# NTSB LAX99MA251: Schempp-Hirth Nimbus 4DM, N807BB, Minden, NV, July 13, 1999 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 1 · Major · Final report - Date: July 13, 1999, 13:10 local (20:10 UTC) - Place: Minden, NV - Coordinates: 38.981666, -119.672775 - Nearby events: https://openairdocs.org/map.md?lat=38.9817&lon=-119.6728&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 2 fatal - Status: Completed, report September 30, 2002 - Report: Board-adopted at Board Meeting - Investigation class: Class 1 - Parties: FEDERAL AVIATION ADMINISTRATION - NTSB case key (mKey): 46811 - NTSB case page: https://www.ntsb.gov/investigations/Pages/LAX99MA251.aspx - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46811/pdf - Board report AAB0206 (PDF): https://www.ntsb.gov/investigations/AccidentReports/Reports/AAB0206.pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=46811 - Page: https://openairdocs.org/ntsb/LAX99MA251 ## Probable cause The pilot's excessive use of the elevator control during recovery from an inadvertently entered spin and/or spiral dive during which the glider exceeded the maximum permissible speed, which resulted in the overload failure of the wings at loadings beyond the structure's ultimate design loads. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, maneuvering - weather condition - thermal lift - weather condition - turbulence,convection induced - airspeed - not maintained, pilot in command - stall/spin - inadvertent, pilot in command - Airframe/component/system failure/malfunction, maneuvering - wing - overload (cause) - airspeed(vne) - exceeded, pilot in command (cause) - pull-up - initiated - elevator - improper use of, pilot in command (cause) - design stress limits of aircraft - exceeded, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled ## Analysis The glider broke up in flight during the recovery phase after a departure from controlled flight while maneuvering in thermal lift conditions. Airborne witnesses in other gliders who saw the beginning of the sequence said the glider was in a tight turn, as if climbing in a thermal, when it entered a spiral or a spin. With a 45-degree nose down attitude, the speed quickly built up as the glider completed two full rotations. The rotation then stopped, the flight stabilized on a northeasterly heading, and the nose pitched further down to a near vertical attitude (this is consistent with the spin recovery technique specified in the Flight Manual). The glider was observed to be pulling out of the dive, with the wings bending upward and the wing tips coning higher, when the outboard wing tip panels departed from the glider, the wings disintegrated, and the fuselage dove into the ground. Several witnesses estimated the wing deflection reached 45-degrees or more before the wings failed. Examination of the wreckage disclosed that the left and right outboard wing sections failed symmetrically at 2 locations. The glider is a high performance sailplane with an 87-foot wingspan and is constructed from fiber reinforced plastic (FRP) composites. The manufacturing process uses a hand lay-up of carbon and glass materials with applied epoxy resins. The glider is certificated in the normal category in Germany under the provisions of the European Joint Airworthiness Regulations. Pilots with experience in the Nimbus 4 series gliders stated that the glider was particularly sensitive to over input of the rudder control during turns due to the 87-foot wingspan, with a resulting tendency for unwanted rolling moments. The manufacturer reported that to avoid undesired rolling moments once the bank is established the ailerons must be deflected against the bank. Maneuvering speed (Va) is 180 km/h (97 kts) and the AFM notes that full control surface deflections may only be applied at this speed and below. Never exceed speed (Vne) is 285 km/h (154 kts) and control deflections are limited to one third of the full range at this speed and a bold print cautionary note reads, "Avoid especially sudden elevator control movements." The manufacturer reported that design dive speed (Vd) is 324 km/h (175 kts). The manufacturer also said that, assuming a 45-degree nose down attitude with airbrakes closed, the glider would accelerate from stall speed to Vne in 8.6 seconds, with an additional 1.8 seconds to accelerate from Vne to Vd. While no specific information on stick force per 'g' was available, certification flight test data showed that the elevator control stick forces were relatively light, with only 11.9 pounds of force (nose down) required to hold a fixed attitude at Vne versus the neutral stick force trim speed of 135 km/h (72.89 kts). Detailed examination of witness marks and other evidence in the wreckage established that the pilot extended the airbrakes at some point in an attempt to slow the glider during the descent prior to the break-up. Concerning limitations on use of the airbrakes, the AFM notes that while airbrakes may be extended up to Vne they should only be used at such high speeds in emergency or if the maximum permitted speeds are being exceeded inadvertently. The manufacturer noted that the airbrakes function like spoilers and have the effect of shifting the aerodynamic loads outboard on the wings. The control linkages for the airbrakes and flaps are interconnected so that when full airbrake deployment is achieved, the flaps are extended to their full down limit. The maximum maneuvering load factor limits (in units of gravity or g's) change with variations in glider speed and flap/airbrake configuration. From a "flaps up" configuration at Va to the condition of airbrakes and flaps extended at Vne, the maximum maneuvering load factor limits decrease from positive 5.3 to a positive 3.5. The pertinent certification regulations require a minimum safety margin of 1.5 above the design limit load, which is defined as ultimate load. Review of the manufacturers data on safety margins in the wing spar disclosed that in the area of the primary wing failures, the structural design safety margin ranged between 1.55 and 1.75. The manufacturer supplied data of the wing deflections under various load and aerodynamic conditions. At the design load limit (3.5g's) with airbrakes extended and at Vd, the wings were deflected to a 31-degree angle. At the ultimate load limit, the deflection was 46.5-degrees, similar to the witness observations of the wing deflection just prior to the break up. An extensive series of scientific investigations were undertaken to establish: 1) if the structure as built conformed with the approved production drawings; 2) that the wing design met pertinent certification standards for strength safety margins; and 3) whether or not the failures occurred in overload beyond the ultimate load limits of the structure. While production control type discrepancies were found in the structure that differed from drawing specifications, none contributed to the failures. The testing established that the structure as built exceeded the minimum safety margin requirements. All the wing failures were overload in character and occurred at loadings well above the ultimate design load limits. ## Factual narrative The full report is available on the NTSB Web site. See http://www.ntsb.gov/publictn/publictn.htm for details. SUMMARY: On July 13, 1999, at 1310 Pacific daylight time, a Schempp-Hirth Nimbus-4DM motorized glider, N807BB, experienced an in-flight breakup while maneuvering near Minden, Nevada. The commercial glider pilot and a passenger were fatally injured, and the glider was destroyed. The glider had departed from Minden-Tahoe airport at 1240 and was operated by the owner/pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91. No flight plan was filed for the local area soaring flight. The glider was certificated in the United States in the experimental category for exhibition and racing, and it was also certificated in Germany in the standard class, utility category. ## Aircraft - Registration: [N807BB](https://openairdocs.org/deregistered/N807BB-1999-10-21), registration cancelled 1999-10-21, S/N 20 (OpenAirDocs) - Reported make and model: Schempp-Hirth NIMBUS 4DM - Registry model: [Schempp-Hirth NIMBUS 4DM](https://openairdocs.org/model/schempp-hirth-nimbus-4dm) (registry code 3801966) (OpenAirDocs) - Category: Glider - Serial number: 20 - Airframe hours: 201 - Engines: Rotax 535C 60 horsepower reciprocating - Damage: Destroyed - Flight: Personal, Part 91 - Operator: William S. Ivans - Registered owner: William S. Ivans Trustee - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Condition, May 18, 1999, 19 hours before - Departed: MEV ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 79; injuries: fatal; commercial; airplane ratings: single-engine land; last flight review October 20, 1998; seat: front; toxicology performed; flight hours: 3,611 total, 103 in this make and model, 3,541 as pilot in command, 8 in the last 90 days, 8 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 6 knots - Visibility: 30 statute miles - Lowest ceiling: none - Temperature: 93 °F, dew point 46 °F - Altimeter: 30.00 inHg - Observed at: MEV, 4 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 19990713008889A](https://openairdocs.org/incident/19990713008889A), Jul 13, 1999: Amtr NIMBUS4DM, Minden, NV, Destroyed, 2 fatal. Schempp-hirth nimbus 4DM glider crashed under unknown circumstances and was destroyed, the 2 POB (including a former FAA administrator) suffered fatal… ## Docket (60 files) The files NTSB released with the investigation on September 20, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=46811. 107 MB in all. - Supplement A (item 1, .PDF, 147 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166691&FileExtension=.PDF&FileName=Supplement%20A-Master.PDF - Supplement B (item 2, .PDF, 202 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166692&FileExtension=.PDF&FileName=Supplement%20B-Master.PDF - Supplement E (item 3, .PDF, 110 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166693&FileExtension=.PDF&FileName=Supplement%20E-Master.PDF - Witness 4 - Factual Report of Group Chairman (item 4, .PDF, 131 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377772&FileExtension=.PDF&FileName=Witness%204%20-%20Factual%20Report%20of%20Group%20Chairman-Redacted.PDF - Witness 4 - Attachment 1 (item 5, .PDF, 572 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377774&FileExtension=.PDF&FileName=Witness%204%20-%20Attachment%201-Redacted.PDF - Witness 4 - Attachment 2 (item 6, .PDF, 46 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377775&FileExtension=.PDF&FileName=Witness%204%20-%20Attachment%202-Redacted.PDF - Meteorology 5 - Factual Report of Group Chairman (item 7, .PDF, 275 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377777&FileExtension=.PDF&FileName=Meteorology%205%20-%20Factual%20Report%20of%20Group%20Chairman-Redacted.PDF - Meteorology 5 - Attachment 1, 14-15 Satellite Image (item 8, .PDF, 3.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166700&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%201,%2014-15%20Satellite%20Image-Master.PDF - Meteorology 5 - Attachment 2, 16-17 Satellite Image (item 9, .PDF, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166701&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%202,%2016-17%20Satellite%20Image-Master.PDF - Meteorology 5 - Attachment 3, 18-19 Satellite Image (item 10, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166702&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%203,%2018-19%20Satellite%20Image-Master.PDF - Meteorology 5 - Attachment 4, 20-21 GEOS Infared Image (item 11, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166703&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%204,%2020-21%20GEOS%20Infared%20Image-Master.PDF - Meteorology 5 - Attachment 5, 22-23 GEOS Infared Image (item 12, .PDF, 3.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166704&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%205,%2022-23%20GEOS%20Infared%20Image-Master.PDF - Meteorology 5 - Attachment 6, 24-25 GEOS Infared Image (item 13, .PDF, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166705&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%206,%2024-25%20GEOS%20Infared%20Image-Master.PDF - Meteorology 5 - Attachment 7, 26-27 GEOS Infared Image (item 14, .PDF, 4.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166706&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%207,%2026-27%20GEOS%20Infared%20Image-Master.PDF - Meteorology 5 - Attachment 8, 28-30 GEOS Infared Image (item 15, .PDF, 7.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166707&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%208,%2028-30%20GEOS%20Infared%20Image-Master.PDF - Meteorology 5 - Attachment 9, Wind Profiles (item 16, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166708&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%209,%20Wind%20Profiles-Master.PDF - Meteorology 5 - Attachment 10, WX Radar Image (item 17, .PDF, 4.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166709&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2010,%20WX%20Radar%20Image-Master.PDF - Meteorology 5 - Attachment 11, Wind Radial Velocity Spectrum Charts (item 18, .PDF, 12.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166710&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2011,%20Wind%20Radial%20Velocity%20Spectrum%20Charts-Master.PDF - Meteorology 5 - Attachment 12, 12-13 Satellite Image (item 19, .PDF, 3.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166711&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2012,%2012-13%20Satellite%20Image-Master.PDF - Meteorology 5 - Attachment 13, METAR Reports (item 20, .PDF, 396 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166712&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2013,%20METAR%20Reports-Master.PDF - Meteorology 5 - Attachment 14, Soaring Forecast (item 21, .PDF, 86 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166713&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2014,%20Soaring%20Forecast-Master.PDF - Meteorology 5 - Attachment 15, Witness Statements (item 22, .PDF, 102 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377779&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2015,%20Witness%20Statements-Redacted.PDF - Meteorology 5 - Attachment 16, Skew T Log P Plot (item 23, .PDF, 900 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166715&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2016,%20Skew%20T%20Log%20P%20Plot-Master.PDF - Meteorology 5 - Attachment 17, Upper Air Data (item 24, .PDF, 109 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166716&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2017,%20Upper%20Air%20Data-Master.PDF - Meteorology 5 - Attachment 19, Surface Isobar Chart (item 25, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166717&FileExtension=.PDF&FileName=Meteorology%205%20-%20Attachment%2019,%20Surface%20Isobar%20Chart-Master.PDF - Airworthiness Group Chairman's Factual Report (item 26, .PDF, 293 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167603&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment I: Drawing, Schempp-Hirth Nimbus 4DM (item 27, .PDF, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167605&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20I%3A%20Drawing,%20Schempp-Hirth%20Nimbus%204DM-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment II: Photographs of an exemplar Nimbus 4DM (item 28, .PDF, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167606&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20II%3A%20Photographs%20of%20an%20exemplar%20Nimbus%204DM-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment III: Wreckage Distribution (item 29, .PDF, 151 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167608&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20III%3A%20Wreckage%20Distribution-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment IV: N807BB, (in flight) Wing Failures (item 30, .PDF, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167609&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20IV%3A%20N807BB,%20(in%20flight)%20Wing%20Failures-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment V: Photographs of the Wreckage (item 31, .PDF, 15.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167610&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20V%3A%20Photographs%20of%20the%20Wreckage-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VI: MM Diagrams, Inboard & Outboard Wing (item 32, .PDF, 146 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167612&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VI%3A%20MM%20Diagrams,%20Inboard%20%26%20Outboard%20Wing-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VII: WSU /NIAR Report, [Investigation of a Schempp-Hirth Nimbus 4DM Motor Glider "In-flight Breakup"] (item 33, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167613&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VII%3A%20WSU%20%2FNIAR%20Report,%20%5BInvestigation%20of%20a%20Schempp-Hirth%20Nimbus%204DM%20Motor%20Glider%20%22In-flight%20Breakup%22%5D-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VII: WSU /NIAR Report (Appendix A) (item 34, .PDF, 2.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167614&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VII%3A%20WSU%20%2FNIAR%20Report%20(Appendix%20A)-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VII: WSU /NIAR Report (Appendix B) (item 35, .PDF, 196 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167615&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VII%3A%20WSU%20%2FNIAR%20Report%20(Appendix%20B)-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VII: WSU /NIAR Report (Appendix C) (item 36, .PDF, 831 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167616&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VII%3A%20WSU%20%2FNIAR%20Report%20(Appendix%20C)-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VII: WSU /NIAR Report (Appendix D) (item 37, .PDF, 6.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167617&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VII%3A%20WSU%20%2FNIAR%20Report%20(Appendix%20D)-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VII: WSU /NIAR Report (Appendix E) (item 38, .PDF, 11.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167618&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VII%3A%20WSU%20%2FNIAR%20Report%20(Appendix%20E)-Master.PDF - Airworthiness Group Chairman's Factual Report - Attachment VIII: Flight Manual References (item 39, .PDF, 376 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167619&FileExtension=.PDF&FileName=Airworthiness%20Group%20Chairman%27s%20Factual%20Report%20-%20Attachment%20VIII%3A%20Flight%20Manual%20References-Master.PDF - Materials Laboratory 15 - Factual Report of Group Chairman (item 40, .PDF, 140 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377781&FileExtension=.PDF&FileName=Materials%20Laboratory%2015%20-%20Factual%20Report%20of%20Group%20Chairman-Redacted.PDF - Aircraft Performance 13 - Factual Report of Radar Target Evaluation (item 41, .PDF, 192 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377783&FileExtension=.PDF&FileName=Aircraft%20Performance%2013%20-%20Factual%20Report%20of%20Radar%20Target%20Evaluation-Redacted.PDF - Maps or Charts of Accident Area, Wreckage Diagrams (item 42, .PDF, 70 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166720&FileExtension=.PDF&FileName=Maps%20or%20Charts%20of%20Accident%20Area,%20Wreckage%20Diagrams-Master.PDF - Wreckage Diagram GPS Coordinates (item 43, .PDF, 291 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166721&FileExtension=.PDF&FileName=Wreckage%20Diagram%20GPS%20Coordinates-Master.PDF - Germany Airworthiness Certification (item 44, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377785&FileExtension=.PDF&FileName=Germany%20Airworthiness%20Certification-Redacted.PDF - Extract of Correspondance from German LBA (item 45, .PDF, 86 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166760&FileExtension=.PDF&FileName=Extract%20of%20Correspondance%20from%20German%20LBA-Master.PDF - German LBA Standards for Structural Substantiation (item 46, .PDF, 785 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40167002&FileExtension=.PDF&FileName=German%20LBA%20Standards%20for%20Structural%20Substantiation-Master.PDF - Extract of Correspondence From Schempp-Hirth 1 (item 47, .PDF, 128 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166761&FileExtension=.PDF&FileName=Extract%20of%20Correspondence%20From%20Schempp-Hirth%201-Master.PDF - Extract of Correspondence with Schempp-Hirth 07-31-01 (item 48, .PDF, 161 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166816&FileExtension=.PDF&FileName=Extract%20of%20Correspondence%20with%20Schempp-Hirth%2007-31-01-Master.PDF - Charts Detailing Effect of Airbrake Extension on Wing Loads (item 49, .PDF, 87 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166763&FileExtension=.PDF&FileName=Charts%20Detailing%20Effect%20of%20Airbrake%20Extension%20on%20Wing%20Loads-Master.PDF - Graph of Control Force versus Speed (item 50, .PDF, 229 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166764&FileExtension=.PDF&FileName=Graph%20of%20Control%20Force%20versus%20Speed-Master.PDF - Graph of Wing Deflections Under Load (item 51, .PDF, 91 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166765&FileExtension=.PDF&FileName=Graph%20of%20Wing%20Deflections%20Under%20Load-Master.PDF - Weight and Balance Computations (item 52, .PDF, 313 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166766&FileExtension=.PDF&FileName=Weight%20and%20Balance%20Computations-Master.PDF - Battery Examination Report (item 53, .PDF, 37 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377786&FileExtension=.PDF&FileName=Battery%20Examination%20Report-Redacted.PDF - US Airworthiness Certificate and Operating Limitations Letter (item 54, .PDF, 385 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377789&FileExtension=.PDF&FileName=US%20Airworthiness%20Certificate%20and%20Operating%20Limitations%20Letter-Redacted.PDF - Glider Maintenance Records (item 55, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377790&FileExtension=.PDF&FileName=Glider%20Maintenance%20Records-Redacted.PDF - Extract of Pilot Logbook (item 56, .PDF, 539 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377791&FileExtension=.PDF&FileName=Extract%20of%20Pilot%20Logbook-Redacted.PDF - Extract of 14 CFR 61.23 (item 57, .PDF, 117 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40166772&FileExtension=.PDF&FileName=Extract%20of%2014%20CFR%2061.23-Master.PDF - Glider Flight Manual Extracts (item 58, .PDF, 653 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377793&FileExtension=.PDF&FileName=Glider%20Flight%20Manual%20Extracts-Redacted.PDF - Toxicological Reports (item 59, .PDF, 93 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377794&FileExtension=.PDF&FileName=Toxicological%20Reports-Redacted.PDF - Release of Aircraft Wreckage, NTSB Form 6120.15 (item 60, .PDF, 95 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40377795&FileExtension=.PDF&FileName=Release%20of%20Aircraft%20Wreckage,%20NTSB%20Form%206120.15-Redacted.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.