# NTSB CEN15LA271: Grumman Acft ENG Cor-Schweizer G 164B, N48687, Foster, NE, June 12, 2015 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: June 12, 2015, 12:15 local (17:15 UTC) - Place: Foster, NE - Coordinates: 42.273887, -97.664443 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=42.2739&lon=-97.6644&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report October 21, 2015 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 91368 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN15LA271 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91368/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91368 - Page: https://openairdocs.org/ntsb/CEN15LA271 ## Probable cause The total loss of engine power during a low-level aerial application flight due to fuel exhaustion following the pilot’s inadequate preflight inspection that led to his assumption that sufficient fuel was on board for the flight based on his reliance on a fuel gauge that indicated the incorrect fuel level. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: expectation/assumption](https://openairdocs.org/ntsb-findings/02041525): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/02041525/cases.md?model=3952802), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/02041525/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 3 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=3952802), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Terrain: wet/muddy terrain](https://openairdocs.org/ntsb-findings/03021035): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 4 cases](https://openairdocs.org/ntsb-findings/03021035/cases.md?model=3952802), [All aircraft, 110 cases](https://openairdocs.org/ntsb-findings/03021035/cases.md) - [Inspection: preflight inspection](https://openairdocs.org/ntsb-findings/02061510): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 2 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md?model=3952802), [All aircraft, 551 cases](https://openairdocs.org/ntsb-findings/02061510/cases.md) - [Fuel system: fuel quantity indicator](https://openairdocs.org/ntsb-findings/01022841): Aircraft › Aircraft systems · Malfunction; cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-findings/01022841/cases.md?model=3952802), [All aircraft, 35 cases](https://openairdocs.org/ntsb-findings/01022841/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: Preflight or dispatch event](https://openairdocs.org/ntsb-events/030); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 1 case](https://openairdocs.org/ntsb-events/030/sequence.md?model=3952802), [All aircraft, 355 cases](https://openairdocs.org/ntsb-events/030/sequence.md) - [Maneuvering-low-alt flying: Fuel exhaustion](https://openairdocs.org/ntsb-events/192); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 2 cases](https://openairdocs.org/ntsb-events/192/sequence.md?model=3952802), [All aircraft, 804 cases](https://openairdocs.org/ntsb-events/192/sequence.md) - [Maneuvering-low-alt flying: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 13 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=3952802), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 17 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=3952802), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Grumman Acft ENG Cor-Schweizer G-164B, 19 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=3952802), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that he departed on a local agricultural application flight with what he believed was sufficient fuel on board for 2 hours of flight. He stated that he based this assumption solely on viewing the fuel quantity gauge and did not insert a stick in the fuel tank to check the fuel amount before departing on the accident flight. About 1 hour 15 minutes into the flight, the airplane lost engine power, and the pilot subsequently conducted a forced landing on muddy and water-logged terrain. The airplane then nosed over and sustained substantial damage. The pilot reported that, during a postaccident examination, the fuel quantity gauge read 1/4 full even though the fuel system was actually empty. The preflight procedures contained in the airplane's flight manual included a fuel quantity check, which was to be accomplished by opening the fuel cap and visually checking the fuel level, and a fuel gauge check to observe the fuel gauge for proper reading. The pilot did not verify the fuel quantity in accordance with these procedures before departing. ## Factual narrative On June 12, 2015, about 1215 central daylight time, a Grumman - Schweizer G 164B airplane, N48687, nosed over during a forced landing following a loss of engine power during an aerial application maneuver near Foster, Nebraska. The commercial pilot sustained minor injuries. The airplane empennage was substantially damaged during the nose over. The airplane was registered to and operated by an individual under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Day visual flight rules conditions prevailed for the flight, which did not operate on a flight plan. The local flight originated from the Bloomfield Municipal Airport (84Y), near Bloomfield, Nebraska, about 1100.According to the pilot's accident report, he indicated that the airplane departed 84Y with two hours of fuel on board. The terrain of the field he conducted the aerial application flight over was flat with scattered trees. He stated that the ground was muddy and water logged and that "all gauges were in the green." His report, in part, further stated: During my last turn to conduct a pass on the pasture head land the engine stopped producing power at an altitude of about 100 feet. I leveled off, checked that mags were on, mixture rich, fuel valve on, [and] I moved the throttle control to full. Noting that my airspeed falling I applied forward stick pressure to regain airspeed. Knowing I didn't have altitude to make the nearest road I was forced to land in a pasture adjacent to the one I was spraying. As my wheels touched down, airspeed slowed reducing lift and putting more weight on the main wheels. With the added weight, the wheels sunk into the mud causing the airplane to nose over onto its top. The pilot said that during a post accident inspection, the fuel quantity gauge, part number A5587-1, was found to be indicating incorrectly. He stated that when the airplane was refueled using the remote single point port to full fuel, as indicated on the fuel quantity gauge; however, the airplane was only 3/4 full and when the fuel quantity gauge read 1/4 full, the airplane fuel system was "actually empty." Another operator was contacted and asked to describe his operational knowledge of the single point refueling system and the fuel quantity gauges. The operator stated that all models of the Ag Cat (G164, G164A, G164B, G164C, G164D) have relied on the simple mechanical fuel gauge in the bottom of the center section fuel tank. The Ag Cat airplanes have been produced with only a center section tank, one fuel tank in each wing in addition to the center section tank, and two tanks in each wing in addition to the center section tank. With each of these configurations, the tanks are connected together and the engine is supplied fuel from the center section tank. The one fuel gauge, mounted in the bottom of the center section fuel tank, indicates the level of the entire fuel system regardless of any other installed fuel tank. There is only one fuel fillerneck and cap in the center section to fill the entire fuel system. With the bottom point fuel system modification, there is a system of valves and hoses installed up to the center section, so fuel can be pumped up to the center section and fill the entire fuel system from the ground. Operationally, the airplane fuel quantity gauges are generally checked to confirm their accuracy when they are full and when they are empty, but when the tanks are partially full, the readings fluctuate especially during heavy maneuvering and or unusual attitudes flown during agricultural application flights. Additionally, the operator indicated that he heard of Ag Cat fuel quantity gauges slipping a tooth in the gearing system and registering a false indication. The fuel filler cap located on the top of the center section can be opened and sticked to determine fuel level. Sticking the center fuel tank required someone to climb onto the top wing of the airplane. The operator reported that a purpose of single point fueling system was to eliminate someone climbing on top of the wing to visual check the center section fuel tank level. According to a fuel gauge manufacturer's brochure, the accident gauge was a senior liquid level, bottom mount, side view dial gauge. The gauge's float operates the gauge dial through gear action. The airplane flight manual, in part, stated: 4.5 NORMAL OPERATING PROCEDURES (a) Pre-flight Check ... 2. Upper Wing Center section Fuel Quantity Check Fuel Tank Cap Secure Fuel Tank Sumps Drain Fuel Gauge Check Fuel Lines Check Vent Pipes Check Cabane Struts & Rigging Check ... 4.7 AMPLIFIED NORMAL PROCEDURES The remainder of this section supplies detailed information, explanatory material, warnings and cautions for normal operating procedures necessary for safe flight of the airplane. ... 4.9 PRE-FLIGHT CHECK ... (b) Upper Wing Center Section Open the fuel cap and check the fuel level and color visually (80/87) red, (100 Low Lead) blue, (100/130) green, (115/145) purple. Ensure the seal is installed and the cap is tight. Observe fuel gauge for proper reading. Drain a small quantity of fuel from each sump into a glass jar and inspect for water, dirt, or sediment. ... Check fuel lines for evidence of leakage. The National Transportation Safety Board aviation accident database was queried for accidents involving G 164 airplanes that showed fuel quantity gauges as an accident cause. The query showed that four accidents occurred before this accident and their case numbers are appended to the docket material associated with this case. The airplane manufacturer was asked to report their service history in reference to the fuel quantity gauge. The manufacturer indicated that they acquired the "AgCat Program" in 1998, and that they sold 600 of the A5587- 1 units. They stated that 400 have been removed for various reasons including stained/illegible dial faces, "sunk" floats, movement obstructions, "or just worn out." The airplane manufacturer furtherindicated that any gauge should not be considered "fuel quantity verification" and AgCat flight manuals have included "fuel quantity" and "fuel gauge" checks as part of pre- flight procedures. The accident pilot confirmed that he relied on the fuel gauge indication and that he did not stick the fuel tank before departing on the accident flight. ## Aircraft - Registration: [N48687](https://openairdocs.org/deregistered/N48687-2016-11-03), registration cancelled 2016-11-03, S/N 157B, built 1976 (OpenAirDocs) - Reported make and model: GRUMMAN ACFT ENG COR-SCHWEIZER G 164B (B) - Registry model: [Grumman Acft ENG Cor-Schweizer G-164B](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164b) (registry code 3952802) (OpenAirDocs) - Registry engine: [Pratt & Whitney R-985 series](https://openairdocs.org/engine/pratt-whitney-r-985-series) (registry code 52008, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 157B - Year built: 1976 - Airframe hours: 7833.9 - Engines: P&W R-1340-AN-1 600 horsepower reciprocating - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Barney Steven K - Registered owner: Barney Steven K - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, February 24, 2015 - Departed: 84Y, BLOOMFIELD, NE - Destination: 84Y, BLOOMFIELD, NE ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; injuries: minor; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review March 6, 2014; seat: single; restraint: 4-point; flight hours: 1,006.4 total, 95.3 in this make and model, 917.4 as pilot in command, 67.3 in the last 90 days, 58.2 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 20° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: 1,800 ft broken - Temperature: 64 °F, dew point 57 °F - Altimeter: 29.92 inHg - Observed at: KYKN, 39 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 20150612008949A](https://openairdocs.org/incident/20150612008949A), Jun 12, 2015: Grumman Acft Eng Cor-Schweizer G-164B, Foster, NE, Substantial damage. On June 12, 2015 at approximately 1100 CDT, a Grumman aircraft, model G-164B, s/n 157B, N48687 departed Bloomfield Nebraska airport (84Y) to conduct an aerial… ## Other investigations on N48687 (3) 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 CHI92DTG04](https://openairdocs.org/ntsb/CHI92DTG04), Aug 14, 1992: Grumman G-164B (N48687), Grandin, ND, substantial damage. Probable cause: THE CRACKED CYLINDER WHICH RESULTED IN A FORCED LANDING. THE LACK OF SUITABLE TERRAIN ON WHICH TO MAKE AN EMERGENCY LANDING WAS A FACTOR. - [NTSB CHI91DTG03](https://openairdocs.org/ntsb/CHI91DTG03), Jun 16, 1991: Schweizer G164 (N48687), Gwinner, ND, substantial damage. Probable cause: INADVERTENT CLOSING OF THE MIXTURE BY THE PILOT. FACTORS RELATED TO THE ACCIDENT ARE INADEQUATE CONTROL SHAPE, OR SIZE, AND INATTENTIVENESS OF THE PILOT. - [NTSB FTW83LA405](https://openairdocs.org/ntsb/FTW83LA405), Aug 31, 1983: Grumman G-164B (N48687), East Bernard, TX, substantial damage ## Docket (7 files) The files NTSB released with the investigation on September 24, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91368. 3.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 583 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432148&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Communication Summary - Pilot (item 2, .PDF, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432149&FileExtension=.PDF&FileName=Communication%20Summary%20-%20Pilot-Master.PDF - Communication Summary (item 3, .PDF, 85 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432150&FileExtension=.PDF&FileName=Communication%20Summary-Master.PDF - Correspondence - Letter from AgCat (item 4, .PDF, 279 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432151&FileExtension=.PDF&FileName=Correspondence%20-%20Letter%20from%20AgCat-Master.PDF - Miscellaneous Information - Fuel Quantity Gauge Brochure (item 5, .PDF, 147 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432152&FileExtension=.PDF&FileName=Miscellaneous%20Information%20-%20Fuel%20Quantity%20Gauge%20Brochure-Master.PDF - Miscellaneous Information - NTSB Grumman G-164 Accidents Citing Fuel Gages (item 6, .PDF, 80 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432153&FileExtension=.PDF&FileName=Miscellaneous%20Information%20-%20NTSB%20Grumman%20G-164%20Accidents%20Citing%20Fuel%20Gages-Master.PDF - Miscellaneous Information - G164B AFM Excerpt NORMAL PROCEDURES (item 7, .PDF, 2.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432154&FileExtension=.PDF&FileName=Miscellaneous%20Information%20-%20G164B%20AFM%20Excerpt%20NORMAL%20PROCEDURES-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.