Low-Altitude Maneuvering · NTSB ANC17FA026
ARCTIC AIRCRAFT CO INC S 1B2 — Salcha, AK
| Date | May 27, 2017 |
| Location | Salcha, AK |
| Aircraft | ARCTIC AIRCRAFT CO INC S 1B2 |
| Purpose of flight | Personal |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Maneuvering-low-alt flying Collision with terr/obj (non-CFIT) |
| Pilot age | 81 |
| Pilot total time | 1,960 hrs · Experienced |
| Time in type | Unknown |
| Fatalities | 2 |
Probable cause
NTSB findings
- Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Airspeed-Not attained/maintained - C
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Angle of attack-Not attained/maintained - C
- Environmental issues-Conditions/weather/phenomena-Wind-High wind-Effect on operation - C
- Personnel issues-Action/decision-Info processing/decision-Decision making/judgment-Pilot - F
- Aircraft-Aircraft oper/perf/capability-Aircraft capability-Maximum weight-Capability exceeded - F
- Aircraft-Aircraft oper/perf/capability-Aircraft capability-CG/weight distribution-Capability exceeded - F
- Environmental issues-Conditions/weather/phenomena-Wind-Gusts-Effect on operation
What happened
The pilot and passenger were searching for an overdue boat with the intent of landing at a remote unimproved airstrip located near the boat's intended destination. A witness reported strong wind conditions as she observed the airplane circle the airstrip. While the airplane was circling, its nose suddenly dropped, and the airplane descended in a near-vertical attitude to ground impact. She stated that the engine continued to run, and the airplane did not make any unusual sounds, other than an increase in engine rpm, during the descent.
A postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. The observed damage to the airplane indicated that it impacted the ground in a nose-down, near-vertical attitude. The witness account and the damage to the airplane were consistent with the pilot failing to maintain sufficient airspeed while maneuvering, which resulted in the airplane's wing exceeding its critical angle of attack and a subsequent aerodynamic stall.
The airplane's estimated gross weight at the time of the accident was about 130.5 pounds over its approved maximum gross weight of 1,650 pounds, and the airplane's estimated center of gravity was about 0.1 inches beyond the approved aft limit at gross weight. As excessive weight increases stall speed and an aft center of gravity decreases controllability, it is likely that the pilot's decision to operate the airplane over gross weight with an aft center of gravity contributed to the loss of control.