In a steampunk world with airships and airplanes, but which lacks radio, how would different aircraft communicate, and how would they communicate with the ground? Would a form of semaphore, using flags controlled from within the aircraft be effective? What other methods would be possible? As a subpoint of that, what combination of message speed, and message complexity would be optimal? Would multiple systems, one for in-combat, quick messages and one for long battle plans be plausible? How could one effectively keep enemies from spying on messages?

  • 3
    $\begingroup$ This --> discworld.wikia.com/wiki/Clacks $\endgroup$
    – Tim
    Commented Oct 17, 2017 at 0:22
  • 2
    $\begingroup$ Hmm, I might use a Morse-type system with a mirror. Semaphore might work well too, but might be too complicated and heavy. $\endgroup$ Commented Oct 17, 2017 at 0:51
  • $\begingroup$ (By "too complicated and heavy", I mean to carry the flags and mechanism) $\endgroup$ Commented Oct 17, 2017 at 0:58
  • $\begingroup$ why am I thinking of fireflies during their mating season? $\endgroup$
    – user6760
    Commented Oct 17, 2017 at 2:41
  • $\begingroup$ I'm imagining a fire-fly shaped plane that actually has a huge lantern in the back. $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 2:41

6 Answers 6


You have a good few options, I think the realistic answer is a bit of everything.

(a) Don't.

I'm sure that a lack of communication between flying planes could be a great plot device.
Maybe if two planes fly in a really tight formation, they can use cans & string.

(b) Heliograph

Use a Morse-type system where one can send messages by covering/uncovering a lamp or flashing sunlight In the other pilot's face with a mirror in some pattern. The lamp could be built into the plane with a lever in the cockpit to open/close the shutter, although this would be rather heavy. Probably a good idea to have a spring to make the shutter "closed by default".

(c) Semaphore

Have semaphore flags affixed to the outside of the plane, controllable with levers from the cockpit. Very heavy. Probably more practical on airships than on planes. May require the receiving pilot to use binoculars.

Of course, none of these work outside line-of-sight, so:

(d) Smoke signals

e.g., the ones used by the war party chasing the war rig in Mad Max: Fury Road. Different colours = different messages.

(e) Messengers

Small, long-range aircraft. Give the pilot a piece of paper, hope he isn't shot down en-route.


  • Airships: Semaphore system for communicating Intel with each other, the ground, and to pilots in good visibility; heliograph in poor visibility.

  • Pilots: heliograph (mirror or lamp) to talk back to the airships and to each other;

  • Couriers: for no-line-of-sight comms; they dock with a blimp and hand over the piece of paper or use one of the other systems to commune directly to pilots.

But it's your novel; you can do whatever you want.

If you write this book please tell me

  • $\begingroup$ heliographs lit by gas lights are what the navy used before electricity, work just as well to aircraft as to other ships. the planes will not have the units but that is what waggling your wings is for. $\endgroup$
    – John
    Commented Oct 17, 2017 at 14:39
  • $\begingroup$ I was thinking that, at least during the day, pilots can use mirrors instead of lamps. Additionally, planes could have one of those gas lamps built into them, with a lever to open/close the shutter inside the cockpit. $\endgroup$ Commented Oct 17, 2017 at 14:40
  • $\begingroup$ It is possible but that is adding a lot of weight. $\endgroup$
    – John
    Commented Oct 17, 2017 at 15:06

It is important to remember that in the age of sail and into the early age of steam warships, captains of warships had a certain level of independence. They didn't need to be told every little maneuver or who to engage. There would also be a series of set battle plans (sweep left, engage at will, etc) that could be activated by a simple set of semaphore flags, a specific color sequence of flares, etc. Redundancy is key, signals in battle must be clear, concise, and unlikely to be mistaken for something else. The battle maneuvers are painstakingly rehearsed beforehand and designed to account for the chaos of battle, loss of the admiral's flagship, broken communications, etc.

The concern with airship is how frequently they make landfall since captains can't just row across to another ship like they might in a naval fleet. If airships are perpetually aloft, then they will need to exchange more complex messages in a more secure manner, including the transfer of personnel and sensitive equipment. If they land every night or dock at a tower or something then face to face meetings can replace most communications.

So for airships, there are numerous ways to ensure commo.

  1. Semaphore flags run out on a long line along the airship.
  2. Large colored panels of fabric stretched out across the inflated bladder. These could even be raised and lowered (or function like those changing billboards) to display real time information.
  3. Signal flares, colored smoke, rockets, even colored powder bags dispersed into the wind, or dropped into the water or land below.
  4. Flashing lights using a form of morse code.
  5. Trained birds, homing in on specific markers on ships, could pass messages.
  6. Balloons released with messages scooped up by planes equipped with wingtip hooks, then dropped into a large basket/funnel on another ship.
  7. Loud air horns blasting audible code sequences or direct speech from one ship to another.
  8. Rappelling from a higher ship to a lower one, possibly even using a glider to carry people or messages. The glider could land in a hanging net below another airship or into suspended nets on top.
  9. Potentially even firing aerodynamic message containers from ship to ship, aiming for a catch funnel or net.
  10. Pilots/passengers in planes could even use hand signals to each other to coordinate actions.

Ultrahigh balloons or blimps could serve as line-of-sight extenders, relaying flashing codes or colors to the entire fleet. Obviously protecting codebooks would be paramount. Long messages with sensitive information would have to be encrypted in case they are intercepted or miss their target.

  • $\begingroup$ Holy, this is even better-researched than my answer. +1. $\endgroup$ Commented Oct 17, 2017 at 18:53

Here are three more options:

(d) Pigeons for one-way communication back to a ground base.

(e) Railway-style mail-hooks. Railways solved the problem 150 years ago of how to grab and drop written records without stopping the train. It's a close shave while flying, but barnstormers in biplanes can do it too. Not something to try with a Zeppelin.

(f) Fulton/Skyhook lifting system for grabbing dispatches from the ground or lower-altitude craft. This is the coolest. Airplanes can do it easiest. Airships have a harder time simply because their fly-around time due to a misjudged wind is so much longer.

Wire catching baskets on the airships will be popular, as will ground targets for dropped mailbags....and floating mailbags at sea.

Most airships communicated with their ground crews using good old megaphones.

  • $\begingroup$ Although these are interesting ideas for the delivery of plans and the like, I'm not entirely sure any of them would be very effective in a combat situation. $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 3:20
  • $\begingroup$ Good, you figured that out. $\endgroup$
    – user535733
    Commented Oct 17, 2017 at 3:31
  • $\begingroup$ In response to your deleted comment, obviously actual airships would not go up against airplanes without significant protection (most likely superior numbers of their own airplanes) $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 3:33
  • $\begingroup$ Because of quite a bit of handwaving, the airships are not bombers. They are carriers for airplanes made of and powered by unobtanium/handwavium (very light, but only 10-15 minutes of flight time), which are required to recharge the airplanes, and obviously also required for any long-range flights. $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 3:50
  • $\begingroup$ This is why radio is (obviously) not an option, as technology levels, with the exceptions of all the stuff the unobtanium lets you do, are around early 15th century europe. $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 3:52

Morse or other code using mirrors or lamps is going to be the best for complex communication, but for simple messages there are other options.

Dipping the wings or wagging the tail can be used for simple signals to other nearby aircraft. This would be important when trying to get a small group of planes to swing left or right or to dive.

Setting off a flare or smoke canister works for longer range messages or communicating with more recipients.


For Zeppelins, it would most likely be Semaphore OR Morse code lamps, but these are line of sight solutions. These were used by Navies up to even WWII and most real world military Zeppelins were developed by Naval components and given names fitting Ocean Vessels.

Most planes used some radio system as the Wireless Telegraph was invented before a military use of air planes. Most planes would have a co-pilot or crew member who's job was to relay messages from the flight deck with the pilot as the officer in charge of the whole plane (for a good demonstration of this, watch the film "Midway" which features the famous battle. Given that it was the first battle to rely on pure carrier tactics rather than battleship theory, it demonstrates the plane to carrier communications quite well. There are some segments that use actual recorded voices from real pilots in real combat in the real battle). Without radio, your airplane communications would be limited to line of sight and given the 10-15 minute limited operation of the planes, it would be better to issue orders to the flight crews and then let them execute them. There are no messaging systems that can overcome the speed and line of sight factors in the short time they have to remain operational.

It's your story, but in this case, one of the earliest uses of military aviation is lost without the radio (recon) so you might want to redesign your fleet to be more Battleship theory than Carrier theory.

  • $\begingroup$ The only problem with a Battleship theory approach is the weakness of airships to enemy fire. They're huge targets, slow, and one incendiary bullet will destroy them (helium not having been discovered yet). $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 13:01
  • $\begingroup$ The only effective way to protect an airship is with planes, but one of the only ways to move planes around is an airship. $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 13:01
  • $\begingroup$ So airships continue to be necessary to carry planes over enemy territory, which would be necessary to protect it on bombing runs, but which could not perform the bombing runs themselves due to their short range. $\endgroup$
    – Gryphon
    Commented Oct 17, 2017 at 13:03
  • $\begingroup$ To my knowledge, bombing airplanes were not fully employed until WWII. While planes were used in WWI, they were largely Recon and Anti-Recon (which would be your standard fighter role. I'm not saying don't use it, I'm just saying that a 10-15 minute fly time is not optimal enough to launch all wings, and be ready to recover the returning group... If you could have two air strips, it might be doable (wave one launches from strip one while wave two preps... when wave one returns, wave two will launch). $\endgroup$
    – hszmv
    Commented Oct 17, 2017 at 15:53
  • $\begingroup$ If you need help with some carrier theory tactics discussions, let me know. $\endgroup$
    – hszmv
    Commented Oct 17, 2017 at 15:54

If we are assuming Zeppelins, airships or blimps, then we can assume analogous signaling as used by surface ships. Signal flags and lights would be very easy to adapt and have the great advantage that airships can be used as adjuncts to naval task forces since they would easily be able to communicate with each other.

For fixed wing aircraft, this was actually an issue during WWI. Aircraft were generally too small to carry the bulky radio sets of the era, and of course vacuum tubes are not very keen on aerobatic manoeuvres, especially if things start crashing into them. Early aircraft also lacked compact reliable alternators or generators needed to power radios, so much more space and lifting power would have to be devoted to batteries if you were to carry a radio.

Pilots instead operated by following plans developed and briefed on the ground, and inside a flight formation, wingmen generally watched their flight leaders and copied whatever manoeuvres they were doing, right up until a dogfight broke out.

Pilots could communicate to each other through a system of rocking or "waggling" the wings to attract attention, then using hand signals to indicate things like the location of the enemy, which direction to go and so on.

Ground troops could signal aircraft using coloured panels and markers to indicate their locations, preventing friendly fire attacks. Pilots could also be briefed on the location of enemy ground targets relative to known friendly locations, so looking for particular panel markers on the ground would indicate the point where they take a bearing and distance as they run in to the attack.

And finally, although this seems like a cheat, airfields were often identified by painting the name of the airfield in large letters on the roofs of hangers. Given air navigation often consisted of following railway lines or canals , having the names of airfields painted on the roofs made locating the start and finish points much easier and more reliable.


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