Cessna 336 N3804U

Summary

On 3 July 2014 at about 23:46 local time, a Cessna 336 registered N3804U, operated by Mobile County Health Department, was involved in an accident near Mobile, Alabama, 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

3 July 2014 at 23:46

Classification

Accident

Location

Mobile, Alabama, United States

Coordinates

30.6642, -88.0383

Aircraft

Cessna 336

Registration

N3804U

Category

Airplane

Year built

1964

Engines

2

Operator

Mobile County Health Department

Operating rule

Public Use

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Route

St. Elmo → St. Elmo

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ERA14TA326

1 person was seriously injured.

The pilot’s inadequate preflight fuel planning during which he did not ensure that there was adequate fuel in the main tanks for the flight, which resulted in a loss of engine power.

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

Read the full NTSB narrative

The pilot reported that he was performing mosquito control spraying operations at 100 ft above ground level (agl) when the rear engine began to sputter and lose power. He switched to the auxiliary fuel tank; however, this did not remedy the situation. He then climbed the airplane to 500 ft agl and continued to troubleshoot the problem by again switching fuel tanks and turning the electric boost pumps on. Shortly thereafter, the front engine began to lose power. Unable to regain full power on both engines, the pilot chose to perform a forced landing in an open field. The airplane touched down on soft soil and stopped abruptly, which resulted in extensive damage to the airplane. Both fuel selectors were found in the right main fuel tank positions. An examination of the fuel system revealed that the main fuel tanks contained only residual fuel and that the auxiliary tanks contained an adequate amount of fuel. Examination of the fuel lines revealed that both supply lines from the gascolators to the engine-driven fuel pumps were contaminated and obstructed with a granular, powder-like substance. The engines ran normally when operated in a test cell after the accident. The auxiliary fuel tanks were designed for level, cruise flight only. The auxiliary tanks fed directly to the fuel selector and had no boost pumps available. It is likely that, due to the fuel system's design, adequate fuel pressure could not be regained once the main tanks were depleted and the pilot switched to the auxiliary tanks. The contamination in the fuel lines might have further restricted fuel flow to the engines. The loss of engine power might have been prevented if the pilot had maintained an adequate amount of fuel in the main tanks.

Quoted verbatim from the NTSB record.