FAA Navigable Airspace
Tree Height Solutions That Are Green & Safe
Trees and airplanes do not interact well, as the below three stories make clear. To assure safety around airports, the FAA has defined a set of standards to create protected airspace. 14 CFR Part 77 establishes a number of imaginary surfaces around the runways. The calculation of these dimensions at an actual airport is not simple and requires great precision.
The basic obstruction evaluation is just the first step in addressing the FAA’s high safety standards. Invariably, this initial iteration identifies issues and in response to that analysis, the regulators are likely to issue a negative declaration. To find a win/win solution requires expertise on the airspace geometry, the flight alternatives and procedures which will satisfy the FAA need to minimize the risks.
All three of the below cases involve, trees and the interference caused by their heights. Detailed analyses might be able to develop options which limit the cutting of the trees and which do not interfere with flight. Solutions may involve factors like:
- the terrain surrounding the airport
- the operating capabilities of the aircraft,
- the prevailing winds/weather/visibility,
- the length/breadth/strength of the runway,
- the configurations of the airport, particularly in reference to the winds/weather/visibility,
- the availability/competence/sightlines of an AT Tower, and
- the flying population (only as to the private airport).
1. Spruce Creek Fly-In
The runway at the Spruce Creek Fly-In has the right stuff again now that trees which had interfered with safety zones around the airfield have been either removed or trimmed.
Circuit Judge Michael S. Orfinger approved an agreement last month which stated that the Spruce Creek Property Owners Association was required by the community’s own articles of incorporation to trim and cut any trees that had grown too tall for the safety zones around the runways.
The judgement also requires the association to promptly take all reasonable action to restore night use of the runway. The too-tall trees had prompted the FAA to strip the airport of its night GPS approach.
2. Dillant-Hopkins Airport
On the guided walk, which followed a public meeting about the Dillant-Hopkins Airport’s new forest management plan, the foresters explained how thousands of pine trees will be removed from land in the Edgewood Forest within the next few months.
By removing pine trees in an 8-acre area of the forest that’s in line with one of the airport’s flight paths, airport director John G. “Jack” Wozmak hopes to eliminate a safety hazard for pilots.
According to Wozmak, the pines, which consistently reach heights of about 80 feet, make it difficult for pilots to land safely at night.
“Sixty to seventy feet is about as high as you’d want a tree to be in the flight path,” he said in an interview with The Sentinel.
Wozmak said he created the forest management plan alongside the foresters to handle the airport’s needs while prioritizing the sustainable development of the 300 acres of city-owned forest land surrounding it.
He said he hopes to launch it and begin with the removal of pine trees before the end of the year.
3. Bowman Field
Tree cutting aimed at protecting pilots would have adverse historical impact in area near Bowman Field.
The federal government’s go-to body on historic preservation has faulted the Federal Aviation Agency’s conclusion that tree cutting near Bowman Field runways would have no adverse impacts.
The Advisory Council on Historic Preservation in a Nov. 3 letter to the FAA urges the FAA and local airport officials develop a more robust plan to offset damage to the historical character of neighborhoods where some tree cutting has already occurred and more is planned for this winter. The council said FAA and the Louisville Regional Airport Authority should enter into formal consultation with state and local officials and others, including the group Plea For Trees, which has has been pressing for a thorough historical and environmental review of the tree-cutting plan.
“The FAA will give full consideration to the (council’s) advisory opinion as well as all other pertinent facts and perspectives before reaching a final decision,” said FAA spokeswoman Kathleen Bergen in a written statement.
It appears that all three of these cases are too late in the process to benefit from an iterative review of the airfield and possible solutions. As/if the tree v. plane conflict develops, with proper O/E analysis, it may be possible to develop solutions which minimize green damage and safety risks.