Public Comment Period Runs Through February 7

The Coast Guard was a little quick last year to propose pulling the plug on the loran. The Aircraft Owners and Pilots Association (AOPA) objected, advising that the government should "look before it leaped" on shutting down a system that still might play an important role in the nation's navigation and airspace surveillance system.

So now the Coast Guard is taking a more studied approach. It's asking for public comments by February 7 on the future of loran.

"But the first question we have to answer is what kind of complementary system we need for GPS," said AOPA President Phil Boyer. "Once we know that, we can then make an intelligent decision about loran-C or deploying enhanced loran."

The issue becomes particularly important in the future as the FAA decommissions many VORs and radar systems, and transitions to ADS-B as the primary surveillance system for air traffic control.

Because ADS-B requires GPS to report an aircraft's position to ATC, a GPS failure could leave pilots without electronic navigation and air traffic controllers blind unless an alternative positioning system were available.

Even with WAAS, the government has yet to develop procedures to ensure that GPS is available for aeronautical operations 100 percent of the time. Today's single-frequency system has some degree of vulnerability to accidental or intentional interference.

"General aviation needs robust positioning systems that ensure we can always navigate in instrument conditions, including making approaches to most airports," said Boyer. "We have that today with GPS and VORs."

But the FAA's long-range plan is to decommission most VORs. And for the future, VORs can't provide aircraft position information to the ADS-B system. An enhanced loran system is one alternative for backing up GPS for ADS-B and system navigation.

"Until a long-term GPS-only strategy is determined, loran should continue operating," said Boyer. "Whatever backup system is selected, it must be affordable, and GA pilots must be allowed a minimum of 15 years to transition to the new system."

As Aero-News reported, UK-based Trinity House, a company that provides maritime navigation aides throughout England, issued a request for proposals in December for an enhanced long-range navigation system -- dubbed eLoran -- for pilots. That system is receiving close scrutiny in the US, as well.

FMI: www.aopa.org, www.faa.gov