The FAA published the following special conditions as part of the type certification basis for Robinson Helicopter Company Model R66 helicopters. The pressure refueling system must be designed and installed as follows:
- Each fueling connection below the fuel level in each tank must have the means to prevent the escape of hazardous quantities of fuel from that tank in case of malfunction of the fuel entry valve.
- For systems intended for pressure refueling, a means in addition to the normal means for limiting the tank content must be installed to prevent damage to the fuel tank in case of failure of the normal means.
- The rotorcraft pressure fueling system (not fuel tanks and fuel tank vents) must withstand an ultimate load that is two (2.0) times the load arising from maximum pressure, including a surge, that is likely to occur during fueling. The maximum surge pressure must be established with any combination of tank valves being either intentionally or inadvertently closed.
The complete issuance is available here. Contact your Robinson maintenance facility for more information.