US 6,289,289 B1Granted

Aircraft structural fatigue monitor

AssigneeHoneywell International Inc.

InventorTerry L. Zweifel

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Abstract

The present invention is a system for monitoring, storing, and reporting the accumulation of fatigue occurrences experienced by an aircraft. The system according to the present invention uses existing aircraft instrumentation to monitor fatigue occurrences. Data is collected on the magnitude and cycles of any turbulence encounters; magnitude and number of gloading accrued by aircraft maneuvering; the number of pressurization cycles that the aircraft has experienced; and the number of takeoffs/landing cycles that have occurred. These data are stored in electronic memory for later review by the flight crew or maintenance personnel. Additionally, the number of accumulated wing flap cycles and landing extensions/retractions may also be monitored to facilitate the maintenance operations of these two critical flight controls.

A system for monitoring, storing, and reporting the accumulation of fatigue occurrences experienced by an aircraft comprising:

a. collecting magnitude and number of cycles of turbulence encounters,
b. collecting magnitude and number of g-loading accrued by aircraft maneuvering,
c. counting pressurization cycles that the aircraft has experienced,
d. counting the number of flap cycles that have occurred, and
e. storing the data obtained in steps a-d in an electronic memory,
wherein said step of collecting magnitude and number of cycles of turbulence encounters further comprises;
f. comparing a pitch attitude parameter θ (10) and an angle of attack parameter α (12) to obtain the algebraic difference of said pitch attitude parameter θ (10) and said angle of attack parameter α′ (12),
g. differentiating said pitch attitude parameter θ (10) to obtain a pitch attitude time derivative parameter θ′ (10′),
h. differentiating said angle of attack parameter α (12) to obtain a time derivative angle of attack parameter α′ (12′),
i. differentiating a true airspeed parameter Vt (16) to obtain a time derivative true airspeed parameter Vt′ (16′),
j. multiplying said algebraic difference of said pitch attitude time derivative parameter θ′ (10′), and said time derivative angle of attack parameter α′ (12′), by said true airspeed parameter Vt (16), to obtain the product
(θ′−α′)·Vt (18),
k. multiplying said algebraic difference of said pitch attitude parameter θ (10) and said angle of attack parameter α (12), by said time derivative time airspeed parameter Vt·(16′), to obtain the product
(θ−α)·Vt′ (17), and
l. summing said product,
(θ′−α′)·Vt (18),
of said first multiplier operator (64) with said product,
(θ−α)·Vt′ (17),
of said second multiplier operator (66) to obtain a sum of products,
(θ′−α′)·Vt (18)+(θ−α)·Vt′ (17),
with a vertical acceleration parameter, av (13).

18 more elements

Facts

Application

09/209,169Filed 10 Dec 1998

Granted

11 Sep 2001

Term ends

Not estimatedThe source records don’t support an estimate.

Classification8 codes

G07C 3/00
Registering or indicating the condition or the working of machines or other
B64F 5/60
Designing, manufacturing, assembling, cleaning, maintaining or repairing aircraft, not otherwise provided for; Handling, transporting, testing…
G01M 5/0016
Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings: of aircraft wings or blades
G01M 5/0033
Investigating the elasticity of structures, e.g. deflection of bridges or air-craft wings: by determining damage, crack or wear

Abstract

Claims40