Your question seems primarily to ask what an air carrier aircraft without radio communication ability (sometimes known as NORDO) should do once it arrives at the airport.
First, a bit of background. FAR 91.185 covers how aircraft operating under IFR (IMC and VMC) should respond if they become NORDO. This applies to both General Aviation and Air Carrier aircraft. Further it covers the expected pilot actions for the following:
- What the pilot should do if in VMC conditions (the rule uses the term "VFR conditions" instead of VMC [visual meteorological conditions]).
What the pilot should do if in IMC conditions (the rule uses the term "IFR conditions" instead of IMC [Instrument meteorological conditions]) pertaining to:
c. Leaving the clearance limit and beginning the approach.
Second, for NORDO aircraft operating under VFR the route, altitude, etc. to get to an airport is left to the discretion of the pilot.
Now, once either a VFR or IFR aircraft arrives at an airport what should the pilot do and what should he/she expect from ATC?
FAR 91.125 specifies ATC (Control Tower) light gun signals and their meaning. These light gun signals represent appropriate clearance and instruction from ATC and are responded to by the pilot based on the signal's meaning. (e.g., cleared to land, do not land, etc.)
Importantly, the Aeronautical Information Manual AIM, para. 6-4-2 instructs pilots to set their aircraft's transponder to code 7600, whether or not the pilot is operating under VFR or IFR.
As can be seen from reading the information above, there is not a regulatory distinction between a General Aviation aircraft and an Air Carrier Aircraft (GA/AC) with respect to NORDO operations.
However, practically speaking the actions of the pilot and of ATC may be quite different between GA and AC aircraft depending on the circumstances.
For example, even if a GA aircraft filed a VFR flight plan, if the pilot was not communicating with ATC prior to becoming NORDO, operating into a busy tower controlled pattern could be hazardous. The tower controller may never even see that an aircraft is circling near the pattern waiting for a light gun signal to land.
An option for a NORDO GA aircraft (operating under VFR) might be landing at an uncontrolled airport without interacting with ATC.
With respect to a NORDO AC aircraft operating under IFR, the handling by ATC, in my opinion, would likely be quite different. Since the AC aircraft is operating on a IFR clearance issued by ATC where the destination and estimated time of arrival are clearly known, ATC's awareness of the aircraft is probably not in question. Also, since the NORDO AC aircraft has been squawking code 7600, and most areas in the U.S., for example, are covered by radar, there is little mystery as to when the aircraft will need to be sent a light gun signal (hopefully showing a clearance to land) from the tower.
Finally, there is no doubt that many who read my answer above can envision a variety of circumstances under which my points could fail or not be sufficient response to the question. However, regulations and procedures can only anticipate a limited number of operational circumstances. Often, in real time, the pilot and ATC must consider the best course of action based on their knowledge of existing rules and procedures, and an understanding of the practical limitations of safely operating in a very complex environment.