The article that appeared in Asahi Shinbun on February 24 this year says the Self Defense Force made one of their helicopter available for the government to conduct an aerial survey of radiation in the early afternoon of March 12, 2011, before the Reactor 1 building blew out at Fukushima I Nuclear Power Plant.
From what I gather from the article, the timeline was something like this:
Sometime in the morning on March 12, 2011, Ministry of Education and Science asked for a SDF helicopter to be used for radiation monitoring.
Ministry of Defense agreed, and sent one medium-size helicopter at 11:10AM from its base in Sendai, Miyagi that had been used for disaster relief to Rokkasho-mura, where the Nuclear Safety Technology Center staff were supposed to be waiting.
The helicopter landed in the meeting place (a park in Rokkasho-mura) at 1PM, but there was no one waiting for the helicopter. So it took off at 1:10PM.
The Nuclear Safety Technology Center in Rokkasho-mura received the instruction from the Ministry of Education at 1:30PM. Two people went to the meeting place, and waited for the SDF helicopter to show up for one hour from 2:40PM.
The center assumed the SDF heli was busy doing the disaster relief, and decided to drive to Fukushima the next day (March 13) at 9AM.
The aerial radiation survey was then scheduled on March 15, but that was canceled because of the information that "Reactor 4 blew up".
The aerial survey wasn't carried out until March 25.
The Nuclear Safety Technology Center's Rokkasho-mura branch had the staff and the equipment to conduct aerial radiation surveys.
What is wrong with this picture?
First, it confirms that the Ministry of Education and Science knew the radiation from Fukushima I Nuclear Power Plant was leaking in the morning of March 12, 2011.
Second, neither the SDF nor the Nuclear Safety Technology Center bothered to try to contact each other when there was no one at the meeting place (Rokkasho-mura park), or when there was no helicopter. I doubt that they had a direct means of communication, but the SDF helicopter pilot could have contacted the base who could have contacted the SDF headquarters/Ministry of Defense who could have contacted the Ministry of Education.
The Asahi article specifically says that the head of the Radiation group at the Emergency Response Center (ERC) under the Ministry of Economy, Trade and Industry was a bureaucrat on assignment from the Ministry of Education. The Ministry of Education blames the ERC of course, saying "It was the ERC under the Ministry of Economy, Trade and Industry who proposed an aerial [radiation] monitoring. It was the ERC who coordinated with the Ministry of Defense. We immediately conveyed the ERC messages to the Nuclear Safety Technology Center."
Third, Asahi didn't report it until February this year.
Fourth, I managed to miss the news when it appeared in February this year.
The US Department of Energy and the US military were conducting the aerial survey using Global Hawk drones from March 17 to 19 last year, and they SHARED the results with the Japanese government. The Japanese government sat on it. Asahi Shinbun first reported it in March 24 last year, and it just reported the news again on June 18 this year.
According to the June 18 article, the Ministry of Foreign Affairs received the fax from the US showing the contamination map created from the actual data collected by Global Hawk drones via the US Embassy in Tokyo on March 18 and 20 last year. The Ministry of Foreign Affairs told Asahi that it immediately forwarded the fax to the Nuclear and Industrial Safety Agency and the Ministry of Education. NISA and the Ministry of Education both sat on it. Probably because it came from the Ministry of Foreign Affairs. What does the Ministry of Foreign Affairs know anything about radiation? Right?
(It is also possible that "immediate" in the minds of the officials at the Ministry of Foreign Affairs was "several hours later" in a reality-based world.)
Moreover, Mainichi Daily (English paper) reported on March 19 last year that the Japanese government was in possession of near-real time video footage of Fukushima I Nuclear Power Plant taken from Global Hawk, with the permission from the US to release to the general public. The Japanese government sat on it. I think it is still sitting on it.
Japan was the worst possible place for a major nuclear accident to occur - bureaucracy that plays bureaucracy in an extreme emergency, politicians who cannot lead in an extreme emergency, and the populace who cannot even properly "panic" in an extreme emergency.