# NTSB DCA11FA072: Bombardier CL600 2B19, N7264V, Phoenix, AZ, April 2, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Field investigation · Final report - Date: April 2, 2011, 09:00 local (16:00 UTC) - Place: Phoenix, AZ - Coordinates: 33.5, -112.166664 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.5000&lon=-112.1667&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) - Highest injury: No injuries - Injuries: 49 uninjured - Status: Completed, report April 6, 2020 - Report: Approved by Office Director - NTSB office: Major Investigations Division - NTSB case key (mKey): 78796 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA11FA072 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/78796/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=78796 - Page: https://openairdocs.org/ntsb/DCA11FA072 ## Probable cause inadequate clearance between the Integrated Drive Generator (IDG) power cables and hydraulic lines in the aft equipment bay that resulted in chaffing of the IDG power cables and hydraulic lines, arcing, and fire. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Electrical power system: electrical pwr sys wiring](https://openairdocs.org/ntsb-findings/01022497): Aircraft › Aircraft systems · Damaged/degraded (probable cause); cases with it: [Bombardier CL-600-2B19, 1 case](https://openairdocs.org/ntsb-findings/01022497/cases.md?model=1390008), [All aircraft, 44 cases](https://openairdocs.org/ntsb-findings/01022497/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach: Fire/smoke (non-impact)](https://openairdocs.org/ntsb-events/150) (defining event); cases with it: [Bombardier CL-600-2B19, 1 case](https://openairdocs.org/ntsb-events/150/sequence.md?model=1390008), [All aircraft, 504 cases](https://openairdocs.org/ntsb-events/150/sequence.md) ## Analysis The flight crew stated that while on final approach, they noted a right engine 10th stage bleed air indication, a right jet pipe over-heat indication, and a right pack over pressure indication. They also noted, after landing, that there was a burning smell. Postaccident examination of the airplane revealed fire damage to the aft equipment bay in the area of the right pylon directly above the auxiliary power unit (APU) exhaust duct. There was evidence of chaffing on the right integrated drive generator (IDG) power feeder cable as well as damage to an adjacent hydraulic line. Additionally, two support brackets, designed to secure the hydraulic line to the aft fuselage, near the area of the fire had fractured, with one bracket no longer attached to the fuselage. Consistent with the chafing, there was a pin-sized hole near the end of the hydraulic line where it connected to a fitting that was mounted on a bracket attaching the line to the airplane's structure. The pin-sized hole was near the chafed IDG cable strand, and about 0.0625 inches from the hydraulic line, instead of the required minimum distance of 2.0 inches specified in Bombardier wiring installation specifications. NTSB Metallurgical examinations of the IDG power feeder cable revealed that the damage to the insulation around the pin-sized hole was consistent with chafing. The examination also found material splatter consistent with electrical arcing of the conductors. The damaged area of the hydraulic line revealed evidence of splattering and material expulsion consistent with electrical arcing against the hydraulic line's external surface. Additionally, the chaffed wire and hydraulic line were examined using energy dispersive x-ray spectroscopy (EDS) to determine if any material transfer consistent with an electrical arcing event, had occurred and the wire and the hydraulic line both had chemical elements not normally found in each. The bracket had fractured into two pieces, and one of the tabs matched the fracture on the main body of the bracket. There was fretting wear damage on the surface of the tab where it was attached to another surface indicative of the tab possibly having rubbed against a bolt or pin used to mount the bracket, and the fracture surface exhibited dimpled ductile fracture that is indicative of overstress bending. As a result of the findings from this accident, both Transport Canada and the FAA released Airworthiness Directives. ## Factual narrative On April 2, 2011, about 0900 central daylight time, Mesa Airlines flight 2651, a Bombardier CL-600-2B19, N7264, experienced an inflight fire while on approach to Phoenix Sky Harbor International Airport (PHX), Phoenix, Arizona. There were no injuries to the 49 passengers and crew onboard but the airplane was substantially damaged. The flight was operating under the provisions of 14 Code of Federal Regulations Part 121, as a regularly scheduled domestic passenger flight from Des Moines International Airport (DSM), Des Moines, Iowa. According to the flight crew, while on final approach to Phoenix Sky Harbor International Airport, they received a right engine 10th stage bleed air indication followed by a right jet pipe over-heat indication and a right pack over pressure indication. Immediately after landing, the flight crew smelled a burning smell but that it went away. There was no electronic flight instrument display or master warning indications of a fire. Postaccident examination of the airplane revealed substantial structural damage as a result of the fire to the fuselage skin, frames, and stringers as well as portions of the pylon from Fuselage Station 640 to about 700. Inspection of the fire damaged area revealed evidence of chaffing on the right integrated drive generator (IDG) power feeder cable and damage to an adjacent hydraulic line. The chafing occurred in the area where the cable was routed adjacent to a pressurized hydraulic line from the right engine driven pump. The hydraulic line contained a pin-sized hole located in the area near the chafed IDG cable strand. The distance between the hydraulic line and the cable was measured and found to be 0.0625 inches. According to Bombardier's wiring installation specifications, electrical wiring should be separated 2.0 inches from flammable liquids and/or gas lines, such that any deflection of the wiring cannot result in a clearance of less than 0.5 inches. Further examination revealed that the two hydraulic line support brackets in the area of the fire had fractured, with one bracket no longer attached to the fuselage. The damaged IDG wire bundle, hydraulic tubing, and support brackets were examined at the NTSB Materials Laboratory. Damage to the IDG wire insulation was consistent with rubbing/chaffing and damage to the conductors was consistent with electrical arcing. Damage to the stainless steel hydraulic line was consistent with electrical arcing against the hydraulic line's external surface. Additionally, the bracket had fractured into two pieces, and one of the tabs matched the fracture on the main body of the bracket. With the associated tab there was fretting wear damage on the surface of the tab where it was attached to another surface indicative of the tab possibly having rubbed against a bolt or pin used to mount the bracket. The fracture surface exhibited dimpled ductile fractures consistent with an overstress bending fracture. Because of this accident, on June 29, 2011,Bombardier issued a service letter recommending that operators perform a detailed visual inspection in the affected area at the earliest possible convenience. The inspection called for operators to pay particular attention to low clearances between the right-hand engine IDG power cables, hydraulic lines, and the support brackets for each. It also went on to provide inspection criteria for said inspections. On July 7, and August 25, 2011, Transport Canada and the FAA respectively released Airworthiness Directives (AD) each, calling for a check for chafed or damaged IDG power cables, and hydraulic lines, and for cracked or broken hydraulic line support brackets in the affected area. The FAA's version of the AD went on to say that "Chafed IDG power cables can generate high energy arcing that can result in an uncontrolled fire in the aft equipment bay." ## Aircraft - Registration: [N7264V](https://openairdocs.org/deregistered/N7264V-2013-09-06), registration cancelled 2013-09-06, S/N 7264, built 1998 (OpenAirDocs) - Reported make and model: BOMBARDIER CL600 2B19 (200) - Registry model: [Bombardier CL-600-2B19](https://openairdocs.org/model/bombardier-cl-600-2b19) (registry code 1390008) (OpenAirDocs) - Registry engine: [GE CF34 series](https://openairdocs.org/engine/ge-cf34-series) (registry code 30015, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 7264 - Airframe hours: 32325 - Engines: General Electric CF34-3B1 8729 lbs thrust turbo fan; General Electric CF34-3B1 8729 lbs thrust turbo fan - Damage: Substantial damage - Fire: In-Flight - Flight: Part 121 - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, April 2, 2011 - Departed: DSM, DES MOINES, IA - Destination: PHX, Phoenix, AZ - Flight plan: IFR - Airport: PHX, Phoenix Sky Harbor Internation, runway 08, 11,489 × 150 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: none; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review April 21, 2010; seat: left; restraint: 5-point; flight hours: 12,104 total, 8,213 in this make and model, 9,382 as pilot in command, 162 in the last 90 days, 85 in the last 30 days, 3 in the last 24 hours - Co-pilot; age 52; injuries: none; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review February 26, 2011; seat: right; restraint: 5-point; flight hours: 7,058 total, 5,567 in this make and model, 185 in the last 90 days, 64 in the last 30 days, 12 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 9 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 34 °F - Altimeter: 29.82 inHg - Observed at: PHX, 5 nm away ## Other investigations on N7264V (1) 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. - [NTSB LAX07IA191](https://openairdocs.org/ntsb/LAX07IA191), Jun 13, 2007: Bombardier CL-600-2B19 (N7264V), Phoenix, AZ, incident, no damage. Probable cause: An out of rig/jammed door. Contributing to the incident was the operator's inadequate maintenance program and the airframe manufacturer's inadequate response to the issue. ## Docket (1 files) The files NTSB released with the investigation on April 16, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=78796. 640 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 640 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40482493&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-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.