Accident Sequence
A flight instructor (CFI) and student pilot were conducting a landing approach when the landing gear was selected down. Only the main landing gear down indicator lights illuminated. The CFI made extensive attempts to extend the nose landing gear using both normal and emergency procedures, but each attempt was unsuccessful. As the aircraft crossed the runway threshold, the CFI directed the student to turn the fuel selector to the off position, and the CFI simultaneously moved the fuel mixture control to the idle-cutoff position.
Witness Video Analysis
A witness videotaped the accident sequence. Review of the tape showed the aircraft making a near wings level, descending approach to the runway. At approximately 30 feet above ground level (AGL), the aircraft's nose oscillated up and down, followed quickly by the onset of a high vertical descent rate. At this point, the aircraft's stabilator was in what appeared to be an almost full nose-up position. The aircraft impacted the runway surface in a near level, slight right wing down attitude.
Examination Findings
Post-impact examination of the aircraft revealed that a nose gear down assist spring assembly had separated from an upper attach point on the strut and was tangled up in the strut support linkage. This condition prevented the strut from free-falling to the down position.