Simplified self-powered attitude survival indicator

[0001] 1. Field of the Invention

[0002] This invention relates to self-powered gyroscopic and non-gyroscopic attitude indicators for use in personal or general aircraft, as well as Ultra-Light aircraft.

[0003] 2. Discussion of the Related Art

[0004] Many devices have been developed to alert the pilot of an aircraft of changes in the attitude of the aircraft. These devices depend upon a gyroscopic device and resultant mechanical display of the horizon or attitude.

[0005] Gyroscopic devices are usually powered by air flow, vacuum, or electric motors. Failure of any of these power sources can render a gyroscopic attitude indicator inoperative. The gyroscopic attitude indicators presently used in most aircraft are generally very accurate, and although they have been simplified over the passing years, it takes practice to understand the gyroscopic indicator and interpret the significance of the display. What is needed is a simple indicator which gives a visual indication of aircraft attitude and provides suitable alarms when needed.

[0006] The present invention provides a simple indicator of aircraft attitude with a visual indication display that is easy to interpret. The indicator device is portable, self-powered and self contained. The attitude indicator device can be transferred between different aircrafts, without complicated electrical or mechanical attachments to the engines or the aircrafts.

[0007] The primary object of this invention is to provide a self-powered, portable and relatively inexpensive device that is adapted to provide an easy to interpret indication of the aircraft attitude simply by means of reliable LED or aircraft incandescent indicators.

[0008] The invention, directed to a simplified self-powered attitude survival indicator, consists of an enclosure which may be manufactured of plastic or metal, an internal or external power source, a plurality of internal attitude sensors, a plurality of piezoelectric alarms, a plurality of small aircraft bulbs or LED (Light Emitting Diodes) indicators, a power switch, and a variety of hook and loop fastening devices for easy attachment and removal of the attitude indicator from the aircraft. The aircraft attitude indicator device is usually placed in the field of view of the pilot. The internal attitude sensors may be switches, LVDT's potentiometers, accelerometers, mercury switches, or a combination of these elements, working together by means of electronic logic. Since there are no active oscillators, the aircraft attitude indicator does not produce electro-magnetic interference.

[0022] Like reference numerals refer to like parts throughout the several views of the drawings.

[0023] Referring to FIG. 1, there is illustrated the front panel display of the aircraft attitude indicator device of the present invention identifying the location of the different indicators, which are not numbered sequentially. When power is applied by the operation of SWI, the GREEN indicators (i14, i23, i1, i2, and i7) are illuminated. i2 and i7 represent a display of the reference attitude and i22 shows that the power is applied, but is of low voltage. This indicates that it is time to replace the internal batteries, or apply external power through J1, J2, and/or J3. Indicators i1, i23, and i14 represent the normal position of the rudder. The display of these indicators (i1, i23, and i14) is static when the aircraft changes attitude. Indicators i2 and 17 are fixed horizontal references. When the aircraft is flying straight and level, a plurality of GREEN indicators (i3, i4, i1, i5, i6 and i7), illustrated in FIG. 1, are presented as a full horizontal line. As the aircraft banks to the right, RED indicators (i8, i9, i10, i11, i12, and i13) are illuminated, as illustrated in FIG. 4. As the aircraft makes a left bank, the previous indicators shut down and RED indicators (i15, i16, i17, i18, i19 and i20) are illuminated. This is illustrated in FIG. 5. As the aircraft climbs, the BLUE indicators (i24 and i26) are illuminated. When descending, YELLOW indicators (i25 and i27) are illuminated. In addition, all indicators are mounted within an individual display tube (18) which may be plastic, or metal, and in which the interior surface is painted flat black, chrome, or left as natural aluminum. This tubular member is used to enhance contrast and visibility of the LED or low voltage, low current (grain or wheat) incandescent lamps, hereafter simply called “incandescent lamps” (22) in high ambient light conditions. The tube assembly is shown in FIGS. 8 and 9. The tubular member is pressed fit into a bore in the invention housing. A large amber flasher (i21) indicator and audible alarm, reveals when the aircraft is inverted, upside-down, or in a stall condition. Blue indicators (i24 and i26) indicate when the aircraft is in a climbing attitude (nose up greater than 10 degrees). RED flashing or YELLOW indicators (i25 and i27), illustrated in FIG. 3, are used to indicate a nose down greater than 10 degrees. These indicators can be used as an assist in landing the aircraft. An upside down condition often cannot be discerned by the pilot, especially when he is flying in a thick fog or in the dark of night. The indicator may save the pilot's life.

[0024] When the aircraft executes a LEFT BANK, and exceeds 30 degrees, a bank of RED indicators on the front panel (indicators i20, i19, i18, i17, i16, and i15) illuminate, generating a line of indicators which present a straight line at about 45 degrees, slanted to illustrate a left bank condition. This condition is shown in FIG. 5.

[0025] When the aircraft executes a RIGHT BANK, and exceeds 30 degrees, a bank of RED indicators on the front panel illuminate, generating a line of indicators (Indicators i13, i12, i11, i10, i9 and i8) which present a straight line at about 45 degrees, slanted to illustrate a right bank condition. This condition is illustrated in FIG. 6.

[0026] For either a right or left bank, when the bank reaches or exceeds 10 degrees, and is less than 30 degrees, the bank indicators may change color or flash, alerting the pilot that he is executing a bank. At 30 degrees, the flashing or color will revert to steady RED.

[0027] For either a left bank, or a right bank, when the bank reaches approximately 40 degrees a warbling or pulsating audible alarm sounds, telling the pilot that his bank is becoming excessive and this is a dangerous condition. One limitation of this device is that the bank indicators can be confusing. Since the indicator lights are physically fixed at 45 degrees on the front panel, these indicators do not display the actual bank. That is solved by illuminating these lights at 30 degrees. However, it is important for the pilot to know when he is entering a banked condition. The sensor is equipped to provide an output when either the right or left bank is 10 degrees. This output can initiate flashing of either the right or left bank indicators.

[0028] Alternatively an LED with a dual color output can be employed. For example, the 45 degree line of indicators can be YELLOW/GREEN at 10 degrees, and convert to RED when the left or right bank is 30 degrees or more.

[0029] When the aircraft is flying level, the green reference indicators (i2, i7, i23, and i14) mentioned above, remain illuminated, but when the nose is pitched up by approximately 30 degrees, the blue indicators i26, and i24 flash and a warbling alarm sounds to indicate the possibility of a stall condition. FIG. 6 illustrates the BLUE indicators.

[0030] If the nose is pointing down by more than 20 degrees, YELLOW indicators (i25 and i27) illuminate to reveal a nose-down condition. If the nose-down condition exceeds 30 degrees, there is a warbling alarm sound and amber indicator (i21) flashes.

[0031] Other indicators include an amber or yellow indicator which tells the pilot that the internal batteries are low. For example, “LOW BATT” (i22), seen in FIG. 7. This indicator may flash to get the pilot's attention. If the 6 volt power buss falls below 5 volts, the low battery indicator i22 is illuminated. The system is fully functional as low as 4.2 volts, allowing sufficient operating time to replace the batteries.

[0032] Power is supplied by four AA carbon-zinc batteries, or four AA alkaline rechargeable batteries. Batteries may be “AA”, “A”, “C”, OR “D”. Provision is also made to accommodate four Nickle Cadmium batteries if desired. In this case, the device shall include a small constant current charger, deriving power from the aircraft power supply (usually 14 or 28 volts). The instant invention may be modified for 48 volt external operation by removing an internal jumper, or directly by applying an external 12, 24, or 6 volts power supply through jacks provided for this purpose.

[0033] FIG. 9 illustrates the detail of the tubes designed to eliminate the effect of high ambient light on the Simplified Self Powered Survival Attitude Indicator of the present invention. A plastic or metal tube assembly or shield (18) is machined to contain a mounting shoulder (19) which is sized to provide an interfering ring that is press fitted into a panel bore (20) in the housing of the present invention. An incandescent bulb or LED (22) is mounted within the housing. Electrical connections to the illuminating device (22) are shown as item (23). It is understood that where an LED is described, the indicator may also be an incandescent “grain of wheat” aircraft bulb. LED's are mentioned for clarity or brevity. When an incandescent lamp is used, the current limiting resistors (470 Ohms) are not required.

[0034] Instead of the individual light-blocking tubes, the front panel may be made of a heavy aluminum or plastic blank. Typically, this blank may be 0.25 or 0.375 inches thick.

[0035] The present invention can be mounted on a section of panel. A hook and loop pad provides attachment and some vibration protection.

[0036] Identification of the indicators is as follows: These may be incandescent or LED's

[0037]

	SYMBOL	COLOR	INDICATES
	i1	GREEN	Power ON
	i2 and i7	GREEN	Horizontal Reference
			Indicators
	i8-i13	RED	Right Bank, green or
			flashing if 10 degrees
	i14-i23	GREEN	Rudder
	i15-i20	RED	Left Bank, green or
			flashing if 10 degrees
	i21	LARGE AMBER	Alarm Limit
			A) Stall with sound,
			flashing
			B) Excessive bank, Right
			bank or Left bank
	i22	RED or AMBER	Low Battery-flashing, and
			audio alarm
	i24	BLUE	Right Climbing Indicator
	i25	AMBER	Right Descending indicator
	i26	BLUE	Left Climbing indicator
	i27	AMBER	Left Descending indicator

[0038] Note that although LED's are preferred because of their low operating voltages, low current requirements, high shock and vibration tolerance, and color, there are certain types of incandescent “grain of wheat” lamps that are of low power requirements, and capable of high shock and vibration. These lamps may be used, but the 470 ohm series current limiting resistors may be changed accordingly.

[0039] FIG. 10 is the functional schematic of the simplified self powered attitude survival indicator. FIG. 11 is the schematic of the pulse generator for operating the indicators between 10 and 30 degrees. If the 555 chip is used, then two separate identical circuits are used. A 556 chip may be used for both circuits. FIG. 12 is a functional schematic of another embodiment of the Simplified Self-Powered Attitude Survival Indicator.

[0040] Although this invention has been shown and described with respect to detailed embodiments thereof, it will be appreciated and understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.