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US3839699A
Expired / Lapsed
US
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Aircraft stall warning indicator system based on rate of change of angle of attack
Assignee: MONITAIR CORP
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Filing: 1971-09-01
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Granted: 1974-10-01
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Expires: 1991-09-01
Abstract
Abstract A signal corresponding to the rate of change of the angle of attack of an aircraft is derived and is operatively summed with a signal corresponding to the actual angle of attack. The resulting signal is compared to a reference level and a stall warning signal, indicating a predetermined time remaining until stall is produced when the former signal bears a predetermined relation to the latter.
Inventors
- 👤 A Heinsohn
- 👤 D Neary
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:34
CPC Classifications
G; G08; G08G; G08G5/00; G08G5/50; G08G5/53; G08G5/55
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
183 words
A stall warning system for use on an aircraft comprising angle of attack sensing means effective to produce a first signal corresponding in magnitude to the angle of attack of the aircraft, means to produce a second signal corresponding in magnitude to the existing rate of change of the angle of attack of the aircraft, and means to combine said first and second signals to provide a signal whose magnitude varies as a function of both angle of attack and rate of change of angle of attack in a direct relationship, said combined signal thereby inversely indicating the time remaining until the angle of attack reaches stall at the existing rate of change of angle of attack, means to provide a reference signal which can be correlated to said combined signal, and means to produce a warning signal when said combined signals bear a predetermined relation to said reference signal, said warning signal thereby indicating the time left until stall occurs at the existing rate of change of angle of attack when the combined signal bears said predetermined relationship to the reference signal.
Claim 2
Dependent Claim
183 words
A stall warning system for use on an aircraft comprising angle of attack sensing means effective to produce a first signal corresponding in magnitude to the angle of attack of the aircraft, means to produce a second signal corresponding in magnitude to the existing rate of change of the angle of attack of the aircraft, and means to combine said first and second signals to provide a signal whose magnitude varies as a function of both angle of attack and rate of change of angle of attack in a direct relationship, said combined signal thereby inversely indicating the time remaining until the angle of attack reaches stall at the existing rate of change of angle of attack, means to provide a reference signal which can be correlated to said combined signal, and means to produce a warning signal when said combined signals bear a predetermined relation to said reference signal, said warning signal thereby indicating the time left until stall occurs at the existing rate of change of angle of attack when the combined signal bears said predetermined relationship to the reference signal.
Claim 3
Dependent Claim
33 words
The system of claim 1, in which said signal combining means comprises means effective to operatively sum said first and second signals and to produce said combined signal corresponding to said operative sum.
Claim 4
Dependent Claim
34 words
The system of claim 2, comprising variable means operatively interposed between said second signal producing means and said summing means and effective to adjust the level of said second signal by a predetermined factor.
Claim 5
Dependent Claim
17 words
The system of claim 3, further comprising means effective to adjust the level of said reference signal.
Claim 6
Dependent Claim
40 words
The system of claim 1, comprising variable means operatively interposed between said second signal producing means and said means to combine said first and second signals and effective to adjust the level of said second signal by a predetermined factor.
Claim 7
Dependent Claim
17 words
The system of claim 5, further comprising means effective to adjusT the level of said reference signal.
Claim 8
Dependent Claim
17 words
The system of claim 1, further comprising means effective to adjust the level of said reference signal.
Claim 9
Dependent Claim
162 words
A stall warning system for use on an aircraft comprising means effective to produce a variable signal corresponding in magnitude to the existing rate of change of the angle of attack of said aircraft, means to produce a separate signal which is proportional to the angle of attack of said aircraft, means to combine said variable signal with said separate signal to produce a combined signal, said combined signal varying as a function of the magnitude of the separate signal and the rate of change of angle of attack in a direct relationship, means to produce a reference signal which may be correlated to the combined signal, and means effective to produce a stall warning signal when the magnitude of said combined signal bears a predetermined relation to said reference signal to thereby give a stall warning signal a preselected time before stall conditions occur at the sensed rate of change of angle of attack when the stall warning signal is produced.
Claim 10
Dependent Claim
162 words
A stall warning system for use on an aircraft comprising means effective to produce a variable signal corresponding in magnitude to the existing rate of change of the angle of attack of said aircraft, means to produce a separate signal which is proportional to the angle of attack of said aircraft, means to combine said variable signal with said separate signal to produce a combined signal, said combined signal varying as a function of the magnitude of the separate signal and the rate of change of angle of attack in a direct relationship, means to produce a reference signal which may be correlated to the combined signal, and means effective to produce a stall warning signal when the magnitude of said combined signal bears a predetermined relation to said reference signal to thereby give a stall warning signal a preselected time before stall conditions occur at the sensed rate of change of angle of attack when the stall warning signal is produced.
Claim 11
Independent Claim
139 words
A method of delivering a stall warning for an aircraft a preselected time prior to stall under differing aircraft operation parameters comprising the steps of providing a first signal corresponding to the angle of attack of the aircraft, providing a second signal corresponding to the existing rate of change of the angle of attack of the aircraft, combining said first and second signals to produce a combined signal indicative of the sum of values of said first and second signals, comparing said combined signal with a reference signal and providing a warning signal when said combined signal bears a predetermned relationship to said reference signal to indicate the time remaining until stall of the aircraft occurs at the existing rate of change of angle of attack when said combined signal is at said predetermined relationship to said reference signal.
Claim 12
Independent Claim
139 words
A method of delivering a stall warning for an aircraft a preselected time prior to stall under differing aircraft operation parameters comprising the steps of providing a first signal corresponding to the angle of attack of the aircraft, providing a second signal corresponding to the existing rate of change of the angle of attack of the aircraft, combining said first and second signals to produce a combined signal indicative of the sum of values of said first and second signals, comparing said combined signal with a reference signal and providing a warning signal when said combined signal bears a predetermned relationship to said reference signal to indicate the time remaining until stall of the aircraft occurs at the existing rate of change of angle of attack when said combined signal is at said predetermined relationship to said reference signal.
Claim 13
Dependent Claim
19 words
The method of claim 9 including the step of combining said first and second signals by summing the signals.
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) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |