SEA01LA096

NTSB accident investigation · Cessna 180A · Mercer Island, WA · May 6, 2001

Accident · No injuriesLimited investigationFinal report
Date
May 6, 2001, 13:45 local (20:45 UTC)
Place
Mercer Island, WA
Injuries
3 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N9732BCessna 180A
Weather
Visual (VMC) · Day
Status
Completed · report July 30, 2001
Report
Approved by Office Director
Parties
Seattle FSDO
FAA report
20010506014599A
Case key
52284

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

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Probable cause

the pilot's inadequate visual lookout during an approach and landing in open water. Factors include a large wave/swell at the location where the pilot elected to land his float-equipped airplane.

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 - roll
Visual lookout - inadequatePilot in commandCause
Terrain condition - large wave/swellFactor

Analysis

After circling the area to observe the water conditions, the pilot executed a water landing in his float-equipped airplane. He touched down in relatively calm conditions, but almost immediately encountered a large wave/swell that he had not noticed from the air. The aircraft was momentarily launched back into the air, and the pilot applied full power for a go-around. Although the pilot initiated a go-around, the aircraft had already slowed to a point where it could not maintain flight. It therefore dropped back to the surface of the water with sufficient force to cause substantial damage to the aircraft structure.

Factual narrative

On May 6, 2001, approximately 1345 Pacific daylight time, a float-equipped Cessna 180A, N9732B, impacted the water during a landing on the waters of Lake Washington, near Mercer Island, Washington. The commercial pilot and his two passengers were not injured, but the aircraft, which is owned by a partnership of which the pilot is a member, sustained substantial damage. The 14 CFR Part 91 personal pleasure flight, which departed the waters of Roche Island, Washington, about one hour and fifteen minutes earlier, was being operated in visual meteorological conditions. No flight plan had been filed. There was no report of an ELT activation.

According to the pilot, he was landing in relatively smooth water in light and variable wind conditions. Just after touchdown, the aircraft encountered a large rolling wave that the pilot had not noticed prior to landing. As a result of passing over the wave, the aircraft was thrown back into the air to a height of at least 10 feet. At that point the pilot added power in order to initiate a go-around, but the aircraft did not have sufficient airspeed to maintain flight. It therefore dropped back onto the surface of the water with sufficient force to create substantial damage in the aircraft structure.

Although the pilot noticed a couple of small boat wakes when he circled the area prior to landing, he did not notice the large rolling wave/swell that he subsequently encountered. It was his opinion that the wave had been created by a large boat that had departed the area prior to his landing.

Aircraft

Registration
N9732B
Reported as
Cessna 180A
Category
Airplane
Serial number
18050030
Airframe hours
5,348
Engine
Continental O-470-K17F, 230 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Operator
Richard M. Pattison, doing business as Wavebusters, Inc.
Registered owner
Wavebusters, Inc.
Airworthiness certificate
Standard, Normal
Last inspection
Annual · February 15, 2001
Departed
9S1 · Roche Harbor, WA
Destination
Mercer Island, WA

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
50
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 3, Valid Medical--w/ waivers/lim
Last flight review
November 7, 2000
Seat
Left
Flight hours
560 total · 250 in this make and model · 470 as pilot in command · 52 in the last 90 days · 9 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Visibility
20 statute miles
Lowest ceiling
None
Temperature
61 °F

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.