Accession Number:

ADA094634

Title:

Feasibility Study for C-141B Reduction of Wing Loads by Uprigging the Ailerons,

Descriptive Note:

Corporate Author:

LOCKHEED-GEORGIA CO MARIETTA

Personal Author(s):

Report Date:

1980-09-10

Pagination or Media Count:

35.0

Abstract:

This report summarizes an investigation into the feasibility of uprigging the ailerons on the C-141B to reduce wing loads. The potential wing loads reductions were based on early wind tunnel data and were corroborated by recent flight test data at a mid-span location. Crack growth computations were made for four wing locations. Significant increases in structural safety limits for the two lower surface locations ranged from an improvement factor of 1.18 3 deg uprig to 2.731 6 deg uprig depending on location. Similar percentage increases could be expected in inspection intervals and structural durability. Two wing upper surface locations showed no significant change from aileron uprigging. An examination of the potential impact on pitch trim requirements, roll response and dutch roll characteristics indicated only negligible effects from moderate aileron uprigging. A negligible degradation in the maximum lift at buffet onset was predicted. Drag increases for a range of uprig positions and lift coefficients were established from coordinated C-141C-5A data. Two methods of uprigging were described which permit changing the uprig inflight if required. Flight tests to confirm predictions are recommended. Author

Subject Categories:

  • Transport Aircraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE