API RP 2L-2006 pdf download.Recommended Practice for Planning, Designing, and Constructing Heliports for Fixed Offshore Platforms.
4 Planning 4.1 GENERAL 4.1.1 This section serves as a guide for the design and construction of heliports on offshore platforms. Adequate planning should be performed before actual design is started in order to obtain a safe and practical heliport with which to accomplish the design objective. Initial planning should include all criteria pertaining to the design of the heliport. The safety departments of the helicopter companies can provide valuable assistance during the planning phase. 4.1.2 In planning the heliport, consideration should be given to the helicopter’s gross weight, landing load distribu- tion, rotor diameter, overall length, and landing gear config- uration, as well as ground cushion area and the number of helicopters to be accommodated by the heliport. 4.1.3 Design criteria presented herein include operational requirements, safety considerations, and environmental aspects which could affect the design of the heliport. 4.2 HELICOPTER SELECTION Considerations for selecting the helicopter for heliport design are: a. Distance from onshore staging areas or helicopter bases. b. Proximity to other offshore heliports, on either satellite structures or adjacent field structures. c. Status as to whether the platform is manned or unmanned and with or without living quarters. d. Helicopter transportation requirement for the platform. e. Crew change requirements. f. Night helicopter needs, whether routine service, medical removal, or emergency evacuation. g. Environmental conditions. 4.3 OPERATIONAL CONSIDERATIONS The following are the operational considerations: 4.3.1 Function The function of the heliport should be classified as either single-helicopter or multi-helicopter operation although a heliport designed for one large helicopter may accommo- date two smaller helicopters if the minimum clearance requirements are met.
18.104.22.168 Approach-Departure Zone This zone should be free from obstruction for at least 180 degrees beginning at the base of the ground cushion area and extending outward and upward on an 8 to 1 slope (8 out- ward to 1 upward). See Figure 1. For design considerations, a properly parked helicopter on a multi-helicopter heliport does not constitute an approach and departure obstruction. 22.214.171.124 Obstruction Free Zone This zone should include an area outward to one-third RD greater than diameter OL and also should extend one-third RD beyond the edge of the approach and departure zone. See Figure 1. 4.3.3 Size Heliport size should depend on platform configuration and equipment arrangement, platform orientation, obstruc- tion clearances, the selected helicopters to be utilized, and prevailing environmental conditions. The heliport ground cushion area should cover a circle of at least one main rotor diameter for helicopters operating at maximum gross weight. See Figure 2. For tandem rotor helicopters, or in harsh environmental areas (such as the Gulf of Alaska), the dimensions of the ground cushion area should equal or exceed the OL of the limiting helicopter. When ground cushion area is less than one RD (or OL for tandem rotor helicopters or in harsh environments), the approach and departure zone should be extended to 360 degrees, and heli- copters landing or taking off from such a heliport should be restricted to less than the certified maximum takeoff weight. For multi-helicopter heliports, the heliport should be of sufficient size to allow for the OL of the operating helicop- ter plus at least one-third the main RD clearance to any por- tion of a properly parked helicopter with its main rotor secured (see Figure 3).
4.3.4 Orientation Orientation of the heliport should be determined by the platform configuration, equipment arrangement, and pre- vailing wind. 4.3.5 Access and Egress The location of access and egress stairways or ladders should be determined from platform configuration, equip- ment arrangement, and safety objectives. One primary access and egress route should be provided. When possible the access and egress routes should be outside the approach and departure zone.