In our “ongoing” subject of AIRCRAFT SYSTEMS I want to reflect on an accident case I have involving a Cessna 421B. The plane was attempting to land at a paved airstrip that belonged to the owner of the aircraft. The strip was located in a cornfield.
On the final to the base leg the aircraft fell out of the sky. Basically the engine quit running even though at first we thought it was a stall situation on a steep turn. Later we found out the aircraft “ran out of fuel”.
During the case the wife of the owner of the plane sent the injured parties a text message that the plane had a “vapor lock.” And this is where I begin this article. An operating Continental engine does not have “vapor lock.” Vapor lock is something that occurs when the thermodynamic of heat affects the fuel flow in an injector line and blocks the flow of fuel with air. Flowing fuel does NOT have vapor lock as the Continental system is a constant flow fuel system. That means the fuel is always pushed out to the cylinder UNDER PRESSURE when the engine is running. The delivery of the air and the fuel is made when the intake valve on the cylinder opens to allow both fuel and air to come into the cylinder and create the “charge” that being the mixture of air and fuel together in the cylinder for the power stroke.
We consistently teach in our ground school how the systems on the aircraft work. We tell pilots if you do not know how the systems work and the PROBLEMS associated with the systems then you CANNOT safely manage an aircraft. People who take initial, recurrent, or just emergency training in the operations of an aircraft should have detailed training in the systems yet very few aircraft training facilities teach systems in depth. Why? Because the instructors do not understand the systems.
Pilots are still shutting down engines on turbocharger failures. Pilots are still not recognizing brake problems or applying the brakes the proper way. Pilots are still not airing up their tires over the pressure in the POH or putting higher ply tires on when they change tires. Pilots do not understand tires and brakes period! Pilots are still not controlling their landing speeds or understanding how to really manage an engine out problem.
The answer is simple. You have to know the systems in the aircraft or you will get caught with “your pants down”. The wrong move on a system failure because you are not familiar with the systems in the aircraft is the only thing that will give you peace of mind. Knowledge is power, especially in dealing with aircraft problems.
We pride ourselves on our ground school classes along with our eighty-four-page handout. Marriages last because you educate yourself to the other party. Airplanes stay safe if you understand “how they work and feel”.
Train Hard. Fly Safe.