Inflight positioning map without wi-fi?
 

How accurate? My iPhone will get a GPS signal and give me a general location on what I assumed is a low-detail locally-stored map in flight.

Google maps, when offline maps are downloaded and saved on the device, Galileo Offline Maps and Flyover Country. I'm sure that there are more apps that are capable of showing your position when not connected to data or WiFi.

On a recent flight from SFO to SAN Google Maps did display a map (and used GPS for location) despite flying over areas without offline maps. I suspect there's a low detail world map for such situations regardless of whether you choose to download additional ones.

Google Maps has a full world map available at all times, even offline.

It will also cache areas that you've been, even where offline maps are not available/downloaded. If you put your phone in airplane made and then pan around in maps you'll see what level of detail is available when offline.

For example, I was in Tokyo last week. Offline maps are not available for Japan, but I can still zoom in to street level for the area around Tokyo even 5 days after I left. If I look elsewhere in Japan, I see only very high-level detail (no roads, only very major city names, etc).

Panning over the area that your flight is going to be going in advance does seem to cache enough information to show good detail when flying.

In addition to the above replies, I would like to add that it might take a while for Google Maps to get the location from inside the plane while in flight. For me, it took anywhere from ~20s to a few minutes.

I use an Android app called "GPS Test" (there are dozens of similar ones available) that will show you the status of the GPS on the phone, including how good a signal it's getting and the location of the satellites.

Once it confirms that I've got a signal, then I jump over to Google Maps.

Also keep in mind that GPS's don't work well (or basically, at all) on 787's. On other aircraft they will work fine near the window, but likely not all that well elsewhere.

Let me add HERE WeGo - Offline Maps & GPS to that list. (Android, iOS)

Baidu maps (much more detailed than Google in China) also works well offline.

There isn't unfortunately a single one of them on the iPhone since unlike on Android, the iOS API doesn't provide that feature. That's really one of the aspects where any cheap Android phone beats the most expensive iPhone.

GPS Status & Toolbox, the Android version of which I have installed on my Samsung S9+ is also available in an iOS version in the App Store.

Unfortunately you just have to look at the comments of the iOS version to see just how bad it is. You can also compare the screenshots : the iOS version is nowhere close to the Android one. Indeed if you look at the webpage of MobiWia they never mention iOS. The issue is well explained in this stackexange post : https://apple.stackexchange.com/ques...ock-on-details

stay clear of Baidu at all costs, unless you like your phone (specially the android versions) compromised. This app, like many Chinese big company apps, slurps up data like a dinosaur. If you dont care about that, then Baidu is a great map, admittedly - for mainland China at least.

One that works flawless and lets you selectively decide which map data to download in detail is Maps.Me. Search for it in your app store. Lets u even save the GPS track.

+1. Agree.
Is Maps.Me better in that respect?

On a recent trip to BJ, I was able to use Google maps for areas that I had not used before. Surprised!