# NTSB FTW98LA404: Piper PA-28RT-201T, N8252S, Duck Creek, UT, September 18, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 18, 1998, 14:00 local (20:00 UTC) - Place: Duck Creek, UT - Coordinates: 37.400924, -112.629119 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.4009&lon=-112.6291&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report December 1, 1999 - Report: Approved by Office Director - NTSB case key (mKey): 43974 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW98LA404 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/43974/pdf - Page: https://openairdocs.org/ntsb/FTW98LA404 ## Probable cause Loose intake valve rocker arm studs that allowed a loss of compression and a loss of oil. A factor was unsuitable terrain on which to make a forced landing and poles next to a cattle guard. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(partial) - mech failure/malf, cruise - normal - engine assembly,rocker arm/tappet - loose part/bolt/nut/clamp/etc (cause) - fluid,oil - leak (contributing factor) - engine assembly,valve,intake - low compression (contributing factor) - Forced landing, descent - emergency - terrain condition - roadway/highway (contributing factor) - object - pole (contributing factor) - On ground/water collision with object, landing - roll ## Analysis The airplane was in cruise flight at 12,500 feet when the pilot noticed the manifold pressure had dropped from 51.8 inches to 25 inches. 'The engine had poor response to throttle movement, and the engine sounded bad when I moved the throttle.' He made the decision not to proceed further due to the remote terrain. As he checked his maps for the nearest airport, the airplane lost altitude. 'The engine did not seem to have much power, and I was about 3,000 feet AGL by this time.' The pilot made a forced landing on a dirt road. During rollout the aircraft struck poles alongside of a cattle guard. According to the salvage company and the FAA inspector who examined the engine, two of the four screws securing the rocker cover on the number 3 cylinder were missing, and oil was leaking out. The rocker cover had a round indention on the outside, and a wear mark on the inside. The exhaust rocker arm studs were also loose. The rear stud was only finger tight. Aluminum was found imbedded in its threads. The front stud was loose, but its nut locking mechanism was still in place. ## Factual narrative On September 18, 1998, approximately 1400 mountain daylight time, a Piper PA-28RT-201T, N8252S, was substantially damaged when it collided with poles during a forced landing near Duck Creek, Utah. The commercial pilot, the sole occupant aboard, was not injured. Visual meteorological conditions prevailed, and a VFR flight plan had been filed for the personal cross-country flight conducted under Title 14 CFR Part 91. The flight originated at Canyonlands Field, Moab, Utah, approximately 1300. In his accident report, the pilot said he was in cruise flight at 12,500 feet, en route to Las Vegas, Nevada, when he noticed the manifold pressure had dropped from 51.8 inches to 25 inches. "The engine had poor response to throttle movement, and the engine sounded bad when I moved the throttle." The pilot made the decision not to proceed further due to the remote terrain. As he checked his maps for the nearest airport, the airplane lost altitude. The pilot said the "engine did not seem to have much power, and I was about 3,000 feet AGL by this time." The pilot made a forced landing on a dirt road. During the landing roll, the aircraft struck poles next to a cattle guard, causing substantial damage. According to the salvage company and the FAA inspector who examined the engine, two of the four screws securing the rocker cover on the number 3 cylinder were missing, and oil was leaking out. The rocker cover had a round indention on the outside, and a wear mark on the inside. The exhaust rocker arm studs were also loose. The rear stud was only finger tight. Aluminum was found imbedded in its threads. The front stud was loose, but its nut locking mechanism was still in place. ## Aircraft - Registration: [N8252S](https://openairdocs.org/deregistered/N8252S-2000-05-08), registration cancelled 2000-05-08, S/N 28R-8031170 (OpenAirDocs) - Reported make and model: Piper PA-28RT-201T (PA-28RT-20) - Registry model: [Piper PA-28RT-201T](https://openairdocs.org/model/piper-pa-28rt-201t) (registry code 7102817) (OpenAirDocs) - Category: Airplane - Serial number: 28R8031170 - Airframe hours: 4792 - Engines: Continental TSIO-360-F 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Wings Of Denver Flying Club - Registered owner: B-Y Enterprises, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, July 24, 1998, 43 hours before - Departed: CNY, MOAB, UT - Destination: VGT, LAS VEGAS, NV - Flight plan: VFR ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: left; flight hours: 2,185 total, 140 in this make and model, 1,839 as pilot in command, 5 in the last 90 days, 4 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 23 knots, gusting 30 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 37 °F - Altimeter: 30.00 inHg - Observed at: CDC, 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 19980918025549A](https://openairdocs.org/incident/19980918025549A), Sep 18, 1998: Piper PA28RT201T, Duck Creek, UT, Substantial damage. Acft esper an engine failure in flight and made an emergency landing on a road, the acft struck a guard rail on landing causing substantial damage, (-23)… ## Other investigations on N8252S (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 CHI99FA164](https://openairdocs.org/ntsb/CHI99FA164), May 23, 1999: Piper PA-28RT-201T (N8252S), Great Bend, KS, destroyed, 1 fatal. Probable cause: the chafed through turbocharger oil supply hose, the failure of maintenance personnel to install a clamp on the turbocharger oil supply hose, and the inability of the pilot to maintain aircraft… 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.