Sometimes, the phrase "perfect storm" refers to a rare combination of events that leads to disaster. Other times, it describes similarly unusual circumstances that create an amazing outcome. Surprisingly, a recent runway safety area project at Monterey Regional Airport (MRY) met both definitions at various points.
One month into the $52 million initiative, the central California airport was sued by a land-use watchdog group called the Highway 68 Coalition. The citizen group argued that the project's environmental impact report didn't adequately address alternatives and greenhouse gas emissions. It also alleged that construction of a new access road was a steppingstone to help the airport build a 45-acre office and industrial park on its north side.
Project: Runway Safety Area Enhancement
Location: Monterey (CA) Regional Airport
Cost: $52 million
Funding: FAA (95%); Passenger Facility Charges & Airport Improvement Program grants (5%)
Unique Challenge: Runway is landlocked & located on a plateau
Dirt Moved: 390,000 cubic yards
Consultant Team: Coffman Associates; Kimley-Horn and Associates
Engineered Material Arresting Systems: Zodiac Arresting Systems (Zodiac Aerospace)
Airfield Lighting: ADB Airfield Solutions
Of Note: Project was delayed 2 yrs. by lawsuit from local citizen group; airport adjusted site plans to address traffic concerns by keeping service road on airport property instead of connecting it to nearby highway
"There are 30 days for a plaintiff to sue, and on the 30th day, they sued," recalls MRY Project Manager Chris Morello. "The project was stopped by the courts and subsequently held up for two years."
When the 498-acre, four-airline airport finally reached a settlement agreement with the Highway 68 Coalition, it had just 18 months to comply with the new federal requirement that requires all commercial airports to have runway safety areas (RSAs) to stop aircraft from overrunning or veering off their runways. Despite the significant delays, MRY met the December 2015 deadline.
Personnel from program manager Kimley-Horn and Associates attribute the on-time, under-budget finish to a perfect storm of people working well together. "All of the stakeholders-the airport board, the airport manager, the contractor and the FAA-checked their egos at the door," says Kevin Flynn, vice president/practice builder for Kimley-Horn. "Everybody was committed to the project and working to resolve issues and challenges in order to get it done on time."
Work began in 2014 to make the airport's primary runway, 10R-28L, meet the FAA's dimensional standards for RSAs (a requirement originally mandated by Congress via House Resolution 3058). Specifically, airports must have a 500-foot
wide RSA that extends 1,000 feet beyond the end of each runway, with a graded area to stop aircraft from overrunning or veering off the sides.
A team from Kimley-Horn and Jim Harris, president of Coffman Associates, conducted extensive environmental studies and presented several solutions before the airport district approved a project that met MRY's needs and satisfied the conditions of its lawsuit settlement.
Due to a perfect storm of site constraints, there simply wasn't enough room for 1,000 feet of safety enhancement on each end of Runway 10R-28L airport. So the airport opted to use an engineered material arresting system (EMAS) to create an acceptable RSA.
For starters, the runway is essentially landlocked by development on both sides. Further upping the project's degree of difficulty, the airport also rests on a plateau. On one side, the plateau drops approximately 30 feet to a military-owned golf course. On the other side, it drops about 80 feet to a shopping center situated below. For yet another challenge, the plateau was missing a considerable size triangular piece on the east end.
Because the FAA requires airports to improve RSAs to the "extent practicable," engineers proposed a number of ways to resolve the issue, notes Flynn. Options included shifting or shortening the runway, building up the plateau's missing corner from below, and constructing a bridge or cantilever extension of the plateau. "We developed and evaluated the alternatives with Coffman Associates to determine which would be feasible, and to put an approximate cost on those alternatives," he recounts. "After that, we worked with the FAA to figure out how much they would pay for each alternative and if they agreed with them."
Ultimately, officials decided the best approach was to re-construct the missing corner of the plateau. A cantilever bridge was deemed too expensive; and shortening the runway wasn't an option, because the existing length was needed to accommodate current airport users. "Building up the corner was constructible and feasible, and the FAA agreed to support it," informs Flynn.
Morello notes that the original project proposal included a 7,008-foot runway, but it had to be shortened 8 feet to meet requirements of the lawsuit settlement. That left the runway at 7,000 feet, the airport's minimum length.
Adding an EMAS cost $12.5 million-95% of which was paid for with FAA funds and 5% with Passenger Facility Charges and Airport Improvement Program grants.
Moving Dirt & Mitigating Impact
Keeping the airport in operation as work progressed was a key consideration throughout the project. (MRY serves approximately 400,000 passengers annually.)
Because construction crews were working in front of the Instrument Landing System (ILS), work had to be phased to keep the instrument approach available during operational hours. This required nighttime closures with very tight windows for construction crews and airlines alike, notes Morello. The contractor started work after MRY's last commercial flight (at 11:30 p.m.) and finished before the first commercial flight the next morning (at 5:30 a.m.). "We were able to accommodate commercial flights as long as they were on schedule; but if they had any delays, they might not be able to land," she says.
To ready the area for construction, crews removed trees and shrubs, modified an existing gate to provide an entrance and exit along Highway 68 for construction equipment, and constructed barriers along the north side of the highway to minimize traffic disruptions. They then built up retaining walls to support the plateau and EMAS bed, and relocated the vehicle service road.
The airport addressed traffic concerns raised in the Highway 68 Coalition lawsuit by adjusting plans to keep the service road for the project on airport grounds rather than connecting it to Highway 68 as originally proposed. "We pulled back our retaining walls and made them a little taller (10 feet)," explains Morello. "By having one less retaining wall, we were able to pull back enough to keep the vehicle service road on airport property."
The service road, originally planned with two lanes to facilitate emergency vehicles, was also reduced to one lane to help everything fit.
"By keeping the road entirely on airport property, we were able to move forward on the project," Morello says. "Doing this required us to redesign the project slightly. Most of it stayed the same, but the retaining walls were changed slightly." In total, crews installed more than 135,000 square feet of retaining walls.
After the retaining walls were completed, crews landscaped the hillside with 366 trees and 4,200 native plants. "The airport is along a scenic highway," Flynn explains. "We did everything we could to mitigate the impacts of construction."
The dirt used to rebuild the missing corner of the plateau was dirt captured as crews relocated the service road. Throughout the project, crews moved 390,000 cubic yards of dirt (230,000 cubic yards from cuts, 160,000 from fills).
"It was a very creative solution to minimize the impacts of moving dirt," observes Flynn. "Had we not been able to design it the way we did, we would have been exporting about as much dirt as we had to import."
In order to create space to install an EMAS bed for 10R-28L, MRY had to move the runway 425 feet to the east and add retaining walls supported with new earthen fill. Zodiac Arresting Systems provided the EMAS, which was custom designed for the specific variables of MRY's challenging site using computer models. Andrea Manning, sales and marketing regional director at Zodiac, notes that the company bases EMAS designs on factors such as available space, runway length, elevation and fleet mix.
"We use all that information to design an EMAS bed that is as long, wide and with varying depth of material to efficiently stop the aircraft using that runway," she explains. Typically, the company provides several designs, so airport officials can assess which one makes the most sense for their budget and project needs.
"We have over 110 systems installed worldwide, and each one is custom," says Manning. "Each one is designed specifically for a particular runway. When there are multiple installations, such as we had at Monterey, you have unique EMAS designs for each one."
With the airport's new EMAS in place, Morello is resting easier, knowing that MRY successfully met the federal deadline for runway safety area improvements. In addition, the airport's new system has a 20-year design life, and repairs should only be needed if a runway incursion occurs. Should that happen, crews will simply need to remove and replace the damaged EMAS blocks, notes Manning.
"We didn't have a choice but to complete this project," notes Morello. "It was congressionally mandated [for all commercial airports]." But it was also a project the airport wanted to undertake, she adds. "Our focus is always on making the airport safer; that's our mantra. This project helped us meet new standards and make an already safe airport safer."