Patent US4790494A successfully refreshed from Google Patents.
US4790494A
Expired / Lapsed
US
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Aircraft empennage with fixed trailing edge horizontal stabilizer
Assignee: Grumman Corp
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Filing: 1986-10-14
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Granted: 1988-12-13
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Expires: 2006-10-14
Abstract
Abstract An aircraft empennage has a vertical stabilizer, a trailing edge fixed horizontal stabilizer rigidly attached to the aircraft and a movable leading edge elevator affixed to the aircraft. The elevator is movable through a high position and a low position relative to the horizontal stabilizer, thereby providing variable camber and incidence deflection and optimizing deflections while providing adequate power for all flight conditions.
Inventors
- 👤 Jerome S. Kohn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:57
CPC Classifications
B; B64; B64C; B64C5/00; B64C5/02
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
210 words
An empennage for an aircraft having a fuselage, comprising: (a) a vertical stabilizer having an upper portion and being affixed to the fuselage of the aircraft; and (b) an aerodynamically smooth horizontal stabilizer having a length and including a fixed trailing edge portion with a forward facing edge having a length and a movable leading edge portion with an aft facing edge having a length, said length of said forward facing edge of said fixed trailing edge portion and said length of said aft facing edge of said movable leading edge portion being substantially equivalent to each other and to said length of said horizontal stabilizer, said fixed trailing edge portion being fixedly attached to said upper portion of said vertical stabilizer and said aft facing edge of said movable leading edge portion being pivotally mounted to said forward facing edge of said fixed trailing edge portion allowing said movable leading edge portion to be movable relative to said fixed trailing edge portion without forming a gap therebetween so that air flows smoothly from said movable leading edge portion to said fixed trailing edge portion with minimal boundary layer separation and turbulance so as to provide the aircraft with increased static and dynamic longitudinal stability and increased landing attitude control.
Claim 2
Dependent Claim
210 words
An empennage for an aircraft having a fuselage, comprising: (a) a vertical stabilizer having an upper portion and being affixed to the fuselage of the aircraft; and (b) an aerodynamically smooth horizontal stabilizer having a length and including a fixed trailing edge portion with a forward facing edge having a length and a movable leading edge portion with an aft facing edge having a length, said length of said forward facing edge of said fixed trailing edge portion and said length of said aft facing edge of said movable leading edge portion being substantially equivalent to each other and to said length of said horizontal stabilizer, said fixed trailing edge portion being fixedly attached to said upper portion of said vertical stabilizer and said aft facing edge of said movable leading edge portion being pivotally mounted to said forward facing edge of said fixed trailing edge portion allowing said movable leading edge portion to be movable relative to said fixed trailing edge portion without forming a gap therebetween so that air flows smoothly from said movable leading edge portion to said fixed trailing edge portion with minimal boundary layer separation and turbulance so as to provide the aircraft with increased static and dynamic longitudinal stability and increased landing attitude control.
Claim 3
Dependent Claim
21 words
An empennage as defined in claim 1; further comprising means for actuating said movable leading edge portion of said horizontal stabilizer.
Claim 4
Dependent Claim
34 words
An empennage as defined in claim 1; further comprising a tubular spar for pivotally mounting said movable leading edge portion of said horizontal stabilizer to said fixed trailing edge portion of said horizontal stabilizer.
Claim 5
Dependent Claim
202 words
An empennage for an aircraft having a fuselage, comprising: (a) a vertical stabilizer affixed to the fuselage of the aircraft; and (b) an aerodynamically smooth horizontal stabilizer having a length and including a fixed trailing edge portion with a forward facing edge having a length and a movable leading edge portion with an aft facing edge having a length, said length of said forward facing edge of said fixed trailing edge portion and said length of said aft facing edge of said movable leading edge portion being substantially equivalent to each other and to said length of said horizontal stabilizer, said fixed trailing edge portion being fixedly attached to the fuselage of the aircraft and said aft facing edge of said movable leading edge portion being pivotally mounted to said forward facing edge of said fixed trailing edge portion allowing said movable leading edge portion to be movable relative to said fixed trailing edge portion without forming a gap therebetween so that air flow smoothly from said movable leading edge portion to said fixed trailing edge portion with minimal boundary layer separation and turbulence so as to provide the aircraft with increased static and dynamic longitudinal stability and increased landing attitude control.
Claim 6
Dependent Claim
202 words
An empennage for an aircraft having a fuselage, comprising: (a) a vertical stabilizer affixed to the fuselage of the aircraft; and (b) an aerodynamically smooth horizontal stabilizer having a length and including a fixed trailing edge portion with a forward facing edge having a length and a movable leading edge portion with an aft facing edge having a length, said length of said forward facing edge of said fixed trailing edge portion and said length of said aft facing edge of said movable leading edge portion being substantially equivalent to each other and to said length of said horizontal stabilizer, said fixed trailing edge portion being fixedly attached to the fuselage of the aircraft and said aft facing edge of said movable leading edge portion being pivotally mounted to said forward facing edge of said fixed trailing edge portion allowing said movable leading edge portion to be movable relative to said fixed trailing edge portion without forming a gap therebetween so that air flow smoothly from said movable leading edge portion to said fixed trailing edge portion with minimal boundary layer separation and turbulence so as to provide the aircraft with increased static and dynamic longitudinal stability and increased landing attitude control.
Claim 7
Dependent Claim
21 words
An empennage as defined in claim 4; further comprising means for actuating said movable leading edge portion of said horizontal stabilizer.
Claim 8
Dependent Claim
34 words
An empennage as defined in claim 4; further comprising a tubular spar for pivotally mounting said movable leading edge portion of said horizontal stabilizer to said fixed trailing edge portion of said horizontal stabilizer.
Claim 9
Dependent Claim
218 words
An empennage for an aircraft having a fuselage, comprising: (a) a pair of vertical stabilizers each having an upper portion and being affixed to the fuselage of the aircraft; and (b) an aerodynamically smooth horizontal stabilizer having a length and including a fixed trailing edge portion with a forward facing edge having a length and a movable leading edge portion with an aft facing edge having a length, said length of said forward facing edge of said fixed trailing edge portion and said length of said aft facing edge of said movable leading edge portion being substantially equivalent to each other and to said length of said horizontal stabilizer, said fixed trailing edge portion being fixed attached to and spanning between said each upper portion of said pair of vertical stabilizers and said aft facing edge of said movable leading edge portion being pivotally mounted to said forward facing edge of said trailing edge portion allowing said movable leading edge portion to be movable relative to said fixed trailing edge portion without forming a gap therebetween so that air flows smoothly from said movable leading edge portion to said fixed trailing edge portion with minimal boundary layer separation and turbulance so as to provide the aircraft with increased static and dynamic longitudinal stability and increased landing attitude control.
Claim 10
Dependent Claim
218 words
An empennage for an aircraft having a fuselage, comprising: (a) a pair of vertical stabilizers each having an upper portion and being affixed to the fuselage of the aircraft; and (b) an aerodynamically smooth horizontal stabilizer having a length and including a fixed trailing edge portion with a forward facing edge having a length and a movable leading edge portion with an aft facing edge having a length, said length of said forward facing edge of said fixed trailing edge portion and said length of said aft facing edge of said movable leading edge portion being substantially equivalent to each other and to said length of said horizontal stabilizer, said fixed trailing edge portion being fixed attached to and spanning between said each upper portion of said pair of vertical stabilizers and said aft facing edge of said movable leading edge portion being pivotally mounted to said forward facing edge of said trailing edge portion allowing said movable leading edge portion to be movable relative to said fixed trailing edge portion without forming a gap therebetween so that air flows smoothly from said movable leading edge portion to said fixed trailing edge portion with minimal boundary layer separation and turbulance so as to provide the aircraft with increased static and dynamic longitudinal stability and increased landing attitude control.
Claim 11
Dependent Claim
21 words
An empennage as defined in claim 7; further comprising means for actuating said movable leading edge portion of said horizontal stabilizer.
Claim 12
Dependent Claim
34 words
An empennage as defined in claim 7; further comprising a tubular spar for pivotally mounting said movable leading edge portion of said horizontal stabilizer to said fixed trailing edge portion of said horizontal stabilizer.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-12-13 | 1992-06-13 | 1992-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-13 | 1996-06-13 | 1996-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-13 | 2000-06-13 | 2000-12-13 | $7700.00 | Window Closed / Lapsed |