There are multiple switches and buttons in the cockpit, with different shapes and layouts. Are they spill proof?

What if the pilot spills water or coffee on them, will they still function?

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    $\begingroup$ You know, I've flown for over two thousand hours and never thought of this. Good question! $\endgroup$
    – Steve V.
    Commented Mar 26, 2015 at 12:28
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    $\begingroup$ See the 1960's movie, "Fate is the Hunter"... $\endgroup$
    – DJohnM
    Commented Mar 26, 2015 at 17:17
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    $\begingroup$ No, they are definitely not. Aircraft technology has sort of a stone age feel to it. Its not like a Sony media deck or something. In some aircraft like crop dusters and stuff there are even no panels, so there are tubes and wires running everywhere along the walls. You are thinking, boy I hope I don't bump into that gas line. Its like a Kafka novel. $\endgroup$ Commented Mar 26, 2015 at 17:35
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    $\begingroup$ Perhaps it would be cheaper to have the pilots drink from sippy cups instead. $\endgroup$
    – Aron
    Commented Mar 27, 2015 at 9:35
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    $\begingroup$ No, and that's why you never make jokes in the cockpit. *8P $\endgroup$ Commented May 16, 2019 at 12:57

2 Answers 2


No they are not, at least not fully. There have been instances of equipment failure caused by coffee spills, resulting in the need to abort the flight.

This example shows a flight that needed to divert because a coffee spill disabled the communication equipment.

This Boeing 707 had to make an emergency landing after the crew inadvertently spilled water on the autopilot panel causing the stabilizer trim wheel started to rotate. Control was lost as the plane pitched up and down. Three people died in the accident.

This Boeing 737 report had smoke in the cockpit because the previous flight crew spilled coffee and sugar over the avionics.

This Boeing 720 suffered control problems (resulting in Dutch roll) after a coffee spill cause a short circuit in the yaw damper.

This Airbus A330 diverted for an emergency landing after liquid was spilled onto electronic devices in the cockpit causing the smoke.

Burned electrics

Source: Transport Accident Investigation Commission of New Zealand

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    $\begingroup$ Good explanation. Does this mean there are regulations by FAA, on what type of food /drinks a pilot can consume in the cockpit, or is it a known issue, which we all have to live with? $\endgroup$
    – Firee
    Commented Mar 26, 2015 at 15:07
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    $\begingroup$ I find this weird. The equipment is tested for so many things, and even making it moderately spill proof doesn't add that much to the already enourmous costs. And given that pilots regularly eat and drink, it makes me wonder if there is not maybe another reason why it is not done. $\endgroup$
    – PlasmaHH
    Commented Mar 26, 2015 at 15:28
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    $\begingroup$ @PlasmaHH I'm more surprised that pilots simply don't use spill-proof cups. C'mon, you give several hundred cups to the people on board and you can't afford couple cups with good lids for the crew? ... $\endgroup$
    – yo'
    Commented Mar 26, 2015 at 16:15
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    $\begingroup$ @yo': are those still spillproof when they slam at the windshield turing turbulences? What about spraying it all over the avionics because you couldn't hold it anymore since the chief steward told such a dirty joke? And I doubt they have invented spill proof tables for the food yet... ^^ $\endgroup$
    – PlasmaHH
    Commented Mar 26, 2015 at 16:19
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    $\begingroup$ @yo' So if the pilot spills pasta on the controls should he just turn the plane upside down and give a good shake? $\endgroup$ Commented Mar 26, 2015 at 16:26

On the old Zeppelins all electrical switches were enclosed, with the actual switching contacts submerged in oil to avoid sparks. And Zeppelins had a lot of switches, containing much more electrical equipment than typical aircraft of their times. All these switches were also spill-proof by design. Airship engineering seems to be a lost art ...

Left: Radio operator of a WW I Zeppelin at his equipment, right: Elektroraum of the LZ 127

Left: Radio operator of a WW I Zeppelin at his equipment, right: Elektroraum of the LZ 127.

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    $\begingroup$ Zeppelins were also notoriously flammable. I don't think there have been enough cases to justify fully insulating electronics against liquids. $\endgroup$
    – Ambo100
    Commented Mar 26, 2015 at 17:03
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    $\begingroup$ In college, I worked at a large power transformer factory and they used oil as electrical insulation. The fact that oil is an electrical insulator is still mystifying to me. Probably a better question for chemistry.SE or electronics.SE... $\endgroup$
    – FreeMan
    Commented Mar 26, 2015 at 17:21
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    $\begingroup$ I'd guess that the decision to do this had something to do with the giant volume of Hydrogen gas, which had a nasty habit of quickly becoming water plus heat in the presence of sparks. $\endgroup$
    – reirab
    Commented Mar 26, 2015 at 18:00
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    $\begingroup$ You can imagine that battleships had much better spark protection in their powder magazine than on the bridge, for a similar reason. $\endgroup$
    – Gabe
    Commented Mar 26, 2015 at 18:36
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    $\begingroup$ @FreeMan It depends on the oil. Transformers don't use oil only because of insulating purposes (although this is the case as well), but they use it for coolant as well, considering that mineral oil is typically a better conductor of heat as compared to air. If a transformer loses its oil, it'll overheat, or arc internally, and melt. $\endgroup$ Commented Sep 30, 2015 at 23:28

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