No fatalities

4 Jun 2016: AMERICAN CHAMPION AIRCRAFT 8KCAB NO SERIES — Black Diamond, WA

Black Diamond, WA, United States

On 4 Jun 2016, an AMERICAN CHAMPION AIRCRAFT 8KCAB NO SERIES was involved in an aviation accident near Black Diamond, WA. No fatalities were reported. Investigators recorded the probable cause as: The pilot's abnormal runway contact during the landing flare, which resulted in a porpoise, aerodynamic stall, impact with terrain, and nose over. This summary draws on records from NTSB; 12 related events involving the same aircraft type or operator are linked below.

SourcesNTSBPrimary reportUpdated 1778583330Data APIEditorial standards

A tailwheel-equipped airplane porpoised and veered off the runway during touchdown. The pilot aborted the landing, but the airplane stalled, struck the ground, and nosed over, sustaining substantial empennage damage.

Incident Overview

A pilot of a tailwheel-equipped airplane reported that during the landing touchdown, the aircraft porpoised and drifted off the runway to the right. In response, the pilot initiated an aborted landing procedure. However, the airplane then aerodynamically stalled, impacted the ground, and nosed over.

Damage

The accident resulted in substantial damage to the empennage of the airplane.

Pilot Statement

According to the pilot, there were no preimpact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

Reference Material

The Federal Aviation Administration's Airplane Flying Handbook (FAA-H-8083-3A, 2004) discusses aerodynamic stalls, noting that stall awareness relies on a pilot's ability to visualize the wing's angle of attack and estimate the margin of safety above stall. It states that stall accidents often result from an inadvertent stall at low altitude without recovery before ground contact.

The same handbook addresses porpoising, describing it as a series of jumps and dives that can occur from improper airplane attitude at touchdown. Contributing factors include inattention, misjudging ground proximity, mistrimming, or forcing the airplane onto the runway. Porpoising can also arise from improper airspeed control, where a fast approach leads to floating and subsequent forcing of the aircraft onto the runway. Corrective action for a porpoise is similar to that for a bounce, varying with severity; for slight porpoising without extreme pitch changes, a follow-up landing with power adjustment may be executed.

Contributing factors

Landing flare — Not attained/maintainedCapability exceededPilot