US3604908A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Landing control system for aircraft
Assignee: Honeywell Inc
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Filing: 1969-05-19
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Granted: 1971-09-14
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Expires: 1989-05-19
Abstract
Abstract An improved automatic landing control system for aircraft in which the automatic control system flarepath control law parameters includes a normally fixed bias term for establishing a nominal descent rate of the aircraft at touchdown, as well as a term which determines the shape or curvature of the flarepath. Accurate and automatic control of craft airspeed in accordance with a reference airspeed is provided. The dispersion of the touchdown point along the runway caused by uncontrollable variable errors (such as errors in measuring absolute altitude, errors resulting from aircraft displacement from the glide slope beam at flare initiation, headwinds or tailwinds, and windshear) is greatly reduced by varying, during the glide slope controlled approach and prior to flare initiation, the nominal touchdown bias term as a function of the reference airspeed of the aircraft, or alternatively, to vary the flare time constant or path curvature term as a function of airmass flightpath angle and the touchdown bias term as a function of both flightpath angle and reference airspeed.
Inventors
- 👤 Raymond G Loome
- 👤 Harry Miller
- 👤 Robert H Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:25
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/04; G05D1/06; G05D1/0607; G05D1/0653; G05D1/0676
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
185 words
A landing control system for an aircraft having pitch control means for controlling the flightpath of the aircraft including a flare computer for supplying a solution of a predetermined flare control law including terms dependent upon the vertical position and movement of the craft relative to the ground and including at least one term defining a predetermined touchdown rate of descent and means for supplying a pitch command signal in accordance with an error in the solution of said flare control law, said system further including a flare point detector means responsive to a predetermined altitude above the runway for coupling said pitch command signal to said pitch control means whereby to cause the craft to follow said flarepath, wherein the improvement comprises: a. means responsive to predetermined conditions determinable at said aircraft and operable prior to said flare initiation point for varying said one control law term in accordance with at least one of said conditions whereby to vary said flarepath; b. and means responsive to said flare point detector means for maintaining the value of said one term at the value then obtaining.
Claim 2
Dependent Claim
185 words
A landing control system for an aircraft having pitch control means for controlling the flightpath of the aircraft including a flare computer for supplying a solution of a predetermined flare control law including terms dependent upon the vertical position and movement of the craft relative to the ground and including at least one term defining a predetermined touchdown rate of descent and means for supplying a pitch command signal in accordance with an error in the solution of said flare control law, said system further including a flare point detector means responsive to a predetermined altitude above the runway for coupling said pitch command signal to said pitch control means whereby to cause the craft to follow said flarepath, wherein the improvement comprises: a. means responsive to predetermined conditions determinable at said aircraft and operable prior to said flare initiation point for varying said one control law term in accordance with at least one of said conditions whereby to vary said flarepath; b. and means responsive to said flare point detector means for maintaining the value of said one term at the value then obtaining.
Claim 3
Dependent Claim
195 words
A landing control system for an aircraft having pitch control means for controlling the flightpath of the aircraft and automatic throttle control means for controlling aircraft speed said system including a flare computer responsive to the vertical position and movement of the craft relative to the ground for defining a predetermined nominal flarepath and including at least one adjustable parameter for varying said flarepath from the nominal path and for supplying a pitch command signal adapted to cause the craft to follow said flarepath, and further including an airspeed computer including means for providing a throttle control command signal proportional to the differences between a measure of the actual approach airspeed of the craft and a measure of a reference speed and for supplying said throttle control signal to said throttle control means whereby to maintain craft airspeed at said reference airspeed wherein the improvement comprises: a. means operable prior to flare initiation for adjusting said one parameter in accordance with said reference airspeed measure whereby to vary said nominal flarepath in accordance with said reference airspeed, and b. means operable at flare initiation for supplying said pitch command signal to said pitch control means.
Claim 4
Dependent Claim
195 words
A landing control system for an aircraft having pitch control means for controlling the flightpath of the aircraft and automatic throttle control means for controlling aircraft speed said system including a flare computer responsive to the vertical position and movement of the craft relative to the ground for defining a predetermined nominal flarepath and including at least one adjustable parameter for varying said flarepath from the nominal path and for supplying a pitch command signal adapted to cause the craft to follow said flarepath, and further including an airspeed computer including means for providing a throttle control command signal proportional to the differences between a measure of the actual approach airspeed of the craft and a measure of a reference speed and for supplying said throttle control signal to said throttle control means whereby to maintain craft airspeed at said reference airspeed wherein the improvement comprises: a. means operable prior to flare initiation for adjusting said one parameter in accordance with said reference airspeed measure whereby to vary said nominal flarepath in accordance with said reference airspeed, and b. means operable at flare initiation for supplying said pitch command signal to said pitch control means.
Claim 5
Dependent Claim
22 words
The apparatus as set forth in claim 2 wherein said one adjustable parameter determines a nominal finite rate of descent at touchdown.
Claim 6
Dependent Claim
53 words
The apparatus as set forth in claim 2 wherein said flarepath is an exponential path defined by the relation J h +h +L 0 where h is the absoLute altitude of the craft, h is the altitude rate and L determines the finite touchdown rate and wherein said one adjustable parameter is L.
Claim 7
Dependent Claim
58 words
The apparatus as set forth in claim 4 wherein J determines the flare time constant and further including means for providing a measure of the flightpath angle of the aircraft and means responsive thereto for adjusting the valve of J and means responsive to said flightpath angle measure and said reference airspeed for adjusting the value of L.
Claim 8
Dependent Claim
30 words
The apparatus as set forth in claim 5 wherein the means for providing said flightpath angle measure comprises means for computing said flight path angle relative to the sustaining airmass.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |