Goldenhawk
28th Jul 2002, 11:28
Folks,
Currently operating a Bell 407, Is there any guidance available regarding minimum FATO dimensions for the helicopter?
Thx for any help.
Is this in UK? If so, here's a bit from the Heli Pilot's Handbook regarding Pleasure Flying Sites. You should be able to match the figures with the FM. If you want a diagram, just email me.
Phil
The Operational Area, which is under positive control of the Company, encompasses the Landing Site, the taxiways, HAAs and IAAs (see below for definitions) and takeoff, climb and approach slopes. It has side surfaces rising upwards and outwards to 100 feet at a gradient of 1:1 from its edges, unpenetrated by obstacles and will be fenced, roped off or otherwise protected from intrusion by unauthorised persons—therefore it should not include a public right-of way. Rope and stakes used for demarcation and public control are not considered obstacles for this purpose, though they may for performance planning).
Final Approach and Takeoff Area (FATO)
This is inside the Safety Area (see below), where the final phase of the approach to hover or landing is completed, and from which takeoff is commenced. It may be square or circular and the minimum size is 1½ x the rotor diameter (for dimensions of popular helicopters see later).
Safety Area (SA)
Surrounds the FATO, for reducing damage to helicopters accidentally diverging from it. It is also square or circular, according to the FATO, and the minimum size is 3m or ¼ of the rotor diameter, whichever is the greater. It must be free from obstacles. The combined size of the FATO and SA should be at least twice the overall length, including rotors, of the helicopter and, where it contains the TLOF (see below), the surface should be firm and not blow away with downwash.
Touchdown and Liftoff Area (TLOF)
A load bearing area for touch down and lift off; it should be free from slopes, to ease passenger embarkation and disembarkation, and not have them walking uphill into tail rotors. The TLOF has a diameter of at least twice the length of the helicopter, including rotors, and is normally contained within the FATO (it's the same minimum size), but may be separate.
Taxiways
Used where the TLOF is remote from the FATO, with a minimum clearance of 1 rotor diameter from obstructions either side of the rotor disc (that is, a minimum overall width of 3 rotor diameters, or 33.9m for the Bell 47).
Helicopter Acceleration Area (HAA)
Should have a minimum width of 30m or twice the overall length of the helicopter, whichever is the greater, obstacle-free and long enough to accommodate one third of the "Takeoff Distance to 100 feet" (168m—Bell 47) given in the Flight Manual (therefore 56m). The surface should be substantially level so a helicopter can land safely if an engine fails, without risk of injury to the occupants or third parties.
Takeoff Area (TA)
At the upwind end of the HAA, with the same width and at least twice the length, and free from significant obstacles. The minimum Takeoff Distance Available (Helicopters) (TODAH) should be greater than the Takeoff Distance Required to achieve a height of 100 feet, e.g. more than the HAA and TA combined. The total length of the TODAH is therefore about 168m.
Note: Performance figures here are for the Bell 206B for +20oC and 1000 feet PA at max AUW (hot Bank Holidays).
The Takeoff Area and downwind two-thirds of the IAA may contain insignificant or frangible obstacles only. The remainder should be obstacle-free (rope and stakes used for demarcation and public control are not considered to be obstacles).
Inner Approach Area (IAA)
For each direction of landing, has the same width as the HAA and accommodates the Landing Distance Required from 100 feet as detailed in the Flight Manual. The upwind third of the IAA should be completely free from obstacles. The minimum Landing Distance Available (Helicopters) (LDAH) should exceed the Landing Distance Required from 100 feet.
Note: The TODAH and the IAA are essentially the same patch of ground, except the TODA is slightly longer. As both the HAA and the upwind third of the IAA must be obstacle-free and are at opposite ends of this area, the whole TODA should be obstacle-free in the first place.
Side Surfaces and Slopes
The Operational Area will have side surfaces rising upwards and outwards to 100 feet at a gradient of 1:1 from the edges of the HAA, Takeoff Area or IAA which will not be penetrated by any obstacle, fixed or transient. It will also be fenced, roped off or otherwise protected from intrusion by unauthorised persons, and therefore should not include an unguarded right of way. Takeoff, climb and approach slopes (which may be curved) must not be over large areas of water unless you can land safely on it in emergency. They should be obstruction-free with a gradient of not less than 1:8 and be 1000m long, possessing areas suitable for emergency landing.
Phil