# NTSB CEN16LA374: Piper PA-28R-201, N786BG, Bowling Green, OH, September 13, 2016 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 13, 2016, 08:00 local (12:00 UTC) - Place: Bowling Green, OH - Coordinates: 41.586944, -83.808052 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.5869&lon=-83.8081&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern downwind: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report February 13, 2017 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA Flight Standards District Office - NTSB case key (mKey): 94032 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN16LA374 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94032/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94032 - Page: https://openairdocs.org/ntsb/CEN16LA374 ## Probable cause The pilots’ failure to complete the Emergency Landing Gear Extension checklist and maintenance personnel’s failure to correctly repair spliced wires on the left main landing gear down limit switch, which prevented the pilots from knowing whether the gear was down and locked. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: use of checklist](https://openairdocs.org/ntsb-findings/02063030): Personnel issues › Task performance · Student/instructed pilot (probable cause); cases with it: [Piper PA-28R-201, 2 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md?model=7102816), [All aircraft, 336 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md) - [Use of equip/info: use of checklist](https://openairdocs.org/ntsb-findings/02063030): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [Piper PA-28R-201, 2 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md?model=7102816), [All aircraft, 336 cases](https://openairdocs.org/ntsb-findings/02063030/cases.md) - [Action: incomplete action](https://openairdocs.org/ntsb-findings/02041040): Personnel issues › Action/decision · Instructor/check pilot (probable cause); cases with it: [Piper PA-28R-201, 1 case](https://openairdocs.org/ntsb-findings/02041040/cases.md?model=7102816), [All aircraft, 105 cases](https://openairdocs.org/ntsb-findings/02041040/cases.md) - [Action: incomplete action](https://openairdocs.org/ntsb-findings/02041040): Personnel issues › Action/decision · Student/instructed pilot (probable cause); cases with it: [Piper PA-28R-201, 1 case](https://openairdocs.org/ntsb-findings/02041040/cases.md?model=7102816), [All aircraft, 105 cases](https://openairdocs.org/ntsb-findings/02041040/cases.md) - [Landing gear system: land gear sys wiring](https://openairdocs.org/ntsb-findings/01023297): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Piper PA-28R-201, 2 cases](https://openairdocs.org/ntsb-findings/01023297/cases.md?model=7102816), [All aircraft, 9 cases](https://openairdocs.org/ntsb-findings/01023297/cases.md) - [Maintenance: repair](https://openairdocs.org/ntsb-findings/02062015): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Piper PA-28R-201, 1 case](https://openairdocs.org/ntsb-findings/02062015/cases.md?model=7102816), [All aircraft, 99 cases](https://openairdocs.org/ntsb-findings/02062015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern downwind: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Piper PA-28R-201, 3 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=7102816), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Taxi: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Piper PA-28R-201, 5 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=7102816), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The two commercial pilots, one of whom was a flight instructor, were planning to conduct touch-and-go landings; the flight instructor reported that he was providing "employee training" to the other pilot. After takeoff and upon returning to the downwind leg of the traffic pattern, the pilot receiving training activated the landing gear switch to lower the landing gear; however, the landing gear control circuit breaker opened. When the circuit breaker was reset, it immediately reopened, which disabled the gear warning system and landing gear annunciator lights. The pilots made a low pass over the runway and maintenance personnel told them that the landing gear appeared to be down. The flight instructor then landed the airplane, and as she was turning it off the active runway, the right main landing gear collapsed. Postaccident examination of the airplane revealed that neither of the main landing gear were down and locked. Subsequently, the school's director of maintenance entered the airplane and used the emergency gear extension, and the landing gear dropped into the down-and-locked position, and the landing gear annunciator lights illuminated. Although he did not report resetting the circuit breaker, he had to have performed that action for the annunciator lights to illuminate. He later cycled the landing gear numerous times, and it operated normally. The circuit breaker remained closed, and all landing gear indications were normal. During the postaccident examination, the left main gear down limit switch wire was found dislodged from the terminal. The wire did not appear to have been properly crimped because the crimp mark was not well defined. Based on maintenance records, a new down indicator switch had been spliced in place less than a month earlier. The electrical schematic showed the wire to be energized. Maintenance personnel reexamined the airplane to determine why the landing gear indication circuit breaker was tripping. According to their report to Federal Aviation Administration, the left main gear down limit switch wire was spliced using the wrong type and gauge of wire. The spliced wires were soldered using heat shrink to cover the splices, which did not cover the wires completely. The three spliced down limit switch wires were bundled together in the left gear well, which allowed them to short, causing the landing gear circuit breaker to trip. The pilots did not complete the Emergency Landing Gear Extension checklist, which calls for the emergency gear extension lever (which releases pressure in the hydraulic system and allows the gear to free fall) to be pushed down. The pilots should have completed the Emergency Landing Gear Extension checklist in an attempt to ensure that the landing gear were in the down-and-locked position, which could have prevented the right main landing gear from collapsing during the turn off the active runway. ## Factual narrative **This report was modified on January 9, 2017. Please see the docket for this accident to view the original report.** On September 13, 2016, about 0840 eastern daylight time (EDT), the right main landing gear on a Piper PA-28R-201, N786GB, collapsed as the airplane was taxiing from landing at the Wood County Airport (1G0), Bowling Green, Ohio. The instructor and student pilot were not injured. The airplane was substantially damaged. The airplane was registered to and operated by Bowling Green State University Flight Center LLC (BGSU), Bowling Green, Ohio, under the provisions of 14 Code of Federal Regulations (CFR) Part 91 as an instructional flight. Visual meteorological conditions (VMC) prevailed at the time of the accident, and no flight plan had been filed. The local flight had just originated from 1G0. According to the chief pilot and flight instructor, the purpose of the flight was for "employee training." They had planned to remain in the traffic pattern and perform touch and go landings. After takeoff and upon turning onto the downwind leg for runway 28, the pilot activated the landing gear switch to lower the landing gear. The CONT (landing gear control) circuit breaker opened. When the circuit breaker was reset, it immediately opened again, which disabled the gear warning system and landing gear annunciator lights. Maintenance personnel were summoned. Several attempts were made to lower the landing gear. A low pass was made over the runway and the pilots were told that the landing gear appeared to be down. The instructor landed the airplane. As she was turning off the runway, the right main landing gear collapsed. Post-accident examination revealed the rear fuselage bulkhead was cracked. When the airplane was placed on jacks for retrieval, it was observed that the left main landing gear was not locked. Further examination revealed neither of the main landing gears were down and locked. The school's director of maintenance (DOM) entered the aircraft and used the emergency gear extension. The landing gear dropped into the full down and locked position and the landing gear annunciator lights illuminated. The airplane was then moved to a hangar for further examination. According to the DOM, the landing gear pump, hydraulic fluid, level, gear warning horns, and lights were checked. No anomalies were noted. With the airplane on jacks, the landing gear was cycled numerous times and operated normally. The circuit breaker remained closed and all landing gear indications were normal. The emergency landing gear extension was also used to verify proper operation and it, too, operated normally. The flight instructor referenced "the previous grounding maintenance squawk on the aircraft and the current level '3' squawk seeking maintenance feedback on the landing gear." According to the DOM, BGSU utilizes a software product, called SkyManager, to track accounting, maintenance, and flight schedules, among other things. When a maintenance squawk isentered into SkyManager with the aircraft's N-number and a description of the problem, it is given a severity classification of "5" (grounding issue), "3" (non-grounding discrepancy), or "1" (information only). Examination of the airframe logbook revealed the following six entries pertaining to recent landing gear maintenance: January 15, 2016 - Replaced nose landing gear up lock switch and switch actuator. February 5, 2016 - Replaced nose landing gear up lock switch. March 15, 2016 - Adjusted left main landing gear down lock witch. April 14, 2016 - Found loose wire on left main landing gear down lock switch. Jacked aircraft, repaired broken wire. July 19, 2016 - Replaced main landing gear down lock switch and adjusted. August 24, 2016 - Replaced MLG down indicator switch. A Federal Aviation Administration (FAA) inspector oversaw the examination of the airplane and noted the following: "Flight Discrepancy on 08/19/2016: "Gear position lights failed to operate properly." The actual logbook entry on 08/24/2016: 'Replaced MLG down indicator P/N 85315-002. Performed ground (retracted) and flight check (air).' The entry was signed off but did not indicate which gear switch was replaced, just part number. The was also no documentation of the flight in SkyManager. "Flight Discrepancy on 09/02/2016: 'Landing gear light did not illuminate when gear was put down.' In SkyManager, the DOM wrote: "Fixed broken wire." No entry was made in the logbook about this discrepancy. "Flight Discrepancy on 09/12/2016: 'During approach back into Wood Co. my student went to drop. . .' In SkyManager, the DOM wrote: 'Ground ops check satisfactory. Need feedback.' "The accident occurred the following day." The FAA inspector said he found a wire dislodged from the terminal. It did not appear to have been properly crimped because the crimp mark was not well defined. The wire was grounding (shorting) against the landing gear, causing the CNTRL LNDG GEAR circuit breaker to trip open. The DOM said he had pulled the wire out while he was troubleshooting after the accident. The inspector said it appeared the DOM had spliced a new limit switch about six inches from the switch. The wire bundle then passed into the wing. The electrical schematic shows the wire to be energized. The FAA inspector told the DOM that he should make the splice in the wing. Maintenance personnel re-examined the airplane to determine why the landing gear indication circuit breaker was tripping. According to their report to the FAA, the left main gear down limit switch wire was spliced using the wrong type and gauge of wire. The spliced wires were soldered using heat shrink to cover the splices. The heat shrink did not cover the wires completely. The three wires spliced were bundled together in the left gear well, which allowed the down limit switch wires to short together, causing the landing gear circuit breaker to trip. The FAA inspector also noted that the flight instructor-chief pilot did not use theemergency checklist completely. According to the checklist, the first step in an emergency gear extension is to cycle the gear. This could not be accomplished because the circuit breaker was open and would not close. The next step is to push down on the emergency gear extension lever (which releases pressure in the hydraulic system and allows the gear to free fall). This was not done. Lastly, the airplane should be yawed abruptly from side to side with the rudder in an attempt to shake the gear loose. The inspector told the instructor that when advised that the landing gear "appears to be down," it may not be locked "over center." Additionally, the airplane should never be turned with a landing gear issue, but rather it should be kept straight on the runway and brought to a complete stop ## Aircraft - Registration: [N786BG](https://openairdocs.org/aircraft/N786BG), registered now, S/N 2844126, built 2006 (OpenAirDocs) - Reported make and model: PIPER PA-28R-201 - Registry model: [Piper PA-28R-201](https://openairdocs.org/model/piper-pa-28r-201) (registry code 7102816) (OpenAirDocs) - Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2844126 - Year built: 2006 - Airframe hours: 4569 - Engines: Lycoming IO-360-C1C6 200 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Bowling Green Flight Center, LLC - Registered owner: Bowling Green Flight Center, LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 19, 2016, 45 hours before - Departed: 1G0, Bowling Green, OH - Destination: 1G0, Bowling Green, OH - Airport: 1G0, Wood County Regional, runway 28, 4,199 × 75 ft, asphalt - Equipment: Electronic multifunction display, Auto-pilot, Electronic primary flight display, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 41; injuries: none; airline transport, flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review September 1, 2015; seat: left; restraint: 3-point; flight hours: 5,993 total, 535 in this make and model, 2,485 as pilot in command, 42 in the last 90 days, 17 in the last 30 days - Pilot; age 23; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; seat: right; restraint: 3-point; flight hours: 555 total, 65 in this make and model, 495 as pilot in command, 72 in the last 90 days, 45 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 57 °F - Altimeter: 30.12 inHg - Observed at: KTDZ, 12 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 20160913017819A](https://openairdocs.org/incident/20160913017819A), Sep 13, 2016: Piper PA-28R-201, Bowling Green, OH, Substantial damage. This was an employee training flight with a crew of [privacy data omitted] and [privacy data omitted] in N786BG, PA28R-201 on the morning of 9/13/2016. At… ## Other investigations on N786BG (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 GAA17CA425](https://openairdocs.org/ntsb/GAA17CA425), Jul 18, 2017: Piper PA28R (N786BG), Bowling Green, OH, substantial damage. Probable cause: The pilot’s and flight instructor’s failure to extend the landing gear. ## Docket (10 files) The files NTSB released with the investigation on December 1, 2016, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94032. 2.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 599 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446861&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - FAA Form 8020-11, Instructor's Statement to FAA (item 2, .PDF, 451 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446862&FileExtension=.PDF&FileName=FAA%20Form%208020-11,%20Instructor%27s%20Statement%20to%20FAA-Master.PDF - Instructor's Statement to FAA (item 3, .PDF, 161 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446863&FileExtension=.PDF&FileName=Instructor%27s%20Statement%20to%20FAA-Master.PDF - Director of Maintenance, Statement to FAA (item 4, .PDF, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446864&FileExtension=.PDF&FileName=Director%20of%20Maintenance,%20Statement%20to%20FAA-Master.PDF - BGSU Aviation Squawk Levels (item 5, .PDF, 105 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446865&FileExtension=.PDF&FileName=BGSU%20Aviation%20Squawk%20Levels-Master.PDF - Record of Telephone Conversation (item 6, .PDF, 30 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446866&FileExtension=.PDF&FileName=Record%20of%20Telephone%20Conversation-Master.PDF - Excerpts from Airframe Maintenance Logbook (item 7, .PDF, 555 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446867&FileExtension=.PDF&FileName=Excerpts%20from%20Airframe%20Maintenance%20Logbook-Master.PDF - Dispatch Ticket (item 8, .PDF, 88 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446868&FileExtension=.PDF&FileName=Dispatch%20Ticket-Master.PDF - Excerpts from the Paper PA-28R-201 Owner's Manual (item 9, .PDF, 309 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446869&FileExtension=.PDF&FileName=Excerpts%20from%20the%20Paper%20PA-28R-201%20Owner%27s%20Manual-Master.PDF - Weather Reports and Records Pertinent to the Investigation (item 10, .PDF, 108 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40446870&FileExtension=.PDF&FileName=Weather%20Reports%20and%20Records%20Pertinent%20to%20the%20Investigation-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.