Cessna 150
Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 200; Flight Crew Total 14000; Flight Crew Type 300
Human-Machine Interface
Aircraft Equipment Problem Critical; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Took Evasive Action
Human Factors; Aircraft
Flight testing had begun several weeks prior to this occurrence regarding the possibility of using a standard Cessna 150 as a potential jump aircraft for a jump planned for above 7;000 AGL; and to occur at a private airport. On the previous two uneventful test flights; two occupants of the same C-150 had worn standard emergency aircraft parachutes and had experimented with the ability to open and close the passenger door in flight; without having it removed. On this third flight; the pilot wore a standard emergency parachute and the brief flight test was to have the right seat occupant wear a standard sport single harness dual parachute system; and test the required space requirements; the amount of force required to open the door; and the possible body exit positions. During the process of maneuvering with the door open; the passenger's main pilot chute accidentally became dislodged and was pulled aft by airflow; and could not be retracted. The passenger elected to depart the aircraft to avoid potential imminent entanglement of the main parachute with the right horizontal stabilizer of the C-150. Upon deployment; the main canopy of the passenger was open but was twisted; and the pilot chute had wrapped around the left steering line; which caused a hard left turn and loss of altitude. The passenger did not use his reserve canopy as he estimated that he was too low. The passenger landed in a grass area in a partially controlled left turn and was unable to flare normally. This otherwise normal flight test became an in flight emergency due to the uncommanded inadvertent release of the passenger's main canopy pilot chute; and the relatively low altitude of the aircraft. As a result of this problem; it has been determined that there is not enough cabin space to use the C-150 as a jump aircraft and that the possibility of [accidental] parachute [deployment] is too great for this aircraft type in standard configuration.
A passenger; wearing a standard sport dual parachute; in the right seat of a C-150 was obligated to jump out in flight when the main chute pilot exited the pack and was threatening to entangle with the right stabilizer. Both the parachutist and the pilot were uninjured in the incident.