What was found
DEPARTING, AT 400 FT AGL, CARGO BOTTLE LOW MESSAGE C/W QRH. RETURN TO LAND, DURING TROUBLESHOOTING, FOUND LOOSE 10TH STAGE CLAMP ON BLEED AIR DUCT. RESECURED CLAMP. LEAK CHECKED IAW AWAC SUPP 99-15. R & R CARGO FIRE BOTTLE IAW AWAC SUPP 10-099. OPS CHECK GOOD.