On March 6, Ambassador Menshikov handed an aide-memoire, dated March 5, to Secretary of State Dulles claiming a violation of Soviet air space by a U.S. military aircraft in the Far East on March 2. A translation of the Soviet aide-memoire, which was attached to a memorandum from Fisher Howe to General Goodpaster, March 6, reads in part:
"According to precisely established data, on March 2, 1958, at 4:05 hours Moscow time, an American military jet aircraft, having appeared from the direction of the Sea of Japan, violated the state border of the Soviet Union in the area of the settlement of Velikaya Kema and penetrated into the airspace of the Soviet Union, remaining over its territory for a considerable period of time. Thereafter, the aircraft left in the direction of the Sea of Japan in the area south of the Olga Bay." (Eisenhower Library, Project Clean Up, Intelligence Matters)
In a memorandum of conversation with the President on March 7, Secretary Dulles wrote:
"The President read the Soviet aide-memoire which had been delivered to us yesterday protesting an alleged invasion of Soviet air space in the Far East on March 2. The President indicated a strong view that such infractions should be discontinued. He thought we should reply to the Soviets by saying that we were not aware of the matter referred to but that strong measures were being taken to prevent any recurrence.
"The President expressed the view that any such operations carried a danger of starting a nuclear war by miscalculation. He said that his military advisers had pressed upon him the necessity of retaliation if there seemed to be a movement of Soviet planes toward the United States. The President felt that the Soviets might have the same attitude and might misinterpret an overflight as being designed to start a nuclear war against which they would react.
"The President instructed General Goodpaster to communicate with the appropriate US officials in this sense." (Ibid., Dulles Papers, Meetings with the President)
The U.S. reply, an aide-memoire dated March 31, said that the United States had been unable to determine whether any U.S. military aircraft were in the vicinity of the Soviet Union on March 2. A copy of this U.S. aide-memoire is attached to a memorandum from C. Burke Elbrick to Secretary Dulles, April 28. (Department of State, Central Files, 761.5411/4 - 2158) According to a memorandum of Dulles' conversation with Menshikov, March 31, when Dulles handed the aide-memoire to the Ambassador, he added orally that the United States had issued renewed instructions to military personnel enjoining them to adhere strictly to standing regulations prohibiting U.S. military aircraft from approaching Soviet territory. (Ibid., 761.5411/3 - 3158)
On April 21, a messenger from the Soviet Embassy delivered a note, dated April 21, which indicated that the U.S. reply was unsatisfactory, reiterated the previous Soviet charges, and expected that the United States would investigate the incident further and punish those guilty of the violation. A translation of the Soviet note is attached to a memorandum from Henry P. Leverich to Fisher Howe, April 21. (Ibid., 761.5411/ 4 - 2158)
On May 5, the Department of State delivered a brief note to the Soviet Embassy reiterating its earlier denial of the Soviet allegations. This note concluded: "The United States Government has nothing further to add to its aide-memoire of March 31, 1958 concerning the alleged incident." (Ibid.)