Wires are by far the major threat we face as helicopter pilot and that is just one reason I advocate flying at higher altitudes. Here are some statics
1. 90% of wire strikes occur below 200 feet.
2. 70% of wire strikes occur below 100 feet.
3. Most wire strikes occur in daylight hours between 10am and 3pm.
4. 90% of wire strikes occur in CLEAR weather.
5. Most wire strikes occur in flat terrain (not mountainous)
6. In 60% of wire strikes victims failed to see the wire. The other 40% saw the wire, but forgot it was there.
7. 60% of wire strikes are fatal
8. 75% of wire strikes completely destroy the aircraft.
9. The US Army has shown that if you hit a wire at 40 MPH it will completely destroy a helicopter (they used a Hughes 500 in there experiment)
10. FARs don’t require antennas or towers below 500 feet to be marked. (AC recommend marking & lighting on anything over 200 feet. Most comply with that)
11. Cell phone and MET towers are built to 199 feet and are not required to be marked or lighted.
12. It has been estimated that 7000 towers are built per year. Most of which are not included on sectional charts.
13. Towers that have guy wires have at least 3 anchor points. The taller the structure the bigger the guy wire footprint. A 2000 foot tower has aproximently a 1-mile footprint.
14. Guy wires are rarely marked.
15. Wires are very difficult to see. Size and material types make it more difficult to identify. Backgrounds, lighting and contrast greatly change the ability to see a wire.
16. As you fly lower, wire sizes gets smaller and are much harder to see.
1. Fly above 500 feet
2. Cross power lines at the Tower
3. Avoid fly below ridge lines in valleys or rivers
4. Keep well clear of the airspace around any tall tower
5. Learn to read wire & tower hardware
6. When flying at lower altitudes, slow down
7. Continually scan out side the helicopter by moving your head.
8. If you have passengers or crew, teach them what to look for and have them verbalize what and where they see the item.
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