[BC] Proposed new tower regs.

[RichardBJohnson at comcast.net]

--------------------
FAR Sec. 91.119 - Minimum safe altitudes: General.

Except when necessary for takeoff or landing, no person may operate an aircraft below the following altitudes:

(a) Anywhere. An altitude allowing, if a power unit fails, an emergency landing without undue hazard to persons or property on the surface.

(b) Over congested areas. Over any congested area of a city, town, or settlement, or over any open air assembly of persons, an altitude of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft.

(c) Over other than congested areas. An altitude of 500 feet above the surface, except over open water or sparsely populated areas. In those cases, the aircraft may not be operated closer than 500 feet to any person, vessel, vehicle, or structure.

(d) Helicopters. Helicopters may be operated at less than the minimums prescribed in paragraph (b) or (c) of this section if the operation is conducted without hazard to persons or property on the surface. In addition, each person operating a helicopter shall comply with any routes or altitudes specifically prescribed for helicopters by the Administrator. 
--------------------

That is the law. Gliders often land in small patches of land and are later towed to an airport on a trailer. Free balloons operate at any altitude, as do aircraft in distress.

That said, guy-wires are invisible from the air, against the texture of the surface. That is why towers above a certain height are "marked" and illuminated. Marking means painting with alternate bands of a specific color of "aviation orange" and "aviation white." 

Newer regulations required "registration" of towers. A registered tower appears on aviation charts and non-registered towers do not. This means that a new tower, 199 feet AGL or less will not appear on an aviation chart or on ATC's Radar. An aircraft in distress might just try to land in the field where the four-tower directional array exists because it may look from the air like a decent clearing, aligned into the wind and it does not show any obstructions on a chart. This is not an exaggeration. As a flight instructor, I have often caught even experienced pilots selecting clearings created for high-tension power lines as emergency landing areas during simulated engine-out scenarios. Wires and towers are very difficult to see in times of stress.

The specific height used to be 150 feet. It was raised some time ago to save money. WDEW's Westfield, MA, tower was 149 feet so it did not require a light. However, it still needed to be "marked," i.e., be painted with the appropriate colors. Times have changed where lobbying has allowed broadcasters and other tower users to save money. If this continues, soon only towers owned by Amateur Radio Operators will need to be marked and illuminated.

Cheers,
Richard B. Johnson
Book: http://www.AbominableFirebug.com/

----- Original Message -----
From: "Mike McCarthy" <towers at mre.com>

I have specific experience with a medical aircraft collision.  The vast
majority of impacts to structures is by rotary air craft.  Not fixed wing.
 There are the rare exceptions, but they're few and far between.  I think
the last fixed wing craft collision was in Texas or Goergia by a military
jet about 10 years ago.  And even then, it was well more than 1000ft. up.