Runway overruns during landing are a major safety issue for commercial aviation. Airbus has developed the Runway Overrun Prevention System (ROPS) to help address this risk. ROPS uses avionics to continuously calculate the aircraft's landing distance and compare it to the remaining runway. It provides visual and audio alerts to pilots if a runway overrun is predicted. It can also automatically apply maximum braking if needed to help prevent an overrun. Airbus hopes making ROPS available globally will significantly reduce runway excursion accidents across the aviation industry.
1. Runway Excursions at Landing : Can We Reduce this Risk
Through Innovative Avionics?
BY: DY COMDT RAJYASHREE RAHORE
2. AGENDA
•Concept
•Statistics
•Causes of Runway Overruns
•Runway Overrun Prevention System (ROPS)
•ROPS, an already available solution on Airbus fleet
•Airbus decision to address globally this top safety priority
•Conclusion and Perspective
3. CONCEPT
• Commercial air transport accident statistics reveal that majority
of them occur during landing and runway overrun is the main
contributor
• Both aviation industry and regulatory agencies are working
towards the prevention of runway overruns
• While the regulatory agencies have come with a new requirement
for landing distance computations, Industry has come with
technological solutions to improve safety
• Honeywell has developed a system called Smartrunway
Smartlanding system, Airbus has developed a Runway Overrun
Prevention System (ROPS) for their aircraft
• We look into ROPS, its features and benefits
4. CONCEPT
• In heavy workload / stress situations most often associated to
accidents at landing, the crew is focused on the primary objective
and has difficulties to consider the alternative to Go-Around
• Runway Excursion Prevention design should be based on very
simple and strong principles
No Airborne Alert: Continuing landing is safe, no unprotected area
Airborne Alert: Go around, no unjustified increase of Go-Around rate
On-Ground Alert: Apply (and maintain) all deceleration means
5. STATISTICS
FLIGHT PHASE INCIDENT COUNT # PASSENGER
FATILITIES
CREW
FATALITIES
En Route (Cruise) 287 3,766 462
Ground - Taxi 301 24 18
Landing - Approach 1,120 8,718 1,802
Landing - Go Around 107 1,324 209
Landing - Initial Descent 178 2,450 415
Landing - Landing Roll 2,587 1,261 202
Take Off - Climb to Cruise 298 5,250 722
Take Off - Initial Climb 541 3,936 854
Take Off Aborted 113 146 20
Take Off Run 407 725 106
•Landing roll, the most critical phase
AIRBUS-WILLIS Analysis on 1985-2010 Period : Incidents Statistics
8. CAUSES OF RUNWAY OVERUNS
Weather
• Heavy Showers/Thunderstorms make the runway wet and slippery,
making it difficult for the pilot to control the aircraft during landing
• Winds also play a factor due to strong cross or tail winds making it
difficult to control the aircraft
• Inaccurate weather information passed by ATC to the pilot due to
slow updating of weather devices paint a wrong and misleading
picture to pilots causing them to miscalculate their landing
techniques
9. CAUSES OF RUNWAY OVERUNS
Pilot Error (Human Factors)
• Incorrect judgment in prevailing weather/runway conditions
leading to the aircraft landing too long or too fast on the runway
• Incorrect Braking Techniques applied upon landing resulting in
insufficient braking force applied rendering the aircraft unable to
stop in time
• Incorrect flare technique upon landing
• Failure to arm spoilers prior to landing
• "Mission-itis" Mindset making the pilot want to accomplish the
mission of landing the aircraft even in adverse weather conditions/
high stress situation when diverting is more appropriate
10. CAUSES OF RUNWAY OVERUNS
Aircraft
• Brakes malfunction
• Anti skid system malfunction
• Hydroplaning
Organization
• Money making especially with the poor economy is of primary
importance and the airline company would like all aircraft to land
and take off on time and not to divert even in bad weather as it
would result in delays and loss of money
11. EXISTING SITUATION
Main contributing factors to runway overrun at landing:
• No regulation defining realistic operational landing distances
• Unstable Approaches at 1000ft / 500ft
• Destabilization of the Approach at low or very low altitude
• Long flare
• Late selection of Reversers (MAX)
• Runway condition / friction lower than reported
• Reversers Max to Reverser Idle at usual procedure speed
• Too weak basic auto-brake setting
• Late or insufficient pedal braking (no auto-brake or after disconnection / override)
• Failures affecting landing distance
13. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-Description
Airbus has developed the Runway Overrun Prevention System (ROPS)
as a response to runway overrun events during the landing phase
This system has two functions
1. It keeps flight crew informed during approach, through its intuitive
interface, so that they can better make the necessary decision on
whether or not to go-around. This it does through a warning function,
called Runway Overrun Warning (ROW), which applies in flight and is
go around oriented
2. It assists and warns the flight crew after touch down on the
necessary actions to reduce the risk of runway overruns, or to limit
the overrun speed. This is done by an active protection function,
referred to as Runway Overrun Protection (ROP), which applies on
ground and is stop oriented
15. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-Design Objectives
• To significantly reduce runway overrun risk at landing, it was necessary to
Compute continuously, in real time aircraft landing distance and remaining
landing/stopping distance
• Compare it in real time with legal Landing Distance Available (LDA)
• Trigger, only when necessary, alerts with simple operating procedures
• Guarantee both reliability and not excessive margins
• Be approved through a dedicated EASA rule (European Aviation Safety
Agency). The ROPS is presently being certified for the A380, under a new
specific EASA performance regulation, in conjunction with the Brake To
Vacate (BTV) system
• Ensure consistency with future FAA TALPA rule (Take off/ Landing
Performance Assessment)
16. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
- The Runway Overrun Warning
• The two functions of ROPS system functionality described in the
following with the assumption that the ROPS is working in BTV
mode, as it allows the operation of all available system
functionalities
I) The Runway Overrun Warning from 500ft Radio Altitude (RA) until
Auto-Brake activation, ROW computes and displays predicted DRY
and WET lines on the Navigation Display (ND). It Triggers alerts in
case of predicted runway overrun conditions
• The DRY line provides a landing distance that can be reasonably
achieved, under normal operating conditions, on a dry runway
– This assumes a realistic manual or automatic landing, normal flare and
de-rotation technique
17. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
- The Runway Overrun Warning
– A deceleration equivalent to Auto-Brake in High mode
– A realistic dry runway with normal rubber contamination
– Idle reversers
– Margins for the system’s accuracy
• The WET line provides a landing distance that can be reasonably
achieved, under normal operating conditions, on a wet runway.
This assumes:
– A realistic manual or automatic landing, normal flare and de-rotation
technique
– A deceleration equivalent to Auto-Brake in High mode
– A realistic wet runway with normal rubber contamination
– Max reversers
– Margins for the system’s accuracy
18. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
- The Runway Overrun Warning
• Above 500ft RA,
– The computation of the DRY and WET lines is based on predicted data,
in the frame of Brake to Vacate achievable operational landing distance
check function
– Whenever a significant change of conditions occurs after BTV
preparation and operational landing distance check (TWR wind and de-
rotation technique change inserted in FMS for appropriate speed
managed, RWY condition change), a quick new operational landing
distance check is possible with minimal crew workload.
19. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
- The Runway Overrun Warning
• Below 500 ft RA,
– The computation of DRY and WET lines is based on measured data, by
computing the operational landing distance realistically achievable, in
real time
– This landing distance is calculated by taking account of the aircraft
weight, ground speed, wind conditions, landing configuration and
vertical/horizontal trajectory with respect to the runway threshold
20. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-The Runway Overrun Warning
• If the WET line moves beyond the end of the runway, it turns
amber on the Airport Navigation Display and a “IF WET : RWY
TOO SHORT” caution is displayed on the PFD
• If the DRY line moves beyond the end of the runway, the DRY
and WET lines turn red on the Airport Navigation Display, and
a “RWY TOO SHORT” . In addition, a “RUNWAY TOO SHORT!”
repetitive audio callout triggers below 200ft
23. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-The Runway Overrun Protection
II) From Auto-Brake activation until the aircraft stops, the
Runway Overrun Protection (ROP) will:
• Compute and display a stop bar on the Navigation Display
• Automatically increase the braking to maximum braking and
trigger appropriate alerts under predicted runway overrun conditions
• This braking is equivalent to that developed in a rejected take-
off by the Auto-Brake in RTO mode, which represents the maximum
physical braking capacity of the system
24. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-The Runway Overrun Protection
ROP : The stop bar on the ND
• The green stop bar indicates the best possible estimation of the
remaining landing roll-out distance, integrating the current
aircraft ground speed, deceleration rate and distance to the
runway end
• It is continuously updated taking account of the actual braking
conditions (runway friction and slope, thrust reversers, anti-skid,
etc…)
25. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-The Runway Overrun Protection
ROP : Automatic braking increase & alerts
• If the landing is performed despite the ROW warnings, or if the
aircraft’s deceleration is not sufficient, the ROP stop bar will
appear, or move, beyond the end of the runway
• In this situation, the path and stop bar turn red on the Airport
Navigation Display, and a “MAX REVERSE” warning is displayed on
the PFD
• Max physical braking is automatically applied (if Auto-Brake or
BTV selected). In addition, a repetitive “MAX REVERSE!” aural
alert is triggered if max reversers are not both selected. This
message will be repeated until the crew selects both max
reversers
26. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-The Runway Overrun Protection
• The “MAX REVERSE” warning remains on the PFD as long as the
stop bar shows a runway overrun condition, whether or not Max
Reverse is set
• If the stop bar still shows a runway overrun condition at 80 knots,
a “KEEP MAX REVERSE!” audio callout is triggered once, to warn
against undue Max Reverse de-selection as recommended in SOP
• Whenever the stop bar comes back inside the runway, and no
longer predicts a runway overrun condition, the ROP reverts and
allows normal BTV braking operation to resume
• Whenever the stop bar comes back inside the runway, and no
longer predicts a runway overrun condition, the ROP reverts and
allows normal BTV braking operation to resume
27. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-The Runway Overrun Protection
ND IN NORMAL CONDITION ND IN CASE OF ROP ALERT
29. RUNWAY OVERRUN PREVENTION SYSTEM (ROPS)
-Summary
• ROPS combined with the BTV mode allows the operation of all
available system functionalities:
- The system is informed of the landing runway selected by the crew
during the approach preparation
- Until 500ft RA, the crew may benefit from the display of the
“predicted” DRY and WET lines on the ND
- From 500ft RA, the crew will benefit from the display of the “real
time” DRY and WET lines
- From 500 ft RA, the crew will benefit from the ROW alerts
- At Auto-Brake activation, the crew will benefit from all ROP
functions: STOP bar display on the ND, automatic braking assistance
and PFD/audio alerts
31. AIRBUS DECISION TO ADDRESS GLOBALLY THIS TOP SAFETY
PRIORITY
• Runway overrun incidents are costly… in lives and treasure!
• Safer runway operations are a key enabler in ensuring sustainable
growth and long-term public acceptance of air transportation
• “In the opinion of the IFALPA team, with ROPS, Airbus has created
a system which will inevitably become a life saving addition to the
safety system.”
• Airbus has decided to share ROPS cutting-edge technology for the
benefit of the whole aviation industry
32. CONCLUSION AND PERSPECTIVE
Reduction of runway excursions/overruns
A top priority for all aviation segments
ROPS on-board technology
A game changer… like EGPWS and TCAS
Complex and long development
A real know-how
33. CONCLUSION AND PERSPECTIVE
• Consistent with future rules (FAA TALPA) and future Airbus in-flight
documentation
• Minimum training
• Clear SOP
• No impact on Go-Around rate… except when justified!
• Homogeneous design on complete Airbus fleet at least
• No hide of vital call outs, i.e. “RETARD”
• Easy to install in one overnight visit
• Delivered ready to fly
• No complex tuning and SOP to be designed and justified by airline
34. CONCLUSION AND PERSPECTIVE
NTSB Safety Recommendations to FAA (March 29, 2011)
“Actively pursue with aircraft and avionics manufacturers the development of
technology to reduce or prevent runway excursions and, once it becomes
available, require that the technology be installed.“
ROPS is that requested technology…
…and it is now accessible for all aircraft manufacturers!
