US3982399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel degassing method
Assignee: Northrop Grumman Systems Corp
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Filing: 1974-09-25
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Granted: 1976-09-28
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Expires: 1994-09-25
Abstract
Abstract The method of purging entrained air or vapor from fuel stored in two or more tanks in an aircraft, and more particularly in multi-engine aircraft during crossfeed fuel delivery when the aircraft is climbing to altitude, which method consists of reversing the fuel booster pump, or pumps, in the temporarily unused tank, or tanks, while all fuel is withdrawn from one tank to supply the engines, whereby the fuel agitation produced by the reversed pump or pumps effectively frees the entrained air or vapor from the fuel to escape to atmosphere through the fuel tank vent system.
Inventors
- 👤 Earl T. Rookey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:35
CPC Classifications
B; B64; B64D; B64D37/00; B64D37/32; Y; Y10; Y10T; Y10T137/00; Y10T137/4673; Y10T137/8593; Y10T137/85978; Y10T137/86131; Y10T137/86163
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
108 words
A method of operating a fuel system in an aircraft equipped with two or more fuel tanks, each tank having a reversible fuel booster pump submerged therein and connected to an engine fuel supply line, said tanks being vented to atmosphere, and means to selectively reverse the rotation of said fuel booster pumps, said method comprising reversing the rotation of the fuel booster pump in the unused fuel tanks when all engine fuel is being supplied from one tank only, whereby the reversed fuel booster pump agitates the fuel in said unused tanks to release entrained air and vapor from said fuel to escape from said tank vents.
Claim 2
Independent Claim
108 words
A method of operating a fuel system in an aircraft equipped with two or more fuel tanks, each tank having a reversible fuel booster pump submerged therein and connected to an engine fuel supply line, said tanks being vented to atmosphere, and means to selectively reverse the rotation of said fuel booster pumps, said method comprising reversing the rotation of the fuel booster pump in the unused fuel tanks when all engine fuel is being supplied from one tank only, whereby the reversed fuel booster pump agitates the fuel in said unused tanks to release entrained air and vapor from said fuel to escape from said tank vents.
Claim 3
Independent Claim
238 words
A method of operating a fuel system in a multi-engine aircraft in which, under normal flight operation thereof, a right hand engine is supplied with fuel by a right hand fuel supply system, and a left hand engine is supplied with fuel by a left hand fuel supply system, each of said engine fuel supply systems including at least one fuel storage tank provided with a reversible fuel booster pump submerged therewithin, fuel supply lines connecting said pumps with said engines, vent means for each tank, a crossfeed fuel supply line interconnecting said right and left hand engine fuel supply lines downstream of said pumps and upstream of said engines, a pilot operated crossfeed control valve connected in said crossfeed fuel supply line between said right and left hand engine fuel supply lines, and means to selectively reverse the rotation of either of said fuel booster pumps in said right and left hand fuel tanks, said method during crossfeed fuel delivery wherein both engines are supplied with fuel pumped from one tank only, comprising reversing the rotation of the fuel booster pump in the unused tank to agitate the fuel therein and thereby expel entrained air or vapor therefrom and out said vent means whereby relatively air-free fuel is supplied from said unused tank upon termination of crossfeed fuel delivery and resumption of normal fuel delivery to both engines from respective right and left hand fuel supply systems.
Claim 4
Independent Claim
238 words
A method of operating a fuel system in a multi-engine aircraft in which, under normal flight operation thereof, a right hand engine is supplied with fuel by a right hand fuel supply system, and a left hand engine is supplied with fuel by a left hand fuel supply system, each of said engine fuel supply systems including at least one fuel storage tank provided with a reversible fuel booster pump submerged therewithin, fuel supply lines connecting said pumps with said engines, vent means for each tank, a crossfeed fuel supply line interconnecting said right and left hand engine fuel supply lines downstream of said pumps and upstream of said engines, a pilot operated crossfeed control valve connected in said crossfeed fuel supply line between said right and left hand engine fuel supply lines, and means to selectively reverse the rotation of either of said fuel booster pumps in said right and left hand fuel tanks, said method during crossfeed fuel delivery wherein both engines are supplied with fuel pumped from one tank only, comprising reversing the rotation of the fuel booster pump in the unused tank to agitate the fuel therein and thereby expel entrained air or vapor therefrom and out said vent means whereby relatively air-free fuel is supplied from said unused tank upon termination of crossfeed fuel delivery and resumption of normal fuel delivery to both engines from respective right and left hand fuel supply systems.
Claim 5
Dependent Claim
22 words
The method according to claim 1 wherein said means for reversing rotation of said fuel booster pump is a pilot operated switch.
Claim 6
Dependent Claim
27 words
The method according to claim 2 wherein said means for reversing rotation of said fuel booster pump is automatically initiated upon opening said crossfeed fuel supply valve.
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) | 1979-09-28 | 1980-03-29 | 1980-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-09-28 | 1984-03-29 | 1984-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-09-28 | 1988-03-29 | 1988-09-28 | $7700.00 | Window Closed / Lapsed |