# NTSB CEN17LA340: Cessna 310G, N8957Z, Broomfield, CO, September 1, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 1, 2017, 15:15 local (21:15 UTC) - Place: Broomfield, CO - Coordinates: 39.908889, -105.117225 - Nearby events: https://openairdocs.org/map.md?lat=39.9089&lon=-105.1172&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 18, 2019 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - Denver FSDO - NTSB case key (mKey): 95959 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN17LA340 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95959/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95959 - Page: https://openairdocs.org/ntsb/CEN17LA340 ## Probable cause A collapse of the right main landing gear due to a bent pushrod, which precluded the gear from fully extending. The reason for the bent pushrod could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: landing gear actuator](https://openairdocs.org/ntsb-findings/01023233): Aircraft › Aircraft systems · Damaged/degraded (probable cause); cases with it: [Cessna 310G, 1 case](https://openairdocs.org/ntsb-findings/01023233/cases.md?model=2074218), [All aircraft, 54 cases](https://openairdocs.org/ntsb-findings/01023233/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Cessna 310G, 1 case](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=2074218), [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. - [Approach: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Cessna 310G, 2 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=2074218), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Landing-flare/touchdown: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Cessna 310G, 1 case](https://openairdocs.org/ntsb-events/094/sequence.md?model=2074218), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The private pilot reported that, upon touchdown in the retractable gear, multi-engine airplane, he experienced a "mushy feeling" and aborted the landing even though the gear down indicator light was illuminated. He made another landing attempt with the same results, but after the second attempt, he noted that neither the red gear-up light nor the green gear-down light were illuminated. Ultimately, the pilot diverted to a nearby tower-controlled airport. The tower personnel confirmed that the right main landing gear was not fully extended. Attempts to lower the landing gear using emergency procedures were unsuccessful, and the pilot landed the airplane, during which the right landing gear collapsed. Subsequent examination revealed that a pushrod from the gear motor was bent, which likely resulted in the inability of the right landing gear to fully extend. The reason for the bent pushrod could not be determined. ## Factual narrative On September 1, 2017, about 1515 mountain daylight time, a Cessna 310G airplane, N8957Z, sustained substantial fuselage damage during a landing gear collapse while landing on runway 30R at the Rocky Mountain Metropolitan Airport (BJC), near Broomfield, Colorado. The pilot and passenger were not injured. The airplane was registered to and operated by Zero Energy Aviation, LLC under the provisions of Title 14 Code of Federal Regulations Part 91 as a training flight. Visual meteorological conditions prevailed for the flight, which operated on a visual flight rules flight plan. The flight originated from the Boulder Municipal Airport (BDU), Boulder, Colorado, about 1315 and the intended destination was the Greeley-Weld County Airport (GXY), Greeley, Colorado. The pilot reported that during approach to GXY, he lowered the landing gear and noted a that the green gear-down indicator illuminated. Upon touchdown, he felt a "mushy feeling" and aborted the landing, leaving the landing gear in the down position. He noted that the gear-down indicator was still illuminated. He attempted another landing with the same result and initiated another aborted landing, again leaving the landing gear in the down position. At this time neither the red gear-up light nor the green gear-down light were illuminated. The pilot left the landing gear in the down position and proceeded toward BDU, which was the airplane's home base. He attempted to contact ground personnel at BDU to assist in verifying the landing gear position. There was no response on the common traffic advisory frequency (CTAF), and he elected to contact the air traffic control tower (ATCT) at BJC. After establishing communication with BJC ATCT, he performed several fly bys of the tower and tower personnel confirmed that the right main landing gear was not fully extended. After making another attempt to lower the landing gear using the emergency checklist, the pilot landed on runway 30R. During the touchdown, the landing gear collapsed. According to the pilot, maintenance personnel found that the pushrod extending from the gear motor to the right main landing gear was found bent. The reason for the bent pushrod was not determined. Federal Aviation Administration records indicated that the pilot held a private pilot certificate with an airplane single engine land rating. He did not hold a multiengine rating. The airplane was a twin-engine retractable-gear airplane. ## Aircraft - Registration: [N8957Z](https://openairdocs.org/deregistered/N8957Z-2020-12-05), registration cancelled 2020-12-05, S/N 310G0057, built 1962 (OpenAirDocs) - Reported make and model: CESSNA 310G (G) - Registry model: [Cessna 310G](https://openairdocs.org/model/cessna-310g) (registry code 2074218) (OpenAirDocs) - Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 310G0057 - Year built: 1962 - Airframe hours: 4035 - Engines: CONT MOTOR IO-470 -D 260 horsepower reciprocating; CONT MOTOR IO-470-D 260 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Zero Energy Aviation LLC - Registered owner: Zero Energy Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 30, 2017, 80 hours before - Departed: BDU, BOULDER, CO - Destination: GXY, GREELEY, CO - Flight plan: VFR - Airport: BJC, Rocky Mountain Metropolitan, runway 30R, 9,000 × 100 ft, asphalt - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; seat: left; restraint: 3-point; flight hours: 13,842 total, 7,259 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 30° at 6 knots - Visibility: 20 statute miles - Lowest ceiling: none - Temperature: 86 °F, dew point 37 °F - Altimeter: 30.20 inHg - Observed at: BJC ## 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 20170901011169A](https://openairdocs.org/incident/20170901011169A), Sep 1, 2017: Cessna 310G, Broomfield, CO, Substantial damage. As aircraft began touch down during a touch and go landing the pilot felt the right main gear had a "mushy feeling" the left main felt stiff and secure as did… ## Other investigations on N8957Z (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 MKC72DCJ05](https://openairdocs.org/ntsb/MKC72DCJ05), Jul 10, 1971: Cessna 310G (N8957Z), Columbus, NE, substantial damage ## Docket (2 files) The files NTSB released with the investigation on July 5, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95959. 609 KB in all. - Pilot Statement (item 1, .PDF, 556 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464738&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Record of Conversation with Pilot (item 2, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40464739&FileExtension=.PDF&FileName=Record%20of%20Conversation%20with%20Pilot-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.