$ ls -l /usr/local/bin/ | grep airport
lrwxr-xr-x  1 root      admin        89 Jul  2 18:05 airport -> /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport

Usage: airport <interface> <verb> <options>

    <interface>
    If an interface is not specified, airport will use the first AirPort interface on the system.

    <verb is one of the following:
    prefs   If specified with no key value pairs, displays a subset of AirPort preferences for
        the specified interface.

        Preferences may be configured using key=value syntax. Keys and possible values are specified below.
        Boolean settings may be configured using 'YES' and 'NO'.

        DisconnectOnLogout (Boolean)
        JoinMode (String)
            Automatic
            Preferred
            Ranked
            Recent
            Strongest
        JoinModeFallback (String)
            Prompt
            JoinOpen
            KeepLooking
            DoNothing
        RememberRecentNetworks (Boolean)
        RequireAdmin (Boolean)
        RequireAdminIBSS (Boolean)
        RequireAdminNetworkChange (Boolean)
        RequireAdminPowerToggle (Boolean)
        WoWEnabled (Boolean)

    logger  Monitor the driver's logging facility.

    sniff   If a channel number is specified, airportd will attempt to configure the interface
        to use that channel before it begins sniffing 802.11 frames. Captures files are saved to /tmp.
        Requires super user privileges.

    debug   Enable debug logging. A debug log setting may be enabled by prefixing it with a '+', and disabled
        by prefixing it with a '-'.

        AirPort Userland Debug Flags
            DriverDiscovery
            DriverEvent
            Info
            SystemConfiguration
            UserEvent
            PreferredNetworks
            AutoJoin
            IPC
            Scan
            802.1x
            Assoc
            Keychain
            RSNAuth
            WoW
            P2P
            Roam
            BTCoex
            AllUserland - Enable/Disable all userland debug flags

        AirPort Driver Common Flags
            DriverInfo
            DriverError
            DriverWPA
            DriverScan
            AllDriver - Enable/Disable all driver debug flags

        AirPort Driver Vendor Flags
            VendorAssoc
            VendorConnection
            AllVendor - Enable/Disable all vendor debug flags

        AirPort Global Flags
            LogFile - Save all AirPort logs to /var/log/wifi.log

<options> is one of the following:
    No options currently defined.

Examples:

Configuring preferences (requires admin privileges)
    sudo airport en1 prefs JoinMode=Preferred RememberRecentNetworks=NO RequireAdmin=YES

Sniffing on channel 1:
    airport en1 sniff 1


LEGACY COMMANDS:
Supported arguments:
 -c[<arg>] --channel=[<arg>]    Set arbitrary channel on the card
 -z        --disassociate       Disassociate from any network
 -I        --getinfo            Print current wireless status, e.g. signal info, BSSID, port type etc.
 -s[<arg>] --scan=[<arg>]       Perform a wireless broadcast scan.
                   Will perform a directed scan if the optional <arg> is provided
 -x        --xml                Print info as XML
 -P        --psk                Create PSK from specified pass phrase and SSID.
                   The following additional arguments must be specified with this command:
                                  --password=<arg>  Specify a WPA password
                                  --ssid=<arg>      Specify SSID when creating a PSK
 -h        --help               Show this help