Incident Overview
A Beech H35 aircraft encountered wake turbulence from a Boeing 727 during an approach to land, resulting in a sudden upset and structural damage. The pilot reported that while approximately 2 miles from the airport, the aircraft suddenly pitched up and flipped over. The pilot regained control, continued the approach, and landed safely without further incident.
Sequence of Events
The pilot was advised of the position of a Boeing 727 that was landing on Runway 29R and acknowledged seeing the aircraft. The pilot was also cautioned about possible wake turbulence from the Boeing and acknowledged the warning. According to the pilot's report, the upset occurred while on approach, about 2 miles from the airport. The aircraft's speed at the time of the upset was approximately 160 knots. The maneuvering speed for the Beech H35 is 124 knots indicated airspeed (IAS).
Damage Examination
A post-landing examination revealed damage to the V-tail. The inboard leading edge of the right stabilizer was deformed downward approximately 1 3/4 inches, and its lower skin was buckled between the front and rear spars. The front spar of the right ruddervator was twisted, and there was skin deformation on both ruddervators.
Investigation Findings
Investigation determined that the Beech H35 had crossed the path of the larger aircraft at approximately the same altitude, with a time separation of about 60 to 65 seconds. The Airman's Information Manual (AIM) recommends a 2-minute separation behind a large aircraft when landing on the same runway or a parallel runway within 2500 feet.