The assault on the weight-based ordinance at Minden-Tahoe Airport has started again. The county is attempting to convince the public that the Federal Aviation Administration is forcing the county into increasing the allowable weight from 30,000 pounds and 50,000 pounds to 60,000 pounds for single-wheel and 75,000 pounds for dual-wheel aircraft, which is a substantial change (100 percent) over the present ordinance. The county hired an engineering company to perform a weight study after the last runway overlay was completed even though no study was required by the FAA.
In January 2008, Doug Johnson, then-chairman of the board of county commissioners asked a local civil engineer, experienced in airport pavement design and also serving on the Airport Advisory Committee, to evaluate the 2002 and 2005 pavement capacity studies.
His findings, published in a report that was submitted to the county commissioners, pointed out the failings of these earlier studies, including failure to follow the FAA guidelines for such work and flawed statistical analysis. His report concluded that with a proper interpretation of the test results, the better airport pavements were no stronger than the loading for which they had been designed (360 annual operations of a 50,000 pound dual wheel airplane). Because of age and usage, the capacity of many of the aprons and taxiway segments were below this design value.
As a result of this report a midwestern engineering firm was hired by the county to re-evaluate the earlier reports. This third study, which focused only on the one principal runway, conceded the earlier reports were wrong, and reduced the capacity of runway 16-34 from the 125,000-pound wheel loading to 75,000 pounds. Our local engineer, who was not allowed to interface with the engineers of this third study, found similar statistical errors in this third study, which invalidates their conclusions. He also pointed out to the board of commissioners that the pavements of the aprons and taxiways, not the runways determine the bearing capacity of an airport.
This airport was designed to support operations in the 30,000 pound/50,000 pound range on a daily basis and it should remain so until the voters, who are owners of the airport, decide to increase the weight bearing capacity to support a higher weight class of airplanes. Any excess weight will damage the asphalt and repairs will cost taxpayers money.
The blatant disregard of the ordinance when a Boeing business jet (Boeing 737), at a maximum takeoff gross weight of 171,000 pounds, was allowed to use our airport is unconscionable and should be grounds for removal of the persons that granted the permission. Allowing this category of jets to use our facility causes irreparable damage to our runways and taxiways and must be stopped. If you agree with the above discussion you should contact your county commissioner or the county manager and make your views known and vote your views in the 2010 election.
This whole confrontation with the FAA can be avoided if the county would send a letter to the FAA stating the weight reports submitted were seriously flawed (as shown by the report from the local engineer) and the county will construct a new ordinance but it will remain at 30,000 and 50,000 pounds in accordance with the attached engineer's report. The new ordinance will be on the 2010 ballot and pending voter's approval will become an enforceable Douglas County ordinance and the FAA documents will be updated to agree with the ordinance. The county has backed itself into this corner by falsely believing a 4-inch runway overlay can increase the bearing capacity of the Airport by 100 percent. The county must be made to consider doing the right thing and realistically accept the current weight limit and rewrite the Ordinance accordingly.
Jon E. Hannan is a Minden glider pilot and retired FAA test pilot.
