# NTSB ANC02LA009: Piper PA-18, N9908D, Anchorage, AK, January 12, 2002 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: January 12, 2002, 13:32 local (17:32 UTC) - Place: Anchorage, AK - Coordinates: 61.214443, -149.846115 - Nearby events: https://openairdocs.org/map.md?lat=61.2144&lon=-149.8461&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report August 26, 2002 - Report: Approved by Office Director - NTSB office: Alaska Regional Office - Parties: FAA-AL-ANC FSDO 03 - NTSB case key (mKey): 54018 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC02LA009 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/54018/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=54018 - Page: https://openairdocs.org/ntsb/ANC02LA009 ## Probable cause The flight instructor's inadequate supervision of the flight. Factors in the accident were the student's failure to maintain directional control of the airplane during the landing roll, icy runway conditions, and snow-covered terrain along the runway edges. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - on ground/water, landing - roll - airport facilities,runway/landing area condition - icy (contributing factor) - directional control - not maintained, dual student (contributing factor) - supervision - inadequate, pilot in command(cfi) (cause) - On ground/water encounter with terrain/water, landing - roll - terrain condition - snow covered (contributing factor) - Nose over, landing - roll ## Analysis The certificated flight instructor was providing instruction to the private pilot/new owner of a tundra tire-equipped, tailwheel airplane. The flight instructor occupied the rear seat of the airplane. The pilot/owner had accrued 66 total flight hours, 14 hours as pilot-in-command, and .5 hours in the accident airplane. Five minutes after takeoff, the student was performing a landing on an asphalt surface runway that had areas of ice along the edges. During the landing roll the airplane began to drift to the right. The instructor applied left rudder, but the airplane departed the right side of the runway into an area of snow. The airplane nosed over and received damage to the propeller, fuselage, and wing lift struts. The right master brake cylinder, installed in the front seat area, was serviced before the flight. A heater hose was installed in the cabin to direct heat into the rear seat area. The instructor reported that the airplane's right brake felt as if it was locked, which she said may have been due to overfilling the brake reservoir, and heating of the brake cylinder by the heater. The instructor cited two previous NTSB reports of brake cylinder locking after extended flight with a heater hose blowing hot air on a brake reservoir. A review of the two previous accidents disclosed airplanes had locked brakes during landing, both within five days of each other in 1997. The previous NTSB accident reports involved two aircraft where a heater hose was directed onto the master brake cylinders after the brake cylinders were serviced. One of the accidents involved 1.5 hours of flight time before landing. The second accident involved 3 hours of flight time before landing. The accident airplane's brake system was not examined postaccident. ## Factual narrative On January 12, 2002, about 1332 Alaska standard time, a tundra tire-equipped Piper PA-18 airplane, N9908D, sustained substantial damage during landing at Merrill Field, Anchorage, Alaska. The airplane was being operated as a visual flight rules (VFR) local area instructional flight when the accident occurred. An airline transport certificated pilot/flight instructor, and the private certificated pilot/owner, were not injured. Visual meteorological conditions prevailed. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on January 12, the flight instructor reported that she occupied the rear of the airplane, and was providing instruction to the airplane's new owner, who occupied the front seat. The pilot/owner had accrued 66 total flight hours, 14 hours as pilot-in-command, and .5 hours in the accident airplane. The instructor said that following a "three point landing" on the asphalt surface of runway 06, the airplane began to drift to the right. The instructor said she told the pilot to apply left rudder. At the same time, the instructor applied left rudder, but the airplane departed the right side of the runway into an area of snow. The airplane nosed over and received damage to the propeller, fuselage, and wing lift struts. The instructor reported the accident flight departed Lake Hood Strip, Anchorage, and landed at Merrill Field about five minutes later. The flight was the pilot/owner's first flight in a tailwheel airplane. The instructor said that the middle of the runway at Merrill Field was sanded, but the edges of the runway were icy. At 1335, an Aviation Routine Weather Report (METAR) at Merrill Field was reporting, in part: Wind, 050 degrees (true) at 3 knots; visibility, 10 statute miles; clouds and sky condition, 2,400 feet overcast; temperature, 25 degrees F; dew point, 19 degrees F; altimeter, 29.92 inHg. In the Pilot/Operator report (NTSB form 6120.1/2) submitted by the instructor pilot, the instructor reported the airplane's right hydraulic brake reservoir was serviced before the flight. In addition, the instructor reported that a heater hose, routed to the rear seat, was installed the day before the accident flight. In the Pilot/Operator report, the instructor indicated the right brake felt as if it was locked. She included two previous NTSB reports containing references to locked brakes in the accident airplane make and model where the brake system was serviced before flight, and the utilization of a rear seat heater hose. A review of the two previous accidents by the NTSB IIC disclosed State of Alaska PA-18 airplanes had locked brakes during landing, both within five days of each other in 1997. The previous NTSB accident reports involved two aircraft where a heater hose was directed onto the master brake cylinders after the brake cylinders were serviced. One of the accidents involved 1.5 hours of flight time before landing. The second accident involved 3 hours of flight time before landing. The accident airplane's master brake cylinders are installed on the forward cockpit floor, adjacent to the front seat rudder pedals. The rear seat position does not have brake cylinders installed. Following the accident, the airplane was recovered from the accident scene. No postaccident inspection of the brake system was conducted. ## Aircraft - Registration: [N9908D](https://openairdocs.org/aircraft/N9908D), registered now, S/N 18-6949, built 1959 (OpenAirDocs) - Reported make and model: Piper PA-18 - Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs) - Registry engine: [Lycoming O-320-B2B](https://openairdocs.org/engine/lycoming-o-320-b2b) (registry code 42138, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18-6949 - Airframe hours: 3009 - Engines: LYCOMING O-320 150 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Greg L. Sternquist - Airworthiness certificate: Standard, Normal - Last inspection: Annual, August 1, 2001, 9 hours before - Departed: Z41, ANCHORAGE, AK - Destination: PAMR, ANCHORAGE, AK - Airport: PAMR, Merrill Field, runway 06, 4,000 × 100 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 67; injuries: none; flight instructor, commercial, airline transport; airplane ratings: single-engine land, multi-engine land, single-engine sea, multi-engine sea; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; last flight review April 23, 2001; seat: rear; flight hours: 25,266 total, 300 in this make and model, 24,535 as pilot in command, 55 in the last 90 days, 10 in the last 30 days, 1 in the last 24 hours - Student pilot; age 47; injuries: none; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; last flight review December 1, 2001; seat: front; flight hours: 66 total, 1 in this make and model, 14 as pilot in command, 8 in the last 90 days, 2 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 28° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: 2,400 ft overcast - Temperature: 25 °F, dew point 19 °F - Altimeter: 29.92 inHg - Observed at: PAMR ## 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 20020112001309A](https://openairdocs.org/incident/20020112001309A), Jan 12, 2002: Piper PA18150, Anchorage, AK, No damage. (-23) Owner/pilot had just purchased this aircraft and was getting tail wheel instruction. Departure was normal and for the first half hour, flight maneuvers… ## Other investigations on N9908D (2) 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 ANC75AA083](https://openairdocs.org/ntsb/ANC75AA083), May 15, 1975: Piper PA-18 (N9908D), Selawik, AK, substantial damage - [NTSB ANC75DAG07](https://openairdocs.org/ntsb/ANC75DAG07), Jul 27, 1974: Piper PA-18 (N9908D), Tyonek, AK, substantial damage ## Docket (3 files) The files NTSB released with the investigation on July 19, 2002, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=54018. 748 KB in all. - Supplement E (item 1, .PDF, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40163319&FileExtension=.PDF&FileName=Supplement%20E-Master.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Greg Sternquist (item 2, .PDF, 324 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378843&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20Greg%20Sternquist-Redacted.PDF - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 - Adelheid Ruess (item 3, .PDF, 309 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40378844&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1%20-%20%20Adelheid%20Ruess-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.