# NTSB ERA20LA261: Cessna 177RG, N1813Q, Salinas, PR, July 24, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: July 24, 2020, 10:02 local (14:02 UTC) - Place: Salinas, PR - Coordinates: 17.956111, -66.284446 - Nearby events: https://openairdocs.org/map.md?lat=17.9561&lon=-66.2844&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Fuel starvation](https://openairdocs.org/ntsb-events/191) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 101681 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA20LA261 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101681/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101681 - Page: https://openairdocs.org/ntsb/ERA20LA261 ## Probable cause Contamination and corrosion within the fuel system that resulted in a blockage, starvation of fuel to the engine, and the total loss of engine power. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Terrain](https://openairdocs.org/ntsb-findings/03021000): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Cessna 177RG, 2 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md?model=2073709), [All aircraft, 267 cases](https://openairdocs.org/ntsb-findings/03021000/cases.md) - [Fluids: fuel](https://openairdocs.org/ntsb-findings/01071010): Aircraft › Fluids/misc hardware · Fluid condition (probable cause); cases with it: [Cessna 177RG, 10 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md?model=2073709), [All aircraft, 1,695 cases](https://openairdocs.org/ntsb-findings/01071010/cases.md) - [Fuel system: fuel filter-strainer](https://openairdocs.org/ntsb-findings/01022821): Aircraft › Aircraft systems · Capability exceeded (probable cause); cases with it: [Cessna 177RG, 1 case](https://openairdocs.org/ntsb-findings/01022821/cases.md?model=2073709), [All aircraft, 52 cases](https://openairdocs.org/ntsb-findings/01022821/cases.md) - [Fuel system](https://openairdocs.org/ntsb-findings/01022800): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna 177RG, 3 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md?model=2073709), [All aircraft, 181 cases](https://openairdocs.org/ntsb-findings/01022800/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Fuel starvation](https://openairdocs.org/ntsb-events/191) (defining event); cases with it: [Cessna 177RG, 2 cases](https://openairdocs.org/ntsb-events/191/sequence.md?model=2073709), [All aircraft, 733 cases](https://openairdocs.org/ntsb-events/191/sequence.md) - [Prior to flight: Fuel contamination](https://openairdocs.org/ntsb-events/193); cases with it: [Cessna 177RG, 1 case](https://openairdocs.org/ntsb-events/193/sequence.md?model=2073709), [All aircraft, 225 cases](https://openairdocs.org/ntsb-events/193/sequence.md) - [Enroute-descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna 177RG, 15 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2073709), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Cessna 177RG, 2 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2073709), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot/owner and the instructor were conducting an instructional flight. The pilot reported finding no water contamination of the fuel during his preflight inspection of the airplane. They departed, performed airwork, and flew to an airport where several landings were performed. The flight then proceeded toward another airport, and during cruise flight at 1,100 ft mean sea level, the engine lost power. The pilot attempted to restore power but was unsuccessful. During the subsequent off-airport forced landing in soft terrain, the airplane nosed over during the landing roll. After the airplane was recovered, small amounts of water were found in samples taken from each fuel tank, the reservoir tank assembly, and the airframe fuel strainer. The fuel tanks were then drained and found to contain about 29 gallons of fuel; the drained fuel did not contain water or contaminants. Postaccident examination of the engine revealed severe contamination of the servo fuel injector inlet screen by ferrous material, as well as evidence of corrosion and water. Additionally, evidence of foreign debris contamination, water, and/or corrosion were found in the fuel strainer, the internal steel valves of the engine-driven fuel pump, and components of the fuel flow divider. No issues were otherwise noted with the engine powertrain, ignition, induction, or exhaust systems. During postaccident testing, leakage was noted from the right fuel cap. The most recent annual inspection was completed about 8 months before the accident. Following the first flight after the annual inspection, the pilot reported discrepancies to maintenance personnel regarding water in the fuel tanks, a rough running engine (which was later attributed to water ingestion), and a slow draining right fuel tank sump drain valve. The discrepancies were addressed by removing fuel tank sealant from the right-wing fuel tank drain valve boss ports and resealing the right inlet plate to the upper wing skin. According to the pilot, resealing the plate corrected the water intrusion issue. Given this information it is likely that the fuel system had been exposed to water for a period that was long enough for significant amounts of corrosion to develop. Ultimately, this resulted in the accumulation of corrosion and debris throughout the fuel system that most likely resulted in a blockage of the fuel injector inlet screen and/or fuel flow divider, fuel starvation, and the total loss of engine power during the accident flight. While the blockage of the servo fuel injector inlet screen occurred over time, it likely did not exist at the time of the airplane’s last annual inspection. The undetected blockage of the right wing fuel tank sump drain valve boss likely existed at the time of the last annual inspection, and may have contributed to the long-term water exposure and on-going water contamination issues after the annual inspection was completed. ## Factual narrative On July 24, 2020, about 1002 Atlantic standard time, a Cessna 177RG, N1813Q, was substantially damaged when it was involved in an accident near Salinas, Puerto Rico. The private pilot and flight instructor were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The pilot, who was the owner of the airplane, stated that before the flight, he performed a thorough preflight inspection with no fuel contamination noted and an engine run-up with no discrepancies. The flight departed from Fernando Luis Ribas Dominicci Airport, San Juan, Puerto Rico, about 0852 with full fuel tanks and flew west. When near Dorado, the pilot briefly performed airwork, then proceeded to Mercedita Airport (TJPS), Ponce, Puerto Rico. There he performed one touch-and-go landing followed by two full-stop taxi back landings. After takeoff from TJPS, while en route to Jose Aponte de la Torre Airport, Ceiba, Puerto Rico, the airplane climbed to about 1,100 ft mean sea level. While flying at that altitude, at an indicated airspeed between 120 and 130 mph, in an easterly direction, the pilot "felt this very mild, very mild vibration" followed by a "very smooth gradual loss of engine power." He informed the flight instructor of the loss of engine power and turned on the auxiliary fuel pump but engine power was not restored. The on-board engine analyzer indicated that the engine was cooling rapidly with corresponding decreases of exhaust gas temperature (EGT) and cylinder head temperature (CHT) readings. He noted an open area to his left and informed the flight instructor of the impending forced landing. He landed in the intended area with the landing gear and flaps full down, and during the landing roll, he retracted the flaps. When the airplane was nearly stopped, it nosed over in the soft terrain. Following recovery of the airplane, inspection by a Federal Aviation Administration inspector revealed small amounts of water in samples taken from each fuel tank, the reservoir tank assembly, and the airframe fuel strainer; the most water was found in the fuel strainer sample. The fuel tanks were then drained and found to contain about 29 gallons of fuel; the drained fuel did not contain water or contaminants. The airplane was relocated to San Juan, Puerto Rico, where examination of the engine fuel system components revealed the servo fuel injector inlet screen was “saturated” with ferrous material and exhibited evidence of corrosion and water. Further examination of the airframe and engine fuel system components revealed the fuel strainer exhibited foreign debris and water contamination; the internal steel valves of the engine-driven fuel pump exhibited “substantial” corrosion; and the components of the fuel flow divider exhibited foreign debris and corrosion. Examination of the power train, ignition, air induction, and exhaust systems of the engine revealed no evidence of pre-impact failure or malfunction. Examination of theleft and right fuel tanks revealed both fuel cap flanges (also called inlet plates) were sealed to the wing with adhesive similar to PRC/Proseal. Both fuel tank drain valves and drain valve boss ports were inspected with no discrepancies noted. Additionally, during testing of the left fuel tank with the wing positioned about 1.4° (wing dihedral was specified to be 1.5°) about 3 ounces of water could not be drained from the tank using the sump drain valve. Examination of the fuel caps, which had been replaced in June 2015 in accordance with supplemental type certificate (STC) SA2458CE, revealed the seals of both appeared to be in good condition. Inspection of the right cap revealed evidence of corrosion at the lower portion of the fuel inlet neck assembly and the inner inlet spring-loaded plate. Additionally, corrosion was noted on the right cap at the connection point of the fuel level gauge. A bolt and nylon self-locking nut secured the fuel level gauge to the bottom side of the inlet filler neck. Operational testing of the fuel caps/inlet plates with attached inlet filler necks was performed by attaching and sealing each of them to the lid of a 5-gallon bucket and flowing water over both assemblies. No leakage was noted from the left fuel cap, but leakage was noted from the hardware used to the secure the fuel level gauge to the inlet filler neck/inner plate of the right fuel cap assembly. According to a representative of the fuel cap manufacturer, the fuel level gauge was originally secured to the inlet filler neck and inlet plate by a rivet but was subsequently changed to a bolt with Loctite applied to the threads and nut. Review of the maintenance records revealed no entries between an annual inspection entry dated July 15, 2016, and the last annual inspection entry dated November 8, 2019. Further review of the airframe maintenance records for entries between October 8, 2001, and July 10, 2020, revealed no mention of sealing of either integral fuel tank. According to the pilot/owner, the first flight after the last annual inspection was performed on February 19, 2020. During that flight, he noted fuel consumption only from the left fuel tank. The asymmetric fuel burn was later determined to be from a blocked fuel vent for the right fuel tank. Beginning on February 20, 2020, maintenance was performed on the airplane to address owner-reported issues regarding water in the fuel tanks, a rough running engine, and the right fuel tank sump drain being slow to drain. In response to the pilot/owner’s complaint about water in the fuel tanks, maintenance personnel drained about 1/2 gallon of water from both fuel tanks, with more coming from the right fuel tank. The fuel tank sump drain of the right wing was replaced, but the issue of slow draining still existed; they removed the right inlet plate to inspect the inside of the fuel tank and determined the sump drain valve boss ports were blocked by fuel tank sealant. The sealant was removed from theports, which corrected the slow-draining issue. The pilot stated that the mechanic in charge told him that during the fuel system maintenance actions, the fuel cap flange or inlet plate, which is secured to the upper wing skin, was “found without sealant,” and it was subsequently sealed. He added that since then, no water was drained from the wing tank sump drain, reservoir tank, or fuel strainer. The mechanic who did the last annual inspection and the mechanic who removed the right inlet plate both reported the right inlet plate was properly sealed when it was first inspected. The mechanics also reported that there was no time when the right inlet plate was not sealed. According to the mechanics, the left inlet plate was not removed by maintenance personnel. The mechanic who signed off the last annual inspection of the engine reported he checked the servo fuel injector inlet screen and reported it was clean at that time with a “normal” amount of corrosion. He also reported that during the inspection, he did not find any water contamination of the fuel system, but he added that the airplane at that time was inside the hangar. The engine-driven fuel pump was not disassembled as part of the fuel system inspections. According to data downloaded from the on-board JPI engine data monitor, about 2 minutes 54 seconds before the end of recorded data, the EGT readings for the Nos. 1 thru 3 cylinders began to decrease, and the EGT reading for the No. 4 cylinder remained substantially higher. While the EGT readings for the Nos. 1 thru 3 cylinders were decreasing, the CHT readings for cylinder Nos. 1 thru 3 also began to decrease, and the CHT reading for the No. 4 cylinder increased. While the majority of the readings for EGT and CHT decreased at the end of the data, the fuel pressure and fuel flow decreased as well. ## Aircraft - Registration: [N1813Q](https://openairdocs.org/deregistered/N1813Q-2021-09-04), registration cancelled 2021-09-04, S/N 177RG0213, built 1971 (OpenAirDocs) - Reported make and model: Cessna 177RG (No Series) - Registry model: [Cessna 177RG](https://openairdocs.org/model/cessna-177rg) (registry code 2073709) (OpenAirDocs) - Registry engine: [Lycoming IO-360-A1B6D](https://openairdocs.org/engine/lycoming-io-360-a1b6d) (registry code 41593, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 177RG0213 - Year built: 1971 - Airframe hours: 3296.8 - Engines: Lycoming IO-360-A1B6D 200 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 8, 2019 - Departed: TJPS, Ponce, PR - Destination: TJRV, Ceiba, PR - Equipment: Stall warning system, ADS-B, Data recorder, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 64; injuries: none; commercial, flight instructor; airplane ratings: single-engine land, multi-engine land, single-engine sea, multi-engine sea; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review October 5, 2018; seat: right; flight hours: 17,287 total, 25 in this make and model, 17,067 as pilot in command, 50 in the last 90 days, 20 in the last 30 days, 2 in the last 24 hours - Pilot; age 52; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review November 22, 2019; seat: left; restraint: 3-point; flight hours: 384 total, 96 in this make and model, 255 as pilot in command, 2 in the last 90 days, 2 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 110° at 10 knots - Visibility: 7 statute miles - Lowest ceiling: 5,000 ft broken - Temperature: 84 °F, dew point 75 °F - Altimeter: 30.04 inHg - Observed at: TJNR, 41 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 20200724015569A](https://openairdocs.org/incident/20200724015569A), Jul 24, 2020: Cessna 177RG, Salinas, PR, Substantial damage. On July 24, 2020, about 1002HRS atlantic standard time, a Cessna 177RG, N1813Q, was substantially damaged when it was involved in an accident near Salinas,… ## Docket (10 files) The files NTSB released with the investigation on August 31, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101681. 27.4 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 20 pages, 13.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12434875&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Record of NTSB conversations (item 2, PDF, 16 pages, 248 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12455467&FileExtension=pdf&FileName=Record%20of%20NTSB%20Conversations_Redacted-Rel.pdf - Statement from owner (item 3, PDF, 2 pages, 65 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12435649&FileExtension=pdf&FileName=Statement%20from%20Owner_Redacted-Rel.pdf - FAA inspector statement (item 4, PDF, 5 pages, 218 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12435389&FileExtension=pdf&FileName=FAA%20Inspector%20Stmnt%20Recd%204%209%202021_Redacted-Rel.pdf - Excerpts of maintenance records (item 5, PDF, 5 pages, 4.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12455821&FileExtension=pdf&FileName=Excerpts%20of%20Maintenance%20Records_Redacted-Rel.pdf - Excerpt of checklist used at last annual inspection (item 6, PDF, 1 page, 125 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12456117&FileExtension=pdf&FileName=Excerpt%20of%20Checklist%20Used%20at%20Last%20Annual%20Inspection-Rel.pdf - Investigative photographs (item 7, PDF, 13 pages, 13 photos, 5.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12458203&FileExtension=pdf&FileName=Investigative%20Photographs-Rel.pdf - Engine monitor device download factual report (item 8, PDF, 2 pages, 2 photos, 429 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12434757&FileExtension=pdf&FileName=JPI_engine_monitor_Download_factual_ERA20LA261%20v02-Rel.pdf - Tabular data for engine monitor device download factual report (item 9, CSV, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12435784&FileExtension=csv&FileName=Flt56_7_24_20_all_data-Rel.csv - Release of aircraft wreckage, NTSB form 6120.15, and evidence control forms (item 10, PDF, 3 pages, 2.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12435659&FileExtension=pdf&FileName=Wreckage%20Release%20and%20Evidence%20Control%20Forms_Redacted-Rel.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.