How it's made

The new RNAV(GPS) Runway 34 instrument approach was a cause for celebration because pilots arriving on an instrument flight plan no longer had to use the RNAV(GPS)-A circling approach, which has higher minimums and too often resulted in a diversion to another airport.

Although one might think the FAA creates all instrument procedures, that’s not always true. In the case of Merrill Field, Hughes Aerospace Corporation, a private-sector air navigation services provider, not only designed and validated the Runway 34 approach, it also created two new RNAV approaches to Runway 7, and an instrument departure procedure.

“We probably have developed close to a thousand procedures,” said Hughes CEO Chris Baur. “We work throughout the United States and overseas. We do work for the Air Force, the Coast Guard, the air ambulance industry. We also donate a lot of time to help the FAA come up with better ways to navigate.” 

Baur has been an airline pilot for 30 years and is a longtime general aviation pilot and AOPA member passionate about protecting and expanding GA’s ability to fly in the national airspace system. “The work that we do is not just a private enterprise,” said Baur. “A lot of what we do benefits GA and benefits pilots because we fight to keep airports open. We work with the FAA to come up with criteria for an aircraft that gives them better accessibility where they don’t have to dive over terrain or approach a runway at an oblique angle. A lot of these approaches, it’s not just the approach, it’s the missed approach that makes it dangerous.”

The airport manager at Merrill Field contacted Hughes looking for help to develop a new instrument approach. “They had this 1930s circling approach and wanted to get a better approach,” said Baur.

Hughes worked with local air traffic control to determine what airspace was available to design a new procedure. Baur quickly realized the airport had never defended its airspace from obstacles. “If you don’t have an instrument procedure at an airport, you don’t own the airspace in and around it,” said Baur. “And that allows the FAA to give a positive determination to a proponent to put an obstacle near your airport, like right at the end of your runway or your heliport.” Hughes monitors more than 100,000 obstacles each year for airports at which the company has developed instrument procedures. “We fight a little bit harder, maybe, than the FAA does to prevent obstacle proliferation around airports,” he said. “In the case of Merrill Field, they allowed buildings to go up in downtown Anchorage, like the Sheraton hotel, that impacts the procedures. It limits you, and you have to get very creative about what you can build.”

Because of the penetrations and the offset approach required, Hughes designed an LP (localizer performance) approach to get the lowest altitude minimums to Runway 34—429 feet. Visibility minimums required further study. Baur explained an airport with a parallel taxiway can have minimums down to three quarters of a statute mile. An approach lighting system can bring the minimums down to half a mile. At Merrill Field it was the runway protection zone (RPZ) for Runway 34 that dictated visibility minimums of one mile; less than one mile would have changed the RPZ requirements.

Hughes also designed an LPV (localizer performance with vertical guidance) approach for Runway 7. “That is for the flight school,” said Baur. “The airport manager said it would save the students a lot of time and money because they have to get a precision approach [for their training]. The FAA counts an LPV for an ILS. So, they asked us, ‘could you build an LPV so the students could train here?’ And we did.” The minimums for this approach are higher at 648 feet and 1-7/8 mile because of the “penetrations and the vertical surface,” he said. “But we were able to mitigate those with a steeper glide path limiting to category A and B aircraft. So, this gave the flight school a procedure that they could train.” 

Hughes maintains the 1,000 instrument flight procedures it has developed for airplanes and helicopters. “There are four elements of that maintenance cycle,” said Baur. “Daily obstacle checks. You don’t have to do daily, but that’s what we do. Daily notam service. So, Hughes issues FAA notams, you wouldn’t know the difference. Then you’ve got the 540-day check, which is where we fly over the final and the missed approach point.” Here Baur said they are looking for any obstacles that weren’t captured by the FAA’s obstruction evaluation/airport airspace analysis (OE/AAA) system. “And then every 24 months we do a biannual review where we deconstruct the procedure and rebuild it to current criteria and incorporate things like magnetic variance changes,” he said.

Baur said the timeframe to develop an instrument procedure is typlically between one year and 18 months.

“This initiative not only demonstrates Hughes commitment to delivering the latest navigation technology to Alaska,” said Baur, “but also ensures Merrill Field remains a vital link in Alaska’s aviation network.”

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