SEA02LA081

NTSB accident investigation · Cook Coot A · Harrison, ID · May 12, 2002

Accident · Minor injuriesLimited investigationFinal report
Date
May 12, 2002, 14:00 local (21:00 UTC)
Place
Harrison, ID
Injuries
1 minor
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N12QQCook Coot A
Weather
Visual (VMC) · Day
Status
Completed · report April 8, 2003
Report
Approved by Office Director
Parties
Spokane FAA FSDO
Case key
54705

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The pilot's failure to detect an unsafe boat wake during the landing process, and his inadvertent initiation of a porpoise after coming in contact with the boat wake just after touchdown on a body of water. Factors include a large wake wave/swell created by the movement of a boat in the area where the pilot chose to land.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

On ground/water encounter with terrain/waterLanding - flare/touchdown
Unsafe/hazardous condition - not detectedPilot in commandCause
Porpoise/pilot-induced oscillation - inadvertentPilot in commandCause
Airport facilities,runway/landing area condition - large wave/swellFactor
Dragged wing,rotor,pod,float or tail/skidLanding

Analysis

The pilot, who had done a number of touch-and-go water landings just prior to the accident, thought he was landing in an area where the water was relatively calm and undisturbed. But he failed to detect the wake of a boat that had been operating in the area, and almost immediately after touchdown, the aircraft encountered the wave/swell from the wake and started porpoising. The aircraft contacted the water two more times, and on the final contact, the right wingtip was buried in the water resulting in substantial damage to the airframe.

Factual narrative

On May 12, 2002, approximately 1400 Pacific daylight time, a Cook Coot A experimental-category amateur-built amphibian airplane, N12QQ, registered to and being flown by the pilot, was substantially damaged in a water landing on Lake Coeur d'Alene near Harrison, Idaho. The airline transport pilot, who was the sole occupant, received minor injuries in the accident. The flight was being operated in visual meteorological conditions, and according to the pilot, the winds were calm at the time of the accident. No flight plan had been filed for the 14 CFR 91 personal flight.

According to the pilot, who had already done a number of touch-and-go water landings that afternoon, he thought he was landing in an area where the water was "quiet." But just after touchdown, the aircraft encountered a boat wake and "...it just started porpoising." The second time the aircraft contacted the water, it hit another wake and pitched into the air again. The third time the aircraft contacted the water, the right wingtip was "buried," and the airframe sustained substantial damage. According to the pilot, there was no evidence that there had been any malfunction of the flight controls or any other aircraft system.

Aircraft

Registration
N12QQ
Reported as
Cook Coot A
Category
Airplane, amateur-built
Serial number
F11
Airframe hours
75
Engine
Lycoming IO-360, 200 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Registered owner
Kenny C. Danielson
Airworthiness certificate
Special, Experimental (Special)
Departed
COE · Coeur d' Alene, ID
Destination
Harrison, ID

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
68
Injuries
Minor
Certificates
Flight instructor, Airline transport
Airplane ratings
Multi-engine land, Single-engine land, Single-engine sea
Instrument ratings
Airplane, Helicopter
Medical
Class 3, Valid Medical--w/ waivers/lim
Last flight review
June 13, 2000
Seat
Left
Flight hours
20,000 total · 25 in this make and model

Weather

Conditions
Visual (VMC) · Day
Wind
Calm
Visibility
10 statute miles
Lowest ceiling
None
Temperature
70 °F

Docket · 1

The files NTSB released with the investigation on December 23, 2002, on NTSB’s docket system: statements, records, photos and specialists’ reports. 292 KB in all.