Stearman
Flight Crew Private
Flight Crew Type 23
Distraction
Flight Deck / Cabin / Aircraft Event Illness / Injury; Ground Event / Encounter Ground Strike - Aircraft; Ground Event / Encounter Loss Of Aircraft Control; Ground Excursion Runway
Aircraft Aircraft Damaged; Flight Crew Regained Aircraft Control
Human Factors
My son [Passenger] and I took an excursion flight from ZZZ south approximately 60 miles; then west over the southwest part of [the nearby city] then returned to ZZZ along the same route. We departed ZZZ at approximately [time] and returned at approximately [two hours later]. Halfway through the flight [Passenger] was becoming nauseous which prompted the return to ZZZ. As we descended into ZZZ we encountered warmer air and more convective turbulence. The active runway was XX and winds were reported from [right-quartering headwind] at 5 kts. Upon touchdown [Passenger] began vomiting. I believe that [Passenger] contracted as he vomited and cradled and slumped over the control stick as I had very little if any stick movement. This lack of stick control prevented me from apply appropriate right input to the control stick to adequately compensate for the cross wind component. The aircraft subsequently veered right; drug the left wing tip and off the right (north) side of the runway. Upon leaving the runway I was immediately able to bring the aircraft to a complete stop. Requested from tower to cross runway XX and taxied back to the hangar. The damage to the left wing tip was minor and limited to the tip and does not constitute an accident. Damage was caused to the runway RVR upon leaving the runway.
Stearman pilot reported losing control of aircraft during landing flare due to sick passenger interfering with flight control movement.