What I Learned Today

Recently on a trip to Ireland, in an effort to reduce my cellular data consumption, I put my phone into airplane mode while driving across the country. Imagine my surprise when, an hour later, I checked my phone and found that it was still correctly reporting my location, and giving me directions!

I scratched my head about this for a little while. The moving map was updating my position even in airplane mode! It was also scrolling the map as I moved. So it must be the case that

1. Google Maps downloads and caches enough information that it can continue to show you the relevant map info even if it loses a data connection to its server, and
2. The GPS receiver in the phone continues to operate in airplane mode.

This had never occurred to me! I was able to confirm it at other times during the trip. If you try to get directions from Google Maps when in airplane mode, it doesn’t work – you can’t search the maps. But if you get the directions started, then go into airplane mode (i.e., turn off cell data), then it will correctly continue to give you directions. However, if you deviate at all, it cannot re-route you, so you have to figure that out for yourself.

I decided to test this during a recent cross-country flight. Right before a flight from Los Angeles to Philadelphia, I got driving directions from Google maps (see right; it wants me to start on Sepulveda Blvd) and then I put the phone into airplane mode.

A few minutes after takeoff from LAX, we were out over the ocean and Google Maps was still urgently telling me to get onto Sepulveda Blvd:

I checked on the directions periodically throughout the 5-hour flight.

Each time we had made some more progress, but we were so far off the (road) track that Google Maps kept saying to go back to Sepulveda Blvd and start over.

As we got close to the Philadelphia airport, we were close enough to match up with a road (briefly) and the directions made more sense.

So cool! This means that even when an airplane doesn’t bother to give you that awesome moving-map track of where the plane currently is, you can still get it, IN AIRPLANE MODE, on your phone! (But only if you got some directions first.)

Recently I got to visit the site of the first transatlantic flight’s landing – in Ireland. The June 1919 flight was achieved by John Alcock and Arthur Brown in a biplane.

These were two interesting aviators! They were both pilots during WWI (although not together), and they were both taken prisoner (Alcock in Turkey, Brown in Germany) and then (presumably) released. Alcock approached an airplane company called Vickers to suggest that he fly their Vickers Vimy IV bomber in the race to see who would be the first to cross the Atlantic. Brown joined up later and due to his exceptional navigational skills was chosen to fly with Alcock.

The 16-hour flight itself sounds pretty harrowing. They departed Newfoundland at 1:45 p.m. They had several equipment problems including the loss of their radio, intercom, and heating. They were flying in a biplane with two open-cockpit seats! Bad weather meant Brown couldn’t use his sextant to help them steer from 5 p.m. until midnight. Happily, they still made it to Clifden, Ireland, and ended up landing next to Marconi’s transatlantic wireless station (an excellent visual landmark). Unfortunately, they thought they spotted a stretch of open ground to land on that turned out to be a bog, so when the plane landed and slowed, it sank nose-in. They escaped unhurt but the plane was damaged. Still, heroes who won the 10,000-pound prize!

From Wikipedia, this appears to be an actual photo taken after landing:

They also carried a small mailbag so they could count their flight as the first transatlantic airmail flight :)

As usual, I am awed by the courage and daring of early aviators!