# NTSB LAX02GA201: Lockheed C-130A, N130HP, Walker, CA, June 17, 2002 - Type: NTSB accident investigation - Classification: Accident · Fatal · Final report - Date: June 17, 2002, 14:45 local (21:45 UTC) - Place: Walker, CA - Coordinates: 38.520557, -119.481941 - Nearby events: https://openairdocs.org/map.md?lat=38.5206&lon=-119.4819&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 3 fatal - Status: Completed, report April 23, 2004 - Report: Approved by Office Director - Parties: Hawkins and Powers, Rolls-Royce/Allison, FAA, USDA-FS, Lockheed Martin - NTSB case key (mKey): 54968 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX02GA201 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54968/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54968 - Page: https://openairdocs.org/ntsb/LAX02GA201 ## Probable cause the inflight failure of the right wing due to fatigue cracking in the center wing lower skin and underlying structural members. A factor contributing to the accident was inadequate maintenance procedures to detect fatigue cracking. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - aerial application - wing - failure,total - wing,spar - fatigue (cause) - maintenance,inspection - inadequate, company/operator management (contributing factor) - wing,skin - fatigue (cause) - In flight collision with terrain/water, descent - uncontrolled - aircraft control - not possible - In flight collision with terrain/water, descent - uncontrolled - terrain condition - mountainous/hilly ## Analysis The airplane was making a fire retardant drop over a mountain drainage valley when the wings separated from the fuselage. A videotape of the accident sequence showed the airplane as it flew down the valley and proceeded to make a fire retardant drop. When the drop was almost completed, the airplane's nose began moving up, and the airplane started to arrest its descent and level out. The nose of the airplane continued to rise, and the airplane's wings folded upward until they detached from the fuselage at the center wing box beam-to-fuselage attachment location. Close examination of the video revealed that the right wing folded upward first, followed by the left wing about 1 second later. Metallurgical examination of the center wing box lower skin revealed a 12-inch long fatigue crack on the lower surface of the right wing beneath the forward doubler, with two separate fatigue crack initiation sites at stringer attachment rivet holes (which join the external doubler and the internal stringers to the lower skin panel). The cracks from both initiation sites eventually linked up to create a single crack. The portion of the wing skin containing the fatigue crack was covered by a manufacturer-installed doubler, which would have hidden the crack from view and, therefore, prevented detection of the crack from a visual inspection of the exterior of the airplane. The investigation found that the airplane was probably operated within the maximum takeoff gross weight limits specified in the airplane flight manual. The airplane was delivered new to the U.S. Air Force (USAF) in 1957 and was retired from military service in 1978. The U.S. Forest Service (USFS) acquired it from the USAF in 1988 for use as a fire suppression tanker. Between 1978 and 1988, it was kept in a desert storage facility. It was transferred to a civilian contractor for firefighting operations and modified for that role, then sold to a Part 135 operator. The airplane was certificated by the FAA in the restricted category under a type certificate held by the USFS. A Lockheed study concluded that firefighting missions were substantially more severe than typical military logistics operations and aircraft operated in this role would require inspection intervals as much as 12 times more frequently than typical military transport usage for meeting damage tolerance requirements. Concerning the detectability of the cracks, Lockheed reported that nondestructive x-ray inspection methods in current industry and military depot level maintenance processes could have detected, with high confidence, the fatigue cracks when they were 0.50 to 0.75 inch long. Inspection intervals appropriate for this detectable crack size can be determined from a damage tolerance crack growth analysis; however, this requires an extensive knowledge of the operational loads environment and internal stresses of the C-130A wing such as would be found in a military depot level maintenance program. The operating limitations accompanying the restricted certificate specified that it be flown and maintained in accordance with the then-current (1988) USAF technical orders for the C-130A. The USAF depot level maintenance program was not included in the maintenance technical orders and was not individually specified on the certificate's operating limitations. The limitations letter did not specify compliance with USAF maintenance program modifications/amendments in technical orders issued after 1988. The operator devised a maintenance and inspection program based on the specified USAF maintenance technical order but did not develop a depot level inspection requirement to ensure continued long-term airworthiness and damage tolerance that would account for the stresses on the airplane resulting from its new firefighting role and the increasing age of the airplanes. Investigation found that there are five separate FAA-issued type certificates owned by five separate firms for the C-130As used as tankers. Although the five certificates have similar maintenance requirements, none are standardized, there is no depot level maintenance program specified for any of them, and none require full compliance with all military airworthiness technical orders. In 1991, the Department of Interior (DOI) began to doubt the continued airworthiness of the C-130A firefighting tanker fleet and was specifically concerned that the lack of a depot level maintenance program or any requirement for compliance with all military airworthiness technical orders could compromise the safety of the airplane. The DOI asked the FAA to standardize the type certificate for the C-130A and mandate improvements in the maintenance and inspection requirements. In a written opinion, the USAF agreed and urged the FAA to mandate that operators establish a depot level type continuing airworthiness program for the airplane and mandate compliance with all technical orders. In a series of meetings held in 1993, FAA management internally agreed that the DOI and USAF positions held merit and began to develop requirements. In late 1993, in a meeting between the FAA, DOI, USFS, and the airplane operators, the USFS and the operators objected to the idea of depot level maintenance programs and full compliance with all technical orders on the basis of the potential economic impact of these requirements. As of the time of the accident, the FAA had not standardized the existing five type certificates nor had they imposed any additional maintenance or inspection program requirements. ## Factual narrative HISTORY OF FLIGHT On June 17, 2002, about 1445 Pacific daylight time, a Lockheed C-130A, N130HP, broke apart in flight while executing a fire retardant delivery near Walker, California. The airplane was registered to Hawkins and Powers Aviation, Inc., Greybull, Wyoming, and operated by the Department of Agriculture (USDA), US Forestry Service (USFS) under 14 CFR Part 91 for the public-use firefighting flight. The three flight crewmembers were fatally injured and the airplane was destroyed. Visual meteorological conditions prevailed, and a company flight plan had been filed. The airplane had departed Minden, Nevada, about 1429, to participate in firefighting efforts near Walker. The accident flight started with the airplane, using the call sign tanker T130, at the Minden Air Tanker Base for loading of fire retardant. According to the relevant Minden Air Tanker Dispatch/Flight Record sheet, tanker T130 was loaded with 3,000 gallons of fire retardant but no fuel was added. The airplane departed Minden at 1429, for its sixth drop of the day, and proceeded directly to the Cannon Fire located adjacent to Walker. Although the aircrew of tanker T130 had already made five previous drops on a north to south axis the day of the accident, the sixth drop was to be their first run on an east/west course. Prior to the run, tanker T130 made a pass over the drop area in the direction of the intended drop. The intended run required a course heading of approximately 90 degrees over and perpendicular to a ridgeline and down a steep drainage valley. A witness to the accident videotaped the accident sequence starting with T130 at the top of the ridgeline to a point after the wings had separated from the airplane. The following account of the accident sequence is based on the video footage. Tanker T130 flew down the east side of the drainage valley and proceeded to make a 1/2 salvo fire retardant drop. Just prior to the completion of the drop, the nose of the airplane appeared to rise and the airplane started to initially arrest its descent and to level out. The nose of the airplane then continued to rise towards a nose up attitude and almost at the completion of the 1/2 salvo fire retardant drop, the airplane's wings folded upwards and detached from the fuselage at the center wing box beam-to-fuselage attachment location. Close examination of the video revealed that the right wing folded upwards first followed slightly less than 1 second later by the left wing. After the wings separated, the fuselage continued to travel in the direction of the intended flight path, the nose pitched down, and the fuselage rolled to the right (clockwise) becoming inverted until the airplane was out of camera shot. Subsequent examination of the wreckage and the right wing disclosed evidence of fatigue cracks in the right wing's lower surface skin panel, with origins beneath the forward doubler at Center Wing Station (CWS) 53R at the stringers 16 and 17 location. The origin points were determined to be in rivet holes, which join the external doubler and the internal stringers to the lower skin panel. These cracks, which grew together to about a 12-inch length, were found to have propagated past the area where they would have been covered by the doubler and into the stringers beneath the doubler and across the lap joint between the middle skin panel and the forward skin panel. PERSONNEL INFORMATION First Pilot Information The pilot held an airline transport pilot certificate with single and multiengine land airplane ratings, rotorcraft helicopter and gliders limited to aero tow. His certificate was endorsed with type ratings for DC-6, DC-7, CY-P4Y, FA-119C, DC-826, L P2V, L-382 (the civil version of the C-130E). His most recent second-class medical certificate was issued on March 12, 2002, and contained no limitations. He also held a flight engineer certificate for turbo propeller powered airplanes and was a certificated airframe and powerplant technician. According to the Forestry Service Airplane Pilot Qualification and Approval Record, dated March 30, 2002, the pilot had recorded a total flight time of 10,833 hours, with 130 hours in the last 12 months. He was approved to fly C130A, P2V, and PB4Y2 aircraft. The form lists 1,790, 915, and 1,450 hours in the approved aircraft as listed. The pilot's last documented biennial flight review occurred on March 30, 2002, in a C130. Copilot Information The copilot held an airline transport pilot certificate with a multiengine airplane land rating. He also held certificates as an advanced ground instructor, an airframe and powerplant technician, and a flight engineer with a rating for turbo propeller powered airplanes. His certificate was endorsed with a type rating in the L-382, the civil version of the C-130E model. The copilot's most recent second-class medical certificate was issued January 23, 2002, and contained the limitation that corrective lenses be worn. The Forestry Service Airplane Pilot Qualifications and Approval Record, dated February 4, 2002, recorded a total flight time of 2,407 hours with 199 hours in the last 12 months. He was approved to fly the C-130, or perform the functions of a flight engineer in the C-130. The record documented 322 hours of flight time as pilot-in-command. The date of his last flight check was September 19, 2001. The copilot's last biennial flight review equivalent occurred on January 29, 2002. Flight Engineer Information This crewmember held a Flight Engineer certificate with ratings for jet and turbo propeller airplanes. In addition, he held a commercial pilot certificate with land airplane ratings for single engine, multiengine and instruments. He also held a Flight Instructor certificate with the same airplane ratings found on his commercial pilot certificate. Other certificates held were a ground instructor and a certificated airframe and powerplant technician. AIRCRAFT INFORMATION General Airplane History The USDA Forest Service promoted the transfer of military surplus C-130A airplanes to the contract fire tanker operators in an effort to update the fleet of airtankers to an all turbine fleet. After the USDA Forest Service facilitated transfer of an airplane, it became the operator's financial responsibility to prepare the airplanes for the airtanker mission. The operators then had to competitively bid for the contract at a low enough price to be awarded a year-long contract for fire suppression missions. According to statements from Forest Service contracting specialists, the monetary element of the bid may be the most critical in getting work for the airplanes because of Forest Service budget constraints. The accident airplane was delivered to the United States Air Force (USAF) in December 1957 as a Lockheed Aircraft Corporation C-130A Hercules, Air Force serial number 56-0538, Lockheed serial number 3146, and was retired from military service in 1978 and placed in storage at the Davis-Monthan Air Force Base near Tucson, Arizona. On May 24, 1988, the Forest Service acquired SN 56-0538, along with six other C-130A airplanes, from the General Services Administration (GSA). According to the a GSA transfer order dated January 1988, the airplane's total time was 19,546.8 hours time since new (TSN). On August 12, 1988, the airplane was sold by the USFS to Hemet Valley Flying Service, Hemet, California, along with five other recently acquired C-130A airplanes, for installation of retardant tanks. Hemet Valley applied for a US civil registration number of N134FF for airplane SN 56-538 on July 19, 1988, and subsequently sold it to Hawkins & Powers Aviation, Inc. (H&P), on December 5, 1988. In accordance with 14 CFR 21.53, on December 10, 1988, H&P prepared and presented to the FAA a Statement of Conformity, FAA Form 8130-9, for civil type certification of the airplane. This statement included a declaration tha ## Aircraft - Registration: [N130HP](https://openairdocs.org/deregistered/N130HP-2002-12-16), registration cancelled 2002-12-16, S/N 56-538 (OpenAirDocs) - Reported make and model: Lockheed C-130A - Registry model: [Lockheed C-130A](https://openairdocs.org/model/lockheed-c-130a) (registry code 5262502) (OpenAirDocs) - Category: Airplane - Serial number: 56-538 - Airframe hours: 21863 - Engines: Allison T56A-9D 3750 horsepower turbo prop - Damage: Destroyed - Fire: On-Ground - Flight: Aerial application, Public use - Operator: USDA - Forestry Service - Registered owner: Hawkins and Powers Aviation - Airworthiness certificate: Special, Restricted (Special) - Last inspection: AAIP, September 1, 2001, 168 hours before - Departed: MEV, Minden, NV - Flight plan: Company VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 42; injuries: fatal; flight engineer, airline transport, flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; last flight review March 30, 2002; seat: left; toxicology performed; flight hours: 10,833 total, 110,290 as pilot in command, 108 in the last 90 days, 87 in the last 30 days - Co-pilot; age 36; injuries: fatal; flight engineer, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review January 29, 2002; seat: right; flight hours: 2,407 total, 1,614 as pilot in command, 156 in the last 90 days, 87 in the last 30 days - Flight engineer; age 59; injuries: fatal; flight instructor, flight engineer, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: rear; flight hours: 1,630 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 15 knots, gusting 21 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 36 °F - Altimeter: 30.20 inHg - Observed at: TVL, 46 nm away ## 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 20020617012619A](https://openairdocs.org/incident/20020617012619A), Jun 17, 2002: Lkheed C130A, Walker, CA, No damage, 3 fatal. (-23) Both wings separated from the fuselage during a firefighting retardant drop. ## Docket (87 files) The files NTSB released with the investigation on June 10, 2004, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54968. 45.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Forest Service (item 1, .PDF, 261 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428302&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Forest%20Service-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Hawkins & Powers (item 2, .PDF, 350 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428303&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Hawkins%20%26%20Powers-Redacted.PDF - Meteorology 5 - Factual Report of Group Chairman (item 3, .PDF, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167467&FileExtension=.PDF&FileName=Meteorology%205%20-%20Factual%20Report%20of%20Group%20Chairman-Master.PDF - Statement of Party Representatives to NTSB Investigation (item 4, .PDF, 308 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428304&FileExtension=.PDF&FileName=Statement%20of%20Party%20Representatives%20to%20NTSB%20Investigation-Redacted.PDF - Toxicological Report (item 5, .PDF, 56 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428305&FileExtension=.PDF&FileName=Toxicological%20Report-Redacted.PDF - Service Difficulty Report, April 1998 (item 6, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180703&FileExtension=.PDF&FileName=Service%20Difficulty%20Report,%20April%201998-Master.PDF - Fowler Inc. Metallurgical Report (item 7, .PDF, 22 photos, 7.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428306&FileExtension=.PDF&FileName=Fowler%20Inc.%20Metallurgical%20Report-Redacted.PDF - Lockheed C-130 Service Life Analysis/Summary (item 8, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180706&FileExtension=.PDF&FileName=Lockheed%20C-130%20Service%20Life%20Analysis%2FSummary-Master.PDF - Report of Excess Personal Property (item 9, .PDF, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428307&FileExtension=.PDF&FileName=Report%20of%20Excess%20Personal%20Property-Redacted.PDF - USFS Service Contract on Aircraft Maintenance Excerpt (item 10, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180709&FileExtension=.PDF&FileName=USFS%20Service%20Contract%20on%20Aircraft%20Maintenance%20Excerpt-Master.PDF - Lockheed Support of C-130 Investigation (item 11, .PDF, 180 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428308&FileExtension=.PDF&FileName=Lockheed%20Support%20of%20C-130%20Investigation-Redacted.PDF - Lockheed Crack Growth Analysis (item 12, .PDF, 509 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428309&FileExtension=.PDF&FileName=Lockheed%20Crack%20Growth%20Analysis-Redacted.PDF - Briefing Papers on Certification and Maintenance (item 13, .PDF, 166 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428310&FileExtension=.PDF&FileName=Briefing%20Papers%20on%20Certification%20and%20Maintenance-Redacted.PDF - FAA Inspector Recommendations for Accident Prevention Memo (item 14, .PDF, 94 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428311&FileExtension=.PDF&FileName=FAA%20Inspector%20Recommendations%20for%20Accident%20Prevention%20Memo-Redacted.PDF - DOI Memo Dated February 26, 1993 (item 15, .PDF, 73 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428312&FileExtension=.PDF&FileName=DOI%20Memo%20Dated%20February%2026,%201993-Redacted.PDF - WR-ALC Required Maintenance Information (item 16, .PDF, 378 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428313&FileExtension=.PDF&FileName=WR-ALC%20Required%20Maintenance%20Information-Redacted.PDF - DOI Memos on Inspection and Maintenance (item 17, .PDF, 352 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428314&FileExtension=.PDF&FileName=DOI%20Memos%20on%20Inspection%20and%20Maintenance-Redacted.PDF - Aircraft Performance Information (item 18, .PDF, 387 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428315&FileExtension=.PDF&FileName=Aircraft%20Performance%20Information-Redacted.PDF - Maintenance Record (item 19, .PDF, 63 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428316&FileExtension=.PDF&FileName=Maintenance%20Record-Redacted.PDF - Cedtech Inspection Report (item 20, .PDF, 77 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428317&FileExtension=.PDF&FileName=Cedtech%20Inspection%20Report-Redacted.PDF - Crew Information (item 21, .PDF, 635 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428318&FileExtension=.PDF&FileName=Crew%20Information-Redacted.PDF - Air Tanker Dispatch/Flight Record (item 22, .PDF, 94 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428319&FileExtension=.PDF&FileName=Air%20Tanker%20Dispatch%2FFlight%20Record-Redacted.PDF - USDA Memo Regarding C-103A Wing Cracks (item 23, .PDF, 40 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180737&FileExtension=.PDF&FileName=USDA%20Memo%20Regarding%20C-103A%20Wing%20Cracks-Master.PDF - Application for Airworthiness Certificate/Operating Limitations (item 24, .PDF, 701 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428320&FileExtension=.PDF&FileName=Application%20for%20Airworthiness%20Certificate%2FOperating%20Limitations-Redacted.PDF - FAA Memo Addressing Restricted Category (item 25, .PDF, 101 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428639&FileExtension=.PDF&FileName=FAA%20Memo%20Addressing%20Restricted%20Category-Redacted.PDF - FAA Memo on Airworthiness Concerns (item 26, .PDF, 71 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428640&FileExtension=.PDF&FileName=FAA%20Memo%20on%20Airworthiness%20Concerns-Redacted.PDF - FAA Action Plan (item 27, .PDF, 113 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428641&FileExtension=.PDF&FileName=FAA%20Action%20Plan-Redacted.PDF - FAA Restricted Category Aircraft Operations Draft (item 28, .PDF, 241 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180743&FileExtension=.PDF&FileName=FAA%20Restricted%20Category%20Aircraft%20Operations%20Draft-Master.PDF - Information on the Operation of Public Aircraft (item 29, .PDF, 498 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180744&FileExtension=.PDF&FileName=Information%20on%20the%20Operation%20of%20Public%20Aircraft%20-Master.PDF - Hemet Valley Flying Service Registration Information (item 30, .PDF, 285 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428642&FileExtension=.PDF&FileName=Hemet%20Valley%20Flying%20Service%20Registration%20Information-Redacted.PDF - Hawkins and Powers Registration Information (item 31, .PDF, 774 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428643&FileExtension=.PDF&FileName=Hawkins%20and%20Powers%20Registration%20Information-Redacted.PDF - Photo 1. Center wing lower doubler installation. (item 32, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180747&FileExtension=.PDF&FileName=Photo%201.%20%20Center%20wing%20lower%20doubler%20installation.-Master.PDF - Photo 2. Still photo showing unusual wind patterns. (item 33, .PDF, 466 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40213498&FileExtension=.PDF&FileName=Photo%202.%20%20Still%20photo%20showing%20unusual%20wind%20patterns.-Master.PDF - Photo 3. Still photo showing unusual wind patterns. (item 34, .PDF, 451 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40213499&FileExtension=.PDF&FileName=Photo%203.%20%20Still%20photo%20showing%20unusual%20wind%20patterns.-Master.PDF - Lockheed Service Bulletin on Doubler Removal (item 35, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40180748&FileExtension=.PDF&FileName=Lockheed%20Service%20Bulletin%20on%20Doubler%20Removal-Master.PDF - Rolls-Royce Report (item 36, .PDF, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428644&FileExtension=.PDF&FileName=Rolls-Royce%20Report-Redacted.PDF - Wreckage Diagram (item 37, .PDF, 60 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40181431&FileExtension=.PDF&FileName=Wreckage%20Diagram-Master.PDF - Airworthiness Factual Report of Group Chairman (item 38, .PDF, 11 photos, 731 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182737&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 1 (item 39, .PDF, 41 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182738&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%201-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 2 (item 40, .PDF, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182872&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%202-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 3 (item 41, .PDF, 13 photos, 639 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182873&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%203-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 4 (item 42, .PDF, 22 photos, 7.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428661&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%204-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 6 (item 43, .PDF, 393 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428645&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%206-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 7 (item 44, .PDF, 98 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428646&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%207-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 8 (item 45, .PDF, 174 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428647&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%208-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 9 (item 46, .PDF, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428648&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%209-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 10 (item 47, .PDF, 228 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428649&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2010-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 11 (item 48, .PDF, 359 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428650&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2011-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 12 (item 49, .PDF, 136 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428651&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2012-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 13 (item 50, .PDF, 258 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428652&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2013-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 14 (item 51, .PDF, 83 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428653&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2014-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 15 (item 52, .PDF, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182748&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2015-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 16 (item 53, .PDF, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182749&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2016-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 17 (item 54, .PDF, 97 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428657&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2017-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 18 (item 55, .PDF, 323 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182751&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2018-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 19 (item 56, .PDF, 326 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182752&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2019-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 20 (item 57, .PDF, 522 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428658&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2020-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 21 (item 58, .PDF, 225 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428659&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2021-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 22 (item 59, .PDF, 704 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182755&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2022-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 23 (item 60, .PDF, 252 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182756&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2023-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 24 (item 61, .PDF, 76 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428679&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2024-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 25 (item 62, .PDF, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428660&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2025-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 26 (item 63, .PDF, 323 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182759&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2026-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 27 (item 64, .PDF, 229 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182760&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2027-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 28 (item 65, .PDF, 257 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182761&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2028-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 29 (item 66, .PDF, 156 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182766&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2029-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 30 (item 67, .PDF, 181 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428680&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2030-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 31 (item 68, .PDF, 236 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428678&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2031-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 32 (item 69, .PDF, 223 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428677&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2032-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 33 (item 70, .PDF, 185 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428676&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2033-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 34 (item 71, .PDF, 245 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428675&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2034-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 35 (item 72, .PDF, 232 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428674&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2035-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 36 (item 73, .PDF, 229 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428673&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2036-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 37 (item 74, .PDF, 190 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182773&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2037-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 38 (item 75, .PDF, 218 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428672&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2038-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 39 (item 76, .PDF, 554 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428671&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2039-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 40 (item 77, .PDF, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428670&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2040-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 41 (item 78, .PDF, 133 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428669&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2041-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 42 (item 79, .PDF, 103 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428668&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2042-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 43 (item 80, .PDF, 141 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428667&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2043-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 44 (item 81, .PDF, 135 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428666&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2044-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 45 (item 82, .PDF, 152 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428665&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2045-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 46 (item 83, .PDF, 183 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428664&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2046-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 47 (item 84, .PDF, 257 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428663&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2047-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 48 (item 85, .PDF, 193 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182785&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2048-Master.PDF - Airworthiness Factual Report of Group Chairman - Attachment 49 (item 86, .PDF, 446 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40428662&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2049-Redacted.PDF - Airworthiness Factual Report of Group Chairman - Attachment 50 (item 87, .PDF, 893 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40182787&FileExtension=.PDF&FileName=Airworthiness%20Factual%20Report%20of%20Group%20Chairman%20-%20Attachment%2050-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.