I have been searching for 1/100th scale aircraft for gaming in 15mm, and was surprised at what I found. The following are lines I have discovered (so far):

UPC (out of production)
7049 'Oscar'
7050 ME 109
7051 P 51D
7052 P 38L
7053 YAK 9D
7054 'George'
7055 'Tony'
7056 'Zero'
7057 JU 87
7058 Spitfire
7059 FW 190
7060 P 47N
7061 'Shinden'
7062 P 40N
7063 F61F-5
7064 F4U-5
7065 'Grace'
7066 F 84
7067'Judy'
7068 ME 262A
7069 'Tojo'
7030 F 86F
7031 F 104
7032 x 15
7033 'Nick'
7034 E.E. Lightning
7036 IF 105
7037 IF 4
7038 Vigilante

Revell
AH 64
Hind-D
PT-207 (a boat!)

Dovusha (at American Eagles)
6 Japanese fighters (I have the Zero)

Accurate Models (at American Eagles. Soon to be out of production)
UH 1 B gunship
AH 1G
Blackhawk (3 versions)
Apache

Tamiya
L.T.V. A 7A
F. Mk 6
A 4E
Mirage IIIE

These aircraft are out there, you just have to look around for them.