# NTSB ERA12LA147: Boeing DHC-8-102, N839EX, Huntington, WV, January 16, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 16, 2012, 07:00 local (12:00 UTC) - Place: Huntington, WV - Coordinates: 38.366943, -82.558609 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=38.3669&lon=-82.5586&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi: Ground handling event](https://openairdocs.org/ntsb-events/080) - Highest injury: No injuries - Injuries: 36 uninjured - Status: Completed, report September 5, 2013 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 82696 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA12LA147 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/82696/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=82696 - Page: https://openairdocs.org/ntsb/ERA12LA147 ## Probable cause The inadequate communication among ground crew personnel, which resulted in the airplane’s collision with a deice truck. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Communication system: visual communication](https://openairdocs.org/ntsb-findings/03016030): Environmental issues › Operating environment · Contributed to outcome (probable cause); cases with it: [Boeing DHC-8-102, 1 case](https://openairdocs.org/ntsb-findings/03016030/cases.md?model=1386002), [All aircraft, 1 case](https://openairdocs.org/ntsb-findings/03016030/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Ground crew (probable cause); cases with it: [Boeing DHC-8-102, 1 case](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=1386002), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi: Ground handling event](https://openairdocs.org/ntsb-events/080) (defining event); cases with it: [Boeing DHC-8-102, 1 case](https://openairdocs.org/ntsb-events/080/sequence.md?model=1386002), [All aircraft, 108 cases](https://openairdocs.org/ntsb-events/080/sequence.md) ## Analysis According to the captain and the first officer, they were instructed to taxi the airplane to an unspecified deice area to remove frost from the airframe. As they taxied, a ground crewmember stood by the wing to ensure the airplane’s clearance from another airline’s equipment and signaled thumbs up to the flight crew to indicate when they were clear of the equipment. After taxiing a short distance, the flight crew stopped and awaited further instructions from a ramp agent on the radio for positioning the airplane. Unknown to the flight crew, the deicing team misunderstood the thumbs-up signal to mean that deicing could begin. Consequently, they moved into a position behind the airplane’s left wing and in front of the left horizontal tail. The ramp agent working the radio could not see the airplane from the radio location and, believing it was still at the gate, instructed the flight crew to taxi 50 feet and stop for deicing. The flight crew initiated taxiing and almost immediately felt a bump, colliding with the boom arm of the deice truck. They then stopped the airplane. The deice truck was not equipped for radio communication; therefore, the team’s movement and position could not be coordinated with the other ground personnel or flight crew. ## Factual narrative On January 16, 2012, about 0700 eastern standard time, a Boeing DHC-8-102, N839EX, registered to US Airways Express and operated by Piedmont Airlines as flight 4117, sustained substantial damage to the left horizontal stabilizer and elevator when it collided with a deicing truck while taxiing at Tri-State Airport (HTS), Huntington, West Virginia. The scheduled domestic passenger flight was conducted under the provisions of 14 Code of Federal Regulations Part 121. Visual meteorological conditions prevailed and an instrument flight rules flight plan had been filed. The 2 pilots, 1 flight attendant and 33 passengers were not injured. The flight was originating from HTS and was destined for Charlotte/Douglas International Airport, Charlotte, North Carolina. According to the Director of Safety for US Airways, HTS had recently changed from deicing on the gate to off-gate deicing. Prior to the airplane leaving the gate, the Captain spoke with the ramp agent, telling him that he would like to taxi out with one engine, and leave the engine in feather while the airport personnel (vendor) conducted the deicing. The ramp agent (1) then walked to the deice vehicle and conveyed the Captain's request, to which the vendor personnel agreed. The ramp agent (1) then went back to the airplane to confirm with the Captain that his plan was acceptable with the vendor. The ramp agent then said that he told the Captain to taxi out in front of Gate 2, but the Captain said he was told to taxi out in a non-specific manner. After the Captain started the #1 engine, an agent pulled the wheel chocks and then went inside to station operations to man the radio, while another agent marshalled the aircraft out of the Gate 1 parking area. Because of the proximity of another airline’s piece of equipment, the agent doing the marshalling then stood by the wing to ensure sufficient clearance, and gave thumbs up to the flight crew to signal that they were clear of the equipment. After the airplane taxied out and was positioned near gate 2, the Captain stopped the airplane and asked the First Officer (FO) to call station operations and clarify where they were to go for the deicing. The FO spoke with the ramp agent who was working the radio, but the agent could not see the airplane and did not realize the aircraft had left the gate. Assuming that the aircraft was still at the gate, the agent told the crew to taxi 50 feet or so and stop. Without the flight crew’s knowledge, the vendor’s deicing team misunderstood the agent’s thumbs up signal as the signal that deicing could begin. Consequently, the deicing team moved into a position behind the left wing and in front of the left horizontal tail when the aircraft first stopped, and started spraying the rear of the aircraft. Having received guidance from station operations to move 50 feet, the flight crew initiated taxiing and almost immediately felt a bump, then stopped. After seeing the aircraft start to move, the bucket operator yelled tothe driver to "back up" and tried to lower the boom, but the aircraft tail had already struck the boom arm. ## Aircraft - Registration: [N839EX](https://openairdocs.org/aircraft/N839EX), registered now, S/N 226, built 1990 (OpenAirDocs) - Reported make and model: BOEING DHC-8-102 - Registry model: [Boeing DHC-8-102](https://openairdocs.org/model/boeing-dhc-8-102) (registry code 1386002) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PW120](https://openairdocs.org/engine/pratt-whitney-canada-pw120) (registry code 52114, turbo-prop) (OpenAirDocs) - Category: Airplane - Serial number: 226 - Airframe hours: 40609 - Engines: P&W CANADA PW120 1800 horsepower turbo prop; P&W CANADA PW120 1800 horsepower turbo prop - Damage: Substantial damage - Flight: Part 121 - Operator: Piedmont Airlines Incorporated, doing business as Piedmont Airlines Incorportated - Registered owner: US Airways Inc - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, December 11, 2011, 291 hours before - Departed: HTS, Huntington, WV - Destination: CLT, Charlotte, NC - Flight plan: IFR - Airport: HTS, Tri-State Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 56; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: left; flight hours: 20,800 total, 19,500 in this make and model, 210 in the last 90 days - Co-pilot; age 40; injuries: none; commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; seat: right; flight hours: 8,000 total ## Weather - Conditions: Visual (VMC), Dawn - Wind: 180° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 39 °F, dew point 45 °F - Altimeter: 30.28 inHg - Observed at: HTS ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20120116000849A](https://openairdocs.org/incident/20120116000849A), Jan 16, 2012: Boeing DHC-8-102, Huntington, WV, Substantial damage. A piedmont flight 4117, in aircraft N839EX, struck a deicing truck boom with the left horizontal stabilizer, elevator and elevator trim tab, while taxiing on… ## Docket (11 files) The files NTSB released with the investigation on July 22, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=82696. 10.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 5.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371944&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Ground operation statement-Smith (item 2, .PDF, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371945&FileExtension=.PDF&FileName=Ground%20operation%20statement-Smith-Redacted.PDF - Deice truck driver statement-C Hay (item 3, .PDF, 122 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371946&FileExtension=.PDF&FileName=Deice%20truck%20driver%20statement-C%20Hay-Redacted.PDF - Marshaller statement-Douglas (item 4, .PDF, 169 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371947&FileExtension=.PDF&FileName=Marshaller%20statement-Douglas-Redacted.PDF - Other Pertinent Forms and Reports-US Airways Ground deicing manual pages (item 5, .PDF, 364 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371948&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-US%20Airways%20Ground%20deicing%20manual%20pages-Master.PDF - Other Pertinent Forms and Reports-US Airways training pages (item 6, .PDF, 85 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371949&FileExtension=.PDF&FileName=Other%20Pertinent%20Forms%20and%20Reports-US%20Airways%20training%20pages-Master.PDF - Statement of Party Representatives to NTSB Investigation-Piedmont (item 7, .PDF, 173 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371954&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Piedmont-Redacted.PDF - Statement of Party Representatives to NTSB Investigation-ALPA (item 8, .PDF, 183 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371955&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-ALPA-Redacted.PDF - Photo 1- FAA photo-Elevator damage underside (item 9, .PDF, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371952&FileExtension=.PDF&FileName=Photo%201-%20FAA%20photo-Elevator%20damage%20underside-Master.PDF - Photo 2-FAA photo-Deice truck boom arm (item 10, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40371953&FileExtension=.PDF&FileName=Photo%202-FAA%20photo-Deice%20truck%20boom%20arm-Master.PDF - Cockpit Voice Recorder 12 - Specialist's Factual Report (item 11, .PDF, 37 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40397142&FileExtension=.PDF&FileName=Cockpit%20Voice%20Recorder%2012%20-%20Specialist%27s%20Factual%20Report-Master.PDF 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.