NAVIGATION MENU GPWS presentation 1/35 NAVIGATION MENU GPWS presentation 2/35 The GPWS monitors the aircraft flight path and generates visual and audio warnings/alerts when the aircraft is in one of the defined hazardous situations. These warnings will be overridden by stall or windshear warnings. The A320 family is equipped with a Ground Proximity Warning System (GPWS). Its purpose is to enhance safety by alerting the crew to potentially hazardous situations involving terrain collision or incorrect landing configuration. GPWS NAVIGATION MENU GPWS presentation 3/35 ILS 1 FMGC 1 LGCIU 1 GPWS The GPWS processes the data from: - RA 1, - ADIRS 1, - ILS 1, - FMGC 1, - LGCIU 1. Failures of these units will be studied in the abnormal operation modules. RA 1 ADIRS 1 NAVIGATION MENU GPWS presentation 4/35 Most GPWS alerts and warnings are generated as a result of changes in radar altimeter heights or the rates of those changes. The system predicts potential hazards from these trends, but has no forward looking capability. NAVIGATION MENU GPWS presentation 5/35 Therefore impact with a near vertical cliff face can not be predicted. GPWS does not absolve the crew from monitoring aircraft position and safety altitude ! NAVIGATION MENU GPWS presentation 6/35 The GPWS control panel is located on the left side of the overhead panel. NAVIGATION MENU GPWS presentation 7/35 GPWS visual warnings are provided on the MISCELLANEOUS panels . The system can be tested by pressing either GPWS-G/S pb sw. This test is normally performed by the maintenance crew. In addition, two loudspeakers located on each lower side of the main panel broadcast GPWS aural warnings even if they are turned off. NAVIGATION MENU GPWS presentation 8/35 GPWS enhances safety by alerting/warning the crew of potentially hazardous situations during flight at low heights. Crews should react to any GPWS warning immediately without attempting to assess its validity. GPWS operation is fully automatic in the normal lights out configuration. We will now study the aural and visual alerts and warnings. NAVIGATION MENU GPWS presentation 9/35 NAVIGATION MENU GPWS presentation 10/35 If a high rate of descent is detected at low level, GPWS will generate an aural, repeated “Sink rate” alert. If this rate is, or becomes excessive, the repetitive aural warning “Whoop whoop pull up” will be generated. In both cases, the red GPWS lights will illuminate. NAVIGATION MENU GPWS presentation 11/35 NAVIGATION MENU GPWS presentation 12/35 If rising ground is detected as a potential threat to the safety of the aircraft, GPWS will alert the crew with a repeated “Terrain” aural alert. The system will generate a “Whoop whoop pull up” warning after the terrain alert has been repeated twice. The red GPWS lights will illuminate in either case. NAVIGATION MENU GPWS presentation 13/35 If GPWS detects a rate of descent during the initial climb after take-off or following a go-around, it will give a repeated “Don’t sink” alert with accompanying GPWS red lights. NAVIGATION MENU GPWS presentation 14/35 If the landing gear and flaps are retracted and GPWS detects that the aircraft is close to the ground, it generates a “Too low, terrain” aural warning and the GPWS red lights illuminates. NAVIGATION MENU GPWS presentation 15/35 At very low levels, the aural warning “Too low gear” would be generated if the landing gear is still retracted. NAVIGATION MENU GPWS presentation 16/35 If the landing gear is down, but the flaps are not in landing configuration, the warning is “Too low flaps”. Note that the “Too low gear” warning has priority over the “Too low flaps”. NAVIGATION MENU GPWS presentation 17/35 Below approximately 1000 ft on an approach, a GPWS glide slope aural and visual alert will be generated if: - the runway is ILS equipped, - the ILS is tuned, - the ILS signal is valid, - the aircraft is significantly below the glide slope. Both amber G/S lights will illuminate. NAVIGATION MENU GPWS presentation 18/35 The aural message will become louder, to indicate a warning, if no corrective action is taken as the aircraft gets closer to the ground, or if it descends further below the glide slope. NAVIGATION MENU GPWS presentation 19/35 Note that some airports around the world have approaches and departures which are not compatible with standard GPWS operation. These airports are programmed into the GPWS database and the warning thresholds are modified to avoid nuisance warnings. The GPWS panel allows the crew to inhibit some warnings. NAVIGATION MENU GPWS presentation 20/35 Flap 3 is a recognised landing configuration. If the option is used or if required by an ECAM procedure, the crew should select LDG FLAP 3 pb sw ON to ensure that the GPWS does not generate warnings when it detects that the aircraft is not in the full flap configuration. The associated green GPWS FLAP 3 memo message is displayed on the E/WD. NAVIGATION MENU GPWS presentation 21/35 Following certain failures, a landing may have to be made with a reduced flap setting. The crew can select the FLAP mode pb sw OFF to inhibit GPWS flap warnings. If the FLAP mode is OFF, the green FLAP MODE OFF message is displayed on the E/WD. NAVIGATION MENU GPWS presentation 22/35 When selected OFF, the G/S MODE pb sw will inhibit the GPWS glide slope warning. NAVIGATION MENU GPWS presentation 23/35 The white OFF light illuminates when the GPWS is selected off. All warnings are inhibited. NAVIGATION MENU GPWS presentation 24/35 If your aircraft is equipped with the Enhanced GPWS (EGPWS), a forward looking capability for terrain is added. The basic functions, we have just studied, remain unchanged. EGPWS is based on terrain database and FMGC current position, not on radar returns. The purpose of the EGPWS is to avoid a Control Flight Into Terrain and to give enough time to the crew to perform an avoidance manoeuvre. NAVIGATION MENU GPWS presentation 25/35 ++ 22000000 fftt ++ 11000000 fftt Aiirrccrraafftt eelleevvaattiioonn - 250 ft when gear down - 500 ft when gear up -- 11000000 fftt -- 22000000 fftt Unnkknnoownn aarreeaass The terrain information is displayed on the ND except in PLAN mode. A different image texture, an image display which sweeps from center outward to both ND sides and a “TERR” indication instead of the radar “TILT”indication help the crew to make the difference between the EGPWS terrain computed data and the ground picture sensed by the radar. The terrain elevation surrounding the aircraft is color coded. NAVIGATION MENU GPWS presentation 26/35 Two TERR ON ND pb sw are fitted on each side of the main panel. To display the terrain picture on his ND, a pilot will have to switch on his respective TERR ON ND pb sw. Note that the weather radar information is replaced even if it is switched on. NAVIGATION MENU GPWS presentation 27/35 In the lights out position, the EGPWS operation is fully automatic. The TERR pb sw, in the OFF position allows the crew to inhibit the “enhanced” functions but keeps the basic GPWS functions operative. In case of failure of the “enhanced” functions, the FAULT light comes on but the basic GPWS functions remain operative. As for the basic GPWS, the SYS pb sw controls the basic functions. NAVIGATION MENU GPWS presentation 28/35 The EGPWS uses a terrain database coupled with a FMGS position to calculate two terrain envelopes ahead of the aircraft. When a conflict is detected between these terrain envelopes and the terrain memorized in the database, an alert is triggered. One terrain envelope corresponds to a caution level while the second one to a warning level. NAVIGATION MENU GPWS presentation 29/35 NAVIGATION MENU GPWS presentation 30/35 • If the caution terrain envelope is penetrated, the areas which violate the caution envelope limits turn to a solid yellow color. • An amber “TERR AHEAD” message appears and a repeated “TERRAIN AHEAD” aural alert is generated. • If the terrain warning envelope is penetrated, the areas which violate the warning envelope turn to a solid red colour. A red “TERR AHEAD” message appears and a repeated “TERRAIN AHEAD, PULL UP” aural alert is generated. In both cases, the red GPWS lights will illuminate. NAVIGATION MENU GPWS presentation 31/35 As for the basic GPWS warnings, crews should react immediately without attempting to assess its validity. NAVIGATION MENU GPWS presentation 32/35 In case of caution or warning, if TERR ON ND is not selected on, the terrain display is set automatically to on and the ON light on the TERR ON ND pb sw comes on. NAVIGATION MENU GPWS presentation 33/35 The second EGPWS protective function provides a terrain clearance floor envelope for each runway stored in the database. This function warns a premature descent below this floor regardless of aircraft configuration. Runway NAVIGATION MENU GPWS presentation 34/35 CAUTION: • The relative height is calculated using the Captain baro setting. Thus, the system does not protect against baro setting errors. • The position is calculated using FM 1. The system does not protect against FM 1 position errors. NAVIGATION MENU GPWS presentation 35/35 NEXT MMoodduullee ccoommpplleetteedd When the aircraft position accuracy, provided by the FMGS, is not sufficient, the "enhanced" functions of the EGPWS are automatically deselected. “TERR STBY” appears in green on the ECAM memo and the terrain display is deselected until a high level of navigation accuracy is restored. The basic GPWS functions remain operative. NAVIGATION MENU GPWS presentation 36/35 LLIISSTTOOFFSSUUBBJJEECCTTSS EXIT AUDIO GLOSSARY FCOM RETURN GGPPWWSS GGPPWWSSppaanneellss GGPPWWSSccoonnttrroollss EExxcceessssiivveerraatteeooffddeesscceenntt EExxcceessssiivveetteerrrraaiinncclloossuurreerraattee AAllttiittuuddeelloossssaafftteerrttaakkeeooffffoorrggooaarroouunndd UUnnssaaffeetteerrrraaiinncclleeaarraannccee EExxcceessssiivveeddeevviiaattiioonnbbeelloowwgglliiddeessllooppee EEnnhhaanncceeddGGPPWWSS作者: bocome 时间: 2011-7-31 10:01:18