ANC99LA107

NTSB accident investigation · de Havilland DHC-6-300 · Ketchikan, AK · August 7, 1999

Accident · No injuriesLimited investigationFinal report
Date
August 7, 1999, 09:30 local (17:30 UTC)
Place
Ketchikan, AK
Injuries
34 uninjured
Phase of flight
Standing
Aircraft
N288SAde Havilland DHC-6-300N224SAde Havilland DHC-6-300
Weather
Visual (VMC) · Day
Status
Completed · report December 5, 2000
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Case key
47177

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

A failure of ground handling personnel to verify a release procedure/directive, and removal of the airplane's tiedown, and subsequent collision with a parked airplane.

A failure of ground handling personnel to verify a release procedure/directive, and removal of a second airplane's tiedown, and subsequent collision from a second 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.

Collision between aircraft (other than midair)Standing - engine(s) not operating
Object - aircraft parked/standing
Procedures/directives - not verifiedGround personnelCause
Tie down - removedGround personnelCause
Collision between aircraft (other than midair)Standing - engine(s) operating
Object - aircraft parked/standing
Procedures/directives - not verifiedGround personnelCause
Tie down - removedGround personnelCause

Analysis

A pair of float equipped, twin engine airplanes were each parked parallel to a dock. The airplanes were separated by about eight feet, one in front of the other. Both airplanes, operated by the same company, were preparing to depart on sightseeing flights. The crew of first airplane, N288SA, was beginning a passenger briefing. The passengers were on board the airplane, but the engines had not been started. The crew of the second airplane, N224SA, had completed a briefing to their passengers, and had started the engines. N224SA was tethered to the dock by ropes attached to the floats at the forward and aft end of the airplane. Each rope was tended by a company dock handler. Due to a slight change in the manner the passengers arrived from a cruise ship, the passengers had not received a briefing booklet before boarding the airplane. A company representative approached the forward dock handler to hand the briefing booklets to the airplane crew. The aft dock handler observed this activity and mistook its meaning as a 'thumbs up' signal. He released the docking rope, allowing N224SA to begin moving forward under idle power. The nose of N224SA collided with the tail of N288SA. N288SA received damage to the rudder and trim tab assembly. N224SA received minor damage to the left pitot tube, and the left side of the nose.

A pair of float equipped, twin engine airplanes were each parked parallel to a dock. The airplanes were separated by about eight feet, one in front of the other. Both airplanes, operated by the same company, were preparing to depart on sightseeing flights. The crew of first airplane, N288SA, was beginning a passenger briefing. The passengers were on board the airplane, but the engines had not been started. The crew of the second airplane, N224SA, had completed a briefing to their passengers, and had started the engines. N224SA was tethered to the dock by ropes attached to the floats at the forward and aft end of the airplane. Each rope was tended by a company dock handler. Due to a slight change in the manner the passengers arrived from a cruise ship, the passengers had not received a briefing booklet before boarding the airplane. A company representative approached the forward dock handler to hand the briefing booklets to the airplane crew. The aft dock handler observed this activity and mistook its meaning as a 'thumbs up' signal. He released the docking rope, allowing N224SA to begin moving forward under idle power. The and nose of N224SA collided with the tail of N288SA. N288SA received damage to the rudder and trim tab assembly. N224SA received minor damage to the left pitot tube, and the left side of the nose.

Factual narrative

On August 7, 1999, about 0930 Alaska daylight time, a float equipped deHavilland DHC-6-300 airplane, N288SA, sustained substantial damage while docked at Ketchikan, Alaska, when it was struck by another float equipped deHavilland DHC-6-300 airplane, N224SA. Both airplanes were being operated as visual flight rules (VFR) local area sightseeing flights under Title 14, CFR Part 121, when the accident occurred. Both airplanes were operated by Seaborne Aviation Inc., Ketchikan. The captain, the first officer, and the 15 passengers on N288SA, were not injured. The captain, the first officer, and the 15 passengers on N224SA, were not injured. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on August 9, 1999, the Director of Operations for the company reported the crew of N288SA was beginning a passenger briefing to passengers before departing on a sightseeing flight. The passengers were on board the airplane, but the engines had not been started. N224SA, was also tied to the Ketchikan dock, parked behind N288SA. Each airplane was separated by about eight feet.

The director of operations said the crew of N224SA had completed their briefing to the passengers on board the airplane, and had started the engines. The airplane was tethered to the dock by ropes attached to the floats at the forward and aft end of the airplane. Each rope was tended by a company dock handler. Due to a slight change in the manner the passengers arrived from a cruise ship, the passengers had not received a briefing booklet before boarding N224SA. A company representative approached the forward dock handler to hand the briefing booklets to the airplane crew. The aft dock handler observed this activity and mistook its meaning as a "thumbs up" signal. He released the docking rope, allowing N224SA to begin moving forward under idle power. The nose of N224SA collided with the tail of N288SA.

N288SA received damage to the rudder and trim tab assembly. N224SA received minor damage to the left pitot tube, and the left side of the nose.

On August 7, 1999, about 0930 Alaska daylight time, a float equipped deHavilland DHC-6-300 airplane, N288SA, sustained substantial damage while docked at Ketchikan, Alaska, when it was struck by another float equipped deHavilland DHC-6-300 airplane, N224SA. Both airplanes were being operated as visual flight rules (VFR) local area sightseeing flights under Title 14, CFR Part 121, when the accident occurred. Both airplanes were operated by Seaborne Aviation Inc., Ketchikan. The captain, the first officer, and the 15 passengers on N288SA, were not injured. The captain, the first officer, and the 15 passengers on N224SA, were not injured. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect.

During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on August 9, 1999, the Director of Operations for the company reported the crew of N288SA was beginning a passenger briefing to passengers before departing on a sightseeing flight. The passengers were on board the airplane, but the engines had not been started. N224SA, was also tied to the Ketchikan dock, parked behind N288SA. Each airplane was separated by about eight feet.

The director of operations said the crew of N224SA had completed their briefing to the passengers on board the airplane, and had started the engines. The airplane was tethered to the dock by ropes attached to the floats at the forward and aft end of the airplane. Each rope was tended by a company dock handler. Due to a slight change in the manner the passengers arrived from a cruise ship, the passengers had not received a briefing booklet before boarding N224SA. A company representative approached the forward dock handler to hand the briefing booklets to the airplane crew. The aft dock handler observed this activity and mistook its meaning as a "thumbs up" signal. He released the docking rope, allowing N224SA to begin moving forward under idle power. The nose of N224SA collided with the tail of N288SA.

N288SA received damage to the rudder and trim tab assembly. N224SA received minor damage to the left pitot tube, and the left side of the nose.

Aircraft · 2

Registration
N288SA
Reported as
de Havilland DHC-6-300
Category
Airplane
Serial number
389
Airframe hours
33,938
Engine
P&W PT6A-27, 620 horsepower, turbo prop
Damage
Substantial damage
Flight
Part 121
Operator
Seaborne Aviation Inc.
Registered owner
Twin Otter International, Ltd
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · July 20, 1999 · 61 hours before
Flight plan
Company VFR

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.

Registration
N224SA
Reported as
de Havilland DHC-6-300
Category
Airplane
Serial number
247
Airframe hours
34,290
Engine
P&W PT6A-27, 620 horsepower, turbo prop
Damage
Minor damage
Flight
Part 121
Operator
Seaborne Aviation Inc.
Registered owner
Twin Otter International, Ltd
Airworthiness certificate
Standard, Normal
Last inspection
AAIP · July 27, 1999 · 37 hours before
Flight plan
Company VFR

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 · 2

As NTSB recorded them. NTSB leaves out names.

Role
Pilot, aircraft N288SA
Age
44
Certificates
Airline transport, Flight instructor
Airplane ratings
Multi-engine land, Single-engine land, Multi-engine sea, Single-engine sea
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--no waivers/lim.
Seat
Left
Flight hours
14,200 total · 2,400 in this make and model · 12,580 as pilot in command
Role
Pilot, aircraft N224SA
Age
51
Certificates
Commercial, Flight instructor, Airline transport
Airplane ratings
Multi-engine land, Multi-engine sea, Single-engine land
Instrument ratings
Airplane
Medical
Class 1, Valid Medical--w/ waivers/lim
Seat
Left
Flight hours
10,000 total · 3,500 in this make and model · 9,800 as pilot in command · 277 in the last 90 days · 100 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
150° at 10 knots, gusting 35
Visibility
10 statute miles
Lowest ceiling
None
Temperature
64 °F, dew point 54 °F
Altimeter
29.00 inHg
Observed at
PAK, 1 nm away

FAA reports on this event · 2

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