Re post #4, yes the Convair 880/990 had nose wheel brakes. To the best of my recollection they only operated when the brake pedals were fully depressed (desperation mode) and were either full on (relying on the antiskid to prevent lock up) or off. Nosewheel steering inputs beyond a certain point would also release the nw brakes if applied. The nosewheels were on a common axle with a single antiskid transducer and antiskid valve. I think they might have looked after the spin down braking on retraction but it was a very long time ago. I believe there was an incident, before my time on 880's, where one had full nosewheel braking applied on touchdown due to a malfunction and came to a rapid stop with square nose wheels and damage to the bottom end of the nose leg. I cannot recall ever replacing nosewheel brakes due to wear.