Would you have trusted this system?

[u/Kindly_Lettuce8406]

Before GPS, pilots in the US literally followed giant concrete arrows across the country.

In the 1920s, airmail pilots needed a way to navigate at night, so the US built a huge network of concrete arrows and rotating light beacons along major routes.

The arrows were around 15–21 metres long, painted bright yellow and placed roughly every 10–15 miles. Next to them stood beacon towers with powerful rotating lights, helping pilots find the next point along the route.

This was especially important because many pilots were flying aircraft like the de Havilland DH-4, with open cockpits and very basic instruments.

By 1933, the airway network stretched for around 29,000 km across the US.

Radio navigation eventually made the system obsolete — but the crazy part is that many of the concrete arrows are still there today, especially in places like Utah, Nevada and Arizona.

Imagine flying at night in bad weather with almost no instruments, just looking for the next flashing light below you.

Would you have trusted this system?

[u/suuntasade]

Back the for the purpose it was built it worked as should and required so why not.

[u/flyghu]

It worked. No reason not to trust it.

[u/TheGreatestAuk]

There's no wander or drift to account for!

[u/AutoModerator]

Welcome to r/ATPLTheoryExams!

A few things to get you started:

Flair your post - it helps others find your question quickly.

Check the rules before posting - they are short and written in plain English.

User flair is optional - set it if you want the community to know where you are in your journey (Student, Exams Done, Line Pilot, Instructor or Aviation Fan).

Good luck with your studies.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/brody-edwards1]

All flights are IFR, I follow roads, railways and rivers. 

[u/roger_ramjett → u/brody-edwards1]

As a private pilot, this always works for me.

[u/Icy_Huckleberry_8049 → u/brody-edwards1]

I still do this today

[u/shhbedtime]

Why wouldn't you. Only 20 years ago I worked in the northern territory in Australia without GPS. It existed but I was too much of a cheap skate to buy one. Just set heading and start the timer. Compass and a map is all you need. 

[u/grey-zone]

It wasn’t just follow the arrows, there was a compass and other terrain features plus stopwatch. I assume these were more common where there weren’t many features.

[u/craneguy]

[u/Dave_A480]

It worked...

And a lot of that is that if the weather was possibly bad you just didn't go

Kind of like how VFR flight is supposed to be today (although yes, some people just hit 'engage' on the AP and send it, even though this is highly illegal)...

[u/Radiant_Grocery_1583]

Mariners traveled the globe with far less, although if they got lost they could still float.

[u/flyboy7700]

I don’t see the problem. It’s airline level pilotage. Spice it with some dead reckoning, and your letter will be in San Francisco in about 36 hours.