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Are switches reqired to have an "Off" label?

Steve Crewdog

Steve Crewdog

Well Known Member
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Are switches required to have an "Off" label?

Might be urban legend, but I heard about a builder being denied a sign-off because they had labeled the switches for function, knew that Up was ON and Down was OFF, but the examiner made them go back and add OFF labels before they'd sign it off. Or, another instance, UP and DOWN for pitch trim.

Thoughts? TIA.
 

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My DAR mentioned that during my inspection too. You need to have labeling that shows enough to give clear explanation as to the function. With the label above, the word OFF would fit nicely below. But I think if you had ON above it, that would be ok too. But it has to be marked for direction of function in some way. For some switches it would be best to mark both directions.
 
I've seen this below a row of switches. It should suffice.

-----------------OFF---------------

The line should probably be solid rather than dashed.
 
At least in Canada its part of the inspection check list. For part 23 its in the rules. (yes I know both are not directly relevant :) ).

Assuming others will confirm for the US,

The least intrusive solution I've seen is a thin line along the bottom with the word "OFF", or add "ON" to the labels at the top.

Options I considered:

1. Skip it and print a bunch of sticky "OFF" labels I could apply in case I got push back.

2. Create a placard that says 'Operation of all switches is such that down is "OFF" ', and prepare to argue.

3. Embrace the suck, which was a bit more painful for "THROTTLE PUSH OPEN" when the engine controls match the shape, color and location as required by Part 23, so in my mind super obvious :D

Went with 3.
 
[USA here] I chose to embrace the suck too. Everything on my panel that lights up or can be manipulated by the user is labeled or placarded, including the bog-standard engine controls. I'm glad I did, too. My DAR actually pointed them out and thanked me for doing them "properly".

 
I'm not aware of any regulation in the US that requires it, but if there is, maybe someone will post it.
 
rv6n6r said:
I'm not aware of any regulation in the US that requires it, but if there is, maybe someone will post it.
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FAR 23.1367 and AC 23-17C both have some guidance, but it is somewhat vague.

Sec. 23.1367 — Switches.
Each switch must be—

(a) Able to carry its rated current;

(b) Constructed with enough distance or insulating material between current carrying parts and the housing so that vibration in flight will not cause shorting;

(c) Accessible to appropriate flight crewmembers; and

(d) Labeled as to operation and the circuit controlled.

AC 23-17C adds this:
Switches are required to be labeled for operation and the circuit controlled. A switch that operates by a push once for ON and once for OFF should be labeled “PUSH OFF/ON.”

How the above relate to Experimental (ie, non certificated part 23 aircraft) is up to debate, but it is probably good advice to fully label your switches as described.
 
Getting ready for my DAR and he mentioned it needs to make sense. My switch have the desired out come marked. Meaning that master is labeled on top or above the switch to indicate I want the master or naves etc. all my ons are fwd switch locations and off has no label but every switch in the plane is off if in the aft position with the exception of NAV STROBE and that is clearly label as to which one you want. Not sir it will pass but it’s simple
 
Make your DAR and every future owner of your craft happy ... label it. Looks nice and professional and eliminates any questions down the line.

Some of the labels in use today do make one wonder tho... Boeing throttles have a label that says "increase thrust" with an arrow pointing forward. Duh

Although it is true that Boeing light switches go forward for on and Airbus is backward (ok, opposite!)

So ya never know!
 
Label them. It is not that hard, looks ok, and eliminates any confusion. Intuitive is very, very subjective. I have been in many meeting on cockpit layouts for new military aircraft and getting even two pilots and one engineer to agree can be difficult.
Even you, as the builder, can forget the switchology. My oil cooler lever is only used Twice a year so I forget if push is on or pull is on and what does “on” mean. It is labeled so just glance down and I know.
 
Huh?

I guess I never really thought about it. I have a center off toggle controlling the landing lights for steady and flash. I put an off placard in the middle. The other switches are labeled on top and I just go by the convention that on is up and off is down. But, ya can’t always assume. A friend’s Cessna 140 has all the switches “backwards.” Wired and placarded that way from the factory. Even the mag switches are down for on. That can be scary if you’re not paying close attention. My mentor had a story of a Champ getting away from him when his headset fell off the hook, turning a mag on. It started unexpectedly during solo hand-propping and taxied itself into another airplane.
 
It was required for mine

Pleasant conversation with my DAR included the suggestion that all switches be labeled with function and clear indication of OFF and ON. Well, it wasn’t actually a suggestion. :)
 
It must be up to the DAR. The last 4 planes that I owned were all experimental. None of the switches were labeled on off. My 10 has rocker switches. Never even thought about it until I read this thread. Unless push pull, up is on. Pretty intuitive. Not needed in my opinion.
 
Pull the throttle and off you go

I have never actually seen or heard of a plane where engine controls are installed backwards.
I can't recall the name of the movie but it was certainly a poorly done example.
Some guy stole an airplane and bragged about how he "pulled the throttle and off he went"
I guess it wasn't properly labeled.:rolleyes:
I think labeling engine controls is a bit much but switches, yes.
The next owner will appreciate it.
 
Which way is "off"?

Tooch said:
It must be up to the DAR. The last 4 planes that I owned were all experimental. None of the switches were labeled on off. My 10 has rocker switches. Never even thought about it until I read this thread. Unless push pull, up is on. Pretty intuitive. Not needed in my opinion.
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I have found this conversation interesting. Convention makes many things we do intuitive. None of the light switches in my house are labeled off/on. No door knob has an arrow showing which way to turn it to get the door open. No toilet has a "push down to flush" label. None of the switches in any of my cars have on/off labels. I can feel the switches on the side panel of SuzieQ and know which are off and which are on by their position without looking. The stick does not have a label "push this way to turn left; push this way to turn right".;)

I can see the point of having things labeled but there are things that are intuitive and are left to the intelligence of the user. Oddly enough, I just installed a small switch for my ANR (hard-wired to the airplane rather than battery box) and put "ON" and "OFF" labels on the switch...:D

I guess we do have to do things to satisfy the DAR, however.....and what keeps confusion out of the cockpit....
 
Switches

Roadjunkie1 said:
I have found this conversation interesting. Convention makes many things we do intuitive. None of the light switches in my house are labeled off/on. No door knob has an arrow showing which way to turn it to get the door open. No toilet has a "push down to flush" label. None of the switches in any of my cars have on/off labels. I can feel the switches on the side panel of SuzieQ and know which are off and which are on by their position without looking. The stick does not have a label "push this way to turn left; push this way to turn right".;)

I can see the point of having things labeled but there are things that are intuitive and are left to the intelligence of the user. Oddly enough, I just installed a small switch for my ANR (hard-wired to the airplane rather than battery box) and put "ON" and "OFF" labels on the switch...:D

I guess we do have to do things to satisfy the DAR, however.....and what keeps confusion out of the cockpit....
Click to expand...

I suppose a builder could install every switch upside down and labels would be needed. :D
I agree. Too many regs don't make sense.
 
The book "The Design of Everyday Things" is a good and quick read about how visual and tactile cues can either make operation obvious, or instill confusion.

Have you ever pushed on a symmetrical exit door push bar on the hinge side of the door? Stuff like that.

It will help you think about human factors in your switch layout, and why that pretty row of eight identical switches might not be the best idea.
 

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N427EF said:
I have never actually seen or heard of a plane where engine controls are installed backwards.
I can't recall the name of the movie but it was certainly a poorly done example.
Some guy stole an airplane and bragged about how he "pulled the throttle and off he went"
I guess it wasn't properly labeled.:rolleyes:
I think labeling engine controls is a bit much but switches, yes.
The next owner will appreciate it.
Click to expand...

I read that when France bought American military airplanes in the early days of WWII, they specified throttles that worked in the French direction, backwards from the convention of Everywhere That Was Not France. When some (most? all?) of those exports fell thru with the fall of France, those airplanes went to other customers after having their engine controls returned to normal. And yeah, I seem to remember some guy dramatically pulling big chrome handles back to go to full throttle on some big spaceship. Buck Rogers, maybe? Anyway, it seems that now, almost all basic aircraft controls are on a universal standard, at least as far as pushing or pulling goes.
 
Switches....(humor, of a Sunday Morning....)

(Said in my best Mr. Rodgers Voice): OK, boys and girls. Can you tell which one of these switches is on and which of these switches are off?:D:D:D

Sunday Morning Humor.....;)
 

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Before we all go to far down the road of “any good pilot knows intuitively how controls work - they don’t need not stinking label!”, I’ll point out that some fairly bad mishaps have been traced back directly to control/switch confusion - and I am not talking about average pilots in GA planes - I am talking about experienced test pilots in experimental jet/rocket aircraft! In my career I have been astounded at how often this kind of thing happens - trim directions are not obvious if the switch is moved from the center console to the panel, for instance.

And if you need further evidence of labeling, just look at the incredible…uhh… ”variety” of ways that pilots here on VAF have used the various switches on multi-switch stick grips. Sure, you’ve memorized what you did, but if someone else gets in, how are they going to know that the coolie hat works pitch trim as expected, but switches radios if moved left or right?

Labeling is not trivial…..
 
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Just label it, would ya....!

Ironflight said:
And if you need further evidence of labeling, just look at the incredible…uhh… ”variety” of ways that pilots here on VAF have used the various switches on multi-switch stick grips. Sure, you’ve memorized what you did, but if someone else gets in, how are they going to know that the coolie hat works pitch trim as expected, but switches radios if moved left or right? Labeling is not trivial…..
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All true. A little consistency goes a long way to making our crafts safer. I have a multi-switch stick grip (Infinity, which I REALLY like) and the coolie hat is not conventional: it switches frequencies on the radio and squawks the transponder code. But all switches on it are labeled as I need to remember what they are for....;) including the "Air Refueling Disconnect" switch.....:D:D

I'm waiting for someone to notice in the very old photograph of my side panel the breaker is labeled but the switch itself is not. I thought at the time that it would be "obvious". That was long-ago corrected.
 
Labels

Don't laugh but all the switches in our house are labeled.
I have a labeler so why not.
Someday, I'm going to label all the switches and outlets with a breaker number too.
 
wirejock said:
Someday, I'm going to label all the switches and outlets with a breaker number too.
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Why not just label the breaker?
after all, you can't see the breaker number from the electrical box, but you can sure see the switches and outlets the breaker controls from the labeled electrical panel....

-Marc
 
What circuit does THIS one control.....?

Plummit said:
Why not just label the breaker?
after all, you can't see the breaker number from the electrical box, but you can sure see the switches and outlets the breaker controls from the labeled electrical panel....
Click to expand...

I've been in this house since 1992 and I still haven't discovered what breakers run what circuit. I'd love to slap the person around who strung wires in this house....:mad: I should do what Wirejock did and label them when I find out what breaker it is..... Let's see: #12 bedroom. ...covers all lights and outlets....except those on THIS wall.....:confused:
 
Labels

Plummit said:
Why not just label the breaker?
after all, you can't see the breaker number from the electrical box, but you can sure see the switches and outlets the breaker controls from the labeled electrical panel....

-Marc
Click to expand...

Huh?
Breaker panel isn't big enough to label with every outlet and switch. You do know I'm talking about the household outlets and switches getting a breaker number label.

Roadjunkie1 said:
I've been in this house since 1992 and I still haven't discovered what breakers run what circuit. I'd love to slap the person around who strung wires in this house....:mad: I should do what Wirejock did and label them when I find out what breaker it is..... Let's see: #12 bedroom. ...covers all lights and outlets....except those on THIS wall.....:confused:
Click to expand...

Exactly. I designed our house but neglected to provide an electrical drawing so we have breakers that share outlets and lights in different rooms. So annoying.
 
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Roadjunkie1 said:
Convention makes many things we do intuitive. None of the light switches in my house are labeled off/on. No door knob has an arrow showing which way to turn it to get the door open. No toilet has a "push down to flush" label.
Click to expand...

Convention isn't necessarily international.

Conventionally, down is on for switches in Australia (I'm not sure which other countries that applies but I'm sure we aren't alone). Aircraft are the only example I can think of here where up is on. It's quite possible for an experimental builder to reverse their switches based on personal preference.

Switches in houses frequently have a light that indicates whether they are on or off...

(Toilets are different here too - we have 1/2 flush and full flush. Sometimes it's push for full flush lift for 1/2, sometimes there's a split button with one side for 1/2 the other for full, or maybe it's both for full... labels are helpful.)
 
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