# NTSB SEA99LA056: Piper PA-18-150, N7483L, Salem, OR, May 9, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 9, 1999, 14:20 local (21:20 UTC) - Place: Salem, OR - Coordinates: 45.009681, -122.910827 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.0097&lon=-122.9108&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report March 31, 2000 - Report: Approved by Office Director - NTSB case key (mKey): 46288 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA99LA056 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/46288/pdf - Page: https://openairdocs.org/ntsb/SEA99LA056 ## Probable cause The pilot's improper decision not to apply carburetor heat during a reduced power descent in conditions conducive to carburetor icing. Factors include weather conditions conducive to carburetor icing, and high vegetation and a fence post in the area where the forced landing was attempted. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of engine power(total) - nonmechanical, approach - vfr pattern - final approach - in-flight planning/decision - improper, pilot in command (cause) - fuel system,carburetor - ice (cause) - weather condition - carburetor icing conditions (contributing factor) - On ground/water collision with object, emergency landing - terrain condition - high vegetation (contributing factor) - object - fence post (contributing factor) ## Analysis The pilot, who had been cleared for a straight-in approach, began a reduced-power descent from approximately 2000 feet above ground level (AGL) while about five miles from the runway. About half way through the descent, the pilot retarded the throttle to idle but did not apply carburetor heat. When he reached 400 feet AGL, the pilot realized he was getting too low on the approach, so he pushed the throttle forward in order to add power and arrest his descent. Upon moving the throttle forward, the engine did not respond. The pilot then applied full carburetor heat, but he could not get the engine to restart. It was ultimately determined that his descent had been made under conditions where severe carburetor icing could be expected at glide power. Although the PA-18 Owners Handbook did not call for the use of carburetor heat during all approaches, it did require it when '... icing conditions prevail.' ## Factual narrative On May 9, 1999, approximately 1420 Pacific daylight time, the pilot of a Piper PA-18-150, N7483L, collided with tall brush while attempting a forced landing in a field about 1/2 mile short of the runway at McNary Field, Salem, Oregon. The private pilot was not injured, but the aircraft, which was owned and operated by the pilot, sustained substantial damage. The local 14 CFR Part 91 flight, which was being conducted in visual meteorological conditions, began about one hour and 30 minutes prior to the accident. No flight plan had been filed, and there was no report of an ELT activation. According to the pilot, as he was returning from the pleasure flight, he contacted Salem Tower and was cleared for a straight-in VFR approach to runway 34. While about five miles from the airport, he reduced the engine power to a setting less than it had been at during cruise flight, and started a descent from about 2,000 feet above the ground (AGL). About half way through the descent, the pilot pulled the throttle to idle but did not apply carburetor heat. When he was about 400 feet AGL, the pilot realized he was getting low on the approach, so he moved the throttle forward, but there was no response from the engine. He applied carburetor heat, but was unable to get the aircraft to restart. He therefore made a forced landing in a field about 1/2 mile from the end of runway. During the landing roll, the pilot maneuvered to miss a fence post he had not seen from the air, but in so doing, the aircraft collided with tall shrubs and sustained substantial damage. Subsequent to the accident, the aircraft was moved to McNary Field where the engine was test run and inspected. The inspection revealed no anomalies, and during the test run, the engine operated normally with proper responses to magneto and carburetor heat checks. The investigation revealed that the surface weather observation (METAR) taken at Salem Airport at the time of the accident (2120 UTC) showed a temperature of 54 degrees Fahrenheit and a dew point of 36 degrees. According to the Carburetor Icing Probability Chart obtained from DOT/FAA/CT-82/44 (see attached chart), the pilot was making the approach in conditions where serious carburetor icing could be expected at glide power. A review of the PA-18 Owners Handbook revealed that, although carburetor heat is not required for all approaches and landings, it is required when "...icing conditions prevail." ## Aircraft - Registration: [N7483L](https://openairdocs.org/aircraft/N7483L), registered now, S/N 18-7509075, built 1975 (OpenAirDocs) - Reported make and model: Piper PA-18-150 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-7509075 - Airframe hours: 3939 - Engines: Lycoming O-320-A1 150 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: Larry H. Nunn, Trustee - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 4, 1999, 9 hours before - Departed: SLE ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 53; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: front; flight hours: 753 total, 133 in this make and model, 641 as pilot in command, 14 in the last 90 days, 4 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 120° at 4 knots - Visibility: 10 statute miles - Temperature: 54 °F, dew point 36 °F - Altimeter: 30.00 inHg - Observed at: KSE, 1 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 19990509020439A](https://openairdocs.org/incident/19990509020439A), May 9, 1999: Piper PA18150, Salem, OR, Substantial damage. On may 9, 1999, approximately 1420 pacific daylight time, the pilot of a Piper PA-18-150, N7483L, collided with tall brush while attempting a forced landing in… 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.