One of our readers recently sent us an email and asked something that, at first, had us scratching our heads:
Do planes have horns?
If you think about it, nearly every other typical mode of transportation with a motor has a horn. Obviously, cars do. And trucks. Trains have horns. If you’ve ever been on a cruise ship, you know they have horns. But planes? Hmmm…
I did some research and it turns out that yep, planes have horns. Well, sort of. But not all planes, and the “horns” aren’t used the same reason as the other vehicles we mentioned earlier.
Reasons for horns on other vehicles
Cars, trucks, and, to a lesser extent, trains and ships, use their horns to alert other cars, trucks, trains and ships.
For cars and trucks, the reasons for honking horns can be as varied as the people honking them, but it’s usually to get peoples’ attention.
- Stop looking at your phone, the light turned green, ya idiot!
- Watch where you’re going, you A-hole!
- Hi! (that one is usually if the driver sees someone they think is cute)
- Specific to trucks: “Trucker Salute” for kids who ask the trucker to blow their horn via “arm bump” <3
Trains will use their horn for attention too, as in, “The train is approaching a railroad crossing” or “Get off the track!” But the conductor also uses the horn to relay information to other workers on the train or at the station. Not surprisingly, these are all mandated by the federal government. From Wikipedia:
| Rule | Sequence | Indication[9] | |
|---|---|---|---|
| 14 (a) | . | Applying air brakes while standing. | |
| 14 (b) | * | – – | Proceeding. Releasing air brakes. This signal is often referred to as “whistling off,” despite it being given by an air horn. |
| 14 (f) | * | . . – | Acknowledging a flagman’s stop signal |
| 14 (g) | * | . . | Acknowledging any signal not otherwise provided for |
| 14 (h) | * | . . . | Backing up |
| 14 (j) | . . . . | Calling for signals | |
| 14 (l) | * | – – . – | 1. Trains or engines approaching public highway grade crossings shall sound the horn at least 15 seconds, but no more than 20 seconds before the lead engine enters the crossing. Trains or engines travelling at speeds greater than 45 mph shall begin sounding the horn at or about, but not more than, one-quarter mile (1,320 feet) in advance of the nearest public crossing. Even if the advance warning provided by the horn will be less than 15 seconds in duration. This signal is to be prolonged or repeated until the engine or train occupies the crossing; or, where multiple crossing are involved, until the last crossing is occupied. 2. Approaching tunnels, yards, or other points where railroad workers may be at work. 3. Passing standing trains. |
| 14 (m) | * | . | Approaching passenger station |
| 14 (o) | . – | Inspect train for a leak in brake pipe system or for brakes sticking | |
| 14 (p) | * | Succession of sounds | Warning to people or animals |
| 14 (q) | * | – . | 1. When running against the current of traffic: 2. Approaching stations, curves, or other points where view may be obscured: and 3. Approaching passenger or freight trains and when passing freight trains. |
Similarly, cruise ships’ horns serve as communication with other ships in the area. Like the honks for trains, they’re required by maritime law. From Cruzely:
Inland Waters (Near Port)
One short blast = Changing course to starboard (right)
Two short blasts = Changing course to port (left)
Three short blasts = Operating in reverse
Five short blasts = Danger signal
Two long blasts = Leaving berth
Open International Waters
One short blast = Passing on ship’s port side
Two short blasts = Passing on ship’s starboard side
Three short blasts = Operating in reverse
Five short blasts = Danger signal
Additionally, ships will sound their horns, usually regular bursts of sound, in areas of low visibility/fog. They’ll also occasionally have”battling horns” with cruise ships docked next to them ;-).
OK, whatever – but what about PLANE horns?
Oh yeah! Plane horns!
Planes, obviously, don’t have much fear of crashing into another plane when they’re in the air. Each plane is told at what altitude to fly (here’s how they figure it out. Oh, and here’s why some planes were flying at higher altitudes at the height of COVID). And they certainly don’t have to worry about other pilots stopping at red lights in the air and checking their phones. 😉
Instead, commercial planes have a signaling or warning system, via the press of a button in the cockpit, that’s pretty much like a horn. Except it’s generally not used very much by the pilots, but more so by the ground crew.
From KLM:
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.
You can hear it at 0:45 of this video:
Even if you want to call this sound a “horn,” it’s not a very effective one…when the plane is flying, the signaling system is shut off and doesn’t work ;-).
What about other kinds of planes?
Small, private planes, like Cessnas, Beechcrafts, Gulfstreams, etc., don’t have horns. Not even signaling systems.
And military planes? To be 100% honest, I’m not sure. I couldn’t find anything that suggested whether or not military planes have horns like commercial planes do. If someone out there knows, please chime in? Thanks!
Feature Photo: KLM
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