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Ok, so this may be more of an english lanugage question, and I can confirm from context that when the fuel shutoff valve is ON fuel does indeed flow to the engine, but wouldn't that just make more sense to call that valve the fuel valve?

If the component that shuts fuel off is on, operational, in use, functioning, etc., shouln't fuel be shut off, as the name implies?

I realize this could be seen as a quibble, but confusion causes accidents and IMO this is wildly confusing.


Looking at the Cessna 152 checklist today I noticed this interesting quirk. On the regular checklist side (pre-takeoff, maneuver, etc.) the checklist reads "Fuel Shuttof Valve - ON", but on the emergency checklist for an engine fire it merely states "Fuel Valve - OFF".

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It depends on what word is being operated on. The valve is the "Fuel Shut-off Valve", and the fuel is either "On" or "Off", not the valve. This doesn't nessesarily make the most sense from an english language perspective, but from a UI sense, people will see Fuel, and they will see On or Off. This is probably what the first engineers were thinking. In an emergency, you want people to press the button that says Off, so it makes sense to label it as such. – JFA Mar 23 '14 at 19:53
From a UI sense I agree it makes sense. From a UX perspective I think we should call it the "Fuel Valve" – OneChillDude Mar 23 '14 at 21:44

I can see where that can be confusing, but it comes down to perspective.

From a maintenance and engineering perspective, you are actuating the fuel shutoff valve which controls the fuel to the engine. The actual terminology when referring specifically to the valve would be opened or closed, which would result in the fuel being on or off.

From a pilot perspective you are simply turning the fuel selector on and off, which happens to be connected to the fuel shutoff valve. The pilot doesn't even need to know about the valve, so they placard it from the operational perspective in the cockpit and say whether the fuel is on or off.

fuel selector

Note that these are placarded as a fuel selector and fuel off both of which seem pretty clear to me.

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I'd think that 'fuel shutoff valve' is a good name, but I'd think it's more sensible to use alternative terms to on/off. I think however most pilots will very early learn this and that it can't really be a problem. They know which position it should be in.

A few aircraft I can think off will avoid this by only using a using a more expressive term than on or off. For instance: OPEN-ON or likewise CLOSED-OFF or even more simply, OPEN or CLOSED. Some also explicitly state the difference, for instance 'PULL-OFF', like the aircraft below.


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Shutoff has a negative connotation, but the word ON is (highly) associated with the engine running. So if SHUTOFF is ON, is the shutoff valve operational (cutting the fuel off) or do we run with our standard interpretation of the word ON - that something essential (fuel supply) is functioning? I can see a pilot in an emergency, when her or his brain is on the edge of panic, forgetting their training and operating the valve incorrectly. I'd suggest it would be clearer to keep the word Shutoff, but make it one of the options, rather than the name of the whole control.

alternative fuel switch

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emergency, when her or his brain is on the edge of panic, forgetting their training - No. An emergency is exactly when you won't remember anything except your training. – Steve V. Mar 24 '14 at 3:06
@SteveV. Not quite correct either. No matter what do you remember, you act by reflexes. For most people, combination of FUEL and OFF is read as "this selection stops fuel" before they actually read, process and undestand the text. Therefore such signs should be well thought out: OPEN and CLOSED from the other answer seem to be a good choice. – yo' Mar 24 '14 at 9:47
Steve V and I agree: in emergency situations, the cognitive functions of the human brain decrease. In such situations, eliminating the potential for confusion is paramount. In an engine fire, the pilot’s primary problem is that fuel is getting to the fire, not the state of a valve, so go for words whose association with flow is unambiguous. Many pilots have electronics somewhere in their background and – under pressure – could well interpret OPEN and CLOSED to mean flow-inhibited and flow-enabled respectively. ON and OFF do not suffer from that problem. (and OFF is even simpler than SHUTOFF) – Paul Lyons Mar 25 '14 at 2:31

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