# NTSB ERA12LA346: Robinson Helicopter R44, N444WT, Destin, FL, May 19, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 19, 2012, 15:40 local (20:40 UTC) - Place: Destin, FL - Coordinates: 30.399906, -86.490814 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=30.3999&lon=-86.4908&mi=10 - Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping) - Defining event: [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) - Highest injury: No injuries - Injuries: 3 uninjured - Status: Completed, report May 9, 2013 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 83707 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA12LA346 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83707/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83707 - Page: https://openairdocs.org/ntsb/ERA12LA346 ## Probable cause The partial loss of engine power due to a stuck (open) exhaust valve in the No. 5 cylinder. Contributing to the accident was the operator’s failure to follow the engine manufacturer’s directives concerning cooling of the engine after flight. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Damaged/degraded (probable cause); cases with it: [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Terrain: sloped/uneven terrain](https://openairdocs.org/ntsb-findings/03021017): Environmental issues › Physical environment · Effect on operation; cases with it: [All aircraft, 270 cases](https://openairdocs.org/ntsb-findings/03021017/cases.md) - [Engine (reciprocating)](https://openairdocs.org/ntsb-findings/01058500): Aircraft › Aircraft power plant · Incorrect use/operation (probable cause); cases with it: [All aircraft, 497 cases](https://openairdocs.org/ntsb-findings/01058500/cases.md) - [Use of equip/info: use of policy/procedure](https://openairdocs.org/ntsb-findings/02063032): Personnel issues › Task performance · Flt operations/dispatcher (probable cause); cases with it: [All aircraft, 191 cases](https://openairdocs.org/ntsb-findings/02063032/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Initial climb: Loss of engine power (partial)](https://openairdocs.org/ntsb-events/342) (defining event); cases with it: [All aircraft, 1,858 cases](https://openairdocs.org/ntsb-events/342/sequence.md) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Autorotation: Hard landing](https://openairdocs.org/ntsb-events/092); cases with it: [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) ## Analysis The helicopter reached about 200 feet above ground level in the initial climb when the pilot noticed that the engine needle in the dual tachometer (engine/main rotor rpm) had "spiked" and then remained "at the top of the gauge." The pilot turned the helicopter around to return to the airport, and, during the turn, the low rotor rpm warning alarm sounded. The pilot responded by lowering the collective control and increasing throttle but then determined that an airport landing could not be completed because the helicopter had already lost altitude. The pilot selected a forced landing area in a sand pit and responded to another low rotor rpm alarm by again lowering the collective. She attempted to cushion the landing with the available rotor rpm, but the helicopter landed hard, and the main rotor blades severed the tailboom. Examination of the helicopter revealed that the engine had a stuck (open) number 5 exhaust valve caused by buildup of oil carbon deposits. This is an issue with the Robinson Helicopters if the engine is not cooled down properly after flight. Air tour operations seem to be prone to carbon buildup mainly due to quick multiple shutdowns. The operator has established a postflight cool down procedure to prevent further problems. On January 19, 1988, Textron Lycoming published Service Letter No. L197A, Recommendations to Avoid Valve Sticking. The guidance offered included, "Rapid engine cool down from low power altitude changes, low power landing approach and/or engine shutdown too soon after landing or ground runs should be avoided." ## Factual narrative On May 19, 2012, about 1540 central daylight time, a Robinson R44 helicopter, N444WT, was substantially damaged during a forced landing after takeoff from Destin-Fort Walton Beach Airport (DTS), Destin, Florida. The certificated commercial pilot and two passengers were not injured. Visual meteorological conditions prevailed, and a company flight plan was filed for the flight. The local sightseeing flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. According to the pilot, the helicopter had reached approximately 200 feet above ground level (agl) in the initial climb when she noticed that the engine needle in the dual tachometer (engine/main rotor rpm) had "spiked" and then remained "at the top of the gauge." She turned that helicopter to return to the airport, and during the turn, the low rotor rpm warning horn sounded. The pilot responded by lowering the collective control and increasing throttle, but then determined that an airport landing could not be completed due to the resultant loss of altitude. The pilot selected a forced landing area in a sand pit, and responded to another low rotor rpm alarm by again lowering the collective. She attempted to cushion the landing with the available rotor rpm, but the helicopter landed hard, and the main rotor blades severed the tailboom. The helicopter came to rest upright, and the occupants egressed without injury. In interviews and written statements provided to the local sheriff's department, the passengers each stated that the helicopter was "leaning to the right" during the takeoff, and that the helicopter "beeped and descended" twice before it landed hard in the sand. The helicopter was removed from the site, and a detailed examination of the wreckage was scheduled. According to Federal Aviation Administration (FAA) and operator records, the helicopter was manufactured in 2000 and had accrued 1,668 total aircraft hours as of the date of the accident. Its most recent annual inspection was completed April 12, 2012. The pilot held an FAA commercial pilot certificate with ratings for rotorcraft-helicopter and instrument helicopter. She also held a flight instructor certificate with ratings for rotorcraft-helicopter and instrument helicopter. Her most recent FAA second class medical certificate was issued March 16, 2012. The pilot reported 433 total hours of flight experience, of which 143 hours were in the accident helicopter make and model. The helicopter was examined on June 6 and 7, 2012 by FAA inspectors, and the results of that examination were summarized in an email from one of the inspectors who stated, "The engine had a stuck (open) number #5 exhaust valve caused by buildup of oil carbon deposits. This is an issue with the Robinson Helicopters if the engine is not cooled down properly after flight. Air tour operations seem to be prone to carbon buildup mainly due to quick multiple shutdowns. The operator has established a post flight cool down procedure toprevent further problems." On January 19, 1988, Textron Lycoming published Service Letter No. L197A, Recommendations to Avoid Valve Sticking. The guidance offered included, "Rapid engine cool down from low power altitude changes, low power landing approach and/or engine shutdown too soon after landing or ground runs should be avoided." ## Aircraft - Registration: N444WT (not matched to a registry record) - Reported make and model: ROBINSON HELICOPTER R44 - Category: Helicopter - Serial number: 0895 - Airframe hours: 1668 - Engines: LYCOMING VO-540 250 horsepower reciprocating - Damage: Substantial damage - Flight: Other work use, Part 91 - Operator: Timberview Helicopters - Registered owner: Timberview Helicopters - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 12, 2012 - Departed: KDTS, Destin, FL - Destination: KDTS, Destin, FL - Flight plan: Company VFR - Airport: KDTS, Destin, runway 14, 5,001 × 100 ft ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 38; injuries: none; commercial, flight instructor; instrument ratings: helicopter; medical: class 2, without waivers/limitations; last flight review April 17, 2012; seat: right; flight hours: 433 total, 143 in this make and model, 336 as pilot in command, 22 in the last 90 days, 12 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 90° at 9 knots, gusting 16 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 84 °F, dew point 55 °F - Altimeter: 29.96 inHg - Observed at: DTS, 5 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 20120519009399A](https://openairdocs.org/incident/20120519009399A), May 19, 2012: Robinson Helicopter R44, Destin, FL, Substantial damage. Helicopter experienced an engine tachometer system failure (over-speed indication) during takeoff at 200 feet AGL on a 140 degree heading. Pilot elected to… ## Docket (7 files) The files NTSB released with the investigation on March 22, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83707. 2.0 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=40388698&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Pilot and Passenger Statements (item 2, .PDF, 886 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40388699&FileExtension=.PDF&FileName=Pilot%20and%20Passenger%20Statements-Redacted.PDF - Pilot Statement (item 3, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40388700&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Memorandum of Record: FAA Inspector (item 4, .PDF, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40388703&FileExtension=.PDF&FileName=Memorandum%20of%20Record%3A%20FAA%20Inspector-Master.PDF - Lycoming Service Letter 197A Recommendations to Avoid Valve Sticking (item 5, .PDF, 140 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40388704&FileExtension=.PDF&FileName=Lycoming%20Service%20Letter%20197A%20Recommendations%20to%20Avoid%20Valve%20Sticking-Master.PDF - Photo 1: View of helicopter as found (Courtesy of FAA) (item 6, .PDF, 126 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40388705&FileExtension=.PDF&FileName=Photo%201%3A%20View%20of%20helicopter%20as%20found%20(Courtesy%20of%20FAA)-Master.PDF - Photo 2: View of Helicopter and Separated Tailboom Components (Courtesy of FAA) (item 7, .PDF, 123 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40388706&FileExtension=.PDF&FileName=Photo%202%3A%20View%20of%20Helicopter%20and%20Separated%20Tailboom%20Components%20(Courtesy%20of%20FAA)-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.