Piper PA 28-140 N57DB

Summary

On 16 November 2013 at about 16:45 local time, a Piper PA 28-140 registered N57DB, operated by David H Barnhart, was involved in an accident near San Antonio, Texas, United States. One person was on board and one was seriously injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

16 November 2013 at 16:45

Classification

Accident

Location

San Antonio, Texas, United States

Nearest airport

Stinson Muni (SSF)

Coordinates

29.3328, -98.4625

Aircraft

Piper PA 28-140

Registration

N57DB

Category

Airplane

Year built

1969

Engines

1

Operator

David H Barnhart

Operating rule

Part 91: General Aviation

Purpose of flight

Personal

Phase of flight

Not recorded

Route

San Antonio → Pleasanton

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

CEN14LA058

1 person was seriously injured.

A partial loss of engine power after departure due to the collapse of the carburetor air inlet duct, which restricted the airflow to the engine. Contributing to the accident was the overdue annual inspection and the installation of the improper air inlet duct.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot reported that, after advancing the airplane's throttle to full power for takeoff, the engine produced "normal thrust," the airspeed reached 60 mph, and the tachometer indicated 2,700 rpm. The acceleration was smooth and all indications were normal when the airplane reached rotation. About 600 feet above the ground, the airplane's nose began to lower, the airspeed remained 60 mph, and the tachometer indicated 2,000 rpm. The pilot pitched the nose down to prevent a stall and ensured that the throttle and mixture controls were full forward and that the electric fuel pump was on. He reported to the air traffic controller that the airplane's engine was not producing sufficient power and that he was returning to the runway. Shortly after the radio transmission, the airplane impacted terrain and a tree. An examination of the airplane's engine revealed a fuel stain on the carburetor inlet, indicating that the airflow through the carburetor had been decreased. The carburetor induction air inlet duct was single-thickness scat-type ducting, which was not the material described for the part, which should have been installed in accordance with a manufacturer's service bulletin. The material appeared to be beyond its normal service life with frayed edges and loose strings, and most of the wire was loose and separated from the duct. Further, the carburetor air inlet duct appeared to have been compressed due to negative air pressure during high engine rpm, which would have restricted the airflow to the engine and reduced the engine power. The No. 2 cylinder and its associated spark plugs contained dark sooting, likely due to the restricted airflow, which resulted in a rich fuel/air mixture inside the cylinder. The airplane was 12 days overdue for an annual inspection; the improper, damaged air duct could have been identified during the inspection.

Quoted verbatim from the NTSB record.