Air India on January 20 said Boeing had cleared its B777 aircraft for flights to the U.S. following concerns that the 5G roll-out there could interfere with critical aircraft functions.
Telecom companies in the U.S. on January 19 launched the 5G service that uses frequencies in a radio spectrum called the C-band. These frequencies can be close to those used by radar altimeters that measure an aircraft’s height above ground. Data from these altimeters informs other safety equipment on the plane, including navigation instruments, terrain awareness and collision-avoidance systems.
“Boeing has cleared Air India to operate to USA on B777,” the airline said in a statement.
As a result, though the airline had cancelled its U.S. flights for January 20, it was able to operate some flights after a delay- these included a flight each to New York, Chicago and San Francisco.
Later in the day, Air India said “normal flight operations will recommence to and from USA” from January 21.
Alternative Method of Compliance
Air India’s flights were cleared by Boeing after it carried out the Alternative Method of Compliance (AMOC) for its 777 aircraft, which it operate to four out of five U.S. destinations. AMOC refers to a process under which airlines can demonstrate how altimeters can be safe and reliable in certain 5G C-band environments.
“Overnight we received Boeing’s bulletin giving us the all-clear. Following which we got the DGCA’s [Directorate General of Civil Aviation] approval for the AMOC. After this, we started informing passengers and arranging the crew for our flights,” a senior airline official explained.
The airline cancelled eight flights to the U.S. on January 19 when 5G was rolled out in that country.
Flights to Washington DC — the fifth destination served by Air India — were not affected as the airline uses Boeing 787 for the route and had obtained the AMOC for it.
Hours before the 5G roll-out, telecom companies Verizon and AT&T announced that they would defer turning on a limited number of towers around certain airports following warnings from U.S. airlines that there could be a massive disruption to flight connectivity.
Later, the FAA (Federal Aviation Administration) also issued new approvals that allow an estimated 62% of the U.S. commercial fleet to perform low-visibility landings at airports where wireless companies deployed 5G C-band.
