Apex domains cannot have CNAME records.
Question and response
Question
dig open.airstreamcomm.net. NS
Answer
open.airstreamcomm.net. 1 NS ns1.airstreamcomm.net.
open.airstreamcomm.net. 1 NS ns2.airstreamcomm.net.
Authority
The response has no authority records.
Additional
ns1.airstreamcomm.net. 1 A 64.33.165.210
ns2.airstreamcomm.net. 1 A 64.33.167.154
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0