LOCKHEED ( U.S.A. )
Lockheed AH-56 "Cheyenne" Lockheed CL-475 Lockheed Model 86 / CL-575 / XH-51 Lockheed XH-51A "Compound"
LTV / HILLER / RYAN ( U.S.A. )
LTV / Hiller / Ryan XC-142A "Tri Service"
LUALDI ( ITALY )
Lualdi L-59