Propelling and controlling an aircraft by the force of magnetic flux variations is feasible and will be applied on a NASA engineered space shuttle by 5/2/2001. 'Yes' coupons pay $1, 'No' coupons pay $1 otherwise.
I will judge based on the wording of the claim unless it is found to be ambiguous. Such ambiguities will be resolved based on my perception of the author's intent.
This claim requires (1) magnetic flux variations to be shown an effective method for propelling and controlling an aircraft, and (2) a deployment of these technologies on a NASA engineered space shuttle. The deployment could be merely a small-scale experiment which demonstrates the feasibility of the technology for propelling and controlling aircraft.
Note that an aircraft is (by definition) a craft that moves through the air - that is, within the atmosphere. Showing the technology to be effective for stabilizing sattelites, therefore, would not satisfy the claim.
As of 1997-12-18, I am unaware of any technologies or planned experiments that would satisfy the claim.
Efficient propulsion of an aircraft requires the propulsion method to provide sufficient thrust to overcome air resistance and gravity and to sustain flight. Any technology that is seriously considered for application above and beyond the experimental phase (for example, commercial exploitation) is "efficient". If the technology appears inherently unable to competete with other available technologies for air transportation (for example, because of too short flight duration), then it is not "efficient".
A technology for efficiently propelling an aircraft would have to be effective at sea level.