Operation K - Planning

Planning

The planning for Operation K began in the weeks after the attack on Pearl Harbor, when the Imperial Japanese Navy high command considered how to take advantage of the capabilities of the long-range H8K flying boats. Plans to bomb California and Texas were being discussed, when the need for updated information regarding the repairs to US Navy facilities at Pearl Harbor took precedence. An assessment of the repairs to the docks, yards and airfields of O'ahu would help the IJN staff to determine American ability to project power for months to come.

Initial plans called for the use of five H8K aircraft. They would fly to Kānemilohaʻi (also known as the French Frigate Shoals), the largest atoll in the Northwestern Hawaiian Islands, to be refueled by submarines prior to taking off for O'ahu. If the first raid was successful, additional raids would be made.

In a repeat of events just prior to the December 7 attack, American codebreakers warned that the Japanese were preparing for reconnaissance and disruption raids, refueling at Kānemilohaʻi, and again were largely ignored by their superiors.