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 in Salcha, Alaska.
A witness reported strong wind conditions as she observed the Arctic Aircraft S1B2 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. Both the pilot and the passenger died in the crash.
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 hit 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.
Probable cause: The pilot’s failure to maintain adequate airspeed while maneuvering in high winds, which resulted in the airplane exceeding its critical angle of attack and an aerodynamic stall. Contributing to the accident was the pilot’s improper decision to load the airplane beyond its allowable gross weight and center of gravity limits.
NTSB Identification: ANC17FA026
This May 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Don’t understand Bluestar’s comment. Airspeed is airspeed and ground speed isn’t what kills you. Suspect he’s confusing it with wind shear where IAS can drop precipitously.
JJD
I don’t agree with gbigs. What is the difference between an airspeed indicator and an AOA indicator when focusing outside the aircraft? The AOA indicator is one of the most useless features if you don’t pay attention to it. It is a fact that even audible stall alarms don’t avoid LOC accidents. I support Warren Webb jr.
Another low-level flight LOC, similar to what can happen on a photo flight or when flying over some point to get someone’s attention when speed is slow and induced drag is high. I doubt an AoA indicator would have made a bit of difference. Per witness account the pilot apparently wasn’t watching the airspeed – what makes anyone think he/she would do a better job of monitoring an AoA indicator. It’s reasonable to assume the eyes were focused outside – not on any instruments. Having flown a lot of photo flights, I know that basic instrument scan, proper use of power, and division of attention is how these types of accidents are avoided.
The fact remains,be vigelant,keep air under your wings and fly the damn plane,oh,,and dont be a dumbass!
Im sooo sorry for your loss!
Possibly he flew slow into head wind and the wings were happy, turn down wind and the air speed is not the same, and the wings don’t fly.
AoA meters in EVERY aircraft and pilots trained to use them would eleminate these and the base to final turn crashes.