One-Stop Shop for Everything Heliports
Let's Get Started
Helipad Size
Design Aircraft
Perhaps the most basic element of helistop design is ensuring that it meets applicable dimensional clearances, obstruction clearances, load bearing and fuel retention criteria. These clearances are generally based on a “design helicopter,” the largest helicopter expected to land at the facility on a regular basis. In some cases, the design helicopter may be a composite of critical criteria from two or more aircraft.
TLOF
The physical landing pad is known as the touchdown and liftoff area (TLOF). The TLOF size will depend on the design aircraft. The minimum TLOF surface size is one main rotor diameter which, of course, varies with the design helicopter size.
FATO
The final approach and takeoff area (FATO), an obstruction-clearance surface surrounding the TLOF, is a horizontal plane in the surrounding airspace. The FATO sizes would be 66 feet, to meet the FAA Guidelines.
Safety Area
The FATO is surrounded by a “safety area”, also a horizontal surface at TLOF elevation. The minimum safety area is 1/3 the main rotor diameter of the design helicopter.
Flight Path
Obstruction Clearances
Obstruction clearance is one of the most critical factors in helistop design. The criteria have been established by the Federal Aviation Administration in concert with the helicopter industry. They are defined in Part 77, Objects Affecting Navigable Airspace, of the Federal Aviation Regulations. It is critical that any selected helistop site comply with the obstruction-clearance criteria from a permitting standpoint, but even more importantly, from operational safety and the Hospital’s liability standpoints. This means that we need to ensure that nearby objects (other buildings, power lines, trees, flag poles, etc.) will not penetrate the defined obstruction-clearance surfaces.
Approach/Departure Path
8:1 approach/departure surfaces along each identified flight path. Penetrations of these surfaces should not be allowed with unless pre-approved by the flight team as a non-risk.
Transitional Surfaces
2:1 transitional surfaces to the sides of each flight path. Penetrations of these surfaces should not be allowed with unless pre-approved by the flight team as a non-risk.
Prevailing Winds
Helicopters, like fixed-wing airplanes, gain performance and safety advantages by taking off and landing into the wind. Whenever possible, helistops should be located so that approach and departure flight paths can be aligned as closely as possible to prevailing wind directions. If this is not possible due to other factors, quartering headwinds are normally acceptable. However, from an operational safety standpoint, locations that only allow tailwind approaches or departures should be avoided.
Patient Transport Time
Logically, it makes sense to locate the helipad as close to where the patient, passengers, or cargo needs to go. A hospital, for example, can provide better results by locating the helipad as close to the emergency room as possible for faster service and less patient handling. When choosing a site for a ground helipad transport time must be balanced with enough distance to avoid disturbances and other issues where applicable, such as noise and debris from spinning rotor blades of the aircraft.
Cost
Additional Factors
Visibility
This factor tends to vary somewhat from one facility to another. Some prefer for their helistop to be prominently positioned to advertise to the public that they can provide this key rapid transport service. Others prefer that the helistop be somewhat hidden, especially if helicopter transports are controversial with nearby residents. In most cases, however, this is not a major concern one way or another and is overshadowed by the more significant factors listed above.
Secondary Functional Uses
In some cases, the siting of a helistop could preclude a facility from putting the selected area to other uses. This is more of a consideration for ground level helistops than for elevated facilities. With a ground level helistop, the owner must preserve not only the land specifically needed for the TLOF, FATO and safety area but also enough land to ensure that there will be no obstructions in the surrounding airspace. If it is only used sporadically and is part of a parking lot, there must be a plan in place to evacuate any pedestrians of vehicles when the aircraft is en route to the facility.
Neighborhood Concerns
Noise and safety are clearly concerns, although often overstated, of many members of the public who may have little direct personal experience with helicopters. It is important to satisfy neighbors’ concerns as they are the greatest reason for local denial of permits. Key strategies of course are to position the helistop so that it is not adjacent to residential neighborhoods and to minimize overflights of residential areas during approaches and departures.