Area residents who think that fewer low-flying jets will be rattling their crockery and window panes after Dec. 6 are in for a disappointment. The new National Airport traffic and noise control policy does go into effect that day, but for the next year, at least, it means growth.

That is because of the air traffic controllers' strike, which already has cut flights at National by 20 to 25 percent from normal levels, far larger than reductions set by the plan itself.

If the control system does grow back to its old capacity by 1983, as the government promises, takeoffs and landings at National will rise, not fall, toward the levels of the new policy.

The strike and a newly announced postponement of engine-noise limits were unexpected twists in the decade-old political battle over National. Even without them, the policy's immediate effect would be small. Political roadblocks thrown up by Congress and the airline lobbies have ensured that the policy was written so as to bring few significant changes now. Instead, the focus is on capping growth in the future.

When Transportation Secretary Drew Lewis announced the Dec. 6 implementation date, he said the policy "assures continuing high levels of service at National but with less noise and congestion."

Many civic leaders from neighborhoods under National's approach corridors feel that high service and low noise are mutually exclusive. That helps explain why they gave a lukewarm reception when the plan was unveiled in July, calling it only an important first step. Still, they support it in the belief that half a loaf is better than none -- even if the half is delivered late.

Eric Bernthal, president of the Coalition on Airport Problems, argues that the policy retains the status quo in most respects, but in some others it lets the problems get worse. "In no way does it put any meaningful squeeze on National to compel the transfer of flights to Dulles," said Bernthal, referring to the policy's stated goal to promote greater use of Dulles International Airport. Bernthal said the fight over the airport is not over.

Here is where the six major facets of the policy now stand.

* Landing and takeoff "slots." They are to be set at 37 an hour for big airliners, 11 for the smaller commuter airplanes and 12 for general aviation, flights by small, privately owned planes.

Federal Aviation Administration planners estimate this formula would cause a 5- to 10-percent reduction in air traffic from prestrike levels. It is not possible to predict the outcome precisely. That's because a "slot" represents only the chance for a flight (at off-peak hours some slots go unfilled because there are not enough passengers to justify a flight), and much depends on how strictly the FAA enforces the rules.

Steep reductions brought on by the strike make the question academic for now. The FAA is training new controllers as fast as it can, but even with everything working as planned, its officials predict that traffic will not return to former levels until 1983 at the soonest.

* Closing of slot loopholes. New York Air and other airlines found in the last year that there was no enforcement of the slot allocation system. Requests for flights were cleared by controllers regardless of whether the carriers had slots for them or not. The FAA promises this loophole will be closed, though leaving it open would not increase total flights at National as long as the air traffic control system remains below capacity.

* Noise rules. Original plans called for separate daytime and nighttime limits to be imposed immediately, cutting out jet traffic after 10:30 p.m., if properly enforced. In 1986, daytime limits would be tightened to force the airlines to switch to a new generation of quieter jets now under development.

Federal officials now are rethinking or delaying all of this. Nighttime limits will be postponed until March 1, to give airlines time to straighten out their schedules to comply. Currently, though carriers cannot schedule flights between 10 p.m. and 7 a.m., their planes routinely land and take off between those hours without being challenged by the FAA.

The daytime limits were not intended to affect current noise levels, just to prevent airlines from using even noisier planes at the airport. Some carriers protested that their planes, loaded with extra fuel for winter flying, might exceed the 86-decibel limit the FAA had selected. Thus the daytime limits are being suspended pending at least a year's study, federal officials said.

The 1986 limits are also in question. This resulted, Lewis said, from the airline industry's arguments that five years was too short a time in which to complete the costly conversion of their fleets.

* Passenger caps. Currently about 14.5 million travelers use National each year. The new policy would require action if that number reached 16 million. That means, then, that 10 percent further growth in passengers will be allowed, despite the extra pressure this will place on parking lots and roads leading to the airport.

* An expanded nonstop perimeter. Currently, nonstop flights using National can fly no more than 650 miles, though a number of "grandfathered" cities are excepted. The policy expands the perimeter to 1,000 miles, which adds four new cities. However, this will not affect the total number of landings allowed.

* Promotion of Dulles International Airport, which like National is owned by the federal government. The plan calls for accelerated construction of access roads to Dulles and subsidized bus and limousine service. No forced relocation to Dulles is planned, though there has been discussion of granting the airlines antitrust immunity so they could move certain routes to Dulles in unison.