Piasecki Helicopter YH-21, H-21A, H-21B & H-21C Illustrated Parts Breakdown | Online Manuals

Piasecki Helicopter Illustrated Parts Breakdown for the USAF SERIES YH-21, H-21A & H-21B AND ARMY MODEL H-21C HELICOPTERS has 1012 pages issued date: October 15, 1956 revised date: April 15, 1957 TABLE OF CONTENTS: I- INTRODUCTION II- GROUP ASSEMBLY PARTS LIST III- NUMERICAL INDEX.