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Pilots are told to be aware of their surroundings and stay on top of any inclement weather, terrain or problems with the plane, but the dangers of hypoxia can sneak up on even the most experienced pilot without warning. Two air traffic controllers sensed something wrong when a pilot was flying erratically, using their knowledge and experience to help a pilot unknowingly amid a hypoxia event.
The FAA is crediting Rosilla Owen and Scott Ems working at the Boston Air Route Traffic Control Center with an incredible catch in October 2023. Owen and Elms were both experienced controllers, Owen with 12 years and Elms with 16. A Cessna 310 flying on an aerial photography mission at 13,500 feet was handed off to the duo from the New York Terminal Radar Approach Control (TRACON). The Cessna was zig-zagging in and out of the two airspaces and Owen noticed something odd immediately. Owen asked the pilot for his coordinates and his responses were filled with long pauses in between, which is unusual for an experienced pilot.
"He took a really long time to check in," Owen said.
After the first transmission, Owen checked on the pilot, asking him if he was ok. He responded that he was, but Owen and Elms still had a pressing feeling that something was off. Owen began to consider many possibilities, like distracted flying or a medical emergency like a stroke, but she knew that there was a chance that hypoxia was setting in. Hypoxia occurs when there is not enough oxygen to feed the brain, which can lead to a state of unconsciousness. Owen contacted the New York TRACON, which confirmed that the pilot was also slow in responding to their directions. With hypoxia a growing concern, Owen confirmed that the pilot had oxygen on board.
"I was thinking maybe I made a mistake," Owen said. "But I still wasn't convinced it was working the way it should."
Owen asked the pilot to begin to descend to 9,000 feet, an altitude that does not require the use of oxygen. By asking the pilot to descend, Owen could determine whether hypoxia was a factor in the erratic flying and slow responses.
"You're taking the easiest [possibility] and taking it out of the picture," Elms said.
Elms confirmed that the transmissions after the pilot descended were getting clearer and sharper with every response. Minutes later, the Cessna pilot told the controllers his oxygen line had a kink in it, which reduced the oxygen flow.
"Thanks for looking out for me," the pilot told Owen.
"If he's up there for another three to 10 minutes, we might be dealing with something different," Elms said.
The pilot then indicated he was cutting his mission short, opting to return to home base. Elms contacted the New York TRACON, asking them to keep an eye out for the returning pilot.
"I asked them to keep an eye on him," he said. "I told them he's a little shaky, that he had just had a hypoxia event. They let us know he landed safely."
Executive Officer at the Boston Center Adam Currier was impressed with Owen and Elms' quick thinking. The center had encountered a hypoxia event the year before and Elms was involved with that incident as well. The Boston Center air traffic manager Tarah Park said that the lessons learned from that incident were shared widely at the facility and helped to prepare controllers.RELATED STORIES:5 steps to recognize and prevent hypoxiaAOPA video warns of hypoxia dangers after Citation V crashCitation V crashes after breaching restricted airspace in DC; F-16s scrambled
On June 4, 2023 a Cessna Citation V flew over restricted airspace around Washington D.C. and was not responding to radio communications, resulting in multiple F-16 jets being scrambled to intercept the aircraft before it ultimately crashed into a forest in southern Virginia. Intercepting pilots reported seeing the pilot slumped over, believing him to be unconscious or non-responsive at some point in the flight. Initial beliefs were that the pilot and passengers suffered from a hypoxia event that led to the deadly crash.
Hypoxia is divided into four types and all have the same type of effect on health and flying skills. These events have different causes, like anemia, cold temperatures, substances like alcohol or drugs, or most commonly, altitude hypoxia. Hypoxia has what is referred to as an insidious onset, meaning the signs and symptoms occur gradually so they are fully established by the time you become aware of them. Due to this insidious nature, the pilot will likely be unaware of the signs and symptoms before it is too late. Pilots only have seconds to minutes to react depending on the altitude. For this pilot flying at 13,500 feet, he would have had roughly 30 minutes to react to a hypoxia event from the start of the symptoms.
Owen and Elms used their skills and experience to save a pilot from a hypoxia event. Asking the pilot to descend to determine whether hypoxia was the cause likely saved his life and prevented a crash. After the pilot descended and was returning to home base, another pilot sharing the frequency also thanked the controllers for their save.
"Good catch out there," the other pilot said. "I appreciate you guys."