Accession Number : ADA333345

Title :   Structural Design Analysis of the Tail Landing Gear Bay and the Vertical/Horizontal Stabilizers of the RAH-66 Comanche Helicopter.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Shoop, Brian P.

PDF Url : ADA333345

Report Date : SEP 1997

Pagination or Media Count : 80

Abstract : The RAH-66 Comanche's stealth design requires the use of radar-absorbing material (RAM) on the outer skin of the aircraft. The reduced stiffness properties of RAM produce insufficient tail torsional stiffness, necessitating the use of non-radar-absorbing graphite on the outer skin of the tail section. This thesis investigates structural design modifications to increase the tail section's stiffness to allow the use of RAM on the outer skin and still meet all structural requirements. An original model represents the prototype aircraft at first flight. The goal is to create a model using RAM on the outer skin that watches the structural stiffness of the original model. This thesis builds on earlier work conducted at the Naval Postgraduate School (NPS). Two new design modifications to the tailbone are developed. The best modification increases the torsional stiffness of a baseline model by six percent. Integrating earlier NPS modifications increases torsional stiffness by 12 percent. When RAM is applied to the outer skin of the modified model, torsional stiffness is reduced by only six percent from the baseline as compared to a 24 percent reduction with no modifications. Additional modifications to the vertical and horizontal stabilizers further increase structural stiffness and reduce weight.

Descriptors :   *HELICOPTERS, *LANDING GEAR, *STEALTH TECHNOLOGY, MODELS, MODIFICATION, STRUCTURAL ANALYSIS, THESES, PROTOTYPES, BASE LINES, FLIGHT, EXTERNAL, RADAR ABSORBING MATERIALS, HORIZONTAL STABILIZERS, TAILS(AIRCRAFT), VERTICAL STABILIZERS.

Subject Categories : Helicopters
      Radar Countermeasures

Distribution Statement : APPROVED FOR PUBLIC RELEASE