NOTE.
Road flares are an intense source of ignition and may be unsuitable or dangerous in certain conditions. In any case, they must be closely managed and firefighting equipment should be present when used. Other light sources are preferred, if available.
Federal Aviation Administration Twentieth Edition
TBL ENR 6.2.3
Table of Common References for Estimating Wind Velocity
Wind (Knots) Wind Classification Appearance of Wind Effects
On the Water On Land
Less than 1 Calm Sea surface smooth and mirror.like Calm, smoke rises vertically
1.3 Light Air Scaly ripples, no foam crests Smoke drift indicates wind direction, wind vanes are still
4.6 Light Breeze Small wavelets, crests glassy, no breaking Wind felt on face, leaves rustle, vanes begin to move
7.10 Gentle Breeze Large wavelets, crests begin to break, scattered whitecaps Leaves and small twigs constantly moving, light flags extended
11.16 Moderate Breeze Small waves 1.4 ft. becoming longer, numerous whitecaps Dust, leaves, and loose paper lifted, small tree branches move
17.21 Fresh Breeze Moderate waves 4.8 ft taking longer form, many whitecaps, some spray Small trees in leaf begin to sway
22.27 Strong Breeze Larger waves 8.13 ft, whitecaps common, more spray Larger tree branches moving, whistling in wires
28.33 Near Gale Sea heaps up, waves 13.20 ft, white foam streaks off breakers Whole trees moving, resistance felt walking against wind
34.40 Gale Moderately high (13.20 ft) waves of greater length, edges of crests begin to break into spindrift, foam blown in streaks Whole trees in motion, resistance felt walking against wind
41.47 Strong Gale High waves (20 ft), sea begins to roll, dense streaks of foam, spray may reduce visibility Slight structural damage occurs, slate blows off roofs
48.55 Storm Very high waves (20.30 ft) with overhanging crests, sea white with densely blown foam, heavy rolling, lowered visibility Seldom experienced on land, trees broken or uprooted, “considerable structural damage”
56.63 Violent Storm Exceptionally high (30.45 ft) waves, foam patches cover sea, visibility more reduced
64+ Hurricane Air filled with foam, waves over 45 ft, sea completely white with driving spray, visibility greatly reduced
EXAMPLE.
Wind from the South.East, estimated speed 15 knots. Wind shifted from North.East about fifteen minutes ago, and is gusty.
3.7.1.2 If chemical light sticks may be used, care should be taken to assure they are adequately secured against being dislodged by the helicopter’s rotor wash.
3.7.1.3 Another method of marking a LZ uses four emergency vehicles with their low beam headlights aimed toward the intended landing area.
3.7.1.4 A third method for marking a LZ uses two vehicles. Have the vehicles direct their headlight beams into the wind, crossing at the center of the LZ. (If fire/rescue personnel are available, the reflective stripes on their bunker gear will assist the pilot greatly.)
3.7.2 At night, spotlights, flood lights and hand lights used to define the LZ are not to be pointed at the helicopter. However, they are helpful when pointed toward utility poles, trees or other hazards to the landing aircraft. White lights such as spotlights, flashbulbs and hi.beam headlights ruin the pilot’s night vision and temporarily blind him. Red lights, however, are very helpful in finding accident locations and do not affect the pilot’s night vision as significantly.
3.7.3 As in Day LZ operations, ensure radio contact is accomplished between ground and air, if possible.
3.8 Ground Guide
3.8.1 When the helicopter is in sight, one person should assist the LZ Coordinator by guiding the helicopter into a safe landing area. In selecting an LZ Coordinator, recognize that medical personnel usually are very busy with the patient at this time. It is recommended that the LZ Coordinator be someone other than a medical responder, if possible. Eye protection should be worn. The ground guide should stand with his back to the wind and his arms raised over his head (flashlights in each hand for night operations.)
3.8.2 The pilot will confirm the LZ sighting by radio. If possible, once the pilot has identified the LZ, the ground guide should move out of the LZ.
3.8.3 As the helicopter turns into the wind and begins a descent, the LZ coordinator should provide assistance by means of radio contact, or utilize the “unsafe signal” to wave off the helicopter if the LZ is not safe (see FIG ENR 6.2.8). The LZ Coordinator should be far enough from the touchdown area that he/she can still maintain visual contact with the pilot.
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