Plane Diverts for Allergic Reaction: Why No FAA Report?

in Food Allergy, Food Allergy News
Published: September 12, 2022
Airplane flying over the ocean. Food allergy reaction on plane.
Photo: Getty

• Pilot diverted San Francisco-Singapore flight to Hawaii due to passenger’s allergic reaction.
• FAA says: United Airlines didn’t file a report. Wasn’t required, since airline called event a ‘precautionary landing’ not an emergency.
• However, some passengers told diversion was ‘a medical emergency’.
• Capt. Chesley (Sully) Sullenberger, hero of the Hudson River emergency landing, speaks on diversion decision-making.
• Issue: How reliable is data on in-flight allergic reactions if even a major plane diversion isn’t on the record?

The news of an airplane’s diversion related to an allergic reaction flashed across my screen just before my own flight back to the United States from Italy. Aviation blogs were reporting that this was a medical event, related to a passenger’s reaction to either peanuts or nuts.

Five hours into United Airlines’ September 3, 2022 evening flight from San Francisco to Singapore, the pilot to diverted that flight – currently United’s longest at just over 16 hours. The plane landed in Honolulu, an almost three-hour detour. 

Allergic Living asked me to find out more. What happened; what was the condition of the passenger? What was the correct allergic trigger? Was epinephrine used?

Although the diversion disrupted the schedules of about 290 fellow passengers, United Airlines’ communications team wouldn’t say much. They simply said the Singapore flight “diverted to Honolulu due to a medical incident. EMTs met the flight upon landing to assist.” 

I contacted the Federal Aviation Administration (FAA), assuming because the plane had changed course and landed mid-flight, United would have to file a report. When I first read the FAA’s response, I thought I was reading wrong due to jet lag. In short: there is no report.

The FAA does confirm that “the passenger symptoms presented were indicative of an allergic reaction.” They do not know what caused the allergic reaction. 

Diversion Not Labeled ‘Medical Emergency’ 

It turns out, United “did not declare a medical emergency for this incident.” The aviation regulator says that if the airline had declared an emergency, “they would be required to notify the FAA.” Instead, the FAA said the United flight had landed in Honolulu as “a precautionary diversion in the best interest of safety.” Thus again, no report.

But this is where things get contradictory. Passengers on the Singapore-bound flight who asked about the diversion were told: “your flight diverted to Honolulu because of a medical emergency.” Similar replies from the airline popped up on Twitter. 

Food allergy reaction on plane response.
A United Tweet on situation.

So to travelers who faced an 18-hour delay and another 11 hours of flying, it was an emergency landing. But for the FAA, it was precautionary event that didn’t require a report.

I reached out to William J. McGee an aviation consumer advocate, journalist, and former manager in airline flight operations. “First things first, the United Airlines crew made the right call in diverting this flight,” he said. (McGee noted the flight was entering the middle of the Pacific Ocean). “Their actions may have saved a life.”

McGee, who’s now the senior fellow for aviation at the American Economic Liberties Project, oversaw dozens of emergency diversions during the years he worked in airline flight operations. “Such actions are never taken lightly.”

“But it’s very odd that this was not declared a medical emergency,” McGee says. “Because quite frankly, if it was not a medical emergency, then why divert at all?”

Capt. Sullenberger’s Take

Capt. Chesley Sullenberger. Photo: Purdue University

What does in fact constitute an in-flight medical emergency, and how is one declared? I spoke to Captain Chesley Sullenberger, the aviation safety expert best known for his 2009 heroic emergency landing of a US Airways flight in the Hudson River.

Under federal regulations, it is the pilot who has ultimate authority to declare an emergency medical landing. Sullenberger spoke, not in relation to United’s Singapore flight, but in general from his long experience as a (now-retired) pilot. He said he never had qualms about declaring a medical emergency and believes most commercial pilots would say the same. 

When a life is at stake, for a pilot “there is a low threshold to declare an emergency. The obligation to protect and save lives is one that is understood clearly and felt deeply by aviation professionals,” he said. 

As for the difference between a precautionary and medical emergency landing, Sullenberger said it depends on the nature and severity of the emergency, and on whether the flight might require assistance and priority handling by air traffic control to land as soon as possible.

“There is no downside to the pilot declaring a passenger medical emergency except “a bit more paperwork.” He stresses again, what’s important to a pilot is to save a life.

Diversion and Data on Allergies 

With the Singapore flight’s diversion, there is a larger issue. The allergy community has long been told that the information collected on in-flight medical emergencies shows a low rate of anaphylaxis, the severe form of allergic reaction. This incident raises the issue of: what does get recorded, and just how complete are the data on in-flight medical emergencies? 

Map showing where the food allergy reaction on plane took place.
Map showing Singapore flight’s diversion. Photo:

How can we know whether severe allergic reactions aboard planes are becoming more common? In recent articles, a growing number of doctors have told Allergic Living about assisting with in-flight anaphylaxis cases in the air. If airlines classify diversion as a medical “precaution” not an emergency, are we hearing about all in-flight anaphylaxis cases?

“The reason this matters is that aviation safety and health issues are addressed in large measure through statistics,” says McGee.

“The FAA responds to problems and subsequently drafts regulations based in part on the number of cases reported about a given issue.” He questions how the FAA can truly measure the seriousness of in-flight allergy emergencies if airlines don’t always report such incidents to the FAA. 

Food allergy reaction on plane response.
United's notice to a passenger re flight diversion.

I mentioned this concern about “emergency” terminology to Captain Sullenberger. “It is imperative that we have an accurate idea of how many of these kinds of events happen, so we can plan for them and have the best procedures in place for handling them,” he said.

Allergic Living recently reported that in less than a year and on two flights, Dr. Kimberly Blumenthal assisted in-flight allergy emergencies. On her JetBlue flight, the Massachusetts General allergist did not have to fill out a report. Yet on her Delta flight, she did. Both plane incidents were allergic reactions, but only one was recorded. So what percentage of these reactions are tracked? 

There are several issues surrounding the limited data we do have on in-flight reactions. At my No Nut Traveler blog, for instance, I receive testimonials about in-flight reactions that are not reported to airline staff. (They’re usually self-treated by passengers.) Plus, it is unclear if airlines are required to report an incident if the emergency medical kit is not cracked open.

“Critical Need” to Report Incidents

The food allergy epidemic grows worldwide. Yet the data we have on allergic reactions on planes is not robust. That is why I am looking forward to a global food allergy and airline travel survey, which the Center for Food Allergy and Asthma Research (CFAAR) at Northwestern University will soon launch. 

Of the Singapore flight’s diversion, McGee concludes that “it’s critical that all such events be fully reported and analyzed. How can we expect airlines and the FAA to stock enhanced medical kits and prepare for such life-threatening emergencies if real-world crises are not being reported?” 

I agree; transparency matters. This is not about one airline or one pilot, it’s about capturing an accurate picture of anaphylaxis events in the skies. If there are holes in the data that’s being collected, that won’t help anyone – not the pilot, not the sick passenger, not the physician called into assist. 

I do hope the passenger with the allergic reaction on the flight that diverted to Hawaii had a good outcome. But given the current reporting, we may never know. 

Lianne Mandelbaum is Allergic Living’s airlines correspondent, and the founder of

Related Reading:
MD Ignites Debate: Why No Auto-Injectors, Other Drugs in Plane Medical Kits?
Why Your Plane’s Medical Kit May Lack Drugs Like Epinephrine
It’s Come to This: ‘Borrowing’ Epinephrine on Planes