“VIEWPOINT,” Tuesday, 11:30 p.m. (7) (3) (10)...

“VIEWPOINT,” Tuesday, 11:30 p.m. (7) (3) (10) (42)--Why only heads of state? Ron Powers, whose reflections about the media are a continuing highlight on “CBS Sunday Morning,” proposes that the heads of the TV networks also have a summit meeting. The subject: setting guidelines for covering such difficult and volatile stories as the recent TWA hijacking/hostage ordeal.

It’s an appealing plan, though one with little chance of being enacted, as Powers well knows. Networks are usually too busy fighting on behalf of ratings to consider cooperating on behalf of the public.

Thus for now we must be content with free-for-all TV examinations of media coverage of the Beirut dilemma, examinations that may be interesting to watch but usually are quickly forgotten.

Perhaps Tuesday night’s “Viewpoint”--ABC’s quarterly critique of broadcast journalism--will yield better results when it takes up media coverage of the TWA hijacking.

For one thing, the 90-minute panel discussion will have the perspective of time, that is to say at least a little more time than the nearly continuous media self-analysis that immediately followed the 17-day ordeal. For another thing, skilled Ted Koppel will be there to guide the discussion by TV executives, critics of the TV coverage and some of the persons closely associated with the hostage incident.

There are numerous questions to be discussed, one of them the pestering of hostage families by some of the media. And there are also these weighty issues:

It’s a given that the media were exploited by the Shiite Muslim hijackers and hostage jailers. But did the media have a choice? Were ABC and CNN, in particular, correct in presenting considerable live coverage, thereby giving Nabih Berri’s Amal an unfiltered forum?

Did the media, through their coverage, pressure President Reagan and limit his options?

Was NBC ethical in buying round-trip fares to West Germany for hostage families to make sure the “Today” show would get first crack at them?

Did the media cover this hostage incident differently than they did the 440-day Iranian hostage saga that sapped the presidency of Jimmy Carter?

And a final question: Isn’t Powers right? Isn’t a network summit needed-- now ?