AIM  8/15/19 NOTE − It is recommended that communications be established a minimum of 10 minutes prior to planned arrival time. This practice may be a requirement of some offshore owner/operators. NOTE − 1. See subparagraph 10 − 2 − 1d for Tanker Operations. 2. Private use Heliport. Offshore heliports are privately owned/operated facilities and their use is limited to persons having prior authorization to utilize the facility. 1. Background. Standardized procedures can enhance the safety of operating a second helicopter on an offshore helideck, enabling pilots to determine/maintain minimum operational parame- ters. Orientation of the parked helicopter on the helideck, wind and other factors may prohibit multi − helicopter operations. More conservative Rotor Diameter (RD) clearances may be required under differing condition, i.e., temperature, wet deck, wind (velocity/direction/gusts), obstacles, approach/ departure angles, etc. Operations are at the pilot’s discretion. 2. Recommended Practice. Helideck size, structural weight capability, and type of main rotor on the parked and operating helicopter will aid in determining accessibility by a second helicopter. Pilots should determine that multi − helicopter deck operations are permitted by the helideck owner/ operator. (a) Minimum one − third rotor diameter clearance ($^{1}$/$_{3}$ RD). The landing helicopter main- tains a minimum $^{1}$/$_{3}$ RD clearance between the tips of its turning rotor and the closest part of a parked and secured helicopter (rotors stopped and tied down). (b) Three foot parking distance from deck edge (3’). Helicopters operating on an offshore helideck land or park the helicopter with a skid/wheel assembly no closer than 3 feet from helideck edge. (c) Tiedowns. Main rotors on all helicopters that are shut down be properly secured (tied down) to prevent the rotor blades from turning. (d) Medium (transport) and larger helicopters should not land on any offshore helideck where a light helicopter is parked unless the light helicopter is property secured to the helideck and has main rotor tied down. (e) Helideck owners/operators should ensure that the helideck has a serviceable anti − skid surface. 4. Weight and limitations markings on helideck. The helideck weight limitations should be displayed by markings visible to the pilot (see State of Louisiana “Offshore Heliport Design Guide” and FAA AC 150/5390 − 2A, Heliport Design Guide). NOTE − Some offshore helideck owners/operators have restrictions on the number of helicopters allowed on a helideck. When helideck size permits, multiple (more than two) helicopter operations are permitted by some operators. 1. Background. Helicopter Rapid Refueling (HRR), engine(s)/rotors operating, can be conducted safely when utilizing trained personnel and observing safe practices. This recommended practice provides minimum guidance for HRR as outlined in National Fire Protection Association (NFPA) and industry practices. For detailed guidance, please refer to National Fire Protection Association (NFPA) Docu- ment 407, “Standard for Aircraft Fuel Servicing,” 1990 edition, including 1993 HRR Amendment. NOTE − Certain operators prohibit HRR, or “hot refueling,” or may have specific procedures for certain aircraft or refueling locations. See the General Operations Manual and/or Operations Specifications to determine the applicable procedures or limitations. (a) Only turbine − engine helicopters fueled with JET A or JET A − 1 with fueling ports located below any engine exhausts may be fueled while an onboard engine(s) is (are) operating. (b) Helicopter fueling while an onboard engine(s) is (are) operating should only be conducted under the following conditions: (1) A properly certificated and current pilot is at the controls and a trained refueler attending the fuel nozzle during the entire fuel servicing process. The pilot monitors the fuel quantity and signals the refueler when quantity is reached. 10 − 2 − 6 Special Operations l. Two (2) Helicopter Operations on Offshore Helidecks 3. Recommended Criteria 2. Recommended Practices m. Helicopter Rapid Refueling Procedures (HRR)