Hi Rolland. A-2 was Chengdu and there was a complex of B-29 fields nearby (p.67 this link).
A-1 Hsingching
A-3 Kwanghan
A-5 kiunglai
A-7 Pengshan ..........also 5 fighter bases. Chengdu chosen mainly for availability of labour. The 426th was to defend them (as detachments) and protect the B-29s. Their main base until moving to China as a squadron in November was Madhaiganj in Bengal (India).
Nick
https://media.defense.gov/2010/Nov/0...101105-012.pdf