# NTSB CEN12LA492: Maule M-4, N12026, Springfield, MN, July 10, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: July 10, 2012, 15:45 local (20:45 UTC) - Place: Springfield, MN - Coordinates: 44.231109, -94.998886 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.2311&lon=-94.9989&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report April 25, 2013 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 84502 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12LA492 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/84502/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=84502 - Page: https://openairdocs.org/ntsb/CEN12LA492 ## Probable cause The tailwheel spring's overload failure during landing, resulting in a ground loop and runway excursion. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: nose/tail landing gear](https://openairdocs.org/ntsb-findings/01023220): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Maule M-4, 1 case](https://openairdocs.org/ntsb-findings/01023220/cases.md?model=5460104), [All aircraft, 185 cases](https://openairdocs.org/ntsb-findings/01023220/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Maule M-4, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=5460104), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-landing roll: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Maule M-4, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=5460104), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [Maule M-4, 2 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=5460104), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Maule M-4, 1 case](https://openairdocs.org/ntsb-events/300/sequence.md?model=5460104), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The pilot reported that the accident landing proceeded normally until he moved the control yoke from full forward to full aft, and the airplane’s tail moved abruptly to the left. The pilot's application of full left rudder and power did not stop the movement, and the airplane entered a ground loop to the right and departed the runway. Examination of the airplane found that the tailwheel spring failed during landing. The observed spring separation was consistent with overload. ## Factual narrative On July 10, 2012, about 1545 central daylight time, a Maule M-4, N12026, ground looped during a landing on runway 31 (3,400 feet by 75 feet, dry asphalt) at the Springfield Municipal Airport (D42), near Springfield, Minnesota. The private pilot and the flight instructor passenger were not injured. The airplane’s left wing was substantially damaged. The airplane was registered to a private individual and operated by the pilot, under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as a personal flight. Day visual flight rules conditions prevailed for the flight, which did not operate on a VFR flight plan. The local flight originated from the New Ulm Municipal Airport (ULM), near New Ulm, Minnesota, about 1410. According to the pilot’s accident report, a new engine had been installed in the accident airplane and a local flight was conducted in the ULM area that was about an hour in duration. A mechanic examined the engine and the airplane was subsequently flown to Sleepy Eye Municipal Airport (Y58), near Sleepy Eye, Minnesota, where 11 landings to a full stop were conducted on the grass strip there. This flight returned to ULM and its duration was 1.5 hours. The aircraft was refueled. The pilot and flight instructor flew to Y58 for 10 more landings where the landings were all to full stop, using various flap configurations and executing both three-point and wheel landings. The landing surface at Y58 was reported as "rough." The airplane was then flown to D42 where three landings were completed without incident. The flight instructor indicated the pilot was not getting full aft control movement in to "pin the tail to the runway." The pilot, in part, stated: The accident landing proceeded normally with a smooth mains touchdown and reduction of speed until the tail settled. I move[d] the control yoke from full forward to full aft, at which time the tail of the aircraft abruptly moved the left. Full left rudder and application of power did not stop the movement, and we entered a ground loop to the right. I cut power, and the aircraft came rest approximately 10 feet off the right side of the runway. At 1553, the recorded weather at the Redwood Falls Municipal Airport, near Redwood Falls, Minnesota, located about 19 nautical miles and 350 degrees from the accident site, was: Wind variable at 3 knots; visibility 10 statute miles; sky condition few clouds at 6,500 feet; temperature 31 degrees C; dew point 12 degrees C; altimeter 30.14 inches of mercury. The pilot further indicated that one of the three leaf springs of the tailwheel assembly was broken and this break occurred sometime between takeoff and the conclusion of the accident landing at D42. Eighteen landings were estimated to have been conducted during that time frame. This break reportedly reduced the stiffness of the tail gear and allowed the tailwheel to twist from its vertical position and applied a strong force to the left that could not be corrected by application of full leftrudder. The pilot reported that the spring accumulated 3,181 hours of total time and 4 hours since an annual inspection. A Federal Aviation Administration inspector examined the airplane and observed the broken spring. The inspector confirmed the separation in the spring and indicated that the separation was consistent with overload. ## Aircraft - Registration: [N12026](https://openairdocs.org/aircraft/N12026), registered now, S/N 38, built 1963 (OpenAirDocs) - Reported make and model: MAULE M-4 - Registry model: [Maule M-4](https://openairdocs.org/model/maule-m-4) (registry code 5460104) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 38 - Airframe hours: 3181 - Engines: CONT MOTOR O-300-A 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 8, 2012, 4 hours before - Departed: ULM, New ULM, MN - Destination: ULM, New ULM, MN - Airport: D42, Springfield Municipal Airport, runway 31, 3,400 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 48; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review April 22, 2012; seat: left; flight hours: 458 total, 4 in this make and model, 421 as pilot in command, 17 in the last 90 days, 12 in the last 30 days, 7 in the last 24 hours - Flight instructor; age 79; injuries: none; flight instructor, airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea; instrument ratings: airplane; medical: with waivers/limitations; last flight review June 12, 2011; seat: right; flight hours: 32,620 total, 70 in this make and model, 32,000 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 54 °F - Altimeter: 30.13 inHg - Observed at: RWF, 19 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 20120710014179A](https://openairdocs.org/incident/20120710014179A), Jul 10, 2012: Maule M-4, Springfield, MN, Substantial damage. During the wheel landing, as the pilot was setting the tailwheel down, the aircraft veered right. As a result, the left wintip dragged on the runway and the… ## Other investigations on N12026 (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 MKC78FCG22](https://openairdocs.org/ntsb/MKC78FCG22), Mar 27, 1978: Maule M-4 (N12026), Sedalia, MO, substantial damage ## Docket (2 files) The files NTSB released with the investigation on March 7, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=84502. 458 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 400 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40386004&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Miscellaneous - Communications Summary (item 2, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40386112&FileExtension=.PDF&FileName=Miscellaneous%20-%20Communications%20Summary-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.