《近地警告系统ppt课件.ppt》由会员分享，可在线阅读，更多相关《近地警告系统ppt课件.ppt（44页珍藏版）》请在三一办公上搜索。
1、近地警告系统（GPWS）,CFIT（可控飞行撞地）,CFIT: Controlled flight into terrain. 为民航两大主要航空事故之一（ALA：Approach and Landing），为一架飞机由机师正常控制，但因为一些失误而撞上地面、阻碍物或水面坠毁。根据国际民航组织的统计，可控飞行撞地是加装GPWS之前商用喷气飞机机体损毁事故和人员死亡事故的元凶。1974年，FAA开始对在美国空域飞行的航班上的GPWS进行强制安装要求（Honeywell），此后CFIT事故急剧减少。1985年后，CFIT事故每年仅发生1到2次，而强制要求安装前每年发生7到8次。目前，全球几乎所有的
2、商用喷气飞机均装备GPWS。 GPWS is a system developed to help prevent CFIT accidents.,GPWS,定义：地面迫近警告系统（GPWS, Ground Proximity Warning System），又称近地警告系统，是防止飞机因为离地过近而发生事故的系统，与TCAS搭配成为保护飞航安全的两大防线。原理：GPWS在起飞开始到降落地面为止，持续监视飞机离地高度，利用无线电高度表获得离地高度，并且以电脑计算出飞机的飞行趋势，若有危险时会以视觉与语音警告飞行员采取避险措施。,EGPWS,Enhanced Ground Proximity W
3、arning Systems(EGPWS), also calledTerrain Awareness Warning Systems (TAWS).A limitation of GPWS is the fact that with radar altimeter information the aircraft is only capable of seeing terrain directly below. In the case of rapidly rising terrain it may not react quick enough to issue a warning in t
4、ime.EGPWS corrects this problem by integrating an aircraft navigational source into the system. GPS position in conjunction with a terrain database is used to help predict terrain conflict.Honeywe11公司在原有GPWS基础上，开发出新型增强型近地警告计算机系统，该系统不仅增加了警告时间，还提供非常直观的地形显示，方便机组发现潜在的危险地形状况，避免 CFIT事故的发生。,HOW IT WORKS,GP
5、WS是当航机在异常接近地障的状况下,使用语音,灯号以及在萤幕显示警告文字来警告飞行员.这套系统只有在RA(Radio Altitude)2450尺以下才会作用启动. The heart of the GPWS is a computer processor which which can analyze the data from:Radar altimeter（雷达高度计）Air data computer（大气数据计算机）UHF Nav receiver（Ultra-high frequency导航接收机）Gear and flap indicating system（起落架和襟翼指示系统
6、）Roll attitude input sensor（滚动姿态输入传感器）The computer analyzes a number of parameters including aircraft configuration, speed, proximity to terrain, and descent rate in order to issue appropriate warnings.,Enhanced GPWS Features,In addition to retaining current GPWS alerting functions, the EGPWS offers
7、 two new major features : Look-ahead terrain alerting. Terrain display.,EGPWS: Look-ahead Terrain Alerting,The EGPWS provides caution-andwarning-level alerts to the flight crew about potential terrain conflicts earlier than basic GPWS.The alerts are based primarily on the airplane position and barom
8、etric altitude information passed to the EGPWS. Either a flight management system (FMS) or global positioning system (GPS) can provide airplane position (latitude and longitude) to the EGPWS. The look-ahead distance varies mainly with ground speed, The look-ahead caution alert is provided approximat
9、ely 40 to 60 seconds before a potential terrain conflict, and the look-ahead warning alert is provided approximately 20 to 30 seconds before such a conflict.The altitude offset is normally 700 feet (213m) below the airplane. The purpose of the offset is to provide terrain alerting when the airplane
10、has less than the normal terrain clearance.,EGPWS: Terrain Display,The EGPWS terrain display is designed to increase flight crew awareness of the surrounding terrain and to potentially avoid terrain conflicts entirely. The terrain display can be selected manually by the flight crew or displayed auto
11、matically when a look-ahead caution or warning alert activates. The terrain is displayed on the Electronic Horizontal Situation Indicator (EHSI) or navigation display (ND), or on a dedicated weather radar display in flight decks without map displays. The terrain is shown on the display in dotted pat
12、terns of red, amber, and green, with the colors indicating the height of the terrain relative to the current airplane altitude .-dotted red: 2,000 feet (610m) above the airplane altitude -dotted amber: from 500 feet (152m) below the current airplane altitude to 2,000 feet (610m) above-dotted green:
13、500 feet (152m) below,To reduce clutter on the display, any terrain more than 2,000 feet (610m) below the airplane is not displayed, and instead remains the background color of black. Because the terrain colors are displayed relative to the current airplane altitude, the colors will change as the ai
14、rplane climbs or descends. In those areas of the world for which the EGPWS terrain database does not yet contain terrain data, a dotted magenta pattern will show on the display.,EGPWS: Terrain Display,Reference altitude,Peak display,The following image illustrates the Peaks display at a high relativ
15、e altitude.,The following image illustrates the Peaks display at a low relative altitude.,如何发出警告,EGPWS可以向机组提供警戒或警告信息。当前飞行状况导致EGPWS警戒或警告启动时，无论机组是否选择，地形图将强制性的自动显示在飞行仪表上。在EGPWS中，计算机沿着飞机的预定航迹连续搜索地形数据库，这样可使系统具有虚拟的前视能力。若飞机正在下降，计算机会沿下滑航迹进行搜索；若飞机正在转弯，则沿转弯航迹搜索。如果EGPWS认为飞机的航迹在某处与地形太近，它会提前一分钟以上发出音频和视频告警信号。当EGP
16、WS系统发出告警时，在飞行仪表上将用彩色固定方块来加以强调，表示会引发危险的地形，同时还伴随有相应的音响告警。固定的红色方块表示地形处在30秒的飞行时间范围内，要求机组立即执行避开地形机动程序；而固定的黄色方块则表示地形处在大约30到60秒的飞行时间范围内，要求机组立即检查飞行轨迹按需修正，并执行相应地形机动程序。,Operation mode,Mode 1: Excessive Descent Rate(过度的下降速率)。（SINK RATE PULL UP）Mode 2: Excessive Closure to Terrain(过度的地障接近率)。（TERRAIN.TERRAIN PUL
17、L UP）Mode 3: Altitude Loss After Takeoff(在航机起飞（Takeoff）或重飞（Go around）爬升时航机高度值过度下降(Altitude loss)。（DONT SINK）Mode 4: Unsafe Terrain Clearance(与地障的间距不足)（未放下起落架或襟翼小于30度等）。（TOO LOW - TERRAIN TOO LOW - GEAR TOO LOW - FLAPS）Mode 5: Excessive Deviation Below Glide slope(仪器降落时与下滑道（Glide slope）的误差过大)。(GLIDE
18、SLOPE)Mode 6: Advisory Callouts(正常下降时的提醒)。(“Bank Angle” “Five Hundred” “Minimums”)Mode 7: Windshear Alerting(当飞机遭受风切变警讯)。(“Caution, Windshear” “Windshear, Windshear, Windshear”),Operation mode,Mode 1: Excessive Descent Rate(过度的下降速率),Operation mode,Mode 2: Excessive Closure to Terrain(过度的地障接近率),Opera
19、tion mode,Mode 3: Altitude Loss After Takeoff(在航机起飞（Takeoff）或重飞（Go around）爬升时航机高度值过度下降(Altitude loss),Operation mode,Mode 4: Unsafe Terrain Clearance(与地障的间距不足)（未放下起落架或襟翼小于30度等）,Operation mode,Mode 5: Excessive Deviation Below Glide slope(仪器降落时与下滑道（Glide slope）的误差过大),Operation mode,Mode 6: Advisory C
20、allouts(正常下降时的提醒),callouts would be made by the pilot not flying (PNF).,Terrain Clearance Floor(TCF),The Terrain Clearance Floor (地形净空基底或地形净空平面 ) function (enabled with TAD) enhances the basic GPWS Modes by alerting the pilot of descent below a defined Terrain Clearance Floor regardless of the aircr
21、aft configuration. The TCF alert is a function of the aircrafts Radio Altitude and distance relative to the centre of the nearest or destination runway included in the database.,TCF envelope,Runway Field Clearance Floor(RFCF),跑道高于周围地形的机场。A RFCF feature is similar to the TCF feature except that RFCF
22、is based on the current aircraft position and height above the destination runway, using Geometric Altitude (in lieu of Radio Altitude). This provides improved protection at locations where the runway is significantly higher than the surrounding terrain as illustrated below.TCF and RFCF alerts resul
23、t in illumination of the EGPWS alert lights and the aural message TOO LOW TERRAIN.,Terrain database,Terrain database,Terrain database,Airport database,Databases process and certification,System architecture,System interface,System interface,System interface,System interface,System interface,System interface,System interface,System interface,System interface,我国EGPWS现状,按中国民航总局要求，从2005年1月1日起，我国所有最大审定起飞重量超过15000公斤或客座数超过30的涡轮发动机飞机，都要安装EGPWS系统，目前，进展顺利。2002年9月，民航总局正式颁发了TAWS安装政策。 根据民航总局2002年9月颁发的文件，国内航空公司将于2004年底前在30座以上的客机上全部安装增强型近地警告系统。,
