SBAS and Aviation

Ed Williams Technology &

Asset Planning

Contents

• Problem

• Analysis

• Statistics - Australia

• Solution

• Enabling Technology

• International

• World Direction

Problem

Runway 14 Baucau

Accident Site

Extended Centre Line

Ilyushin IL-76Baucau, Timor-LesteJanuary 2003

Problem …

A300BirminghamAlabama

Problem …

Problem …

B738

RWY overrun

Analysis

Flight Safety Foundation

Controlled Flightinto Terrain (CFIT)

> 60% within 8NM Final Approach Segment Lateral tracking not

the cause

Analysis …

Lateral tracking not the cause Vertical tracking is major factor Loss of vertical situational awareness Most of aircraft were stabilized on a approx 3°glidepath

Flight Safety Foundation

Analysis …

Adjustment in the vertical in the last few miles Height / Speed = Energy management

Flight Safety Foundation

Statistics - AustraliaAustralia experience - warning signs / free lessons

1993: 7 deaths – Navajo, Young 2004: 6 deaths – Chieftain, Mt Hotham 2005: 15 deaths – Metroliner, Lockhart River 2003: Near Miss – RFDS King Air, ripped off main gear on wall

jet transport aircraft have deviated well below altitude stepslack of continuous vertical guidance a significant factor:

4 & 9 May 2010 A330 OOL ATSB Report: AO2010027 30 July 2011 E190 MEL ATSB Report: AB2012044 24 July 2011 B777 MEL ATSB Report: AO2011086 12 Feb 2012 B737 CBR ATSB Report: AO2012040 9 Sep 2012 B744 MEL ATSB Report: AO2012120

But for the grace of …

Solution – Vertical guidance

ICAO:“A hull loss is 25 times more likely to occur during a

circling approach than a straight in ILS Approach.”

Why ?

ILS provides: Straight in approach

(usually runway aligned) Continuous lateral guidance

(localiser) Continuous vertical guidance

(glide path)

Instrument Landing System (ILS)1954John Wayne

flying an ILS to RWY 28 in SFO

2015ILS is still the state of the art landing

aid in SFO …Brisbane, Melbourne, Adelaide,

Perth …(Sydney has both ILS & GLS)

Many regional airports and all smaller airports do not have ILS

ILS = M$2 +++ per runway endAustralia has 430 runway ends

International Civil Aviation Organisation

ICAO, 33rd Assembly (2001) - Resolution A33-16• direction world-wide add Continuous Vertical Guidance to

Instrument Approach (APV) as the mitigation

ICAO, 36th Assembly (2007) - Resolution A36-23 APV deployment time frame

30% by 2010 70% by 2014 all by 2016

ICAO, at the 37th Assembly (2010) - Resolution A37-11 Reiterated A36-23 with minor change

Satellite Navigation LimitationsNon Precision Approach (NPA) Lateral guidance integrity limit = 556 m (0.3 NM)

(accuracy very much better)Precision Approach (PA) Lateral guidance integrity limit = 40m Vertical guidance integrity limit = 10m (very demanding)

GPS Limitations / Errors Ephemeris – satellite is not (exactly) were it is stated to be Clock – time of the satellite signal is not (exactly) correct Signal passage through Troposphere delays signal (variable) Signal passage through Ionosphere delays signal (variable)

Corrections required = Space Based Augmentation System (SBAS)

The Solutions• Baro VNAV

• modern Air Transport Jet, larger regional, some BizJet• 15% of aircraft operating IFR• 95% of paying passengers

• GPS/SBAS• Regional, Charter, most BizJets & smaller aircraft inc GA• 85% of aircraft operating IFR• 5% of paying passengers• Aero medical

• Royal Flying Doctor Service• Angel Flight• Rescue helicopter• Timing driven by

medical needs• 4 Feb 2016 GPS Mandate -> 95%+ SBAS capable

SBAS internationally

USA - WAAS LP = 560; LPV = 3,450; LPV-200 = 885

Canada - WAAS LP = 0; LPV = 167 Growing rapidly

Europe - EGNOS LPV = 260 at 146 Airports at 16 Countries Growing rapidly

Japan – MSAS India – GAGAN China – SNAS Russia - SDCM

SBAS brings greater Accuracy, Integrity, Availability and Continuity to Positioning Navigation Timing (PNT)

SBAS brings sovereign control over PNT GPS - controlled by USA – not by Aust/NZ PLUS Augmentation (Corrections & Integrity) – controlled by us – sovereign control Result (GPS plus Corrections) is under sovereign control as is the integrity

World Direction USA Policy

GPS/SBAS: down to & including CAT-I Approach GPS/GBAS: CAT-III Approach Europe expected to follow

Airbus A350 – first air transport jet with SBAS / LPV capability

Can be expected to flow to all new Airbus aircraft

Boeing B738 MAX – announced with SBAS capability Can be expected to be included in all new Boeing aircraft

SBAS brings economical Vertical Guidance to all aircraft and all airports / helipads; even the smallest

Summary SBAS brings greater Accuracy, Integrity, Availability and

Continuity to Positioning Navigation Timing (PNT)

SBAS brings sovereign control over PNT

SBAS is widely used by and beneficial to all areas of society

SBAS is an economical enabling technology for continuous vertical and lateral guidance for Aircraft approach operations (CAT-I standards) Immediately for regional and smaller aircraft Over time for all aircraft

Discussion

SPARE SLIDES

Discussion

“The time to fix the roof is when the sun is shining”

John F. Kennedy

Phases of Flight Oceanic:

Over ocean, remote terrestrial – low traffic density Implies: low accuracy nav (astro, inertial); poor comms (HF) Large separation standards – 100/100; 10min, 50/50 (GPS 4NM)

En Route: Over land – medium traffic density Implies: accurate nav (VOR/DME); good comms (VHF) Medium separation standards – VOR/DME, NDB (GPS 2NM)

Terminal Area: Airport Terminal Area – high traffic density Implies good comms (VHF); accurate nav (close to VOR/DME) Small separation standards – VOR/DME (GPS 1NM)

NPA: Close to RWY – position for landing Implies accurate nav (position aircraft for landing) (GPS 0.3NM)

Context – GPS 101Navigation:- Know where I am (positioning)- Path to destination (need not be straight)- Guidance along path to destination (direction)

Positioning - GPS:- 27+ Satellites on orbit (geometry 3 planes of 5 + 3 planes of 4)- Satellites transmits signal with precise timing (10nS)- Receiver (avionics) receives signal – time delay (tx to rx) = range- Receiver knows satellite position (almanac)- Simultaneous equations to determine position which satisfies range

to each satellite

Accuracy, Availability, Continuity, IntegrityGPS - enough for Ocean, En Route, TMA and NPA (integrity limit 556m)

GPS Mandate: 4 February 2016 all IFR aircraft GPS navigation

Basics of Satellite Navigation …

Satellite GeometryAccuracy best if satellites widely distributedVertical Accuracy poorer than Horizontal

Always Changing Satellites, Aircraft all moving Geometry & Accuracy changing

Adequate to support:Oceanic, En-Route, Terminal Area and Non Precision Approach

Vertical Guidance & IonosphereVertical Guidance – Accuracy – 8m; Integrity – 20m PROBLEM!

GPS errors: Satellite Position – not (exactly) where it says it is (< typically: 2m) Satellite Clock – not exactly on time (< typically: 30nS = 2m) Signal delay through ionosphere (4m to 30m)