U.S. aviation authorities are considering drastic measures to curb growth at United Airlines Holdings Inc., including preventing the carrier from adding new routes, following a series of safety incidents.

The Federal Aviation Administration has discussed temporary actions it may take with the airline’s leadership in recent days, according to people with knowledge of the matter. In addition to route restrictions ahead of the all-important summer travel season, United may be barred from flying paying customers on newly delivered aircraft, said the people, who asked not to be identified describing the closed discussions. 

The FAA already is suspending United’s ability to approve and promote pilots to fly different aircraft models, two of the people said.

The proposed clampdown would effectively pause growth for an unspecified period at one of the largest U.S. airlines, underscoring the heightened scrutiny on commercial aviation safety following a near-catastrophe earlier this year involving a Boeing Co. plane. Since the January incident, in which a panel blew out in midair from an Alaska Airlines jet, United has endured multiple headline-grabbing mishaps.

The renewed focus reflects stresses on commercial air travel after years of rapid growth coming out of the depths of the pandemic. 

United shares fell 3.6% to $44.80 in premarket March 25 trading. 

United declined to comment on the potential restrictions. The FAA said in a statement late March 23 that it’s increasing oversight of United to ensure it’s complying with safety regulations.

“Certification activities in process may be allowed to continue, but future projects may be delayed based on findings from oversight,” the FAA said.

The agency plans to increase oversight of United in the coming weeks to review processes, manuals and facilities, the carrier told employees in a memo. Sasha Johnson, United’s vice president of corporate safety, said in the message that regulators and the company agree it needs “to ensure we are doing all we can to promote and drive safety compliance.”

Johnson also said the FAA planned to “pause a variety of certification activities for a period of time,” without specifying which ones.

The limits under consideration would restrict United from adding new routes beyond those the airline has already sold tickets for, according to one of the people familiar with the matter.

Leaders of an Orlando-area local union for United pilots sent a message to members saying that the FAA recently stepped in to “take substantial action” against the carrier, including restricting its abilities around pilot approval. The so-called line check process to certify and promote pilots has been paused pending further action from the FAA, according to two people familiar with the situation.

Increased Presence

There are now “regulator-imposed restrictions on our ability to operate and grow our airline,” according to the message from the Local Council 150 chapter of the Air Line Pilots Association. “We will also see an increased FAA presence in our daily operation.”

ALPA’s United Master Executive Council hasn’t issued formal communications on the matter to its members and declined to comment to Bloomberg.

Among the incidents at United just in March, a plane in Houston ran off the taxiway into a grassy area, while another aircraft lost a tire shortly after departing from San Francisco. And a Houston-to-Florida flight had to make an emergency landing after one of its engines began spewing flames. The FAA has announced investigations of those and other incidents.

United chief executive officer Scott Kirby this week promised customers that the carrier would review the incidents and its employee training.