# NTSB CEN12LA335: Short Bros Shorts SD3-60, N617FB, Houston, TX, May 17, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 17, 2012, 07:15 local (12:15 UTC) - Place: Houston, TX - Coordinates: 29.985277, -95.346946 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=29.9853&lon=-95.3469&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report November 6, 2013 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA FSDO Houston - NTSB case key (mKey): 83853 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA335 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83853/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83853 - Page: https://openairdocs.org/ntsb/CEN12LA335 ## Probable cause The pilots’ improper decision to burn fuel during the taxi by operating the engines at a higher-than-normal power setting and using the wheel brakes to control taxi speed, which resulted in a wheel fire. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Flight crew (probable cause); cases with it: [Short Bros SHORTS SD3-60, 1 case](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=8100605), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Action: incorrect action performance](https://openairdocs.org/ntsb-findings/02041015): Personnel issues › Action/decision · Flight crew (probable cause); cases with it: [Short Bros SHORTS SD3-60, 1 case](https://openairdocs.org/ntsb-findings/02041015/cases.md?model=8100605), [All aircraft, 1,386 cases](https://openairdocs.org/ntsb-findings/02041015/cases.md) - [Landing gear system: brake](https://openairdocs.org/ntsb-findings/01023242): Aircraft › Aircraft systems · Incorrect use/operation (probable cause); cases with it: [Short Bros SHORTS SD3-60, 1 case](https://openairdocs.org/ntsb-findings/01023242/cases.md?model=8100605), [All aircraft, 297 cases](https://openairdocs.org/ntsb-findings/01023242/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Short Bros SHORTS SD3-60, 1 case](https://openairdocs.org/ntsb-events/900/sequence.md?model=8100605), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) ## Analysis The pilots reported that the cargo airplane was about 60 pounds over its maximum takeoff weight. Because their taxi to the assigned runway was long, they decided to reduce weight by using higher-than-normal engine power settings to burn fuel before takeoff while using the wheel brakes to control the airplane’s speed while taxiing. During the taxi, a fire ignited in the right wheel housing. The pilots brought the airplane to a stop on the taxiway, evacuated, and attempted to extinguish the fire with two handheld fire extinguishers. Airport firefighting personnel arrived on scene and extinguished the fire using foam suppressant. Although the fire damage was extensive, postaccident examination of the airplane did not show evidence of mechanical malfunctions or failures with the wheel and brake system that could have caused the fire. The right and left main landing gear tires deflated when the fusible plugs in the wheels blew due to overheating. The fusible plugs are designed to “fail” if the wheels overheat, and those plugs functioned as designed. The pilots stated that they had been trained to not ride the brakes while taxiing. However, the captain stated that he did not realize that he was in danger of blowing the tires much less causing a fire, otherwise he would not have attempted to bum off excess fuel while taxiing. ## Factual narrative On May 17, 2012, about 0715 central daylight time, a Shorts SD3-60, N617FB, registered to ACC Integrated Services Inc., of Milwaukee, Wisconsin, was substantially damaged following a wheel brake fire during taxi at the George Bush Intercontinental Airport, Houston, Texas. The airline transport pilot and commercial co-pilot were not injured. The airplane was being operated by Air Cargo Carriers LLC of Milwaukee, Wisconsin, as an air cargo flight under the provisions of 14 Code of Regulations Part 135. Visual meteorological conditions prevailed and a flight plan was filed. The airplane was taxiing to position for takeoff from runway 8R and its intended destination was Austin, Texas. The flight crew reported that the airplane was about 60 pounds over its maximum weight for takeoff. Since their taxi to the assigned runway was long, they decided to reduce weight by using higher-than-normal engine power settings while maintaining some amount of braking to control speed while taxiing in order to burn fuel prior to takeoff. During the taxi, the right and left main landing gear tires deflated when the fusible plugs in the wheels blew out due to over-heating, and a fire ignited in the right wheel housing. The crew reported that they felt the airplane yaw as the tires deflated and were informed via radio by a following airplane that their right wheel was on fire. The crew brought the airplane to a stop on the taxiway, evacuated, and attempted to extinguish the fire with two hand-held fire extinguishers. Airport fire fighting personnel arrived on scene and extinguished the fire using foam suppressant. The fire resulted in substantial damage to the wing support structures. No injuries were incurred to the flight crew or ground personnel. Although the fire damage was extensive, postaccident examination of the airplane by an FAA inspector, a NTSB investigator, and the operator's maintenance personnel did not show evidence of mechanical malfunction or abnormalities with the wheel and brake system. The Shorts SD3-60 is a twin turbo-prop, strutted, high-wing airplane. Each of the main wheels are equipped with fusible plugs that are designed to blow out in the event of severe wheel overheating. Inspection of the airplane's wheel and brake systems after the accident showed that the plugs on both main wheels blew out as designed. The fire caused severe damage to the right main gear housing, which was part of the stub wing assembly structure and incorporates the attachment fitting for the wing strut. The operator's maintenance department believed that the fire caused substantial structural damage to the extent that repair was not practical. The operator submitted in NTSB Form 6120 that both crew members stated that they had been trained to not ride the brakes while taxiing. Additionally, the Captain stated that he did not realize that he was in danger of blowing the tires much less causing a fire, otherwise he would not have attempted to bum off excess fuel whiletaxiing. The operator revised its training program to highlight the hazards of excessive brake use during all ground operations, including taxi. Additional emphasis will be placed on the purpose of the fusible plugs and photographs of the event will be used in all future training classes where the brake system is taught. ## Aircraft - Registration: [N617FB](https://openairdocs.org/deregistered/N617FB-2013-02-12), registration cancelled 2013-02-12, S/N SH3617, built 1983 (OpenAirDocs) - Reported make and model: SHORT BROS SHORTS SD3-60 - Registry model: [Short Bros SHORTS SD3-60](https://openairdocs.org/model/short-bros-shorts-sd3-60) (registry code 8100605) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Airplane - Serial number: SH3617 - Airframe hours: 27504 - Engines: Pratt & Whitney PT6A-65AR 1425 horsepower turbo prop; Pratt & Whitney PT6A-65AR 1425 horsepower turbo prop - Damage: Substantial damage - Fire: On-Ground - Flight: Part 135 - Operator: Acc Integrated Services Inc, doing business as Air Cargo Carriers LLC - Registered owner: Acc Integrated Services Inc - Airworthiness certificate: Standard, Transport - Last inspection: AAIP, May 9, 2012 - Departed: IAH, Houston, TX - Destination: AUS, Austin, TX - Flight plan: Unknown - Airport: IAH, Geotge Bush International ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 31; injuries: none; airline transport, flight instructor, private, commercial; airplane ratings: single-engine sea, multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review February 8, 2012; seat: left; flight hours: 5,348 total, 2,305 in this make and model - Co-pilot; age 25; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review February 3, 2012; seat: right; flight hours: 832 total, 171 in this make and model ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 72 °F - Altimeter: 29.82 inHg - Observed at: IAH ## 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 20120517012469A](https://openairdocs.org/incident/20120517012469A), May 17, 2012: Short Bros SHORTS SD3-60, Houston, TX, Substantial damage. Pilot stated the aircraft was loaded to maximum capacity and he had about 60 to 100 lbs of fuel to burn off before take-off. Pilot said he did not want to get… ## Docket (9 files) The files NTSB released with the investigation on August 7, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83853. 6.8 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 3.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396143&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Statement from Operator (item 2, .PDF, 72 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396383&FileExtension=.PDF&FileName=Statement%20from%20Operator-Redacted.PDF - Captain's Statement (item 3, .PDF, 19 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396384&FileExtension=.PDF&FileName=Captain%27s%20Statement-Redacted.PDF - First Officer's Statement (item 4, .PDF, 16 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396385&FileExtension=.PDF&FileName=First%20Officer%27s%20Statement-Redacted.PDF - Photo 1 Airplane with Fire Damage to Right Stub Wing Assembly (item 5, .PDF, 601 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396386&FileExtension=.PDF&FileName=Photo%201%20Airplane%20with%20Fire%20Damage%20to%20Right%20Stub%20Wing%20Assembly-Master.PDF - Photo 2 Closeup of Fire Damage to Right Stub Wing Assembly (item 6, .PDF, 627 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396387&FileExtension=.PDF&FileName=Photo%202%20Closeup%20of%20Fire%20Damage%20to%20Right%20Stub%20Wing%20Assembly-Master.PDF - Photo 3 Fire Damage to Right Wheel and Brake Assembly (item 7, .PDF, 674 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396388&FileExtension=.PDF&FileName=Photo%203%20Fire%20Damage%20to%20Right%20Wheel%20and%20Brake%20Assembly-Master.PDF - Photo 4 Closeup of Fire Damage to Right Wheel and Brake Assembly (item 8, .PDF, 719 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396389&FileExtension=.PDF&FileName=Photo%204%20Closeup%20of%20Fire%20Damage%20to%20Right%20Wheel%20and%20Brake%20Assembly-Master.PDF - Photo 5 Rear Aspect of Fire Damage to Right Stub Wing Assembly (item 9, .PDF, 371 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40396390&FileExtension=.PDF&FileName=Photo%205%20Rear%20Aspect%20of%20Fire%20Damage%20to%20Right%20Stub%20Wing%20Assembly-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.