Warning device on an aircraft

• US 4,870,412 A
• Filed: 08/18/1987
• Issued: 09/26/1989
• Est. Priority Date: 09/10/1986
• Status: Expired due to Fees

• Current Assignee: Air-Zermatt AG
• Original Assignee: Air-Zermatt AG
• Inventors: Vuichard, Claude
• Primary Examiner(s): Orsino, Joseph A.
• Assistant Examiner(s): Swarthout, Brent A.
• Application Number:
  US07/086,639
• Time in Patent Office: 770 Days
• Field of Search: 340/945, 340/946, 340/963, 340/967, 73/178 H, 73/178 T, 364/434, 364/435, 364/424, 244/17.13, 416/31, 416/42, 416/61
• US Class Current: 340/946
• CPC Class Codes: G05D 1/0066 for limitation of acceleration or stress

Abstract

A measuring device (1, 12, 13, 14) is equipped with a blade angle indicator (1) indicating the blade angle adjustment of the rotor blades of a helicopter, a pressure altimeter (13) and an outside temperature probe (14). The measuring device (1, 12, 13, 14) is linked to a control device (4-6) which has a central processing unit (4) and a program memory (5). The memory (5) stores data processing instructions for determining density height from pressure height and outside temperature as well as data processing instructions corresponding to the helicopter operating instructions for determining the permissible maximum value of the blade angle from the density height. The control device (4-6) periodically determines the density height on the basis of the prevailing pressure height and outside temperature and the corresponding permissible maximum value of the blade angle. It compares the blade angle value of the blade angle indicator (1) with the maximum value and when the value exceeds the maximum value controls an audible signal generator (21) linked to the transceiver (20) of the helicopter which emits an audible signal to the headphones (23) of the transceiver for as long as the value is exceeded.

Claims

1. A warning device in a rotary wing aircraft provided with a blade angle adjusting device for adjusting the blade angle of the rotor blades and a transceiver (20) with headphones (23), comprising an audible signal generator (21) connected to the transceiver (20), a measuring device (1, 13, 14) having a blade angle indicator (1) disposed on the blade angle adjusting device, a pressure altimeter (13) and an outside temperature probe (14), a control device (4-6) having a central processing unit (4) and a program memory (5) linked to the measuring device (1, 13, 14) containing a program memory (5) in which are stored data processing instructions for determining density height from pressure height and outside temperature, and data processing instructions corresponding to the predetermined operating thresholds of the aircraft to prevent overload, for determining the permissible maximum value of the blade angle from the determined density height, wherein said control device (4-6) determines the maximum permissible value of the blade angle for the density height determined according to the relevant pressure height and outside temperature, periodically calculates the quotient from the blade angle value and the maximum value, and in the case of the quotient exceeding the value 1, controls said audible signal generator (21) depending on the quotient in such a way that an audible impulse sequence is generated and emitted to the headphones (23), the pulse repetition frequency of which is greater, the greater the value of the quotient.

2. A warning device in a rotary wing aircraft provided with a blade angle adjusting device for adjusting the blade angle of the rotor blades and a transceiver (20) with headphones (23), comprising an audible signal generator (21) connected to the transceiver (20), a measuring device (1, 13, 14) having a blade angle indicator (1) disposed on the blade angle adjusting device, a pressure altimeter (13) and an outside temperature probe (14), a control device (4-6) having a central processing unit (4) and a program memory (5) linked to the measuring device (1, 13, 14) containing a program memory (5) in which are stored data processing instructions for determining density height from pressure height and outside temperature, and data processing instructions corresponding to the predetermined operating thresholds of the aircraft to prevent overload, for determining the permissible maximum value of the blade angle from the determined density height, wherein said control device (4-6) determines the maximum permissible value of the blade angle for the density height determined according to the relevant pressure height and outside temperature, periodically calculates the quotient from the blade angle value and the maximum value, and in the case of the quotient exceeding the value 1, controls said audible signal generator (21) depending on the quotient in such a way that an audible signal is generated and emitted to the headphones (23), the audible signal consisting of an impulse sequence up to a predetermined threshold value of the quotient, and above said threshold value consisting of a continuous audible signal.

3. A warning device in a rotary wing aircraft provided with a blade angle adjusting device for adjusting the blade angle of the rotor blades, comprising a warning signal generator (21), a measuring device (1, 13, 14) including a blade angle indicator (1) connected to the aircraft to provide a value of the angle of the blades of the aircraft, a pressure altimeter (13) and an outside temperature probe (14), a control device (4-6) having a central processing unit (4) and a program memory (5) linked to the measuring device (1, 13, 14) containing a program memory (5) in which are stored data processing instructions for determining density height from pressure height and outside temperature, and data processing instructions corresponding to the predetermined operating thresholds of the aircraft to prevent overload, for determining the permissible maximum value of the blade angle from the determined density height, the control device (4-6) operative for determining the maximum permissible value of the blade angle for the density height determined according to the relevant pressure height and outside temperature, comparing it with the blade angle value obtained from the blade angle indicator (1) and, for as long as the angle value from said blade angle indicator exceeds the maximum permissible value, operating said warning signal generator (21) to produce a warning signal, a control memory (7) connected to said control device, and said control device (4-6) further operative for periodically calculating the quotient from the blade angle value from said blade angle indicator (1) and the maximum value and storing every such quotient exceeding the value 1 by a specific amount for a specific time.

4. A warning device as set forth in claim 3, including a clock (15) connected to said control device (4-6), and said control device (4-6) operative to store every said such quotient exceeding the value 1 by a specific amount together with the appropriate time shown on said clock (15) in said control memory (7).

5. A warning device as set forth in claim 3, including a portable connecting unit (31) adapted to be coupled to said warning device and operative to read and to delete the contents of said control memory (7), whereby the contents of said control memory (7) can only be deleted by means of said connecting unit (31), and wherein said connecting unit is not to be carried on the aircraft so that the pilot cannot delete the contents of the control memory recording every such quotient exceeding the value 1 by a specific amount which can only be checked and deleted by an authorized person having said connecting unit.

6. A warning device in a rotary wing aircraft provided with a blade angle adjusting device for adjusting the blade angle of the rotor blades and a transceiver (20) with headphones (23), comprising an audible signal generator (21) connected to the transceiver (20), a measuring device (1, 13, 14) having a blade angle indicator (1) disposed on the blade angle adjusting device, a pressure altimeter (13), an outside temperature probe (14), a control device (4-6), an input device (10) connected to input to said control device (4-6) the amount of fuel and weight of aircraft personnel so said control device can calculate the take-off weight of the aircraft, a fuel consumption meter (12) and a display means (22) connected to said control device, said control device (4-6) having a central processing unit (4) and a program memory (5) linked to the measuring device (1, 13, 14) containing a program memory (5) in which are stored data processing instructions for determining density height from pressure height and outside temperature, and data processing instructions corresponding to the predetermined operating thresholds of the aircraft to prevent overload, for determining the permissible maximum value of the blade angle from the determined density height, and for determining the maximum permissible flight speed from the determined density height and weight at a given moment, wherein said control device (4-6) determines the maximum permissible value of the blade angle for the density height determined according to the relevant pressure height and outside temperature, compares the blade angle value obtained from the blade angle indicator (1) and the permissible maximum value of the blade angle and controls said audible signal generator (21) to emit a distinctive audible signal from said headphones (23) for as long as the comparison value exceeds the permissible maximum value, and said control device (4-6) determines the maximum permissible flight speed for the said density height and aircraft weight at a given moment, determined from the difference between the take-off weight and weight of fuel used determined from the fuel consumption meter (12), and displays the maximum permissible flight speed on said display means (22).

7. A warning device in a rotary wing aircraft provided with a blade angle adjusting device for adjusting the blade angle of the rotor blades and a transceiver (20) with headphones (23), comprising an audible signal generator (21) connected to the transceiver (20), a measuring device (1, 13, 14) having a blade angle indicator (1) disposed on the blade angle adjusting device, a pressure altimeter (13), an outside temperature probe (14), a control device (4-6), an input device (10) connected to input to said control device (4-6) the amount of fuel on take-off, weight of aircraft personnel, height and outside temperature and the height difference to be overcome during the flight, a display means (22), said control device (4-6) having a central processing unit (4) and a program memory (5) linked to the measuring device (1, 13, 14) containing a program memory (5) in which are stored data processing instructions for determining density height from pressure height and outside temperature, and data processing instructions corresponding to the predetermined operating thresholds of the aircraft to prevent overload, for determining the permissible maximum value of the blade angle from the determined density height, and for determining the maximum aircraft load on the basis of the values entered by said input device (10), wherein said control device (4-6) determines the maximum permissible value of the blade angle for the density height determined according to the relevant pressure height and outside temperature, compares the blade angle value obtained from the blade angle indicator (1) and the permissible maximum value of the blade angle, and controls said audible signal generator (21) to emit a distinctive audible signal from said headphones (23) for as long as the comparison value exceeds the permissible maximum value, and said control device (4-6) determines the maximum aircraft load according to the values entered by said input device (10), and displays the determined maximum load on said display means (22).

8. A warning device in a rotary wing aircraft provided with a blade angle adjusting device for adjusting the blade angle of the rotor blades, a landing gear and a transceiver (20) with headphones (23), comprising an audible signal generator (21) connected to the transceiver (20), a measuring device (1, 13, 14) having a blade angle indicator (1) disposed on the blade angle adjusting device, a pressure altimeter (13) and an outside temperature probe (14), a control device (4-6), clock means (15), switch means (16) disposed on the landing gear of the aircraft to be actuated on take-off and to be actuated on landing of the aircraft, said switch means (16) and clock means (15) connected to said control device, said control device (4-6) having a central processing unit (4) and a program memory (5) linked to the measuring device (1, 13, 14) containing a program memory (5) in which are stored data processing instructions for determining density height from pressure height and outside temperature, and data processing instructions corresponding to the predetermined operating thresholds of the aircraft to prevent overload, for determining the permissible maximum value of the blade angle from the determined density height, wherein said control device (4-6) determines the maximum permissible value of the blade angle for the density height determined according to the relevant pressure height and outside temperature, compares the blade angle value obtained from the blade angle indicator (1) and the permissible maximum value of the blade angle, and controls said audible signal generator (21) to emit a distinctive audible signal from said headphones (23) for as long as the comparison value exceeds the permissible maximum value, another memory (7) connected to said control device (4-6), and said control device (4-6) operative to store in said another memory (7) a code number at every actuation of said switch means (16) designating take-off or landing with the appropriate time shown on said clock means (15).