美国联邦航空管理局(Federal Aviation Administration，简称faa)正在为Verizon和AT&T开启更多5G无线网络塔扫清道路，该监管机构对5G信号干扰大多数机场商用客机上关键安全设备的担忧已经缓解。但一些机场仍可能出现严重的航班延误、改道和取消，因为美国联邦航空局(FAA)仍未证实某些飞机在恶劣天气下起飞和降落时不会受到5G干扰。这些仍然受到飞行限制的飞机大多是地区性航空公司的小型飞机，这些航空公司与美国航空(American)、达美航空(Delta)和联合航空(United)等大型干线航空公司合作。由于美国中西部、大西洋中部和东北部地区的严重冬季风暴，本周末已经发生了大量航班中断，5G问题可能会加剧这一情况。
美国国家气象局(National Weather Service)在一份报告中说，本周末来自东北部的大风和大雪将造成暴风雪般的天气，使一些地方的旅行“几乎不可能”。但在一些能见度较低的机场，航班仍然可以起降，一些支线飞机仍然被禁止飞行，因为担心附近5G手机发射塔的无线电信号会干扰飞机上的无线电高度表。高度表可以精确测量飞机离地面的高度，是飞行员在能见度降低的恶劣天气下进行着陆的重要工具。Verizon和AT&T正在为他们的5G服务使用无线电频谱的“C”波段，这与高度表使用的无线电频率非常接近。美国联邦航空局说，无线宽带操作的干扰会使高度计读数不准确和不可靠，因此，某些关键的飞机系统可能在起飞和降落时不能正常工作。
"This should not have happened," he said.
All of the flights cancelled at Paine Field are operated by Horizon Air, which is a regional carrier owned by and flying exclusively for Alaska Airlines. Of the 300 flights Horizon operates on average each day, about 135, or 45% of them, are on the 76-seat Embraer E175.
"Really, it's a disproportionate impact on this E175 aircraft, which is common not only in our fleet but in a number of other regional airlines around the country, as well," Horizon CEO Joe Sprague said.
And Sprague fears even more smaller airports served by regional airlines like his will be affected as the telecom companies activate more high-speed 5G wireless service, as Friday's announcement by the FAA allows them to do.
"The activation of 5G towers near airports that took place last week was just the initial wave that AT&T and Verizon are planning and that there are multiple subsequent waves of activations, with each one likely to include smaller and smaller communities," affecting even more airports, airlines and would be air travelers, Sprague said.
The rollout of new 5G service near U.S. airports this month by Verizon and AT&T has been plagued by delays, confusion and controversy. After delaying the start of the high-speed wireless service late last year, the telecom giants were to switch on their 5G towers Jan. 5. But they agreed to another two-week delay as the FAA and airlines raised concerns about altimeter interference.
On Jan. 18th, after the FAA and the major airlines warned of potentially catastrophic flight disruptions, they reached an agreement with Verizon and AT&T to further postpone powering on some 5G network towers near some airports while the FAA worked to determine which aircraft altimeters are free of interference and would be reliable and accurate in 5G areas.
The FAA has now determined that 20 types of radio altimeters are safe and reliable in 5G environments and has thus approved 90% of commercial aircraft for takeoffs and landings in low visibility at most of the nation's airports.
In a statement Friday, the FAA said the wireless companies "have provided more precise data about the exact location of wireless transmitters and supported more thorough analysis of how 5G C-band signals interact with sensitive aircraft instruments. The FAA used this data to determine that it is possible to safely and more precisely map the size and shape of the areas around airports where 5G signals are mitigated, shrinking the areas where wireless operators are deferring their antenna activations. This will enable the wireless providers to safely turn on more towers as they deploy new 5G service in major markets across the United States."
But that doesn't provide the all-clear for many regional jets, including the E175 and its smaller sibling, the Embraer E145.
And these and other smaller, regional jets actually make up a significant portion of the commercial aviation network in the U.S.
Often times, when you're flying on a regional airline, you might not even know it. You likely booked the flight on a carrier like American, Delta or United. The pilots and flight attendants are dressed in those airlines' uniforms and the small planes are called United Express, American Eagle or Delta Connection.
But they're actually 17 separate airlines, including SkyWest, Horizon, Endeavor, and Republic, among others.
"The major airlines and their equipment, they're all too large to serve smaller airports that have fewer passengers traveling each day," Regional Airline Association President and CEO Faye Malarkey Black said. "So they partner with regional airlines and regionals specialize in operating smaller regional aircraft that's the right size to reach those customers that are traveling from smaller and often rural towns."
Malarkey Black says though they're not as well known, regional airlines fly 43% of the nation's departures, reaching 94% of the country. In fact, regionals fly the only commercial air service to 66% of U.S. airports.
But they were largely left out of the recent deal between the big airlines, the FAA and Verizon and AT&T over how to minimize possible 5G interference with airplane navigation systems.
"We do have a feeling and a sense that when this deal was cut, it was cut in consultation with the bigger users of the system," Malarkey Black said. "And for that reason, it didn't meet our needs."
The problems with 5G come at a very difficult time for the regional airlines, as they struggle to recover from the huge slump in air travel demand caused by the pandemic and try to cope with an acute shortage of pilots, flight attendants and aviation mechanics, many of whom are leaving the regionals to move up the ranks to the better-paying bigger airlines.
Malarkey Black said that's leading some of the major airlines, including American and United, to cut back on regional flights to smaller cities.
"When we're dealing with a scarcity in workforce that is forcing a capacity retraction, and history tells us that anytime the major airlines are forced to retract capacity that the smallest communities get hit first and worst and we're seeing that now with the pilot shortage."
The pandemic already forced four regional airlines to go out of business. To avoid further disruptions, the regional carriers are asking the FAA and the telecom companies to find a way to work through the 5G issues and approve more regional jets to fly into and out of smaller airports in bad weather.