.

(ii) When considering the missed approach flight path, the divergence of the obstacle accountability area only applies after the end of the take-off distance available.

NOTE:

• Where DR is the distance travelled from the end of TODAH.
• Where D is the largest dimension of the helicopter when the rotors are turning.
• Standard course guidance includes automatic direction finder (ADF) and VHF omnidirectional radio range (VOR) guidance.