- Date
- December 7, 2016, 11:45 local (17:45 UTC)
- Place
- Denton, TX
- Injuries
- 2 uninjured
- Damage
- Substantial damage
- Phase of flight
- Taxi
- Aircraft
- N2844TPiper PA 34
- Defining event
- Taxi-from runway: Loss of control on ground
- Weather
- Visual (VMC) · Day
- Status
- Completed · report July 20, 2017
- Report
- Approved by Office Director
- NTSB office
- General Aviation Accidents
- Parties
- FAA
- FAA report
- 20161207024701A
- Case key
- 94495
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 flight instructor’s decision to continue to taxi the airplane to the parking area with a known brake malfunction, which resulted in a loss of directional control and subsequent impact with a parked airplane.
Findings · 3
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.
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
According to the flight instructor in the multiengine airplane, he occupied the right seat during the instructional flight. The flight instructor reported that, during the landing roll, the brakes on his side were inoperative, but the brakes used by the pilot under instruction appeared to function normally. The flight instructor allowed the pilot under instruction to taxi to parking. During the right turn in the parking area, the pilot under instruction was told to apply both brakes, and the airplane started to "pull left." The flight instructor attempted to use differential thrust to arrest the left pull by increasing the right engine speed, but the attempt had no effect. The flight instructor shut down both engines; however, the left wing struck a parked airplane and came to a stop. The airplane sustained substantial damage to the left wing. The flight instructor reported that the accident could have been prevented if he had stopped on the taxiway and not entered the parking ramp. A postaccident examination of the brake assembly revealed that the right brake actuator piston "o" ring had failed, which decreased hydraulic brake pressure and prevented proper brake function of the airplane.
Factual narrative
According to the flight instructor in the multi-engine airplane, he occupied the right seat during the instructional flight. The flight instructor reported that during the landing roll, the brakes on his side were inoperative, but the brakes used by the pilot under instruction appeared to function normally. The flight instructor allowed the pilot under instruction to taxi to parking. During the right turn in the parking area, the pilot under instruction was told to apply both brakes, and the airplane started to "pull left". The flight instructor attempted to use differential thrust to arrest the left pull by increasing the right engine speed, but the attempt had no effect. The flight instructor shut down both engines, however, the multi-engine airplane's left wing struck a parked single-engine airplane and came to a stop. The multi-engine airplane sustained substantial damage to the left wing. The flight instructor reported that the accident could have been prevented if he would have stopped on the taxiway and not entered the parking ramp. The brake assembly was examined to determine the scope of pre-accident mechanical malfunctions or failures with the airplane's brake system, that would have precluded normal operation. It was determined that the right side brake actuator piston "o" ring failed, which decreased hydraulic brake pressure, preventing proper brake function of the airplane.
Aircraft
- Registration
- N2844T
- Reported as
- Piper PA 34 (200)
- Category
- Airplane
- Serial number
- 34-7250174
- Built
- 1972
- Airframe hours
- 10,733.6
- Engines
- Lycoming LIO-360, 200 horsepower, reciprocatingLycoming IO-360-CEI6, 200 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Instructional · Part 91
- Operator
- U S Aviation Group LLC
- Registered owner
- U S Aviation Group LLC
- Airworthiness certificate
- Standard, Normal
- Last inspection
- 100 hour · October 17, 2016
- Departed
- KDTO · Denton, TX
- Destination
- KDTO · Denton, TX
- Flight plan
- VFR
- Airport
- DTO · Denton Enterprise, runway 36, 7,002 × 150 ft, asphalt
- Equipment
- Stall warning system, Electronic primary flight display, ADS-B
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
- 24
- Injuries
- None
- Certificates
- Commercial, Flight instructor
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Without waivers/limitations
- Last flight review
- February 26, 2016
- Seat
- Right
- Restraint
- 3-point
- Flight hours
- 657.4 total · 248.5 in this make and model · 585 as pilot in command · 204.1 in the last 90 days · 51.2 in the last 30 days
- Role
- Student pilot
- Age
- 23
- Injuries
- None
- Certificate
- Private
- Airplane ratings
- Single-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Without waivers/limitations
- Last flight review
- July 22, 2016
- Seat
- Left
- Restraint
- 3-point
- Flight hours
- 227.8 total · 13.1 in this make and model · 124.6 as pilot in command · 13.1 in the last 90 days · 5 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- Calm
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 48 °F, dew point 39 °F
- Altimeter
- 30.11 inHg
- Observed at
- DTO
Docket · 3
The files NTSB released with the investigation on June 21, 2017, on NTSB’s docket system: statements, records, photos and specialists’ reports. 3.9 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.