Undercarriage Group – Civil Aircraft

Chapter 7 describes undercarriages and their types in detail. Undercarriage size depends on an aircraft’s MTOM. Mass estimation is based on a generalized approach of the undercarriage classes that demonstrate strong statistical relations, as discussed herein.

Tricycle Type (Retractable) – Wing-Mounted (Nose and Main Gear Estimated Together)

For a low-wing-mounted undercarriage:

Tricycle Type (Retractable) – Fuselage-Mounted (Nose and Main Gear Estimated Together)

These are typically high-wing aircraft. A fuselage-mounted undercarriage usually has shorter struts.

Muc_fus — 0.04 X MTOM

For a fixed undercarriage, the mass is 10 to 15% lighter; for a tail-dragger, it is 20 to 25% lighter.