How do I AirDrop from a MacBook to its tethered iPhone?

My MacBook (OSX Yosemite 10.10.5) is tethered to my iPhone (10.0.2) in order to provide Internet access.

How do I AirDrop from my Macbook to an app on my iPhone?

Currently I have to use Dropbox, ie. move the file into Dropbox, wait for the (possibly large file) to upload, then download it on my iPhone to the desired app (causing another sync).

You will need to turn off Personal Hotspot before you can AirDrop.

AirDrop transfers data over Wi-Fi between the two peer devices (in this case, your MacBook and your iPhone). Since your iPhone is providing a Personal Hotspot via Wi-Fi, that connection is not available for AirDrop.

If turning Personal Hotspot off and on repeatedly is too cumbersome, you can provide tethering through USB instead. Then your Wi-Fi connection will always be available for AirDrop.

Like Phong said, you will need to turn off your Personal Hotspot before you can AirDrop since it is using the network from your phone. However your MacBook does not need to be on a Wi-Fi network in order to send or receive files through AirDrop. As long as both Wi-Fi and Bluetooth are on on both of your devices, it can send the files without being connected to each other or the internet.

To send things through AirDrop on your Mac, simply right-click on the file(s) you want to send, mouse over share, then click on AirDrop. Then once your iPhone shows up, click send and click accept on your iPhone.

If you would like to know how AirDrop works, you can go here and it explains it in easy-to-understand terms: https://www.lifewire.com/what-is-airdrop-how-does-it-work-1994512

Just in case in anyone is coming across this for a more recent version of macos (Catalina 10.15.5) and iOS (13.5.1) If I am tethered using Bluetooth, rather than Wi-Fi, I can use Personal Hotspot and Airdrop at the same time.