# NTSB CEN16LA387: Pahnke Vernon A Vans RV 9A, N699RV, Newark, IL, September 22, 2016 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: September 22, 2016, 14:00 local (19:00 UTC) - Place: Newark, IL - Coordinates: 41.519443, -88.605552 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.5194&lon=-88.6056&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report June 3, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 94118 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN16LA387 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/94118/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=94118 - Page: https://openairdocs.org/ntsb/CEN16LA387 ## Probable cause The pilot's failure to properly assemble the fuel pump, which resulted in the loss of fuel pressure and the subsequent partial loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Maintenance: installation](https://openairdocs.org/ntsb-findings/02062035): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Lyons Nathan F VANS RV-6A, 1 case](https://openairdocs.org/ntsb-findings/02062035/cases.md?model=05606V1), [All aircraft, 371 cases](https://openairdocs.org/ntsb-findings/02062035/cases.md) - [Fuel system: fuel pumps](https://openairdocs.org/ntsb-findings/01022822): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Lyons Nathan F VANS RV-6A, 1 case](https://openairdocs.org/ntsb-findings/01022822/cases.md?model=05606V1), [All aircraft, 71 cases](https://openairdocs.org/ntsb-findings/01022822/cases.md) - [Engine fuel and control: fuel pump](https://openairdocs.org/ntsb-findings/01057314): Aircraft › Aircraft power plant · Incorrect service/maintenance (probable cause); cases with it: [Lyons Nathan F VANS RV-6A, 1 case](https://openairdocs.org/ntsb-findings/01057314/cases.md?model=05606V1), [All aircraft, 34 cases](https://openairdocs.org/ntsb-findings/01057314/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Attain/maintain not possible; cases with it: [Lyons Nathan F VANS RV-6A, 1 case](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=05606V1), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Lyons Nathan F VANS RV-6A, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=05606V1), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Enroute: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [Lyons Nathan F VANS RV-6A, 1 case](https://openairdocs.org/ntsb-events/342/sequence.md?model=05606V1), [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) ## Analysis The pilot was conducting a cross-country flight in an experimental airplane when he observed the fuel pressure fluctuating, and the engine began to surge. The pilot turned on the backup fuel pump but the engine continued to surge, so he diverted to a nearby airport. The pilot stated that he had difficulty visually acquiring the airport and was losing altitude while circling over the airport. He performed an "S" turn but was still too high. He was running out of runway below him, so he performed a "hard slip" to lose altitude. The airplane stalled 10-15 ft above the runway, hit the ground, and slid about 30 ft before stopping. The primary fuel pump had failed 4 days before the accident. The pilot replaced the fuel pump with a new unit that required partial assembly. He noted during assembly that there was not an O-ring where the lower fitting attached but that the mating surfaces were different between the two pumps and he had believed one was not required. The instructions with the new pump did not address the installation of an O-ring at the fitting. After the accident, the pilot reexamined the box the new fuel pump came in and found an O-ring for the lower fitting. Without the O-ring installed, the fuel system was not able to maintain the fuel pressure necessary to ensure smooth engine operation and resulted in the partial loss of engine power. The pilot stated the accident resulted from this maintenance issue. ## Factual narrative On September 22, 2016, about 1400 central daylight time (CDT), a Vans RV9A experimental airplane, N699RV, was substantially damaged during a forced landing near Cushing Field Ltd Airport (0C8), Newark, Illinois. The private pilot was not injured and the passenger suffered minor injuries. The airplane was privately registered and operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, and no flight plan was filed. The pilot and passenger were conducting a cross-country flight when the pilot observed the fuel pressure fluctuating, and the engine began sto surge. The pilot turned on the backup fuel pump; the engine continued to surge so he diverted to 0C8. The pilot stated he had difficulty maintaining visual reference to the airport and the airplane was losing altitude as he circled over the airport. The pilot performed an "S" turn and found he was still too high. He was running out of runway below him, so he performed a "hard slip" to lose altitude. The airplane stalled 10-15 ft above the runway, hit the ground, and slid about 30 ft before stopping. The pilot reported he conducted a flight four days before the accident, on September 18, and he felt a "couple small pauses in the powerplant." The engine quit after landing and did not restart until the auxiliary fuel pump was turned on. He subsequently tested the primary fuel pump, which did not work, and ordered a new fuel pump. When the new pump arrived it did not have the bottom fitting attached, whereas the previous replacement was fully assembled. The pilot took the fitting off the old pump and there was an O-ring present; however, he did not see an O-ring with the new pump "kit." He said the mating surfaces were different between the two pumps and the new pump did not appear to require an O-ring. Additionally, the instructions that came with the new pump did not mention an O-ring. The pilot installed the new fuel pump without an O-ring and conducted a successful test of the new pump. Following the accident flight, the pilot questioned whether there could have been an O-ring accompanying the new fuel pump that he had not seen. He examined the area where he performed the maintenance and subsequently located a 5/8" O-ring inside another component that came from the box containing the new pump. The pilot stated the accident was caused by this maintenance issue. ## Aircraft - Registration: [N699RV](https://openairdocs.org/aircraft/N699RV), registered now, S/N 22144 (OpenAirDocs) - Reported make and model: PAHNKE VERNON A VANS RV 9A (NO SERIES) - Registry model: [Lyons Nathan F VANS RV-6A](https://openairdocs.org/model/lyons-nathan-f-vans-rv-6a) (registry code 05606V1) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane, amateur-built - Serial number: 90537 - Year built: 2006 - Airframe hours: 515 - Engines: Subaru EJ25 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Condition, June 11, 2016 - Departed: 1C5, BOLINGBROOK, IL - Destination: K34, GARDNER, KS - Airport: 0C8, Cushing Field Ltd, runway 18, 2,831 × 180 ft, grass/turf - Equipment: Electronic multifunction display, Electronic primary flight display, Onboard weather, ADS-B, Angle of attack indicator, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 68; injuries: none; private; airplane ratings: single-engine land; medical: class 3, waiver time limited special; last flight review September 16, 2014; seat: left; restraint: 5-point; flight hours: 1,573 total, 515 in this make and model, 1,573 as pilot in command, 19 in the last 90 days, 8 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: 2,300 ft broken - Temperature: 79 °F, dew point 68 °F - Altimeter: 30.06 inHg - Observed at: KC09, 10 nm away ## Docket (3 files) The files NTSB released with the investigation on February 28, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=94118. 2.5 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480915&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot Statement (item 2, .PDF, 356 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480916&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Pilot Email (item 3, .PDF, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40480917&FileExtension=.PDF&FileName=Pilot%20Email-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.