SWA 737 overrun at BUR - Dec 6 2018
EMAS is an expense to the airport or the city/authority. A hull loss doesn't cost them anything - that is a cost to the airline or its insurer or the leasing co., or whoever.
Different pots of money controlled by different people and entirely separate budgets.
Unless airlines want to pay for their own EMAS installations at difficult airports they serve. Or threaten to stop service unless the airport pays for EMAS. Or lobby the FAA or equivalent regulators to lean on the airports to do it.
Different pots of money controlled by different people and entirely separate budgets.
Unless airlines want to pay for their own EMAS installations at difficult airports they serve. Or threaten to stop service unless the airport pays for EMAS. Or lobby the FAA or equivalent regulators to lean on the airports to do it.
A divert would certainly be an option, but if the airport was above landing minimums and your perfromance calculations indicated the aircraft could be stopped on the runway, would you divert?
This SAFO is important,all crew should have thought about the practical implications of it.
Subject: Turbojet Braking Performance on Wet Runways
Purpose: This SAFO warns airplane operators and pilots that the advisory data for wet runway landings
may not provide a safe stopping margin under all conditions.
Background: Landing overruns which occur on wet runways typically involve multiple contributing factors such as long touchdown, improper use of deceleration devices, tailwind and less available friction than expected. Several recent runway landing incidents/accidents have raised concerns with wet runway stopping performance assumptions. Analysis of the stopping data from these incidents/accidents indicates the braking coefficient of friction in each case was significantly lower than expected for a wet runway as defined by the Federal Aviation Administration (FAA) in Federal Air Regulation (FAR) 25.109 and Advisory Circular (AC) 25-7C methods. These incidents/accidents occurred on both grooved and un- grooved or non-Porous Friction Course overlay (PFC) runways. The data indicates that applying a 15% safety margin to wet runway time-of-arrival advisory data as, recommended by SAFO 06012, may be inadequate in certain wet runway conditions.
Discussion: The root cause of the wet runway stopping performance shortfall is not fully understood at this time; however issues that appear to be contributors are runway conditions such as texture (polished or rubber contaminated surfaces), drainage, puddling in wheel tracks and active precipitation. Analysis of this data indicates that 30 to 40 percent of additional stopping distance may be required in certain cases where the runway is very wet, but not flooded.
For non-grooved or non-PFC runways, experience has shown that wheel braking may be degraded when the runway is very wet. If active moderate or heavy precipitation exists, the operator should consider additional conservatism in their time-of-arrival assessment.
For grooved or PFC runways, experience has shown that wheel braking is degraded when the runway is very wet. If active heavy precipitation exists; the operator should consider additional conservatism in their time-of-arrival assessment.
Possible methods of applying additional conservatism when operating on a runway which experience has shown is degraded when very wet are assuming a braking action of medium or fair when computing time- of-arrival landing performance or increasing the factor applied to the wet runway time-of-arrival landing performance data.
Distributed by: AFS-200 AFS-240
In some cases manufacturers have provided improved performance landing data for grooved/PFC runways. This improved performance grooved/PFC runway landing data should only be used when following any other Airplane Flight Manual (AFM) requirements and/or requirements of section 7 of AC 121-195(d)-1a, “FAR PART 121 OPERATIONAL APPROVALS OF AIRCRAFT WITH OPERATIONAL LANDING PERFORMANCE ON WET RUNWAYS” or equivalent operation specification.
Some of the wet runway braking shortfalls have occurred at US airports where Title 14 of the Code of Federal Regulations (14 CFR) 139 runway design and maintenance standards apply. Operators should be aware that the aforementioned runway design and maintenance standards may not be met in other countries. Many country’s standards for design, construction and maintenance of runways are based on International Civil Aviation Organization (ICAO) Annex 14 runway design and maintenance standards, however they may lack oversight in implementation of these standards. Also, outside of the United States there is often less usage of grooving or PFC overlay which, when present, will normally aid in drainage and mitigate the risk of hydroplaning during active precipitation, thus impacting braking action.
Operators should be aware of the runway maintenance program and wet runway friction capability at the airports to which they operate. Mitigation should be considered at airports where aircraft operators have reason to suspect the runway’s capability of creating good friction while very wet during active precipitation.
As stated initially the other common contributing factors for wet runway excursions are long touchdown, improper application of deceleration devices and tailwind landings. Aircraft operators should review their flight training programs to ensure flight crews are familiar with the assumptions used in creating the data used for the time-of-arrival assessment such as the assumed distance from threshold to touchdown, recommended uses of deceleration devices; aircraft operators should also ensure flight crews are aware of the wind assumed in the original dispatch calculations for the flight. Advisory Circular 91-79A has been recently updated to address these issues and operators should review the guidance contained therein.
In 2015 a committee of manufacturers and regulators will further investigate the issues with wet runway braking performance shortfalls. Airport and aircraft operators will be included in this investigation.
Recommended Action: Directors of safety and directors of operations (Part 121); directors of operations (part 135, and 125), program managers, (Part 91K), and Pilots (Part 91) should take appropriate action within their operation to address the safety concerns with landing performance on wet runways discussed in this SAFO.
Contact: Questions or comments regarding this SAFO should be directed to the Air Transportation, New Program Implementation Branch, AFS-240 at (202) 267-8166.
Purpose: This SAFO warns airplane operators and pilots that the advisory data for wet runway landings
may not provide a safe stopping margin under all conditions.
Background: Landing overruns which occur on wet runways typically involve multiple contributing factors such as long touchdown, improper use of deceleration devices, tailwind and less available friction than expected. Several recent runway landing incidents/accidents have raised concerns with wet runway stopping performance assumptions. Analysis of the stopping data from these incidents/accidents indicates the braking coefficient of friction in each case was significantly lower than expected for a wet runway as defined by the Federal Aviation Administration (FAA) in Federal Air Regulation (FAR) 25.109 and Advisory Circular (AC) 25-7C methods. These incidents/accidents occurred on both grooved and un- grooved or non-Porous Friction Course overlay (PFC) runways. The data indicates that applying a 15% safety margin to wet runway time-of-arrival advisory data as, recommended by SAFO 06012, may be inadequate in certain wet runway conditions.
Discussion: The root cause of the wet runway stopping performance shortfall is not fully understood at this time; however issues that appear to be contributors are runway conditions such as texture (polished or rubber contaminated surfaces), drainage, puddling in wheel tracks and active precipitation. Analysis of this data indicates that 30 to 40 percent of additional stopping distance may be required in certain cases where the runway is very wet, but not flooded.
For non-grooved or non-PFC runways, experience has shown that wheel braking may be degraded when the runway is very wet. If active moderate or heavy precipitation exists, the operator should consider additional conservatism in their time-of-arrival assessment.
For grooved or PFC runways, experience has shown that wheel braking is degraded when the runway is very wet. If active heavy precipitation exists; the operator should consider additional conservatism in their time-of-arrival assessment.
Possible methods of applying additional conservatism when operating on a runway which experience has shown is degraded when very wet are assuming a braking action of medium or fair when computing time- of-arrival landing performance or increasing the factor applied to the wet runway time-of-arrival landing performance data.
Distributed by: AFS-200 AFS-240
In some cases manufacturers have provided improved performance landing data for grooved/PFC runways. This improved performance grooved/PFC runway landing data should only be used when following any other Airplane Flight Manual (AFM) requirements and/or requirements of section 7 of AC 121-195(d)-1a, “FAR PART 121 OPERATIONAL APPROVALS OF AIRCRAFT WITH OPERATIONAL LANDING PERFORMANCE ON WET RUNWAYS” or equivalent operation specification.
Some of the wet runway braking shortfalls have occurred at US airports where Title 14 of the Code of Federal Regulations (14 CFR) 139 runway design and maintenance standards apply. Operators should be aware that the aforementioned runway design and maintenance standards may not be met in other countries. Many country’s standards for design, construction and maintenance of runways are based on International Civil Aviation Organization (ICAO) Annex 14 runway design and maintenance standards, however they may lack oversight in implementation of these standards. Also, outside of the United States there is often less usage of grooving or PFC overlay which, when present, will normally aid in drainage and mitigate the risk of hydroplaning during active precipitation, thus impacting braking action.
Operators should be aware of the runway maintenance program and wet runway friction capability at the airports to which they operate. Mitigation should be considered at airports where aircraft operators have reason to suspect the runway’s capability of creating good friction while very wet during active precipitation.
As stated initially the other common contributing factors for wet runway excursions are long touchdown, improper application of deceleration devices and tailwind landings. Aircraft operators should review their flight training programs to ensure flight crews are familiar with the assumptions used in creating the data used for the time-of-arrival assessment such as the assumed distance from threshold to touchdown, recommended uses of deceleration devices; aircraft operators should also ensure flight crews are aware of the wind assumed in the original dispatch calculations for the flight. Advisory Circular 91-79A has been recently updated to address these issues and operators should review the guidance contained therein.
In 2015 a committee of manufacturers and regulators will further investigate the issues with wet runway braking performance shortfalls. Airport and aircraft operators will be included in this investigation.
Recommended Action: Directors of safety and directors of operations (Part 121); directors of operations (part 135, and 125), program managers, (Part 91K), and Pilots (Part 91) should take appropriate action within their operation to address the safety concerns with landing performance on wet runways discussed in this SAFO.
Contact: Questions or comments regarding this SAFO should be directed to the Air Transportation, New Program Implementation Branch, AFS-240 at (202) 267-8166.
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EMAS is an expense to the airport or the city/authority. A hull loss doesn't cost them anything - that is a cost to the airline or its insurer or the leasing co., or whoever.
Different pots of money controlled by different people and entirely separate budgets.
Unless airlines want to pay for their own EMAS installations at difficult airports they serve. Or threaten to stop service unless the airport pays for EMAS. Or lobby the FAA or equivalent regulators to lean on the airports to do it.
Different pots of money controlled by different people and entirely separate budgets.
Unless airlines want to pay for their own EMAS installations at difficult airports they serve. Or threaten to stop service unless the airport pays for EMAS. Or lobby the FAA or equivalent regulators to lean on the airports to do it.
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No, I’m honest to say that I would not divert in this situation.
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Oh dear - a landing in driving rain onto a short runway with an 11kt tailwind followed by the inevitable meeting with Uncle EMAS. When will they ever learn?
Pre-Xmas tea and biscuits without mince pies I fancy
Pre-Xmas tea and biscuits without mince pies I fancy
How do you figure? Tower reported winds 270/10 to them right before landing. Before that, a higher than a 10 knot tailwind component reported on ATIS would have locked out their landing data numbers and said no can do when they retrieved it,
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They’ve possibly landed long on a short wet runway with a TWC approaching limits. Could’ve been carrying excess speed (easy to do on an NG) and maybe an inappropriate autobrake setting and possible late application of reverse thrust (think Midway Accident a few years back). All speculation and I sympathise with the guys at the coal face. The aircraft is renowned to bite in similar scenarios. I’ll be interested to see the NTSB report when it becomes available however I do wonder what’s pushing people into accepting approaches on to RW08 with a tailwind at BUR?
Last edited by Callsign Kilo; 7th Dec 2018 at 22:10.
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NTSB 830
§830.2 Definitions.
As used in this part the following words or phrases are defined as follows:
Aircraft accident means an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage. For purposes of this part, the definition of “aircraft accident” includes “unmanned aircraft accident,” as defined herein...
...Substantial damage means damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, and damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips are not considered “substantial damage” for the purpose of this part.
As used in this part the following words or phrases are defined as follows:
Aircraft accident means an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage. For purposes of this part, the definition of “aircraft accident” includes “unmanned aircraft accident,” as defined herein...
...Substantial damage means damage or failure which adversely affects the structural strength, performance, or flight characteristics of the aircraft, and which would normally require major repair or replacement of the affected component. Engine failure or damage limited to an engine if only one engine fails or is damaged, bent fairings or cowling, dented skin, small punctured holes in the skin or fabric, ground damage to rotor or propeller blades, and damage to landing gear, wheels, tires, flaps, engine accessories, brakes, or wingtips are not considered “substantial damage” for the purpose of this part.
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As far as the wind picking up, tower gave them a report on fairly short final of 270/10. 10 knot tailwind component again. Which is probably why they said “perfect”, finger on the TOGA button had it been 260/11 or something. That’s the last wind info they received.
Im just trying to keep it real here regarding the specific issue of did they think they had an 11 knot tailwind component and just landed anyway. To that I’d say it’s monumentally and fantastically implausible.
KBUR 061715Z 29008KT 1SM +RA BR FEW005 BKN013 OVC031 08/08 A2993 RMK AO2 AIRCRAFT MISHAP P0026 T00830078
KBUR 061653Z 28011KT 1 1/2SM +RA BR FEW004 OVC013 08/08 A2991 RMK AO2 SLP122 P0033 T00830083
EMAS at Burbank was partly paid for by an FAA grant after the 2000 Southwest overrun.
Overriding that of course is yay or nay from performance data calc which have beefy margins built in.
Whether or not the margins are ‘beefy’ is a matter of opinion. The margin in this case would be around 220m if a 1500ft touchdown was made, that’s 2.8 seconds of float if the surface friction is perfect and the machine performs as advertised. If the surface friction is not as good as the performance software assumes, how many seconds float is it? 2? 1?
The FAA put out a SAFO in 2015 saying that on wet runways the beefy margins can be inadequate due to less than ideal runway surface friction ( rubber build up, water pooling in tyre tracks, surface treatment compounds etc) and they encouraged a ‘nay’ from the PinC even when ‘computer says yes’.
