My esteemed colleague was obviously never a Kamikaze pilot. The main reason for such a pilot to wear a helmet is because the majority of missions were unsuccessful. This could be for a number of reasons.
1. Inclement weather could make it impossible to see the target
2. The plane could miss the angle of approach and be unable to crash at a vital point
3. The American naval fleet could see the plane and open up anti-aircraft fire, making it clear that the plane would never hit the target.
Under those circumstances, which happened the overwhelming majority of the time, the pilot would return to base and wait for the next chance to fly a mission. According to eyewitness testimony, including some kamikaze pilots who were drafted near the end of the war, and thus never had a chance to carry out a succesful mission, thus surviving, were almost inconsolable with depression when flying back and the only thing that could comfort them was the thought of the next mission.
Under these circumstances it made sense to give the pilot a helmet, because the number of skilled pilots who were able to slam a Mitsubishi Zero into an air craft carrier was quite low - you needed to fly above the cloud barrier, gauge correctly where the boat was, then sweep out of the clouds to hit the boat before the anti aircraft battery went off - you don't want to lose a pilot like that in a banal accident.
Note: the author of this writeup gives you the above information for historical purposes only. He does not condone kamikaze missions under any circumstances.
Hmm...is this going to turn into the great helmet debate?
The Guardian UK recently published the translation of a Japanese Manual for Kamikaze Pilots. I hereby quote: " Aborting your mission and returning to base: In the event of poor weather conditions when you cannot locate the target, or under other adverse circumstances, you may decide to return to base. Don't be discouraged. Do not waste your life lightly. You should not be possessed by petty emotions. Think how you can best defend the motherland. Remember what the wing commander has told you. You should return to the base jovially and without remorse."
The link above is being left the way it is for now. However I feel the responsibility to update the readers as follows. We have located a definite source to confirm that, in fact, Kamikaze pilots did NOT wear helmets. Mauler is right, they wore flight caps and goggles. The most important issue for these pilots was the ability to maneuver, and a helmet would have gotten in the way. On the other hand, it seems that a significant number of pilots did return to the base, although there was generally a maximum of two to three missions before they would pick a smaller vessel and crash and burn. Someone is working on this issue now, and there seems to be a significant discrepancy between sources in America and Japan. Essentially, most US sources claim that "the planes only had enough fuel to reach the target" and some US sources even quote Japanese to that effect. Paradoxically, some of those Japanese are Kamikaze pilots who are supposed to have survived. I have as of yet seen no explanation to how they survived if they had only enough fuel to reach the target. Japanese sources seem to differ. It is indisputable that pilots were ordered to return when unable to hit the target: however the entire operation was carried without the sense of bureaucratic meticulosity characteristic of certain other Japanese allies in WWII which we shall not mention. Therefore, there appears to be a huge debate as to 1. How many of these missions were successful 2. How many of these pilots returned to base and were resent later 3. What percentage of all missions resulted in a return to base. The problem of getting accurate information is compounded by the fact that the idea of a Kamikaze pilot reacts all sorts of contradictory emotions in Japan including pacifism, nationalism, shame, and pride (just to name two pairs of opposites). If anyone has any information on this, please /msg me and we'll get to the bottom of Kamikaze Return To Base ratios once and for all.
In the meantime, I can confirm Mauler's point: They did not wear helmets. Thank you for pointing this out, and on my side, an apology for putting some notes in a military tactics class together with a joke node and coming up with the wrong answer. 2+2=5 for higher values of 2