# NTSB ATL01LA043: Globe GC1B, N78321, Cherry Point, NC, April 1, 2001 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 1, 2001, 14:00 local (18:00 UTC) - Place: Cherry Point, NC - Coordinates: 35.067222, -77.415557 - Nearby events: https://openairdocs.org/map.md?lat=35.0672&lon=-77.4156&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 26, 2002 - Report: Approved by Office Director - Parties: Greensboro FSDO - NTSB case key (mKey): 52012 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL01LA043 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/52012/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=52012 - Page: https://openairdocs.org/ntsb/ATL01LA043 ## Probable cause Fatigue cracking of the propeller hub that resulted in the in-flight separation of a propeller blade. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Airframe/component/system failure/malfunction, maneuvering - propeller system/accessories,hub - fractured (cause) - propeller system/accessories,hub - fatigue (cause) - Forced landing, emergency descent/landing ## Analysis A Globe GC1B lost a propeller blade in-flight while maneuvering in the number two position of a formation of three airplanes, a propeller blade separated from the propeller hub assembly. The second propeller blade, along with the hub assembly, subsequently separated from the engine crankshaft. Examination of the recovered propeller hub fracture faces disclosed fatigue cracking. The fatigue fracture propagated until it intersected the outside hub surface. According to McCauley Propeller the fatigue fracture reduced the propeller hub load carrying capacity until it was no longer a sufficient cross section to carry the centrifugal load of the propeller. ## Factual narrative On April 1, 2001, at 1400 eastern daylight time, a Globe GC1B, N78321, registered to a private owner, lost a propeller blade in-flight while maneuvering at an air show in Cherry Point, North Carolina. The formation flight was operated by the pilot under the provisions of Title 14 CFR Part 91 with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The commercial pilot was not injured, and the airplane sustained substantial damage. The flight departed Cherry Point, North Carolina, at 1350. According to the pilot, while maneuvering in the number two position of a formation of three airplanes, a propeller blade separated from the propeller hub assembly. The second propeller blade, along with the hub assembly, subsequently separated from the engine crankshaft. The second propeller blade was subsequently recovered for examination. Examination of the airplane revealed a catastrophic engine failure as a result of a propeller blade separation. Examination also revealed part of the crankshaft was sheared at the hub attachment, and numerous engine attachment bolts were sheared. The propeller assembly examination revealed a hub facture that originated in the root of the second inboard retention thread of the No. 2 socket. The facture was aligned along the trail edge side of the hub. Examination of the fracture faces revealed features consistent with fatigue cracking. The fatigue fracture propagated until it intersected the outside hub surface. According to McCauley Propeller the fatigue fracture reduced the propeller hub load carrying capacity until it was no longer a sufficient cross section to carry the centrifugal load of the propeller. The propeller examination also revealed that it had been modified for oil-fill crack detection, in accordance with McCauley Propeller, service bulletin 182, dated July 16, 1990. However, there was no evidence of the red oil found inside the hub or on any pitch change components. No oil film was present on any of the components. The retention bearing races were rusted and brinnelled consistent with the absence of lubrication while the propeller had been in operation. The condition of the components suggests that the propeller had been drained of its red oil. A review of the aircraft records showed that the airplane was modified with a Meryln Product Supplemental Type Certificate (STC), P3EA that included the installation of a McCauley model D2A34C67-NP/76C-2 propeller. Reportedly, McCauley Propeller did not approve or seek the Federal Aviation Administration (FAA) approval of a specific airframe/engine/propeller installation of the D2A34C67 propeller on the Globe GC-1B aircraft. Note #9 of Type Certificate data sheet No. P3EA, list certain propeller engine combinations that are approved vibration wise for use on "Normal Category Single-Engine Tractor Aircraft". According to Merlyn Products and McCauley Propeller System, the accident propeller hub assembly was not approved for aerobatics flight. Reportedly, aerobatic usage of the accident type propeller hub assembly can increase the propeller operating stresses beyond the approved allowable limits. According to the pilot/owner, N78321 was not used for aerobatic flight. Meryln Products reported that the D2A34C67 propeller hub assembly is no longer available as part of STC P3EA. ## Aircraft - Registration: [N78321](https://openairdocs.org/aircraft/N78321), registered now, S/N 2321 (OpenAirDocs) - Reported make and model: Globe GC1B - Registry model: [Globe GC-1B](https://openairdocs.org/model/globe-gc-1b) (registry code 9230104) (OpenAirDocs) - Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2321 - Airframe hours: 4968 - Engines: Continental IO 360C 210 horsepower reciprocating - Damage: Substantial damage - Flight: Air race/show, Part 91 - Registered owner: Michael P. Kennedy - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 27, 2001, 6 hours before - Departed: NKT, CHERRY POINT, NC - Destination: CHERRY POINT, NC - Airport: NKT, Cherry Point, runway 32L, 8,000 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 58; injuries: none; medical: class 2, valid medical--w/ waivers/lim; last flight review May 15, 2000; seat: left; flight hours: 6,500 total, 2,500 in this make and model, 6,000 as pilot in command, 20 in the last 90 days, 6 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 160° at 5 knots - Visibility: 6 statute miles - Lowest ceiling: 2,000 ft overcast - Temperature: 54 °F, dew point 50 °F - Altimeter: 29.59 inHg - Observed at: NKT ## 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 20010401006599A](https://openairdocs.org/incident/20010401006599A), Apr 1, 2001: Swftms GC1B, Mankato, MN, No damage. (-23) During an airshow in cherry point, NC, Mr. Kennedy was participating in an aerial demonstration team called the swift magic team. Mr. Kennedy was flying… ## Other investigations on N78321 (2) 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 MIA94LA119](https://openairdocs.org/ntsb/MIA94LA119), Apr 10, 1994: Globe 9C-1B (N78321), Okeechobee, FL, substantial damage. Probable cause: BOTH PILOTS MISJUDGED THEIR CLEARANCE FROM EACH OTHER. - [NTSB MIA71DLD49](https://openairdocs.org/ntsb/MIA71DLD49), Feb 14, 1971: Globe GC-1B (N78321), Wauchula, FL, substantial damage ## Docket (4 files) The files NTSB released with the investigation on July 31, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=52012. 811 KB in all. - McCauley Propeller Report (item 1, .PDF, 102 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469894&FileExtension=.PDF&FileName=McCauley%20Propeller%20Report-Master.PDF - Supplemental Type Certificate (item 2, .PDF, 246 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469895&FileExtension=.PDF&FileName=Supplemental%20Type%20Certificate-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 3, .PDF, 381 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40469893&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Weather Data (item 4, .PDF, 82 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40163975&FileExtension=.PDF&FileName=Weather%20Data-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.