In Windows, a RiverBed AirPcap NX is required for packet capture. On a Mac, it is possible to capture with a normal, built-in Apple wireless card, since OS X properly supports monitor mode.
Wireless Packet Capture in OS X
Follow these instructions to perform a wireless packet capture in OS X.
1. Press Command+Space to open Spotlight
2. Type in Wireless Diagnostics, and press enter when it appears at the top of the list in Spotlight
3. Click the Window menu, and Sniffer.
4. Select the channel and channel width that you want to capture, and click Start.
5. OS X will prompt you for your password, since admin rights are needed to put the WiFi adapter in monitor mode.
6. The Wireless Diagnostics Tool will now capture packets on the channel, until you click Stop.
7. A .WCAP file will appear on your desktop. Move it to your Windows PC with Dropbox, BitTorrent Sync, Google Drive, or sneakernet (thumbdrive), or move it to your Windows virtual machine on your Mac.
8. In Eye P.A., click File > Open File..., and open the .WCAP file as usual.