ERA12CA278

NTSB accident investigation · Piper PA-18A · West Palm Beach, FL · April 12, 2012

Accident · Minor injuriesData collectionFinal report
Date
April 12, 2012, 14:30 local (18:30 UTC)
Place
West Palm Beach, FL
Injuries
1 minor, 1 uninjured
Damage
Substantial damage
Phase of flight
Landing
Aircraft
N12003Piper PA-18A
Defining event
Landing-landing roll: Nose over/nose down
Weather
Visual (VMC) · Day
Status
Completed · report October 15, 2012
Report
Approved by Office Director
NTSB office
Eastern Region Aviation
Parties
FAA/FSDO
FAA report
20120412005349A
Case key
83382

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

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Probable cause

The inadequate assembly of the brakes, which caused them to lock during the landing roll when the airplane transitioned from asphalt to turf, resulting in the airplane nosing over.

Findings · 4

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Aircraft capability: braking capabilityAircraft › Aircraft oper/perf/capability · Attain/maintain not possibleAll aircraft: 57 casesProbable cause
Maintenance: installationPersonnel issues › Task performance · Maintenance personnelAll aircraft: 371 casesProbable cause
Landing gear system: brakeAircraft › Aircraft systems · Incorrect service/maintenanceAll aircraft: 297 casesProbable cause
Airport facilities/design: runway/landing area conditionEnvironmental issues › Operating environment · Effect on operationAll aircraft: 61 cases

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

**This brief was modified on November 1, 2013. Please see the public docket for this accident to view the original report.** The pilot stated that when he returned to the airport after a local flight, he elected to land on the turf runway, which intersected an asphalt runway. He said he touched down on the main landing gear "fairly long" on the first portion of the turf runway at a speed of about 60 mph. The pilot delayed lowering the tailwheel until the airplane was crossing the asphalt surface and then lowered the tailwheel firmly to the ground. The airplane began to veer left, and the pilot applied full right rudder and a "slight amount" of right brake to regain directional control. When the airplane transitioned from the asphalt surface to the turf runway, it abruptly nosed over. The airplane came to rest inverted, incurring substantial damage to the rudder. An examination of the runway's asphalt to turf transition section revealed that the airplane's main landing gear tires dug into the turf as it left the slightly higher asphalt. The pilot reported no mechanical malfunctions or failures during the landing and rollout. While the airplane was being repaired after the accident, a mechanic determined that the bolts holding the main wheel halves in position were excessively long, causing the wheel halves to separate and the brake discs to change position when the airplane transitioned from the asphalt to the turf runway. This condition likely caused the brake discs to jam in their housing and the wheels to stop rotating.

Factual narrative

**This report was modified on November 1, 2013. Please see the public docket for this accident to view the original report.**The pilot stated that upon returning to the airport from a local flight, he elected to land on the grass turf runway, which had an asphalt runway intersection within the first quarter of its length. His landing speed was about 60 mph, the airplane touched down long on the first portion of the grass turf. The pilot held off lowering the tail wheel initially but then lowered it firmly onto the ground. During the landing roll on the asphalt portion, the airplane began to arc to the left, the pilot applied full right rudder and then eased on a "slight amount" of right brake. As the airplane departed the asphalt section, it abruptly nosed over, the propeller struck the ground and the airplane came to rest inverted on the grass turf runway, incurring substantial damage to the vertical section and rudder. An inspection of the runway's asphalt to grass turf transition section revealed that the airplane's main landing gear tires dug into the turf as it left the slightly higher asphalt. An aviation safety inspector from the Federal Aviation Administration responded to the accident scene and interviewed the pilot, who reported no mechanical malfunctions or failures during the landing and rollout. While the airplane was being repaired after the accident, a mechanic determined that the bolts holding the main wheel halves in position were excessively long, causing the wheel halves to separate and the brake discs to change position when the airplane transitioned from the asphalt to the turf runway.

Aircraft

Registration
N12003
Reported as
Piper PA-18A
Category
Airplane
Serial number
18 6013
Airframe hours
6,249
Engine
Lycoming O-320-B2B, 160 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · June 4, 2011
Departed
F45 · West Palm Beach, FL
Destination
F45 · West Palm Beach, FL
Airport
F45 · North Palm Beach County, runway 08L, 3,679 × 75 ft, dirt

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
69
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land
Instrument ratings
Airplane
Medical
Class 3, With waivers/limitations
Last flight review
April 7, 2012
Seat
Front
Flight hours
640 total · 54 in this make and model · 26 in the last 90 days · 8 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
350° at 6 knots
Visibility
10 statute miles
Temperature
81 °F, dew point 61 °F
Altimeter
30.03 inHg
Observed at
PBI, 12 nm away

Docket · 7

The files NTSB released with the investigation on August 13, 2012, on NTSB’s docket system: statements, records, photos and specialists’ reports. 1.7 MB 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.