Piper PA-31 N9011Y

Summary

On 12 December 1984 at about 00:32 local time, a Piper PA-31 registered N9011Y was involved in an accident near Pontiac, Michigan, United States. 2 people were on board and 2 died. The aircraft was destroyed. No probable cause statement is available for this record.

Date

12 December 1984 at 00:32

Classification

Accident

Location

Pontiac, Michigan, United States

Nearest airport

Oakland Pontiac (PTK)

Coordinates

Not recorded

Aircraft

Piper PA-31

Registration

N9011Y

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 135: Air Taxi & Commuter

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Bolivar → Pontiac

Aircraft damage

Destroyed

Weather

IMC

Light

Night/Dark

NTSB number

CHI85FA070

2 people died.

The NTSB has not published a probable cause for this record. No probable cause statement is present in the source data.

Nothing about the cause is stated here that is not in the source record.

Read the full NTSB narrative

THE AIRCRAFT DEPARTED THE AIRPORT WITH ONE DRY AIR PUMP INOPERATIVE AND THE OTHER PUMP READING LOW. AIRCRAFT CONTROL WAS LOST DURING AN INSTRUMENT APPROACH IN IMC APPROXIMATELY 2.5 HOURS LATER. BOTH PUMP DRIVESHAFTS WERE FOUND SHEARED IN THE WRECKAGE AND BOTH BROKEN SHAFT SURFACES SHOWED POLISHED SURFACES. DURING FURTHER TESTING IT WAS DISCOVERED THAT TAPE OR PIPE DOPE HAD BEEN USED IN THE THREADING OF THE INTAKE & OUTFLOW FITTINGS OF THE LEFT PUMP. NO CONTAMINANTS WERE FOUND IN THE RT PUMP BUT THE PUMP WALL INNER SURFACES GAP WAS APPRX .005 IN. THIS GAP IS APPROX 50 PERCENT OVER THE ALLOWABLE TOLERANCE FOR A SERVICEABLE AIR PUMP.THE PRESSURE REGULATOR VALVE TO THE ATTITUDE INDICATOR GYRO & THE COMPASS GYRO WERE EXAMINED & FOUND TO REQUIRE PRESSURE EXCEEDING NORMAL REQUIREMENT STANDARDS.

Quoted verbatim from the NTSB record.