GB2466223A

GB2466223A - Aircraft ground lock detection device.

Info

Publication number: GB2466223A
Application number: GB0822767A
Authority: GB
Inventors: Robert John Sykes
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-12-15
Filing date: 2008-12-15
Publication date: 2010-06-16
Also published as: GB0822767D0

Abstract

A ground lock detection device consists of a reader, display device (aircraft fault monitoring display, electronic tech log or independent device) and ground locks fitted with RFlD tags. The device or devices may be powered by aircraft generated power, battery power, solar power of a combination of any of the previous. The device detects an undesirable ground lock status and warns the aircrew or engineer of the problem.

Description

Ground Lock Detection Device.

Statement of Invention.

This invention relates to an aircraft undercarriage ground lock detection device.

When an aircraft has maintenance performed or is towed from one part of an airport to another, undercarriage ground locks are fitted to prevent the undercarriage being inadvertently retracted or col lapsing.

These ground locks consist of steel pins which are fitted to an over centre strut within the undercarriage mechanism and should be removed and stowed on the flight deck before the aircrafts next flight.

Occasionally the ground locks are left in place when the aircraft next taxis out for take off. In flight, when the aircrew attempt to retract the undercarriage, the ground locks prevent undercarriage retraction and the aircraft must acquire an acceptable landing weight (fuel dumping is often required) before returning to the airport to have the pins removed (An Air Turn back is executed).

To overcome this, the present invention proposes a ground lock detection device which will highlight the presence of fitted ground locks and prevent aircraft despatch prior to their removal.

Advantages.

The device would audibly andlor visually warn aircrew in the flight deck to check the ground locks when ground locks are detected not stowed or fitted.

The device would be capable of making the aircrew or engineer override its warning before the aircraft parking brake can be released.

The device would have a visual indicator displaying if ground locks were fitted or stowed.

The human factors which lead to ground locks being left in place would be better guarded against than at present.

Less unnecessary environmental pollution would be encountered.

Airlines reputations would be better protected.

Airlines costs would be reduced as an Air turn back can cost tens of thousands of pounds.

Ground Lock Detection Device.

Detailed Description.

There now follows a series of text referring to attached drawings to describe the operation of the ground lock detection device.

Desi2n 1: Ground Locks Not Stowed Detection Device.

This application is designed as a simple to fit aftermarket device which would be contained within the flight deck of the aircraft.

Aircraft have an undercarriage ground lock stowage in the flight deck where the aircrafts ground locks should be stowed before the aircraft is despatched. This design would detect ground locks which were not stowed and therefore possibly still fitted. It would prompt the crew to check the undercarriage groundlocks are not fitted before flight.

List of components: Park Brake status unit Plastic case.

Close proximity RF!D reader and RF emission device.

Close Proximity RFID tag.

Power low level indication.

Solar energy cell.

Battery.

Ground Lock Detection Device.

Plastic case.

RFID Reader.

LED display.

Caption decals.

Speaker.

Circuit board and memory chip Motion sensor (if applicable).

Switch unit.

Battery.

Solar energy cell.

Ground Lock Detection Device.

Ground Locks and RFID tags.

Ground lock steel pins (supplied by aircraft manufacturer).

Bonded RFID tags.

Figure 1 shows the flight deck stowage on one aircraft The ground locks are steel pins supplied by the aircraft manufacturer.

The ground locks in the figure are fitted with Radio Frequency Identification (RFID) tags. When interrogated by an RFID tag reader, these tags emit a radio signal response which the reader recognises. Also see figure 4 "System Operation".

The tags are bonded to the groundlocks such that the groundlock provides an electrical ground for the tag on which its operation depends. if a tag becomes detached from the ground lock it will lose its electrical ground and therefore be undetectable by the RflD reader. This is to prevent a detached tag in the cockpit being detected as a stowed ground lock.

and figure 2 shows again the position of the ground lock stowage.

Figure 2 shows the Ground Lock Detection Device fitted to the Flight Deck Glare Shield.

The Device consists of a plastic case, an RFID reader with an output to display LEDs, one red next to a caption "Ground Locks Not Stowed" and one green next to the caption "Ground Locks Stowed".

A small speaker connected to a circuit board and memory chip is housed within the device. The circuit board is connected to the RFID reader via a motion sensor by an electrical wire.

A reset switch is provided.

A manual scan switch is provided.

A disable switch is provided.

A suitable mounting bracket is supplied suitable for the aircraft type.

The unit is battery powered and charged by solar energy.

A lower power warning LED is incorporated.

When the reader is enabled, the RFID reader scans the ground lock stowage for the ground locks and their tags, the tags respond if present; if the reader detects a missing tag and groundlock, it sends an output to the display unit and the motion sensor. The red LED is illuminated on the display. When the motion sensor is triggered the memory chip delivers a pre-recorded alert through the speaker "Ground Locks not stowed" (another version of the ground lock detection device would contain a motion sensor and would immediately initiate the pre-recorded alert when enabled and a ground lock is missing).

When the reader is enabled and all ground locks are detected the green LED is illuminated.

Ground Lock Detection Device.

The reset switch is used in both cases to return the ground lock device to sleep mode until the next change in parking brake status.

The manual scan switch can be pressed by the Aircrew or aircraft engineer to initiate a ground lock check.

Once enabled the ground lock detector will operate until the reset switch is pressed.

When the reset switch is pressed the ground lock detection device enters sleep mode until next enabled. In sleep mode, power is available but no RF emissions are present.

The disable switch kills all power to the device and prevents RF emissions.

See also Figure 5 detailing the "Ground Lock Detection Device".

fjgre 3 shows the Aircraft Parking Brake Status Device (APBSD) in situ.

Figre 6 shows an assembled APBSD and an exploded view.

The device consists of: A plastic case housing the RFID reader.

A close proximity RFID reader and RF emission device.

A close proximity RFID tag.

A disable switch.

A battery A solar energy cell.

It uses the existing parking brake handle with an RFID tag embedded in it. The RFID reader and RF emission device are mounted to the aircraft centre pedestal such that the reader can detect the tag in the on position only.

Figure 3 When the park brake status changes, from on to off or off to on, the RF emission device signals the glare shield mounted Ground lock detection device enabling it and beginning its ground lock check sequence. This is further explained below:-I.The RFLD tag and readers range is such that when the parking brake is in the off position (in fact from out of the on position through to the off position) the reader cannot sense the tag.

2.In the on position the tag is sensed by the reader.

3. The park brake handle moves through the arc shown in figure 3 during operation, the tag therefore moves through the same arc.

Ground Lock Detection Device.

4.Whenever the tag change from sensed to not sensed or not sensed to sensed, the device is programmed to emit a signal which the ground lock detection device (GLDD) uses as a trigger to begin its ground lock check sequence.

The disable switch kills all power to the device and prevents RF emissions.

Any type of proximity sensor could be used to sense the park brake movement to trigger the signal to the GLDD.

Variation on Design 1.

This design variant would use the aircraft Electronic Log (ETL) to issue a warning to crew attempting to depart with an aircraft having ground locks "not stowed".

As per previous variants, the ground locks are fitted with RFID tags.

For information about ETLs please see appendix 1.

Ground Locks not stowed device.

This variant has an RFID reader built into the ETL or attached to the ETL using one of its free ports (USB etc). When the ETL "sign off' tab is open the reader is enabled and the reader scans for the presence of the RFID tags fitted to the Ground Locks.

If the ground locks are detected then no action is taken. The crew sign off the electronic technical log page, the ETL transmits the sector information and the aircraft is allowed to depart.

If the ground locks are not detected, when the flight crew attempt to sign off the sector page, a window opens on the ETL screen informing the user that the ground locks are not detected in the stowage and advising them to confirm they are not fitted in the undercarriage. They will be asked to check a tick box relevant to their situation. For example "Physical check of undercarriage carried out, no ground locks present".

This is performed by a software interface between the reader and the ETL.

Design 2: Ground Locks Fitted Detection Device.

This design would be fitted as a modification to an aircraft, use aircraft power, data transfer devices and displays.

This design would detect fitted groundlocks.

List of components.

Ground Lock Detection Device.

X3 Landing Gear Mounted Ground Lock Detection Devices (LGM GLDD).

X3 Bridging Harnesses (to connect device to existing aircraft systems).

X3 Ground Locks fitted with RFID tags.

Description and operation.

RFID readers in each of the three aircraft undercarriage bays are powered when the aircraft is on the ground by utilizing the aircraft air/ground sense system.

When powered they scan the undercarriage for the presence of ground locks which are fitted with RFID tags.

When ground locks are detected fitted to the undercarriage a signal is sent through the aircraft warning system using data buses to the flight deck where a caution message is displayed on the flight deck center pedestal (for example on Airbus the ECAM display or on Boeing the EICAS display) for the captain and First Officer to view (should the caution message prove to be erroneous after a physical check of the landing gear then the message would not be erasable but would clear on successful undercarriage retraction in flight).

Sketch of the RFID reader: The RF1D readers would be similar to that featured in figure 6 however the unit would not require an emission device.

Figure 7 shows a typical aircraft undercarriage and bay. The RFID readers would be mounted in a suitable position dependant on aircraft type.

Variation A on Design 2.

This design variant would use a display device similar to that shown in figures 2 and 5.

This device would replace the RFID reader with a radio receiver.

The RFID readers in the undercarriage would not use the aircraft data busses to transmit the signal of "pins fitted" but would send a radio signal to the flight deck display unit.

The undercarriage RFID readers would be battery or aircraft powered.

Variation B on Design 2.

This design variant would use the aircraft Electronic Log (ETL) to issue a warning to crew attempting to depart with an aircraft having ground locks "fitted".

As per previous variants, the ground locks are fitted with RFID tags.

For information about ETLs please see appendix 1 Ground Lock Detection Device.

Ground Locks fitted device.

With this variant the undercarriage mounted reader described above would signal a receiver fitted to the ETL (either internally or utilizing one of its free ports).

If the ground locks are not detected then no action is taken. The crew sign off the electronic technical log page, the ETL transmits the sector information and the aircraft is allowed to depart.

If the ground locks are detected, when the flight crew attempt to sign off the sector page, a window opens on the ETL screen informing the user that the ground locks are not detected in the stowage and advising them to confirm they are not fittcl in the undercarriage. They will be asked to check a tick box relevant to their situation. For example Physical check of undercarriage carried out, no ground locks present".

This is performed by a software interface between the reader and the ETL.

Ground Lock Detection Device Figure Key.

Ground Lock Detection Device Key to Figures.

FIGURE 1: GROUND LOCK PINS COMPONENT DESCRIPTION

PART (A) GROUND LOCK PINS SHOWN IN

STOWAGE IN AN AIRCRAFT FLIGHT

__________________________ DECK, SIDE WALL, STOWAGE.

PART (B) GROUND LOCK PINS SHOWN IN _________________________ STO WAGE, ENLARGED.

PART (C) A SINGLE GROUND LOCK SHOWN WITH AN RFID TAG ATTACHED.

GROU1JD LOCK PINS ARE

NORMALLY STEEL PINS

APPROXIMATELY 8" LONG. THEY

FIT INTO AIRCRAFT

UNDERCARRIAGE TO PREVENT

______________________________ COLLAPSE.

FIGURE 2:POSITION OF COMPONENT DESCRIPTION

COMPONENTS ON AIRCRAFT

FLIGHT DECK. __________________________ PART (A) GROUND LOCK DETECTION DEVICE PART (B) GROUND LOCK STOWAGE PART fç) AIRCRAFT PARKING BRAKE LEVER ______________________________ POSITION.

FIGURE 3: PARK BRAKE STATUS COMPONENT DESCRIPTION

DEVICE POSITION ___________________________

PART (A) PARKING BRAKE LEVER SHOWN THREE TIMES; ITS POSITION ON THE FLIGHT DECK CENTER PEDESTAL; ITS ORIENTATION TN ITS MODULE; A

CLOSE UP SHOWING ITS POSITION IN

RELATION TO THE RFID TAG

READER AND RF EMISSION DEVICE

__________________________ (PARKING BRAKE STATUS).

PART (B) RFID TAG READER AND RF EMISSION DEVICE (PARKING BRAKE _____________________________ STATUS).

PART (C) CLOSE PROXIMITY RFID TAG Ground Lock Detection Device Figure Key.

FIGURE 4: AIRCRAFT COMPONENT DESCRIPTION

UNDERCARRIAGE AND POSITION

OF GROUND LOCK LOCATING

HOLE! POSITION OF RFLD READER MOUNTING FOR DESIGN TWO. _________________________ PART (A) GROUND LOCK LOCATION WHEN ______________________________ FITTED.

PART (B) UNDERCARRIAGE LOCK STAY PART (C) UNDERCARRIAGE SIDE STAY AND

LOCATION SUITABLE FOR RFID

_________________________ READER MOUNTING DESIGN TWO.

PART (D) UNDERCARRIAGE MAIN STRUT PART (E) UNDERCARRIAGE MAIN WHEEL

FIGURE 5: GROUND LOCK COMPONENT DESCRIPTION.

DETECTION DEVICE EXPLODED

AND PLAN VIEW. _________________________ PART (A) CASE LID AND DISPLAY PART (B) SPEAKER PART (C) RFID READER CIRCUIT BOARD WITH POWER SOURCE, MEMORY CHIP __________________________ AND DISPLAY LEDS.

PART (D) CASE TRAY PART (E) PLAN VIEW OF ASSEMBLED DEVICE.

FIGURE 6: AIRCRAFT PARKING COMPONENT DESCRIPTION

BRAKE STATUS DEVICE FOR

DESIGN 1. ___________________________ PART (A) UPPER CASE PART (B) PRINTED CIRCUIT BOARD CONTAINING RFID READER (OR OTHER PROXIMITY DEVICE) AND RF _____________________________ EMISSION DEVICE.

PART (C) LOWER CASE PART (D) ASSEMBLED DEVICE Ground Lock Detection Device Figure Key.

FIGURE 7: AIRCRAFT COMPONENT DESCRIPTION

UNDERCARRIAGE AND POSITION

OF GROUND LOCK LOCATING

HOLE! POSITION OF RFID READER MOUNTING FOR DESIGN TWO. ________________________ PART (A) GROUND LOCK LOCATION WHEN ______________________________ FITTED.

PART (B) UNDERCARRIAGE LOCK STAY PART (C) UNDERCARRIAGE SIDE STAY AND

LOCATION SUITABLE FOR RFID

__________________________ READER MOUNTING DESIGN TWO.

PART (D) UNDERCARRIAGE MAIN STRUT PART (E) UNDERCARRIAGE MAIN WHEEL