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The European Organisation for the Safety of Air Navigation EUROCONTROL – Univ. Politehnica of Bucharest & ROMATSA Project Volcanic Ash Safety presented.

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Presentation on theme: "The European Organisation for the Safety of Air Navigation EUROCONTROL – Univ. Politehnica of Bucharest & ROMATSA Project Volcanic Ash Safety presented."— Presentation transcript:

1 The European Organisation for the Safety of Air Navigation EUROCONTROL – Univ. Politehnica of Bucharest & ROMATSA Project Volcanic Ash Safety presented at ICAO IVATF, Montreal, July 2011

2 Ash Safety Prof. dr. ing. C. BERBENTE S.l. dr. ing. mat. A. BOGOI Conf. dr. ing. T. CHELARU S.l. drd. Ing. C. E. CONSTANTINESCU, MBA Prof. dr. ing. S. DANAILA D. DIMITRIU, PhD Drd. Ing. V. DRAGAN S.l. dr. ing. D. D. ISVORANU E. HALIC, M.D. S.l. dr. ing. L. MORARU Conf. dr. dr. ing. O. T. PLETER, MBA As. drd. A. RAJNOVEANU, M.D. Prof. dr. ing. V. STANCIU Conf. dr. ing. M. STOIA-DJESKA Drd. Ing. D. C. TONCU R. ULMEANU, M.D. PhD Studies on the Measurement and the Effects of the Volcanic Origin Particles in Suspension in the Atmosphere on the Safety of Aircraft

3 Ash Safety Presentation TitleAsh Safety Research Results Version / Date / Author1.1 / / OTP BeneficiaryEUROCONTROL Keywordsvolcanic ash, volcanic dust, sand aerosols, impact on aviation, impact on flow management

4 4 Presentation Overview 1.Introduction – research subject, objectives, and relevance 2.Risks, vulnerability, and the scale of the phenomenon 3.Ash vs. Dust; sand aerosols; why does particle size matter? 4.Extent of the danger area: volcanic ash cloud estimation 5.Human health effects 6.Concentration measurement and forecasting 7.Selected conclusions

5 5 Research Subject Studies on the Measurement and the Effects of the Volcanic Origin Particles in Suspension in the Atmosphere on the Safety of Aircraft Research Objectives: to provide objective, relevant, and scientifically validated information for the future decisions on the air traffic in volcanic ash contaminated atmosphere, for the best trade-off for the most fluent air traffic under the circumstances, with uncompromised flight safety. Ash Safety Project was triggered by Eyjafjalla

6 6 Read the Scientific Report to find that … Visible volcanic ash cloud is dangerous to aviation, but it does not travel very far (1-200 NM, max. 550 NM down the wind in the greatest eruption in history, Pinatubo 1991); Volcanic dust contamination in concentrations comparable to that current for sand aerosols (410 3 g/m 3 ) is not a safety issue and rather a maintenance issue (like flying at Ryadh or Cairo); Tactical avoidance of volcanic dust contamination based on on-board instruments is not practical;

7 7 Worries about volcanic ash/dust contamination impact on the human respiratory system of the occupants of an aircraft are not justified; Volcanic Ash/Dust Concentration is a noisy random variable, very difficult to measure with certainty and consistency; the concentration measurements should be averaged on a cubic hectometre scale (1,000,000 m 3 ; the hectometric principle); Concentration measuring unit: 1 kg/hm 3 = 10 3 g/m 3 Read the Scientific Report to find that … (2)

8 8 Volcanic Dust Concentration is less important than the size distribution of particles; volcanic dust particles resulting from differential sedimentation in the natural atmospheric dispersion process do not cause abrasion and/or glass deposits inside the turbofan engine, regardless the concentration; The best option to address volcanic ash/dust problems in the future is a quick reaction algorithm to estimate volcanic ash cloud and a prediction based on an Euler dispersion model with data assimilation from hectometric in-situ sensors Read the Scientific Report to find that … (3)

9 9 Parts / OccupantsCauseEffectResponse Turbine engines fuel injection and combustor deposits of melted ash (glassy coatings) surge, shut-down, difficult restart in flight idle thrust, evasive maneuver Turbine engines clogging the turbine cooling vents overheatingidle thrust, evasive maneuver Pitot-staticclogging the sensors unreliable air speed indications attitude-based flying, indicated air speed deducted from ground speed and wind velocity Turbine enginesabrasion with hard particles wear of fan, compressor, turbine, transmission idle thrust, evasive maneuver Pneumatic controlsclogging the ventsfailureevasive maneuver Windshield, body, wings, empennage cracks, abrasion with hard particles wear, opaquenessevasive maneuver Avionics, on-board instruments clogging air-cooling vents, electrostatic discharges overheating, malfunctionevasive maneuver Human occupants breathing contaminated air, eye cornea contact with ash/dust particles respiratory problems, eye damage nose breathing, replace contact lenses with eyeglasses Turbine engines, body and instruments metallic parts acidity, exposure to associated SO 2 and sulfurous acid corrosion (in time)maintenance check and replacement What can go wrong in a VA encounter

10 10 Air Breathing Order of Magnitude Description Affected Hardware or Liveware 1,000 m 3 /s High flow non-filtered air breathing turbine engines 100 m 3 /s Directly exposed to airflow windshield, empennage, body and wing 0.01 m 3 /s Low flow non-filtered air breathing human occupants, Pitot-static sensors, computers, electrical engines and other air- cooled parts IrrelevantAir breathing through filters piston engines, air- cooled parts with air filters Vulnerability ~ Air Breathing Flow

11 11 Turbofan engines are huge vacuum cleaners, sucking an average of 1,000,000 m 3 = 1 hm 3 each in 10 minutes of flight The Silica particles in the core flow will be deposited as glass in the combustion chamber and on the HPT One kilogram of deposits is enough to cause turbine overheating and even engine failure (restarting is possible though outside the contaminated area) Vulnerability is Critical for Turbofan Engines

12 12 Characteristic time scope = 10 minutes of flight = exposure of an average turbine engine to 1,000,000 m 3 = 1 hm 3 of air 10 minutes is the maximum exposure of an aircraft engaged in an evasive manoeuver after an unanticipated volcanic ash encounter Scale of phenomenon = 1 Cubic hectometre

13 13 Example of quantity of contaminant accumulated in 10 minutes of flight in a concentration of g/m 3 Air Breathing Order of Magnitude Quantity of contaminant accumulated in 10 minutes flight at a concentration of g/m 3 Affected Hardware or Liveware 1,000 m 3 /s1.2 kgturbine engines 100 m 3 /s120 g windshield, empennage, body and wing 0.01 m 3 /s12 mg human occupants, Pitot-static sensors, computers, electrical engines and other air-cooled parts Irrelevant0 gpiston engines, air-cooled parts with air filters

14 Terminology discriminator: Volcanic Ash = 1/16 mm – 2 mm (Coarse ash) Volcanic Dust < 1/16 mm (Fine ash) Volcanic AshVolcanic Dust Particle size (µm) < 63 Location1-200 NM around the volcano Floats around the world Sedimentation time 1/2 hour (for 1 mm)23 Days (for 10µm) 14

15 15 Volcanic Dust < 1/16 mm (Fine ash) Volcanic Ash = 1/16 – 2 mm (Coarse ash) Ash vs. Dust

16 16 Volcanic Dust Haze (Contamination) Thin layers of dust only visible from selected viewing angles or from a far distance e.g. satellite Volcanic Ash Cloud Cloud clearly visible to naked eye from all angles, clear boundary Visible Volcanic Ash Cloud vs. Volcanic Dust Contamination

17 17 Eruption Case Study: H=10 km, W=50 kts Falling speed (m/s) from: 1 mm (ash) 100 m (ash) 10 m (dust) 1 m (dust) 10,000 m ·10 5 8,000 m ·10 5 6,000 m ·10 5 4,000 m ·10 5 2,000 m ·10 5 Average falling speed (m/s) ·10 5 Ash: Dust 1/16 mm = 62.5 mm Ash: visible, dangerous, local / short term Dust: Less threatening, globe trotter / long term

18 1 mm (ash) 100 m (ash) 10 m (dust) 1 m (dust) Number of particles in 1 m 3 at a concentration of 2·10 3 g/m 3 (2 kg/hm 3 ) 32,7282,728,3702,728,370, mm (ash) 100 m (ash) 10 m (dust) 1 m (dust) Sedimentation Time (h) ,682.5 Distance travelled (NM) ,7801,984,125

19 Sand Blasting Effect on Particle Size Effects of particle impact velocity and particle size on substrate roughness, from Weidenhaupt, W., 1970, Über den Einfluß der Entzunderungs- und Ziehbedingungen auf die, Oberflächen-Feingestalt von Stab- und Profilstahl, Dissertation, RWTH Aachen, Germany. as referenced by Momber, A., 2008, Blast Cleaning Technology, Springer

20 20 Abrasion Caused by Ash vs. Dust Ash follows airflow streamlines imperfectly and impacts walls: inertial forces > aerodynamic forces Dust follows airflow streamlines: inertial forces << aerodynamic forces

21 21 Glass Coating / Clogging by Ash vs. Dust

22 22 Relative Safety Risk vs. Size: m (qualitative representation)

23 23 Highest-Risk Dust Particle Segment: 1-10 m Turbofan engines (tests on simulated engines): Larger> The turbofan functions like a centrifugal separator (no issue with the volcanic ash/dust in the by-pass flow) Smaller> Particles exit the engine without touching any wall Human respiratory system: Larger> filtered by body barriers Smaller> get out with expiration (not retained in the lungs)

24 Volcanic Ash / Dust / Sand Aerosols Volcanic Ash CloudVolcanic Dust Contamination Sand Aerosol Contamination VisibilityClearly visible from all angles, easily identifiable by dark colour, distinct boundary Visible only from selected angles, hard to distinguish, visible in satellite imagery Visible sometimes from selected angles, visible in satellite imagery Where?Within NM of the eruption up to 500 NM Very large areas (>1000 NM in size) Large areas Typical Concentrations (1 kg/hm 3 = 10 3 g/m 3 ) 1000 kg/hm kg/hm 3 Particle size range (µm) Floatability in atmosphere (age) 12 Hours (due to ash- dust differentiated sedimentation) 6 Days (traces remain for years) 3 Days 24

25 Volcanic Ash Cloud Volcanic Dust Contamination Sand Aerosol Contamination Aviation Safety Risk Serious incidents, no injury accidents None on recordNone Impact on aviation LocalGlobal due to misinterpretation Maintenance issues Source: Prof. Ulrich Schumann, DLR Institute of Atmospheric Physics, NASA Earth Observatory 25

26 26 Severity vs. Frequency Safety Risk

27 16/02/2007 = 14 aircraft: windshield failures within 3½h 19/01/2011 = 3 aircraft: windshield failures within ½h 27 Ash-Sized Sand – a New Safety Concern (Denver, CO) Source for photos: Skywest Canadair CRJ-700 on behalf of United Airlines, flight OO-6761/UA-6761 from Denver, CO to Cleveland, OH (USA), reported a cracked windshield during initial climb out of runway 34R and returned to Denver. Skywest Canadair CRJ-200 on behalf of United Airlines, registration N978SW performing flight OO-6576/UA-6576 from Denver, CO (USA) to Winnipeg, MB (Canada), reported a windshield cracked during initial climb out of runway 34L and returned to Denver Delta Airlines Boeing , flight DL-1916 from Denver, CO to Atlanta, GA (USA), during initial climb out of runway 34L reported a cracked windshield and returned to Denver

28 28 Future Eruption First Reaction Checklist Location of the eruption / time: LAT, LONG, HHMMz, DDMMYY {repeat until eruption ends} How tall is the eruption column? ECH (m AMSL) Download wind profile in the area (e.g. from NOAA): WD/WV Calculate how far will the volcanic ash cloud go: VA MAX Draw a contour with VA MAX as major axis on the map: DA Ash4D

29 29 Volcanic Ash Danger Area Shape: defined by the variability of wind direction and amplitude of wind velocity

30 30 Volcanic Ash Danger Area How far does the VA travel? Function of: H (height of eruption column), FL (flight level), and WV (wind velocity) Eruption columnH (m)30000 Flight Level(100 ft)100 Wind Velocity(kts)50 Danger area(NM)535 Pinatubo 1991 Eruption columnH (m)9000 Flight Level(100 ft)100 Wind Velocity(kts)100 Danger area(NM)236 Eyjafjalla 2010 Eruption columnH (m)3500 Flight Level(100 ft)30 Wind Velocity(kts)20 Danger area(NM)21 Etna 2011

31 31 Why 500 NM for Pinatubo = 250 NM for Eyjafjalla? Slide from Jacques Renvier, CFM/SNECMA, Atlantic Conference on Eyjafjallajokull, Keflavik 2010

32 32 Why 500 NM for Pinatubo = 250 NM for Eyjafjalla? (Kilauea, Hawaii 28 years continuous eruption)

33 33 Conclusions on Human Health Effects What was studied: passengers (short-term) and crew (long- term) exposure to volcanic dust concentrations of g/m 3 Well under limits for short time exposure and even lower than those for chronic exposure Reasonable to anticipate no risk for silicosis or lung cancer in passengers and crew members Concentration lower than environmental Silica aerosols in some parts of the world (e.g. Ryadh, Cairo)

34 34 Concentration: volatile, noisy, measured indirectly Direct and consistent methods to measure concentration in real time: none Indirect methods, subject to large methodical errors and measuring historical values of concentration along a line of sight/movement: In-situ sampling; Ground up-looking LIDAR; Airborne down-looking LIDAR; Ground optical photometre; Satellite infrared image.

35 35 Concentration measurement problems: 1. scale of phenomenon and 2. consistency All these technologies deployed in the same area would yield different results

36 36 Hectometric Principle: Why do concentration measurements require averaging at the 1 hm 3 scale? In this example we assume we want to measure the brightness of a halftone image

37 37 Future sensors are shortsighted and the scale of the phenomenon is larger

38 38 Types of concentrationsActualMeasured Forecasted Blindly (open- loop) Forecasted with Data Assimilation When they are available (hours)neverT+2H T18H (up to T180H) Uncertainty due to initial data of the eruption (orders of magnitude) Uncertainty due to the Eulerian diffusion model (orders of magnitude) every 24 hours Uncertainty due to the measurement techniques -0.1 – 1-- Area coverage- Very local 1 Global Overall errors0Significant Very large and rapidly increasing in time Large Relevance to IFR flight operations- Tactical avoidance Flight planning Relevance to ATM-Forecasts Validation Airspace management, Flow management [1] [1] Except the satellite images, which provide a global view

39 Airborne in situ hectometric concentration measurement unit isokinetic 39

40 VADHCMU Volcanic Ash/Dust Hectometric Concentration Measurement Unit 1.Airborne 6 channel (3 wavelengths plus polarizations) backscattering infrared LIDAR, 2.Ground based (mobile) optical photometre, and 3.Airborne insitu hectometric concentration measurement unit. A consistent and systematic measurement technology for data assimilation: 40

41 41 Selected Conclusions Extending the term of volcanic ash cloud as per ICAO Doc9691 to the volcanic dust haze is wrong and misleading; Size of the particles matters more than concentration as impact on aircraft and aircraft turbofan engines; Predicting concentrations using a dispersion model with data assimilation from a systematic daily measurement scheme using hectometric in-situ samplers is the best choice for a way forward; Immediate reaction to a VA threat should be based on a simple kinematic model of the extension of the volcanic ash cloud and not on chasing the dust going round the globe. Please, read the final report for more!

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