Palomar Airport: The Runway Extension Study: The County Position, Blog #41

Soon I will comment on the Palomar Runway Extension Study [RES] that the County just released.   To see the RES, go to the County airport website.  See http://www.sdcounty.ca.gov/dpw/airports/palomar.html.   

On Thursday,  August 15, 2013 the Palomar Airport Advisory Committee [PAAC] may ask the County Board of Supervisors to accept the RES report.  Below is my edited version of the County’s Agenda Item 6 Board letter.

“Background

McClellan-Palomar Airport (Airport), located in the City of Carlsbad, is a County-owned airport with a single 4,897-foot runway.   On June 14, 2011, at the request of airport lessees and aviation stakeholders, and with the support of key members in the cities of Carlsbad, Escondido, Oceanside, San Marcos and Vista, the County Board of Supervisors directed staff to prepare a report with scope, costs and timeline for a study that would thoroughly examine the feasibility, benefits and drawbacks of a runway extension.

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Feasibility Study for Potential Improvements to McClellan-Palomar Airport Runway

This feasibility study …  evaluated various options and alternatives of runway improvements that would increase safety, reduce airport noise, improve operational efficiency, enhance business prospects, and consider environmental impacts  … .

Potential West End Safety Improvements 

“ … [T]he feasibility study recommends enhancing the safety of the area beyond the west end of the runway, regardless of any other runway improvements, by installing a 315-foot Engineered Material Arresting System (EMAS). EMAS is comprised of energy absorbing materials that will reliably and predictably stop an errant aircraft with a speed of up to 70 knots from overrunning the runway, and allow the aircraft to slow and come to a stop with minimal damage. …  The estimated cost for this project is $25.4 million. As a safety project, this is eligible for FAA grant funds and would rank high according to FAA priorities. It’s reasonable to anticipate a future grant, if awarded, would provide 90% of the cost from the FAA, with 10% local share from the County.

Potential East End Runway Extension 

A major factor in determining extension alternatives for the east end of the runway is the impact of solid waste from an inactive landfill in this area. According to the scope for the feasibility study, any extension also needs to be eligible for FAA funding in order to be considered feasible. Because of continued subsidence issues, the FAA will not fund a project built directly over landfill.

Structural Stabilization Options – The feasibility study also identified and evaluated multiple landfill stabilization options, specifically, how well each option addressed current and future settlement, construction impacts to airport operations, and initial and future lifecycle costs. The recommended option for airfield stabilization is to install drilled displacement columns (DDC) supporting lightweight fill and asphalt concrete pavement.   …

Extension Alternatives – In addition to viable options for landfill stabilization, the feasibility study also put forth three alternatives for extending the runway: a 200-foot extension; a 900-foot extension; and a 1,200-foot extension. The 1,200-foot extension was determined to be unfeasible because it would require other changes to the airport that are not practical.

The feasibility study determined the 200-foot and 900-foot extensions each could be viable options. Estimated cost for the 200-foot extension is $22.5 million. There are two versions of the 900-foot extension. If built with one taxiway on the north side only, a 900-foot extension would cost $49.6 million. Taxiways constructed on both the north and south sides of the runway extension would allow better access, but require additional work, including installation of a retaining wall to accommodate the south taxiway. Cost for the 900-foot extension with both taxiways is estimated at $69.7 million.

The feasibility study has determined these alternatives for runway extensions would be eligible for FAA funding, but would be considered capacity projects rather than safety projects. The FAA gives capacity projects a lower priority for grant funding. If an FAA grant were to be awarded for a runway extension, it is probable a much larger local share of the project cost would be required. For example, the FAA might agree to provide 50% of costs if matched with local share of 50%. For this reason, ultimate selection of a preferred alternative will determine FAA funding availability.

The 900-foot runway extension with north and south taxiways is identified in the feasibility study as the preferred solution, because it meets the long-term needs of the airport. An extension could be built in phases or all at one time. If adequate FAA funding is not available for the 900-foot runway extension options, the 200-foot runway extension satisfies the immediate needs of the airport, with minimal impact to the landfill- impacted area. This would still allow an additional 700-foot extension to be completed in the future.”