Can an Android phone with no SIM card make an emergency call? Can an Android phone (specifically, the Huawei Honor 5X) that has never had a SIM card in it make an emergency phone call to 911? 

The Honor 5X (which is GSM Unlocked) will be on WiFi and within range of T-Mobile and AT&amp;T towers, but will not have a SIM card. Can it still make an SOS call in the event of an emergency?
This is actually independent of whether a mobile phone is Android. 

In the United States, the FCC requires wireless service providers to provide 911 service to all phones, regardless of whether they currently have paid service or not. 


  The FCC's basic 911 rules require wireless service providers to transmit all 911 calls to a PSAP, regardless of whether the caller subscribes to the provider's service or not.


...


  If your wireless phone is not "initialized" (meaning you do not have a contract for service with a wireless service provider), and your emergency call gets disconnected, you must call the emergency operator back because the operator does not have your telephone number and cannot contact you.