FAA proposes guidelines for marking meteorological towers

January 26, 2011

AOPA is supporting an FAA proposal to set guidelines for the marking and lighting of proliferating meteorological evaluation towers (METs).

The FAA has asked for comments by Feb. 4 on revisions of the 64-page Advisory Circular 70/7460-1K, “Obstruction Marking and Lighting,” that would address METs. The FAA recommends adopting guidelines for METs that currently apply to other structures including “the alternate bands of aviation orange and white paint for skeletal framework of storage tanks and similar structures, and towers that have cables attached.”

“The FAA also recommends spherical and/or flag markers be used in addition to aviation orange and white paint when additional conspicuity is necessary,” said the notice. In addition, the FAA asked for comments on adding new guidance for use of high-visibility sleeves to marking standards in an effort to create “a uniform and consistent scheme for voluntarily marking” METs.

The FAA said the towers are set up by individuals and companies searching for new sources of renewable energy to measure the suitability of sites for the construction of wind turbines. Once the METs are up, tests last about a year.

“These towers are erected in remote and rural areas, often are less than 200 feet above ground level (AGL), and fall outside of FAA regulations governing tall structures and their impact on navigable airspace,” said the FAA’s public notice of the proposed revisions.

AOPA supports the plan and urges members to take advantage of the opportunity to bring about safety enhancements for general aviation.

“The proliferation of meteorological evaluation towers poses a significant safety hazard to many types of aeronautical operations. The towers are very difficult to see and in some conditions are virtually invisible, e.g. a background of snow cover or other light colored surface,” wrote Tom Kramer, AOPA manager of air traffic services in AOPA’s letter with formal comments submitted Jan. 21.

Members can submit comments online, referring to docket number FAA-2010-1326, by Feb. 4.