SCR-270 Radar - Use of SCR-270 Radar at Pearl Harbor

Use of SCR-270 Radar At Pearl Harbor

Unit s/n 012 was at Opana Point, Hawaii on the morning of the seventh of December 1941 manned by two privates, Elliot and Joseph Lockard. That morning the set was supposed to be shut down, but the soldiers decided to get in additional training time in since the truck scheduled to take them to breakfast was late. At 7:02 they detected the Japanese aircraft approaching Oahu at a distance of 130 miles (210 km) and Lockard telephoned the information center at Fort Shafter and reported "Large number of planes coming in from the north, three points east". The operator taking his report passed on the information repeating that the operator emphasized he had never seen anything like it, and it was "an awful big flight."

The report was passed on to an inexperienced and incompletely trained officer who had arrived only a week earlier. He thought they had detected a flight of B-17s arriving that morning from the US. There were only six B-17s in the group, so this did not account for the large size of the plot.The officer had little grasp of the technology, the radar operators were unaware of the B-17 flight (nor its size), and the B-17's had no IFF (Identification friend or foe) system, nor any alternative procedure for identifying distant friendlies as the British had developed during the Battle of Britain. The raid on Pearl Harbor started 55 minutes later, and signaled the United States' formal entry into World War II a day later.

The radar operators also failed to communicate the northerly bearing of the inbound flight. The US fleet instead was fruitlessly searching to the southwest of Hawaii, believing the attack to have been launched from that direction. In retrospect this may have been fortuitous, since they would have met the same fate as the ships in Pearl Harbor had they attempted to engage the vastly superior Japanese carrier fleet, with enormous casualties.

After the Japanese attack, the RAF agreed to send Watson-Watt to the United States to advise the military on air defense technology. In particular Watson-Watt directed attention to the general lack of understanding at all levels of command of the capabilities of radar- with it often being regarded as a freak gadget "producing snap observations on targets which may or may not be aircraft." General Gordon P. Saville, director of Air Defense at the Army Air Force headquarters referred to the Watson-Watt report as "a damning indictment of our whole warning service".