Why would a petrol engine stall at an altitude?

[Kelly Andrew]

The engine was used to propel a small home made air craft. It worked very well while it taxied away and went airborne, then at a certain altitude it stopped abruptly then came crashing down. Why? And what simple engine design can sustain the air craft?

 

[jedishrfu]

It seems you're asking about why an engine would stall at a certain height, right?

My friend, who was a pilot of small aircraft told me that there are two gas tanks and a valve that you use to switch between tanks. Sometimes if the pilot isn't careful he/she may switch to the secondary tank but not switch it all the way. Consequently the engine stalls due to lack of gasoline.

Other reasons why an engine might stall is due to lack of oxygen either because something has lodged in the air intake or its flying too high or due to a fuel pump failure.

 

[russ_watters]

Is this manned or a model/drone? Is the fuel pumped or gravity fed?

 

[jrmichler]

There are many reasons that an airplane engine can stop running.

An engine needs fuel, air, oil, and ignition to run. Take away anyone of those, and the engine stops.

An engine consists of many mechanical parts. If the wrong part breaks, the engine stops.

An engine has a cooling system. If that system fails, the engine can stop. Think bird nest in an air cooled engine.

The engine is operated by the pilot. If the pilot does certain things wrong, the engine stops. Taking off with fuel selector on an empty fuel tank is a popular way for an engine to stop shortly after lifting off. A friend did that.

Wrong fuel. Jet fuel in a gasoline engine. Water in the fuel. I experienced a fuel line freeze up one night over the Black Hills of South Dakota. Fortunately, the fuel line from the other fuel tank was not frozen.

Icing in carbureted engines.