It could be years, not months, before there is a comprehensive solution to the 5G C-band radar altimeter interference problem, FAA Administrator Steve Dickson warned the House Aviation Subcommittee yesterday. Dickson said the ultimate solution is to develop new standards for radar altimeters and that the FAA is working with the RTCA in that regard and hopes to settle on a new standard early next year.
Dickson and his agency withstood a pointed day of critical hearings on the subject, absorbing barbs from both subcommittee members and aviation industry representatives. The Federal Communications Commission (FCC), which auctioned the C-band frequencies to the wireless carriers, opted not to participate in the hearings, but wireless industry trade association CTIA did.
Dickson blamed the ongoing struggle to issue an ever-growing flurry of alternative means of compliance (AMOC) approvals for aircraft, radar altimeters, and airports to more than 1,500 notams dealing with C-band radar altimeter interference to the lateness with which the FAA received relevant data from the two chief 5G C-band wireless carriers, AT&T and Verizon. But he also soft-pedaled criticism of those companies.
Dickson noted that the companies considered the data proprietary and required non-disclosure agreements before surrendering it, adding, “We’re asking them for data that they’ve never had to provide to the government before.” But he favorably characterized current cooperation from the wireless carriers and said they are even participating in current test flights in FAA aircraft to determine the impact of interference on moving aircraft.
The FAA chief downplayed the impact of C-band interference on general aviation aircraft, claiming, “You’re usually not going to see a general aviation airport with that kind of capability [low visibility IFR Category II & III approaches]. It’s very expensive infrastructure to put in place because you’ve got to have a certified flight crew, certified airplane, and certified runway with approach lights—a lot of very expensive infrastructure. This is usually not what you’ve got at a GA airport.”
Dickson’s assurances appeared unconvincing to several subcommittee members, including Rep. Peter DeFazio (D-Oregon), chairman of the full Transportation Committee, who excoriated the government agencies involved, as well as the wireless carriers. “Having a dropped call is way less serious than having a dropped airplane out of the sky,” DeFazio said. “We don’t really regulate telecoms anymore, and that’s why we have the crappiest cell phone service in the world.”
DeFazio noted that other countries had made far better progress on integrating 5G C-band and aviation safety. “Everybody else has taken measures to protect aviation, but we didn't until the last minute. And it's a temporary agreement and something has to be worked out long term in the next six months. As they [wireless carriers] deploy more of these [C-band] towers, they want to put them right in the flight path.”
Both the Air Line Pilots Association (ALPA) and the Regional Airline Association (RAA) also took issue with the status quo and expressed concerns about future 5G C-band rollout and aviation safety. ALPA president Joe DePete said the 5G Notams and AMOCs created increased pilot workload and injected “more complexity and more risk into already complex fight operations” and had already produced flight cancellations and delays.
DePete noted that 5G C-band deployments in Europe and the U.S. are not comparable and intimated that European solutions to the problem would not work here. “France approved 5G with antennas aimed below the horizon at one-third the transmission power and with runway safety areas two-and-a-half times larger than those in the United States.”
The FAA’s approach to 5G C-band interference is a “patchwork of broad restrictions and case-by-case approvals,” said RAA president Faye Malarkey Black, and “has been disastrous.” She said more than half the nation’s regional airliner fleet remains restricted at “dozens” of airports and urged subcommittee members not to view such disruptions as “mere pockets of pain.”
Black noted that regionals carry 44 percent of the nation’s commercial passenger traffic, two-thirds of the nation’s commercial airports have only regional service, and 5G-related notams had already restricted carrier service at 70 airports. She said over the course of one week, 5G issues caused one regional carrier to cancel 63 flights, displacing 1,800 passengers, while numerous others have experienced delays due to 5G.
Even when flights can operate, the notam-driven AMOCs often limit operations and passenger capacity, she said, citing the case of a 50-seat regional jet limited to 23 passengers due to wet runway conditions. “Airlines are uncertain when and what clearances they might get for which aircraft, if any. The impact on regional airlines has been particularly pronounced,” she said, adding that the FAA’s current approach to the problem “creates two tiers of reliability in our system—one for cities and another for everywhere else.”
Cathryn Stephens, the airport director at Eugene, Oregon (KEUG), warned the subcommittee that the solutions negotiated between the FAA and the wireless industry are “limited and temporary.” She also was speaking on behalf of the American Association of Airport Executives (AAAE) and said that the Notams pose “significant challenges” at her home airport and, had they been in place in 2021, would have impacted 40 percent of flights there during 90 low-visibility days.
Helicopter Association International president James Viola encouraged the subcommittee to consider not just the impact of 5G C-band interference on helicopter operations, but also the emerging eVTOL market. He said helicopters “could very well conduct their entire flight within zones of this [5G] interference” due to their low operating altitudes.
When questioned, the FAA’s Dickson demurred on what the cost would be to harden existing radar altimeters against 5G C-band interference. However, technology consultant Dennis Roberson, a former Motorola executive, told the subcommittee that filtering radar altimeters susceptible to C-band interference amounted to little more than “little pieces of ceramic” that historically cost “nickels and dimes.”