US3590636A
Expired / Lapsed
US
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Method for determining aircraft lift capability using air density measurement
Assignee: Industrial Nucleonics Corp
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Filing: 1968-10-25
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Granted: 1971-07-06
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Expires: 1988-10-25
Abstract
Abstract A lift indicator for either fixed or rotary wing aircraft includes a nucleonic density gauge for deriving a density altitude indicating signal and means for deriving a temperature indicating signal. The signals are nonlinearly combined to derive the lift indication which can be correlated to the ability of a rotary wing aircraft to take off or land vertically or for a fixed wing aircraft to take off from a runway of known length. The density altitude indicating signal is combined with an indicated airspeed signal derived from a pitot tube to derive a true airspeed-indicating signal.
Inventors
- 👤 William C Eddy Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 01:53
CPC Classifications
G; G05; G05D; G05D1/00; G05D1/0055; B; B64; B64D; B64D43/00
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
55 words
A method of determining the flying capability of an aircraft comprising the steps of monitoring the ambient air density in the atmosphere surrounding the aircraft with a penetrating radiation gauge, determining from the monitored air density the lift capability of the aircraft, and comparing the determined lift capability with an indication of required aircraft lift.
Claim 2
Independent Claim
55 words
A method of determining the flying capability of an aircraft comprising the steps of monitoring the ambient air density in the atmosphere surrounding the aircraft with a penetrating radiation gauge, determining from the monitored air density the lift capability of the aircraft, and comparing the determined lift capability with an indication of required aircraft lift.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the lift capability is determined for an altitude in the immediate vicinity of the aircraft.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the lift capability is determined approximately for an altitude different from the aircraft altitude.
Claim 5
Dependent Claim
26 words
The method of claim 1 wherein the lift capability is determined approximately for an altitude on the order of 500 feet different from the aircraft altitude.
Claim 6
Dependent Claim
19 words
The method of claim 1 wherein the required aircraft lift is determined from the gross weight of the aircraft.
Claim 7
Dependent Claim
44 words
The method of claim 1 wherein the lift capability is determined for an altitude in the immediate vicinity of the aircraft, and the required aircraft lift is determined from the gross weight of the aircraft and the length of a runway available for takeoff.
Claim 8
Independent Claim
69 words
A method of determining the flying capability of a turbine powered aircraft comprising the steps of monitoring the ambient air density in the atmosphere surrounding the aircraft with a penetrating radiation gauge, monitoring the ambient temperature in the atmosphere surrounding the aircraft, determining from the monitored air density and temperature the lift capability of the aircraft, and comparing the determined lift capability with an indication of required aircraft lift.
Claim 9
Independent Claim
69 words
A method of determining the flying capability of a turbine powered aircraft comprising the steps of monitoring the ambient air density in the atmosphere surrounding the aircraft with a penetrating radiation gauge, monitoring the ambient temperature in the atmosphere surrounding the aircraft, determining from the monitored air density and temperature the lift capability of the aircraft, and comparing the determined lift capability with an indication of required aircraft lift.
Claim 10
Dependent Claim
21 words
The method of claim 7 wherein the lift capability is determined for an altitude in the immediate vicinity of the aircraft.
Claim 11
Dependent Claim
20 words
The method of claim 7 wherein the lift capability is determined approximately for an altitude different from the aircraft altitude.
Claim 12
Dependent Claim
26 words
The method of claim 7 wherein the lift capability is determined approximately for an altitude on the order of 500 feet different from the aircraft altitude.
Claim 13
Dependent Claim
19 words
The method of claim 7 wherein the required aircraft lift is determined from the gross weight of the aircraft.
Claim 14
Dependent Claim
44 words
The method of claim 7 wherein the lift capability is determined for an altitude in the immediate vicinity of the aircraft, and the required aircraft lift is determined from the gross weight of the aircraft and the length of a runway available for takeoff.
Claim 15
Independent Claim
71 words
A system for determining a parameter related to the lift capability of an aircraft comprising penetrating radiation gauge means adapted to be secured to an aircraft fuselage for deriving a first signal indicative of ambient air density in the atmosphere where the aircraft is located, and means responsive to said signal for deriving an output commensurate with a nonlInear function of said first signal to indicate the actual aircraft lift capability.
Claim 16
Independent Claim
71 words
A system for determining a parameter related to the lift capability of an aircraft comprising penetrating radiation gauge means adapted to be secured to an aircraft fuselage for deriving a first signal indicative of ambient air density in the atmosphere where the aircraft is located, and means responsive to said signal for deriving an output commensurate with a nonlInear function of said first signal to indicate the actual aircraft lift capability.
Claim 17
Dependent Claim
36 words
The system of claim 13 wherein said signal responsive means includes means for deriving the nonlinear function to indicate the weight which the aircraft can lift at an altitude in the immediate vicinity of the aircraft.
Claim 18
Dependent Claim
34 words
The system of claim 13 wherein said signal responsive means includes means for deriving the nonlinear function to indicate density altitude of the atmosphere at an altitude in the immediate vicinity of the aircraft.
Claim 19
Dependent Claim
33 words
The system of claim 13 wherein said signal responsive means includes means for deriving the nonlinear function to indicate approximate density altitude of the atmosphere at an altitude different from the aircraft altitude.
Claim 20
Dependent Claim
39 words
The system of claim 13 wherein said signal responsive means includes means for deriving the nonlinear function to indicate approximate density altitude of the atmosphere at an altitude on the order of 500 feet different from the aircraft altitude.
Claim 21
Dependent Claim
34 words
The system of claim 13 wherein said signal responsive means includes means for deriving the nonlinear function to indicate the weight which the aircraft can lift at an altitude different from the aircraft altitude.
Claim 22
Dependent Claim
40 words
The system of claim 13 wherein said signal responsive means includes means for deriving the nonlinear function to indicate the weight which the aircraft can lift at an altitude on the order of 500 feet different from the aircraft altitude.
Claim 23
Dependent Claim
56 words
The system of claim 13 wherein said signal means includes a nonlinear function generator for deriving a signal indicative of density altitude in response to an input from an operator''s station, and means responsive to the density altitude and air density indicating signal for comparing the density altitude indicating signal with the air density indicating signal.
Claim 24
Dependent Claim
40 words
The system of claim 13 wherein said signal responsive means includes means for deriving a signal indicative of required aircraft lift, and means responsive to said lift indicating signals for comparing the required lift signal with the actual lift capability.
Claim 25
Dependent Claim
59 words
The system of claim 13 wherein said signal responsive means includes means for deriving a signal indicative of required aircraft lift, and means responsive to said lift indicating signals for selectively indicating when: (a) the required lift exceeds the actual lift; (b) the actual and required lift are approximately equal; and (c) the actual lift exceeds the required lift.
Claim 26
Dependent Claim
56 words
The system of claim 22 wherein said indicating means includes fail-safe means for enabling only the (a) indication to be derived if the (a) indication is derived simultaneously with either the (b) or (c) indication and for enabling only the (b) indication to be derived if the (b) indication is derived simultaneously with the (c) indication.
Claim 27
Dependent Claim
39 words
The system of claim 13 wherein said signal responsive means includes means for deriving a signal indicative of aircraft gross weight, and means responsive to the lift indicating and gross weight indicating signals for indicating the aircraft flight ability.
Claim 28
Dependent Claim
59 words
The system of claim 13 wherein said signal responsive means includes means for deriving a signal indicative of required aircraft lift, said required lift signal deriving means including means for combining signals indicative of aircraft gross weight and runway length, and means responsive to said lift indicating signals for comparing the required lift signal with the actual lift capability.
Claim 29
Independent Claim
84 words
A system for determining a parameter related to the lift capability of a turbine powered aircraft comprising penetrating radiation gauge means adapted to be secured to an aircraft fuselage for deriving a first signal indicative of ambient air density in the atmosphere where the aircraft is located, means for deriving a second signal indicative of ambient air temperature at the turbine intake, and means responsive to said first and second signals for deriving a nonlinear output function indicatiVe of the actual aircraft lift capability.
Claim 30
Independent Claim
84 words
A system for determining a parameter related to the lift capability of a turbine powered aircraft comprising penetrating radiation gauge means adapted to be secured to an aircraft fuselage for deriving a first signal indicative of ambient air density in the atmosphere where the aircraft is located, means for deriving a second signal indicative of ambient air temperature at the turbine intake, and means responsive to said first and second signals for deriving a nonlinear output function indicatiVe of the actual aircraft lift capability.
Claim 31
Dependent Claim
36 words
The system of claim 26 wherein said signal responsive means includes means for deriving the nonlinear function to indicate the weight which the aircraft can lift at an altitude in the immediate vicinity of the aircraft.
Claim 32
Dependent Claim
34 words
The system of claim 26 wherein said signal responsive means includes means for deriving a nonlinear function to indicate density altitude of the atmosphere at an altitude in the immediate vicinity of the aircraft.
Claim 33
Dependent Claim
33 words
The system of claim 26 wherein said signal responsive means includes means for deriving a nonlinear function to indicate approximate density altitude of the atmosphere at an altitude different from the aircraft altitude.
Claim 34
Dependent Claim
39 words
The system of claim 26 wherein said signal responsive means includes means for deriving a nonlinear function to indicate approximate density altitude of the atmosphere at an altitude on the order of 500 feet different from the aircraft altitude.
Claim 35
Dependent Claim
34 words
The system of claim 26 wherein said signal responsive means includes means for deriving the nonlinear function to indicate the weight which the aircraft can lift at an altitude different from the aircraft altitude.
Claim 36
Dependent Claim
40 words
The system of claim 26 wherein said signal responsive means includes means for deriving the nonlinear function to indicate the weight which the aircraft can lift at an altitude on the order of 500 feet different from the aircraft altitude.
Claim 37
Dependent Claim
40 words
The system of claim 26 wherein said signal responsive means includes means for deriving a signal indicative of required aircraft lift, and means responsive to said lift indicating signals for comparing the required lift signal with the actual lift capability.
Claim 38
Dependent Claim
59 words
The system of claim 26 wherein said signal responsive means includes means for deriving a signal indicative of required aircraft lift, and means responsive to said lift indicating signals for selectively indicating when: (a) the required lift exceeds the actual lift; (b) the actual and required lift are approximately equal; and (c) the actual lift exceeds the required lift.
Claim 39
Dependent Claim
39 words
The system of claim 26 wherein said signal responsive means includes means for deriving a signal indicative of aircraft gross weight, and means responsive to the lift indicating and gross weight indicating signals for indicating the aircraft flight ability.
Claim 40
Dependent Claim
59 words
The system of claim 39 wherein said signal responsive means includes means for deriving a signal indicative of required aircraft lift, said required lift signal deriving means including means for combining signals indicative of aircraft gross weight and runway length, and means responsive to said lift indicating signals for comparing the required lift signal with the actual lift capability.
Claim 41
Dependent Claim
23 words
The system of claim 26 wherein said nonlinear function deriving means includes means for combining the first and second signals in opposite senses.
Claim 42
Dependent Claim
55 words
The system of claim 26 wherein said nonlinear function deriving means includes means for combining the first and second signals in accordance with: a0+a1 Rho -a2T+a3 Rho 2+a4T2+a5 Rho T, where: a0-a5 are constants; T the value of temperature indicated by the second signal; and Rho the value of density indicated by the first signal.
Claim 43
Independent Claim
79 words
A system for determining a parameter related to the lift capability of a turbine-powered aircraft comprising penetrating radiation gauge means adapted to be secured to an aircraft fuselage for deriving a first signal indicative of ambient air density in the atmosphere where the aircraft is located, means for deriving a second signal indicative of ambient air temperature, and means responsive to said first and second signals for deriving a nonlinear output function indicative of the actual aircraft lift capability.
Claim 44
Independent Claim
79 words
A system for determining a parameter related to the lift capability of a turbine-powered aircraft comprising penetrating radiation gauge means adapted to be secured to an aircraft fuselage for deriving a first signal indicative of ambient air density in the atmosphere where the aircraft is located, means for deriving a second signal indicative of ambient air temperature, and means responsive to said first and second signals for deriving a nonlinear output function indicative of the actual aircraft lift capability.
References Cited (Backward Citations)
US3102199A
Cited
US3196271A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-05 | 1975-01-04 | 1975-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-05 | 1979-01-04 | 1979-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-05 | 1983-01-04 | 1983-07-06 | $7700.00 | Window Closed / Lapsed |