Tim Tibo's main job is a flight captain for a German airline, but he is also an enthusiastic aerobatic pilot.

At an air show abroad, he is amazed to see pilots in close formation writing letters in the sky with their planes.

The audience on the ground is enthusiastic about the ephemeral messages in the sky, because the advertising message made of environmentally friendly paraffin can only be seen for a few minutes.

Then it breaks up into tiny clouds.

Something like that should also exist in Germany.

That's why Tibo, who lives in Bavaria, founded "Skytexter" four years ago together with several experienced aerobatic pilots.

Pioneers of this aerial advertising are pilots in the United States.

The formation of steam is synchronized at this time using punch cards, which all five pilots pull simultaneously through the control system of their aircraft's smoke systems.

As early as the 1960s, five-point matrix writing was created in the sky.

Miles of lettering

The following applies to the planes: They must all have a so-called smoke system that produces the steam.

In addition, all are suitable for aerobatics and have a similar engine, so that the climb performance is comparably good.

All air-cooled six-cylinders have at least 260 hp.

The machines don't have to be really fast.

Because aerial advertising only flies at around 220 kilometers per hour.

That is far below the maximum speed of all five machines, which is between 340 and 400 kilometers per hour, depending on the type.

However, excellent visibility is important.

That's why the pilot always sits exactly in the longitudinal axis of his aircraft - whether in a low- or double-decker aircraft - and can therefore see excellently in all directions.

Each pilot also carries a parachute for safety reasons.

Two of the EA-300 aircraft used come from the German aircraft manufacturer Extra.

An American-built Pitts Special S-2B biplane and the German manufacturer Xtreme Air's single-seat XA-41 and two-seat XA-42 are the Skytexter's commonly used aircraft.

Since the five planes fly at an altitude of around 3,000 meters, the advertising messages are sometimes kilometers long.

When there is no wind, the words remain legible in the sky for at least a few minutes before dissipating again.

“We use environmentally friendly paraffin oil for the lettering.

This is vaporized at high temperature,” explains a team member.

A small extra tank with the paraffin is in the hull.

This is then injected into the hot exhaust pipe using a pump.

“Using a computer-controlled system, we bring the individual letters into the sky.

There are no residues left in the air, just our messages,” he adds.

Each character is 200 meters tall, making it easily recognizable from the ground.

Frankfurt message of peace

In Frankfurt, due to the proximity to the airport, the project is discussed in advance with air traffic control.

All professional pilots in the formation also adhere to the relevant specifications for the so-called Charly or Delta airspaces, some of which extend over the city.

A detailed briefing takes place before the assignment.

It is clarified who flies in which position, which radio frequencies have to be locked during the flight and with which course the letters are drawn in the sky.

Tim Tibo, founder of Skytexter, dubs the whole thing.

He also radios commands to his fellow pilots.

At the operating altitude, all machines catch up to his Extra 300, so that they fly in a row exactly parallel to each other.

This is the only way to ensure that the letters can be read from the ground.

All aircraft are networked with each other via a computer program via WLAN.

The hardware sits in Tibo's plane and looks almost like a second control stick.

When he gives the steam commands with the previously programmed letters and words, paraffin oil is injected into the aircraft's exhaust system at the same time.

This works so well with specially created software that entire sentences such as the message of peace about Frankfurt are created.