# NTSB ANC99LA107: de Havilland DHC-6-300, N288SA, Ketchikan, AK, August 7, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 7, 1999, 09:30 local (17:30 UTC) - Place: Ketchikan, AK - Coordinates: 55.610191, -131.579452 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=55.6102&lon=-131.5795&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 34 uninjured - Status: Completed, report December 5, 2000 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - NTSB case key (mKey): 47177 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC99LA107 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47177/pdf - Page: https://openairdocs.org/ntsb/ANC99LA107 ## Probable cause (aircraft 2) 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. ## Probable cause (aircraft 1) 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 In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Collision between aircraft (other than midair), standing - engine(s) not operating - object - aircraft parked/standing - procedures/directives - not verified, ground personnel (cause) - tie down - removed, ground personnel (cause) - Collision between aircraft (other than midair), standing - engine(s) operating - object - aircraft parked/standing - procedures/directives - not verified, ground personnel (cause) - tie down - removed, ground personnel (cause) ## Analysis (aircraft 2) 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. ## Analysis (aircraft 1) 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 (aircraft 2) 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. ## Factual narrative (aircraft 1) 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 1 - Registration: [N288SA](https://openairdocs.org/deregistered/N288SA-2016-01-14), registration cancelled 2016-01-14, S/N 389, built 1973 (OpenAirDocs) - Reported make and model: de Havilland DHC-6-300 - Registry model: [Dehavilland DHC-6-300](https://openairdocs.org/model/dehavilland-dhc-6-300) (registry code 2802630) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 389 - Airframe hours: 33938 - Engines: 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 ## Aircraft 2 - Registration: [N224SA](https://openairdocs.org/aircraft/N224SA), registered now, S/N 247, built 1969 (OpenAirDocs) - Reported make and model: de Havilland DHC-6-300 - Registry model: [Dehavilland DHC-6-300](https://openairdocs.org/model/dehavilland-dhc-6-300) (registry code 2802630) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52032, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 247 - Airframe hours: 34290 - Engines: 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 ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot, aircraft N288SA; age 44; 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 - Pilot, aircraft N224SA; age 51; 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 (OpenAirDocs). - [Accident 19990807041892A](https://openairdocs.org/incident/19990807041892A), Aug 7, 1999: Dhav DHC6300, Ketchikan, AK, Substantial damage. Seaborne aviation air taxi (float plane) was parked at the dock when it was struck by N224SA, another seaborne aviation DH6 air taxi (float plane), which was… - [Accident 19990807041891A](https://openairdocs.org/incident/19990807041891A), Aug 7, 1999: Dhav DHC6300, Ketchikan, AK, Minor damage. (.4)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… From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.