Date: 201707
Location: POC.Airport, CA
Flight conditions: VMC
Light: Daylight
Aircraft: Small Aircraft
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Parked
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Other / Unknown; Physiological - Other
Anomaly: Flight Deck / Cabin / Aircraft Event Illness / Injury
Detector: Person Flight Crew
When detected: Pre-flight
Result: General Flight Cancelled / Delayed; General Physical Injury / Incapacitation
Contributing factors: Environment - Non Weather Related; Human Factors
Primary problem: Environment - Non Weather Related

Narrative: Prior to an intended flight from POC to ZZZ; I parked at the self-serve fuel pumps to refuel. After chocking and grounding the airplane; I was stung on the wrist by an unseen/unidentified insect. Because I have been stung multiple times on several prior occasions without experiencing any adverse effects; I was not concerned; and fueled the airplane. After securing the fueling islands equipment and retrieving a receipt; I began to feel light-headed as I walked back to the airplane. Almost immediately after that; I began to develop tunnel-vision; so I walked to the empennage in front of the horizontal stabilizer and placed one hand on the empennage and the other hand on the horizontal stabilizer to brace myself. My father was with me; and at this time he noticed I was very pale and asked; 'Are you alright?' I told him; 'Yes; but I have a really big head-rush.' That is the last thing I remember. According to my father; I fell flat on my face so hard the ground shook. I estimate that is was only about 3 or 4 seconds from the onset of light-headedness until loss of consciousness. I estimate that it was about ten (10) minutes from the time I was stung until the moment I was able to discern the light-headedness.Had my system reacted to the sting much faster; and I could have easily passed out while refueling from up on the fuel island's ladder. Had I not decided to purchase fuel at POC I could have easily passed out during taxi; takeoff; or flight. Until this incident; I did not believe I was allergic to anything. It would not have occurred to me that an insect sting could be a safety of flight issue unless the person stung either knew they were allergic; or had never been stung before. I would advise any pilot that does not believe they are allergic to insect stings to delay departure at least half an hour after being stung.

Callback: The reporter stated he did not know what kind of insect had stung him. He stated that it took approximately 10 minutes for him to feel the onset of the headrush and light-headedness and not more than 15 seconds after that to experience unconsciousness. He stated that paramedics were called and after initial treatment he was taken to the hospital for further treatment. He stated that medical personnel at the hospital were unable to determine the type of toxin he had experienced.  He did state that medical personnel at the hospital told him that he had suffered anaphylactic shock and that his blood pressure had fallen to 60/40. He stated that if he had been stung and continued at a normal pace without the delay on the ground to refuel; he would have likely been airborne at the time he experienced the head-rush and unconsciousness. He hypothesized that the sting may have come from an Africanized bee with a more potent toxin than he had been exposed to previously. He suggested that this was a safety of flight issue. He also suggested that pilots be informed that if stung by any creature prior to departure; the departure should be delayed by at least 30 minutes to evaluate one's condition.



Synopsis: GA pilot reported being stung by an unseen; unidentified insect while fueling his aircraft at POC. Light-headedness and loss of unconsciousness occurred shortly thereafter and required hospitalization. He recommended at least a 30 minute delay for pilots who may be stung by an insect prior to any departure.