# NTSB ANC09LA036: Piper PA-24-180, N7352P, Chugiak, AK, April 28, 2009 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: April 28, 2009, 15:00 local (23:00 UTC) - Place: Chugiak, AK - Coordinates: 61.41611, -149.508331 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.4161&lon=-149.5083&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR go-around: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 11, 2010 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: Federal Aviation Administration (Operations) - NTSB case key (mKey): 73748 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC09LA036 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/73748/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=73748 - Page: https://openairdocs.org/ntsb/ANC09LA036 ## Probable cause The flight instructor's inadequate supervision of the pilot during a simulated loss of engine power, and the pilot's failure to use carburetor heat while operating at a reduced engine power while in carburetor icing conditions. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: monitoring other person](https://openairdocs.org/ntsb-findings/02021535): Personnel issues › Psychological · Instructor/check pilot (probable cause); cases with it: [Piper PA-24-180, 1 case](https://openairdocs.org/ntsb-findings/02021535/cases.md?model=7102403), [All aircraft, 200 cases](https://openairdocs.org/ntsb-findings/02021535/cases.md) - [Engine controls](https://openairdocs.org/ntsb-findings/01057600): Aircraft › Aircraft power plant · Not used/operated (probable cause); cases with it: [Piper PA-24-180, 1 case](https://openairdocs.org/ntsb-findings/01057600/cases.md?model=7102403), [All aircraft, 51 cases](https://openairdocs.org/ntsb-findings/01057600/cases.md) - [Action: lack of action](https://openairdocs.org/ntsb-findings/02041030): Personnel issues › Action/decision · Pilot; cases with it: [Piper PA-24-180, 2 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md?model=7102403), [All aircraft, 792 cases](https://openairdocs.org/ntsb-findings/02041030/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-24-180, 2 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=7102403), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) - [Temp/humidity/pressure: conducive to carburetor icing](https://openairdocs.org/ntsb-findings/03031030): Environmental issues › Conditions/weather/phenomena · Effect on equipment; cases with it: [Piper PA-24-180, 3 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md?model=7102403), [All aircraft, 435 cases](https://openairdocs.org/ntsb-findings/03031030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Simulated/training event](https://openairdocs.org/ntsb-events/600); cases with it: [Piper PA-24-180, 1 case](https://openairdocs.org/ntsb-events/600/sequence.md?model=7102403), [All aircraft, 173 cases](https://openairdocs.org/ntsb-events/600/sequence.md) - [Approach-VFR go-around: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event); cases with it: [Piper PA-24-180, 2 cases](https://openairdocs.org/ntsb-events/341/sequence.md?model=7102403), [All aircraft, 3,820 cases](https://openairdocs.org/ntsb-events/341/sequence.md) - [Emergency descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Piper PA-24-180, 4 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=7102403), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The certificated flight instructor (CFI) was administering a biennial flight review to the private pilot/airplane owner whose previous biennial review had expired. The CFI said that while in level flight at 1,600 feet msl, as the airplane approached the accident airport, he closed the engine throttle, and told the pilot that he was simulating an engine failure, then instructed the pilot to make an emergency descent and landing at the airport ahead. During the simulated emergency descent, the CFI momentarily advanced the engine throttle to ensure engine power was still available, and the engine appeared to respond accordingly. As the approach progressed, the pilot lowered the landing gear, and the airplane's descent rate increased significantly. The CFI instructed the pilot to go-around when he realized that the airplane was too low on the approach. The pilot immediately applied full engine throttle, but the engine did not respond, and he selected an area of grass-covered terrain as a forced landing site. During the forced landing the airplane struck a perimeter fence, and the nose and main landing gear collapsed. The airplane sustained substantial damage to the fuselage and wings. An NTSB postaccident inspection disclosed no evidence any preimpact mechanical problems. An aviation weather reporting station indicated that the temperature was 54 degrees F, and the dew point was 32 degrees F. When these values are entered into a carburetor icing probability chart, the results are in the "Serious icing-glide power" category. Both pilots reported that carburetor heat was not used during the simulated emergency descent and approach. A pilot that landed about 15 minutes after the accident reported that while on approach, his airplane's engine developed carburetor ice, which required the use of carburetor heat. Given the lack of any mechanical anomalies it is likely that the formation of carburetor ice resulted in the loss of engine power. ## Factual narrative On April 28, 2009, about 1500 Alaska daylight time, a Piper PA-24-180 airplane, N7352P, sustained substantial damage during a forced landing following a reported loss of engine power while on approach to the Birchwood Airport, Chugiak, Alaska. The certificated flight instructor and the private pilot were not injured. The airplane was being operated as a visual flight rules (VFR) instructional flight under the provisions of Title 14 Code of Federal Regulations (CFR) Part 91, when the accident occurred. Visual meteorological conditions prevailed at the time of the accident, and no flight plan was filed. The flight originated at the Merrill Field Airport, Anchorage, Alaska, about 1450. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC) on April 28, the flight instructor reported that he was in the right seat, and the private pilot/airplane owner was in the left seat. The instructor said that the purpose of the flight was to administer a biennial flight review to the pilot, whose previous flight review had expired. The instructor said that after departing the Merrill Field Airport, they flew north at 1,600 feet msl. He said that as the airplane approached the Birchwood Airport, he closed the engine throttle, and told the pilot that he was simulating an engine failure, then he told the pilot to demonstrate an emergency descent and landing at the Birchwood Airport. The instructor noted that the pilot followed the emergency procedures for a loss of engine power, and immediately entered a right base for landing on Runway 1L. The instructor reported that as the pilot continued the simulated emergency descent, and as the airplane turned from a right base leg to final approach, he momentarily advanced the engine throttle to ensure engine power was still available, and the engine appeared to respond accordingly. The instructor said that while on short final for Runway 1L, the pilot lowered the landing gear, and the airplane's descent rate increased significantly. The instructor then commanded the pilot to go-around when he felt the airplane was too low on the approach, and the pilot immediately applied full engine throttle, but the engine did not respond. The instructor confirmed that the throttle was full open, and the pilot then pulled aft on the control yoke to cushion the landing on the grass-covered terrain. The instructor said that during the forced landing the airplane struck a perimeter fence, then slid for several feet on the grass-covered terrain. The nose and main landing gear collapsed, and the airplane sustained substantial damage to the fuselage and wings. The airplane was equipped with a carburetor-equipped Lycoming O-360-A1A engine. Both the instructor and pilot reported that carburetor heat was not used during the simulated emergency descent and approach. The Piper PA-24-180 Pilot Operating Handbook (POH), engine and propeller descriptions section, approach and landing, states,in part: "Carburetor heat should not be applied unless there is indication of carburetor icing, since the use of carburetor heat causes a loss in engine power which may be critical in the event of a go-around, and can induce detonation in this situation." During a telephone conversation with the NTSB IIC on May 1, a pilot that was flying a Cessna 152, which landed at the Birchwood Airport about 15 minutes after the accident, reported that while on approach, his airplane's engine developed carburetor ice, which required the use of carburetor heat. The closest official weather observation station is located at the Birchwood Airport. At 1453, an Aviation Routine Weather Report (METAR) was reporting, in part: Wind, 310 degrees (true) at 5 knots; visibility, 10 statute miles; clouds and sky condition, clear; temperature, 54 degrees F; dew point, 32 degrees F; altimeter, 30.39 inHg. The Birchwood Airport is situated adjacent to the ocean waters of the Cook Inlet. The temperature and dew point were entered into a carburetor icing probability chart, which coincided with the "Serious icing-glide power" category. In his written report to the NTSB the instructor noted that the accident might have been avoided if he had initiated the simulated engine failure closer to the airport, or concluded the simulation at a higher altitude, resulting in more time to attempt an engine restart. TESTS AND RESEARCH The NTSB IIC, and a Federal Aviation Administration (FAA) airworthiness inspector from the Anchorage Flight Standards District Office (FSDO), went to the accident site on April 30 and examined the wreckage. No preaccident mechanical anomalies were discovered during the examination. Both engine magnetos were removed for bench testing. On May 1, under the direction of the NTSB IIC, the undamaged magnetos were placed on a test bench at Alaskan Aircraft Engines, Anchorage. Both magnetos produced spark at all terminals. ADDITIONAL INFORMATION The FAA's Advisory Circular (AC) 61-23C, Pilot's Handbook of Aeronautical Knowledge, Chapter 2, Carburetor Icing, states, in part: "... if the temperature is between -7 degrees C (20 degrees F) and 21 degrees C (70 degrees F), with visible moisture or high humidity, the pilot should be constantly on the alert for carburetor ice. During low or closed throttle setting, an engine is particularly susceptible to carburetor icing.” The FAA's AC 20-113, Pilot Precautions and Procedures to be taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems, states, in part: "Vaporization icing may occur at temperatures from 32 degrees F to as high as 100 degrees F with a relative humidity of 50 percent or above... Since aviation weather reports normally include air temperature and dew point temperature, it is possible to relate the temperature/dew point spread to relative humidity. As the spread becomes less, relative humidity increases and becomes 100 percent when temperature and dew point are thesame. In general, when the temperature/dew point spread reaches 20 degrees or less, you have a relative humidity of 50 percent or higher and are in potential icing conditions." ## Aircraft - Registration: [N7352P](https://openairdocs.org/deregistered/N7352P-2012-04-14), registration cancelled 2012-04-14, S/N 24-2530, built 1961 (OpenAirDocs) - Reported make and model: PIPER PA-24-180 - Registry model: [Piper PA-24-180](https://openairdocs.org/model/piper-pa-24-180) (registry code 7102403) (OpenAirDocs) - Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-2530 - Airframe hours: 2048 - Engines: LYCOMING O-360-A1D 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Steven Lewis - Registered owner: Dave G. Heusser - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 2, 2009, 0 hours before - Departed: MRL, Anchorage, AK - Destination: BCV, Chugiak, AK - Airport: BCV, Birchwood, runway 01L, 4,008 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 33; injuries: none; flight instructor, commercial, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review June 2, 2008; seat: right; flight hours: 5,200 total, 200 in this make and model - Pilot; age 66; injuries: none; commercial; airplane ratings: single-engine land, single-engine sea, multi-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review March 5, 2007; seat: left; flight hours: 2,976 total, 610 in this make and model, 2,834 as pilot in command, 1 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 54 °F, dew point 32 °F - Altimeter: 30.38 inHg - Observed at: BCV ## 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 20090428046949A](https://openairdocs.org/incident/20090428046949A), Apr 28, 2009: Piper PA-24-180, Birchwood, AK, Substantial damage. While conducting a flight review, the instructor simulated a partial power plant failure. The pilot, and owner of the PA-24 executed an emergency landing with… ## Docket (3 files) The files NTSB released with the investigation on March 29, 2010, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=73748. 847 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 801 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327616&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Telephone Call - Pilot (item 2, .PDF, 31 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327617&FileExtension=.PDF&FileName=Record%20of%20Telephone%20Call%20-%20Pilot-Master.PDF - Receipt of Aircraft Parts (item 3, .PDF, 14 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40327618&FileExtension=.PDF&FileName=Receipt%20of%20Aircraft%20Parts-Redacted.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.