improvement in irvr 'agl credit

IMPROVEMENT IN IRVR

“AGL CREDIT”

Manchester Airports’ 2015 Submission to the

UK CAA Safety & Airspace Regulation Group

Steve Clouston – Airfield Technical Planner

SOURCES OF REFERENCE

• XPX Consulting Ltd, IRVR Improvement Presentation - UK Flight Safety Committee

Briefing November 2012, on behalf of Heathrow Airport

• ICAO Doc 9328 (Third Edition 2005) – Manual of Runway Visual Range Observing and

Reporting Practices

• UK CAA CAP 670 ATS Safety Requirements (April 2013) –Part C, Section 2: NAV 01

Engineering Requirements for Instrumented Runway Visual Range (IRVR) Systems

• UK CAA CAP 168 (February 2014) – Chapter 6, Aeronautical Ground Lighting (AGL),

Maintenance of AGL Systems

• Aeronautical & General Instruments Ltd (AGI) – White Paper (May 2012), The Case for

Forward Scatter Sensors for IRVR

• Tailor Made Systems Ltd (TMS) – Summary report on a research project into ‘runway

lighting intensity’ with the UK CAA, Heathrow & NATS (pre CAP 670 revision 2013)

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DEFINITIONS

• Runway Visual Range (RVR) - ICAO Eighth Air Navigation Conference 1974.

“The range over which the pilot of an aircraft on the centre line of a runway can see therunway surface markings or the lights delineating the runway or identifying its centre line”

• RVR - an ‘assessment’, not an observation or meteorological measurement and appliesonly for the horizontal visual range on the runway and not an approach to it, which maybe significantly different (Slant Visual Range)

• RVR Based on Lights (ICAO Doc 9328 ) - the RVR assessment calculation involvesthree elements related to (Emile) Allard’s Law

1. The intensity of the runway edge and runway centreline lights

2. The optical clarity of the atmosphere - the scattering (fog & snow) and absorption(haze, dust & smoke) of light by airborne particles

3. The visual threshold of illumination of the eye that is required for a point source orsmall light to be visible - related to the luminance of the background against which thelight is viewed

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DEFINITIONS

• Instrumented Runway Visual Range (IRVR) - an ‘assessment’ resulting from the use

of Transmissometers or Forward Scatter Sensors positioned adjacent to the runway at

the touch-down zone, mid-point and stop-end locations

• Transmissometers (installed on Runway 05L-23R) and Forward Scatter Sensors

(installed on Runway 05R-23L mid-September 2015) - measure the optical clarity of the

atmosphere (the scattering and absorption of light). A runway edge lighting intensity

value (inclusive of any de-rating factor) is input into the system based on the electrical

current fed to the lights.

• Background Luminance Meters (BLM) - usually co-located with the

Transmissometers and Forward Scatter Sensors, the latter BLMs being aligned in the

direction of approach

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THE RUNWAY LIGHTING FACTOR

• Runway Centreline vs. Runway Edge Aeronautical Ground Lighting (AGL)

1. UK CAA CAP 670 stipulate that the runway edge lighting values are used

2. The provision of runway edge lighting is also mandatory for all categories of aprecision instrument approach (ICAO, EASA and UK CAA)

• Historical de-rating factors are applied creating an assumed value for runwayedge lighting intensity due to lamp aging (incandescent) and lens contamination

1. ICAO (Doc 9328) & Fifth Meeting of the Visual Aids Panel (1970) - 80% de-ratingfactor (20% degradation)

2. CAP 670 - Initial 40% de-rating factor (60% degradation) for existing systems up tothe ICAO recommended maximum of 80% (20% degradation)

3. UK Historical - 20% de-rating factor (80% degradation) applied to many precisioninstrument approach runways, including Manchester. Thought to originate from circa1950’s / 60’s when runway lighting beam intensity values were deemed to be poor

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CONCEPT OF IRVR “AGL CREDITS”

• The concept of awarding “AGL Credits” started to gain credence within the UKCAA Airspace, ATM & Aerodromes (Infrastructure), Safety & Airspace RegulationGroup (SARG) around the period of 2011 / 12

• Reportedly supported by the TMS led research project into the potential benefitsof adopting actual ‘runway lighting intensity’ as opposed to an assumed value

• Recognition that the historical assumption of runway edge lighting operating atno greater than 20% of design maximum luminescence (peak beam intensity)was unduly pessimistic given the following:

1. Advances in AGL fitting and lamp technology - i.e. LED (LED edge lights installed onRunways 05L-23R and 05R-23L)

2. AGL photometric inspections - Mobile Airfield Light Monitoring System (MALMS)

3. Adoption of an optimised AGL maintenance programme

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MANCHESTER’S SUBMISSION FOR “AGL CREDITS”

• M.A. “AGL Credits” Project Team – Steve Clouston and Mike Curry

• Submission to UK CAA SARG was lodged on the 18th June 2015

• A three-part submission consisting of:

1. A covering letter summarising Manchester’s bi-weekly photometric inspection andweekly maintenance regimes; including details of runway AGL cleaning during winteroperations. That based on supporting evidence, the historical and current de-ratingfactor of 20% is moved upwards to a de-rating factor of 60% (40% degradation) for allfour runways

2. Evidence of the photometric inspection and maintenance programme (April - June2015)

3. Evidence of photometric inspection results over the period of February to June 2015,a total of twenty-three MALMS runs across all four runway edge lighting systems

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Proposal for an Instrumented Runway Visual Range Improvement at

Manchester Airport (EGCC) via Aeronautical Ground Lighting ‘Credits’

Present calculations of IRVR at Manchester assume that runway edge lighting operates at no greater than 20% of design maximum luminescence. This current ‘de-rating’ factor results in Low Visibility Procedures (IRVR <600m) coming into force more often than is operationally necessary.

Manchester operates a robust maintenance programme to both Runway 05L-23R and Runway 05R-23L Aeronautical Ground Lighting (AGL). The programme includes the weekly cleaning of edge, centreline and TDZ (where appropriate) light fittings. During winter months, the cleaning regime also extends to countering the adverse impact of pavement anti-icing agents which can significantly reduce the light output of AGL fittings. Post runway anti-icing events, cleaning of the above AGL takes place as soon as operationally practicable and within three days of such an event if no routine weekly clean is scheduled to take place within that period. The maintenance schedule is supported by the bi-weekly photometric inspection of the same runway AGL services with the use of MALMS.

Recent photometric survey results for 05L, 05R, 23L and 23R edge lighting are provided as evidence of Manchester’s on-going photometric inspection regime. Also included is a recent extract from our inspection and maintenance programme.

Based on our well-established maintenance programme and photometric inspection of runway edge lighting, it is proposed that for the purposes of calculating IRVR an improved AGL ‘de-rating’ factor of 60% (40% degradation) is afforded to Manchester Airport’s four runways.

S. Clouston Airfield Technical Planner

Runway 23R / 05LWO No. WO Decription Requested By Type Status Date

1449471 23R TDZ Clean Airfield PPM COMP 15/06/2015

1449470 23R TDZ Malms Run Airfield PPM COMP 15/06/2015

1449469 23R/05L C/L & Edge Clean Airfield PPM COMP 18/06/2015

1449468 23R/05L C/L & Edge Malms Run Airfield PPM COMP 18/06/2015

1449198 05L TDZ Clean Airfield PPM COMP 18/06/2015

1449197 05L TDZ Malms Run Airfield PPM OPEN 07/06/2015







1448617 05L TDZ Clean Airfield PPM OPEN 24/05/2015

1448616 05L TDZ Malms Run Airfield PPM COMP 18/06/2015







1448052 05L TDZ Clean Airfield PPM COMP 19/05/2015

1448051 05L TDZ Malms Run Airfield PPM OPEN 10/05/2015







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SUBMISSION OUTCOMES

• On the 14th July 2015, UK CAA SARG agreed to the following improved runwayedge AGL de-rating factors:

1. Runway 05L - 60% (40% degradation)

2. Runway 23R - 60% (40% degradation)

3. Runway 05R - 80% (20% degradation) ICAO recommended maximum

4. Runway 23L - 80% (20% degradation) ICAO recommended maximum

• Implemented Runway 05R–23L (R2) September 2015 with commissioning of newForward Scatter Sensors

• Implemented Runway 05L–23R (R1) October 2015 post safety case submissionwith existing Transmissometers

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OPERATIONAL & BUSINESS BENEFITS

• Increased Runway Capacity - increased AGL de-rating factors will improve IRVR

readings and defer the onset of Low Visibility Operations (LVO) and Procedures (LVP)

and hasten their cessation

• Dual Runway Operations - extended period of dual runway operations

• Increased Airport Capacity - with the onset of LVP being deferred and their cessation

hastened, will lead to a reduction in the time that aircraft are taxiing and holding on the

movement area i.e. ‘Block-to-Block’ taxiing in IRVR <200m

• Increased Colleague and External Contractor Productivity (Manoeuvring Area) -

with the deferment and hastened cessation of LVP, extended periods of asset

maintenance and development works plus no restriction on vehicle movements

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COMPARISON OF IRVR “AGL CREDITS” AT

UK AERODROMES

Three UK aerodromes have been awarded IRVR “AGL Credits” to date:

• London Heathrow – 60% (40% degradation) for Runways 09L- 27R and 09R – 27L

• London Gatwick – 60% (40% degradation) for Runway 08R - 26L

• Manchester - 60% (40% degradation) for Runway 05L – 23R and 80% (20%

degradation) for Runway 05R – 23L

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ANY QUESTIONS?

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