Does a Plane have a Horn?

“Why on earth would a plane need a horn?” – that was my first thought when I read the above question, which came in via Twitter. Surely an aircraft doesn’t need to warn other vehicles to get out of its way? To get an answer to this question, I contacted a colleague at Engineering & Maintenance and arranged a meeting in the hangar. My mission: find the horn!


It’s Tuesday morning and I hook up with Johnny, who is communications advisor at KLM Engineering & Maintenance. As we stroll through Hangar 14 together with his colleagues Fred and Jan, they tell me all about the functionalities of the aircraft horn.

Sounds like a steamboat

The signalling or warning system aboard an aircraft could be compared to a horn. When ground engineers are working in the cockpit, they can contact their colleagues on the ground using a signal. When I ask engineer Fred to point out the horn, he taps on a tiny button marked “GND” on the instrument panel in the cockpit. The button is hard to find, but when it is pressed it sounds as if three steamboats are passing under the plane.


If you’d like to hear what that sounds like, click on the play button below.


Hooting through the nose wheel

Sometimes engineers on the ground want to contact their colleagues in the cockpit. They can do so via a button located in a little compartment near the nose wheel at the front of the aircraft. By plugging a headset into this compartment, they can communicate directly with the cockpit.

Hooter Airplane

But how does it sound?

So the horn is primarily a means of communication, but the aircraft itself can also emit a signal to warn engineers when a system breaks down or when there is fire. This signal sounds like a siren running in eighth gear. This happens, for instance, 90 seconds after any problem arises in the system that cools the aircraft’s other systems, which is much like a computer’s cooling system. The signals vary so that engineers know exactly which system is under threat.

This is what a warning signal sounds like.


Functional technology

So, the signalling system aboard an aircraft isn’t really used in the same way as the hooters and horns aboard other vehicles and vessels. A pilot can’t hoot at other aircraft. In fact, the horn doesn’t work when the aircraft is in flight, because the signalling system is turned off.

Whereas horns in cars are mainly used as a warning system, the horn aboard an aircraft is primarily a form of functional technology, which is indispensable when the aircraft is undergoing maintenance in the hangar.

So does a plane have a horn? Yes it does!


Also wondering how to change the wheel on an aircraft? find it out here! Or do you have an interesting question? Please let us know and maybe you will find you answer in the next blog!

Posted by:   Jessey de Graaf  | 
Join the conversation Show comments


Hoor ik nu echt ”Pokkeherrie” bij het warning signal zo rond 00:07??

Jessey De Graaf

Wat zeg je Danny? De toeter blaast erdoorheen! ;-)

Narrow Not Oblivious

This blog post made my day. Who does your graphics it’s great!!!!

Jessey De Graaf

How great to hear! Thank you. Our graphics are made by our fantastic colleague Beau. Keep a close eye on the blog to stay up to date about my upcoming investigations.

Verhaeghe Rudy

now that we know that planes don’t have a key to start up the engines, is my question : can you lock the outer door(s)
with a key?
Or can anybody enters a ‘ cold ‘ plane? Is there a kind of safety system ?
After landing the crew leaves the plane ,who is responsable for ‘closing ‘ the aircraft?



with all the heavy air traffic its like a cat in a room full of rocking chairs.Thats why they have horns and they’re called air horns air horns get it


Is there any plane open top?

Alex777 It’s a great company that produces the runway equipment, and by the colleagues feedback I know that the true professionals work in it.

Pedro Becker

Thanks KLM for the insight!
I’m an aviation fan for many years, but never thought about it.
Keep up with the good work, keep more coming!!


Hello ,
Thanks a lot for this piece of information , i thought Was dreaming when I heard the very same sound on the tarmac ! Indeed it has horns :)

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