New rules proposed for heliport layout

 - March 8, 2007, 5:13 AM

The International Civil Aviation Organization (ICAO) is drafting new rules for heliport layout and construction in a revised Annex 14. The new rules propose changes to the size of the final approach and takeoff (FATO) area, visual cues and surrounding airspace. ICAO expects the rules to be in place next year.

According to Christelle Ruan, a technical advisor on ICAO’s heliport design working group, for helicopters weighing less than 7,000 pounds (the equivalent of Part 27 helicopters in the U.S.), the FATO area will be smaller. “Current rules call for the area to be able to include a circle, the diameter of which is one helicopter length, called D value,” Ruan explained. The new rules will reduce this number to one rotor-disc diameter.

In addition, the new rules do not require that the safety margin around the FATO area be load-bearing. This should translate into simplification and cost savings on rooftop helipads.

Another change involves the takeoff and liftoff area (TLOF). This area is usually located at the center of the FATO and its size is related to the length of the landing gear. Under the new rules, a TLOF can be outside the FATO, provided there is a taxiway in between. A TLOF can thus be in a parking area.

The new rules also change the requirements for visual cues. The change is the result of the smaller FATO for light helicopters. In that instance, the D value will be clearly marked. On a TLOF, the new touchdown positioning marking will be yellow and have a diameter of .5D. “The shapes of the markings are still being discussed,” Ruan told AIN.

The new rules also include lighting changes for night operations. The TLOF will be lighted in green “for better visual acquisition than today’s yellow,” Ruan explained. However, there will be no lighting in a TLOF that is situated in a parking area. Still to be determined is whether the white lighting of the final approach and takeoff area should change.

Discussions are ongoing, too, regarding the airspace surrounding a heliport. Several glideslope angles, probably ranging from 2.6 to 7.2 degrees, will be defined for obstacle limitation surfaces (OLS). “The outer end of the OLS must be 500 feet above ground level,” Ruan said. One OLS will be associated with one heliport. In addition, the two surfaces that define the takeoff and the landing flightpaths will be laid out freely, without the currently required 150-degree minimum between their two axes. In other words, at a given heliport, a helicopter might soon be able to land heading north and take off heading east, with only 90 degrees between the two directions.

Generally speaking, separation distances on the ground have been replaced by protection envelopes. Also, to design a heliport, the architect will no longer be required to have a particular helicopter in mind. Rather, he will be allowed to use a “design helicopter” that can merge the characteristics of a number of different rotorcraft.

These rules are targeted at helicopters with one main rotor. In addition, they apply only to land-based heliports; offshore platforms and ship helipads are not affected.