The purpose of an Engineered Material Arresting System (EMAS) is to stop an aircraft overrun with no human injury and minimal aircraft damage. The aircraft is slowed by the loss of energy required to crush the EMAS material. An EMAS is similar in concept to the runaway truck ramp made of gravel or sand. It is intended to stop aircraft that have overshot a runway when there is an insufficient free space for a standard runway safety area (RSA).
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Guided by, Presented by,
Ms. SARITHA JASWANT CHINNU MOHANAN
Asst. Professor Reg No: 11134435
Civil Department S7 Civil
KVM CE & IT KVM CE & IT
3. CONTENTS3
INTRODUCTION
MATERIAL REQUIREMENTS
MATERIAL COMPOSITION OF ARRESTOR BED
DESIGN CONSIDERATIONS
ARRESTOR BED GEOMETRY
THEORY OF OPERATION
EMAS INSTALLATIONS
SUCCESS RECORDS
CASE STUDIES
ADVANTAGES AND DISADVANTAGES
CONCLUSIONS
REFERENCE
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Aircraft overruns are a frequent occurrence during
landing & takeoff.
It is reported to be the 4th largest cause of airline
fatalities.
Overrun :
• Occurs when aircraft passes beyond the end of
runway during aborted takeoff or while landing
• Responsible for 97% runway accidents
• 30% of all aircraft accidents
To minimize the hazards of overruns, FAA put
forward the concept of a safety area beyond the
runway end into airport design standards.
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Continued…
But construction of RESA becomes impracticable in
airports where there is no area available due to natural
obstacles.
EMAS is a crushable concrete that is placed at the end of
runways in order to stop the failed takeoff or landing of a
fully loaded airliner.
The EMAS bed is composed of blocks of foamed cement
concrete that are joined and sealed on top.
EMAS has an outstanding success record on all incidents
occurred in past years.
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MATERIAL REQUIREMENTS
Water-resistant.
Not attract birds, wildlife or other creatures.
Constant strength and density characteristics.
Resistant to deterioration. (Salts, aircraft fuels, water and UV rays.)
Non sparking and non combustable.
Should not promote any plant growth.
Non flammable.
9. MATERIAL COMPOSITION
Component Quantity
Cement type II A-LL 42,5 R [kg] 05
Limestone filler [kg] 10
Expanded polystyrene [L] 42
Water [L] 07.90
Air entraining agent [g] 81.75
w∕c ratio 01.58
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Recommended by the FAA advisory circular (FAA 2005)
10. DESIGN REQUIREMENTS
Based on:
Weight of the biggest aircraft served by the airport.
Aircraft parameters like type, landing gear configuration and
tyre pressure.
Available runway safety-area space.
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1. Concept 4. Drainage
2. Location 5. Width
3. Design 6. Base
11. Concept:
Designed to stop overrunning aircrafts by exerting
predictable deceleration forces on its landing gear as the
EMAS materials deforms.
Must be designed for 20 year service life.
Location:
Located beyond the end of the runway and centered on the
extended runway centerline.
Usually begin at some setback distance from the end of the
runway to avoid damage due to jet blast and undershoots.1
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12. Design:
EMAS performance is dependent not only on aircraft
weight, but also on landing gear configuration and tyre
pressure.
Design method must be derived from field or lab tests.
Testing may be based either on passage of an actual
aircraft or an equivalent single wheel load through a test
bed.
Drainage:
The EMAS must be designed to prevent water from
accumulating on the surface of the EMAS bed, the runway
or the runway safety area.1
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13. ARRESTOR-BED GEOMETRY
The arrestor system is constructed above paved material.
The arrestor bed begins with a 229mm thickness.
The bed is sloped to attain a 610mm thickness over a 42.7m
length.
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A constant thickness of 610 mm for 42.7m.
Bed sloped from 610mm to 762mm over a 7m length.
762mm thickness for remaining portion of the arrestor-bed
length.
16. THEORY OF OPERATION
As an aircraft enters the bed, wheel crushes the
EMAS material creating a wheel-tire interface.
This interface provides resistive loads to decelerate
the aircraft.
Drag forces are induced on the landing gear.
As the aircraft transition from the rigid pavement
lead to the arrestor bed, landing gear strut
experiences a vertical force drop at the arrestor bed
start.
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EMAS INSTALLATIONS
o Installations constructed only by FAA approved
supplier- ESCO.
o Suited for airports that don’t have adequate space to
meet the required dimensions set forth by FAA.
o 1st in JFK,1996.
o 74 EMAS installed since 1996. (47 U.S. airports)
o 15 EMAS installations remain to be completed during
2015-2016.
o Average of 4 installations yearly occurs in U.S.
o After an EMAS arrestment, only the damaged blocks
need to be replaced.
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INSTALLATIONS OUTSIDE U.S
In China, Spain, Taiwan
Jiuzhai Huanglong Airport, Sichuan Province,
China
Madrid-Barajas International Airport, Madrid,
Spain
Songshan Airport, Taipei City, Taiwan
27. SUCCESS RECORDS27
80 EMAS installed around the world.
Majority in US. (about 74 in 47 airports)
9 aircrafts arrested.
More than 240 people have been protected
from serious injury only due to EMAS.
No negative result is reported yet.
29. McDonnell Douglas MD-11F ,operated by Gemini
Air Cargo.
Due to a late touchdown in normal night visibility , a
runway overrun was resulted.
Only minor damage occurred to the air craft.
All the occupants were uninjured.
29 1. John F-Kennedy Airport incident
May-30, 2003
31. Bombardier CRJ 200 , operated by PSA
Airlines
High speed rejected take off in normal day
visibility.
None of the 34 occupants were injured.
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2. Charleston Airport Arrestment,
19 Jan. 2010
33. Gulfstream G-IV , operated by Jennifer
Friedberg (General Aviation Flying Service)
Due to a deep landing in normal day
visibility, aircraft overran the end of the
runway at a high speed.
None of the occupants were injured.
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3. Teterboro Airport incident on Oct 1, 2010
35. ADVANTAGES
The EMAS material is non-threatening to
Aircraft engines
Avoid foreign-object damage (FOD)
Non-combustible
Highly energy absorbent
Has predictable load-deflection behaviour
Avoids over cost
Avoids environmental issues
Enhance airport and aircraft safety
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36. DISADVANTAGES
The main disadvantage of the EMAS is its
less durability.
Has only 20 year service life with a
maintenance after every 10 year.
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37. DEVELOPMENTS IN EMAS
Lot of researches are carried out in account of the
improvement, cost reduction, durability..
“EMASMAX” is the third generation upgrade of
the EMAS .
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EMASMAX arrestor beds are composed of blocks of
light weight, crushable cellular cement material.
Easy and quick to install.
Improved durability and less cost.
Maximizes the runway safety.
EMASMAX
39. CONCLUSIONS
The issues of risk of safety related to the available RESA in
airports can be solved by EMAS.
Ideal solution for the aircraft overrun problem is the FAA
approved Engineered Material Arresting System (EMAS).
EMAS is highly economic while considering the life cost and
aircraft cost.
Research should be conducted to improve the service life of
EMAS.
EMAS should be installed in more airports to avoid the overrun
and RESA issues.
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40. REFERENCE
Wail N. Al-Rifaie , Nabeel I. Al-Sarraj, Salama G. Sulaiman,
‘‘Development of an Engineered Material Arresting System to
Protect Overrun Aircraft” , September 4, 2014.
Matthew A. Barsotti, John Mark Howard Puryear, David J.
Stevens ,“Developing Improved Civil Aircraft Arresting
Systems” , ACRP report 29, 2013.
Ernest Heymsfield, W. Micah Hale, Tyler L. Halsey, “Aircraft
Response in an Airfield Arrestor System during an Overrun”
ASCE library, 15 March 2012.
E. Heymsfield, W. M. Hale and T. L. Halsey, “Optimizing Low
Density Concrete Behaviour for Soft Ground Arrestor
Systems”, 2012.
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41 Continued..
Chun- shui JIANG, Hong- yu YAO, Xian- bo
XIAO1, Xiang- jun KONG, Ya- jie SHI ,
“Phenomena of Foamed Concrete under Rolling of
Aircraft Wheels”, Science Tech 2014.
Marco Bassani, Emanuele Sacchi and Fulvio
Canonico, “ Performance Prediction for Innovative
Crushable Material Used in Aircraft ArrestorBeds” ,
2011.
Ernest Heymsfield, “Sensitivity Analysis of
Engineered Material Arrestor Systems to Aircraft
and Arrestor Material Characteristics”, 2014.