One of the most authoritative, go-to, books, in English, on the subject of Japanese Naval aviation is Mark Peattie’s Sunburst – The Rise of Japanese Naval Air Power 1909-1941. (See review by Robert Cressman, of the US Naval Historical Command, for the US Naval War College Review, here.)
Peattie makes no mention of a doctrinal mandatory arrestor wire. Starting on page 68 Peattie describes the typical landing process:
“Aircraft waiting to land formed a group to starboard of the ship,
circling to the right. When it was time to land, the next aircraft in
the cycle would break left, circle the ship across the bow and down
the port side, then turn in to the left and line up approximately 700
meters (2,000 feet) astern at approximately 200 meters’ (700 feet)
altitude. Each pilot would establish his glidepath by lining up his
incoming aircraft with a series of adjustable and differently
positioned red and green lights (chakkan shidōtō, ‘landing guidance
lights’) on either side of the deck, an arrangement similar to the
‘call the ball,’ system later developed by the British and used on
American carriers. Each pilot flying in astern of the carrier with
wheels, flaps, and arrester hook down would have to adjust his flight
path until he had both pairs of lights in his sight, a perfect
horizontal line up for landing. To determine the correct height for
his approach to the carrier’s deck, he adjusted his glide angle to the
correct vertical position of the colored lights in his sight. A
perfect glide slope would have the green light positioned immediately
above the red. If he could see only the red light, he was below the
perfect slope, and if the red light was over the green, he was coming
in so low that he would smash into the carrier’s stern if he did not
pull up. If the green light was positioned far above the red, the
pilot was coming in too high and risked missing the arresting gear and
hitting the crash barrier, or worse. He was further aided in this
process by the white-painted outrigger platforms near the aft end of
the flight deck. These platforms helped him gauge the orientation of
the flight deck even if the deck itself was obscured by the nose of
the aircraft.
“The pilot aimed to maintain an airspeed of approximately 10 knots
above stall speed, which typically translated to 70-75 knots.
Assuming he had kept the lights lined up properly, just after crossing
the end of the flight deck the pilot would cut his engine, and gliding
in, his hook would catch the arrestor wire and stop the aircraft. He
would then release the hook and taxi forward.”
Proper adherence to the Japanese lighting guidance system, with the pilot cutting his throttle as he crossed the edge of the flight deck, and presuming he lets things follow their normal course without a last second dive for the deck, would almost preclude hitting the #1 wire. I would suspect, such as in USN service of the day it was the pilot’s preference, where #3 wire was considered optimal but by no means mandatory, that the typical IJN carrier pilot probably, like his USN counterpart, had a particular preference, usually #2 or #3; #1 being cutting things so fine as to require effort and #4 leading one down the rabbit hole of the tetra phobic significance of the number four in Japanese culture, four being associated with death in some contexts.
