# US 4,395,001 A · Attitude selective aircrew escape control

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- Number: US 4,395,001 A
- Document ID: US4395001A
- Status: Granted
- Kind: A
- Application number: 05/890,099
- Filed: 1978-03-27
- Granted: 1983-07-26
- Earliest claimed: 1978-03-27
- Assignees: The United States of America as represented by the Secretary of the Navy
- Inventors: W. James Stone; Vernon D. Burklund; Robert B. Dillinger; Dennis M. Sorges; David A. Reeve
- Web page: https://patentgrep.com/patent/US4395001A

## CPC

- B64D 25/10: Ejector seats
- B64D: EQUIPMENT FOR FITTING IN OR TO AIRCRAFT; FLIGHT SUITS; PARACHUTES; ARRANGEMENT OR MOUNTING OF POWER PLANTS OR PROPULSION TRANSMISSIONS IN AIRCRAFT

## Abstract

A line cutter or discharge valve responsive to aircraft attitude is posited on an aircraft ejection seat to interrupt the gas initiated sustainer rocket system. During inverted ejections, the cutter or valve will either sever or discharge pressure from a tube which leads from the firing squib to the sustainer rocket. Preventing sustainer rocket ignition enhances inverted ejection survivability by reducing crew member velocity toward the ground, thereby lengthening the time available for parachute deployment.

## Claims

### Claim 1

An improved escape system for an aircraft having a catapult-boosted ejection seat, wherein the improvement comprises:
a seat mechanism mounted in the aircraft and adapted to be ejected therefrom;
sustainer motor means associated with said seat mechanism for providing ejection movement of said seat mechanism at a predetermined time;
means for firing said sustainer motor means mounted on said seat mechanism;
a pressure hose in open communication between said means for firing said sustainer motor means and said sustainer motor means; and
interrupter means associated with said seat mechanism for selectively preventing action of said sustainer motor means, wherein said interrupter means disconnects said pressure hose from one of said means for firing said sustainer motor means and said sustainer motor means during an ejection occurring when the attitude of the aircraft exceeds predetermined limits on pitch and roll.

### Claim 2 (depends on 1)

An improved escape system for an aircraft according to claim 1 wherein said sustainer motor means comprises a rocket motor.

### Claim 3 (depends on 1)

An improved escape system for an aircraft according to claim 1 wherein said interrupter means incorporates a seat motion detector switch for detecting motion of said seat mechanism.

### Claim 4 (depends on 1)

An improved escape system for an aircraft according to claim 1 further including a logic network connected to said seat mechanism, said logic network configured to receive signals corresponding to pitch and roll of the aircraft, said logic network having an output connected to said sustainer motor means, said output being dependent upon the pitch and roll of said aircraft.

### Claim 5 (depends on 4)

An improved escape system for an aircraft according to claim 4 wherein an Arm signal appears at the output of said logic network when the nose of the aircraft is more than 75.degree. above the horizontal or when the nose of the aircraft is more than 105.degree. below the horizontal and the roll angle is any value, or the pitch angle is 0.degree. and the roll angle is greater than 90.degree. clockwise or 90.degree. counter clockwise.

### Claim 6 (depends on 4)

An improved escape system for an aircraft according to claim 4 wherein the output of said logic network is an arm signal when the nose of the aircraft is more than 75.degree. above the horizontal or more than 105.degree. below the horizontal and the roll angle is any value and there is seat motion, or when the pitch angle is any value and the roll angle is greater than 90.degree. clockwise or 90.degree. counter clockwise and there is seat motion.

### Claim 7 (depends on 4)

An improved escape system for an aircraft according to claim 4 wherein there is an output arm signal from said logic network when the nose of the aircraft is more than 75.degree. above the horizontal or more than 105.degree. below the horizontal and the roll angle is any value; or when the pitch angle is 0.degree. and the roll angle is greater than 90.degree. clockwise or 90.degree. counterclockwise; or when the nose of the aircraft is more than 75.degree. above the horizontal or more than 105.degree. below the horizontal, roll angle is any value and there is seat motion, or when the pitch angle is any value, the roll angle is greater than 90.degree. clockwise or greater than 90.degree. counterclockwise and there is seat motion.

### Claim 8 (depends on 3)

An improved escape system for an aircraft according to claim 3 further including:
a squib in electrical communication with said seat motion detector switch in said interrupt means;
a seat power source mounted on said seat mechanism;
a latching relay connected between said seat power source and said seat motion detector switch, said latching relay being energized by the output of said logic network.