ANC02LA009

NTSB accident investigation · Piper PA-18 · Anchorage, AK · January 12, 2002

Accident · No injuriesLimited investigationFinal report
Date
January 12, 2002, 13:32 local (17:32 UTC)
Place
Anchorage, AK
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N9908DPiper PA-18
Weather
Visual (VMC) · Day
Status
Completed · report August 26, 2002
Report
Approved by Office Director
NTSB office
Alaska Regional Office
Parties
FAA-AL-ANC FSDO 03
FAA report
20020112001309A
Case key
54018

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The NTSB’s determination of the probable cause, and any contributing factors.

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.

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

The factual narrative524 words

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.

Sequence of events

NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.

Loss of control - on ground/waterLanding - roll
Airport facilities,runway/landing area condition - icyFactor
Directional control - not maintainedDual studentFactor
Supervision - inadequatePilot in command(cfi)Cause
On ground/water encounter with terrain/waterLanding - roll
Terrain condition - snow coveredFactor
Nose overLanding - roll

Aircraft

Registration
N9908D
Reported as
Piper PA-18
Category
Airplane
Serial number
18-6949
Airframe hours
3,009
Engine
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

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew · 2

As NTSB recorded them. NTSB leaves out names.

Role
Flight instructor
Age
67
Injuries
None
Certificates
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
Role
Student pilot
Age
47
Injuries
None
Certificate
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

Docket · 3

The files NTSB released with the investigation on July 19, 2002, on NTSB’s docket system: statements, records, photos and specialists’ reports. 748 KB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.

Other investigations on N9908D · 2

Matched to the same aircraft by N-number and date.