Runway Foaming
Thread Starter
Join Date: Jan 2001
Location: Dirty Sands
Age: 62
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
Runway Foaming
I would like to gather the opinions of savvier, more experienced aviators on this one.
If you came in with a partially deployed gear or for a belly landing, would you have the runway foamed?
Aircraft manufacturers don't seem to agree;
From Boeing FCTM:
..."Foaming the runway is not recommended unless the Capt specifically requests it. Tests have shown that foaming provides minimal benefit and it takes approximately 30 min to replenish the fire trucks foam supply."
Whereas Airbus FCOM says:
..."a hard surface landing is recommended. Full advantage should be taken of any foam, spread on the runway."
What are your views?
Thanks all.
If you came in with a partially deployed gear or for a belly landing, would you have the runway foamed?
Aircraft manufacturers don't seem to agree;
From Boeing FCTM:
..."Foaming the runway is not recommended unless the Capt specifically requests it. Tests have shown that foaming provides minimal benefit and it takes approximately 30 min to replenish the fire trucks foam supply."
Whereas Airbus FCOM says:
..."a hard surface landing is recommended. Full advantage should be taken of any foam, spread on the runway."
What are your views?
Thanks all.
Join Date: Jul 2002
Location: California USA
Posts: 719
Likes: 0
Received 0 Likes
on
0 Posts
I've only been doing ATC for 23 years, but my impression is that foaming the runway (in the US anyway) fell out of favor before I was a pup. And I quote:
The effectiveness of runway foaming is not fully substantiated by the real evidence of operational incident studies. Neither the International Fire Service Training Association (IFSTA) nor the National Fire Protection Association (NFPA) recommends the practice. The International Civil Aviation Organization (ICAO) Airport Services Manual Part 1, Rescue and Fire Fighting, Third Edition – 1990, contains a chapter (Chapter 15) on foaming runways for emergency landings. The chapter addresses the theoretical benefits from foaming runways, but then describes the shortcomings of those benefits. It also describes operational problems that should be evaluated to determine the feasibility of foaming a runway.
Some of the problems are as follows:
• The difficulty of determining for certain the type of emergency that would lend itself to the practice such as the position and condition of landing gear.
• The time element available for accomplishing the production and distribution of the foam covering that may take up to an hour or more.
• The reliability of information on the landing techniques to be used relating to wind and visibility conditions, pilot experience and skill, visual and radio aids available and the aircraft operational problems.
• The foam-making capability and adequacy of the equipment available. Airports not having adequate equipment should not attempt to lay a foam blanket. If the runway is to be foamed, it is essential that additional supplies of foam are available and the ability of the ARFF service to deal with any concurrent or subsequent aircraft accident must be assured.
• The effect the foam laying and clean-up operations will have upon the aircraft movements at the airport and how this will affect the safety of all aircraft operations in progress.
• The weather conditions during and immediately after the laying of a foam blanket. Foam should not be laid during heavy rain or snowfall conditions.
Again, I'm not so much passing on the efficacy of runway foaming myself as I am encouraging you to consider the possibility that your request will be met with a big "unable." Regardless of the manufacturer's recs, and regardless of your request, it simply might not be available. Honestly, in my career I've had a few requests for this, and the answer has always been the same from ARFF... unable.
Dave
The effectiveness of runway foaming is not fully substantiated by the real evidence of operational incident studies. Neither the International Fire Service Training Association (IFSTA) nor the National Fire Protection Association (NFPA) recommends the practice. The International Civil Aviation Organization (ICAO) Airport Services Manual Part 1, Rescue and Fire Fighting, Third Edition – 1990, contains a chapter (Chapter 15) on foaming runways for emergency landings. The chapter addresses the theoretical benefits from foaming runways, but then describes the shortcomings of those benefits. It also describes operational problems that should be evaluated to determine the feasibility of foaming a runway.
Some of the problems are as follows:
• The difficulty of determining for certain the type of emergency that would lend itself to the practice such as the position and condition of landing gear.
• The time element available for accomplishing the production and distribution of the foam covering that may take up to an hour or more.
• The reliability of information on the landing techniques to be used relating to wind and visibility conditions, pilot experience and skill, visual and radio aids available and the aircraft operational problems.
• The foam-making capability and adequacy of the equipment available. Airports not having adequate equipment should not attempt to lay a foam blanket. If the runway is to be foamed, it is essential that additional supplies of foam are available and the ability of the ARFF service to deal with any concurrent or subsequent aircraft accident must be assured.
• The effect the foam laying and clean-up operations will have upon the aircraft movements at the airport and how this will affect the safety of all aircraft operations in progress.
• The weather conditions during and immediately after the laying of a foam blanket. Foam should not be laid during heavy rain or snowfall conditions.
Dave
Join Date: Dec 1999
Location: UK
Posts: 2,584
Likes: 0
Received 0 Likes
on
0 Posts
Why would you want to empty the fire department's tanks immediately before you expect to need them full?
Which bit would they foam? The touchdown zone? The stop end? All the 3000m runway? The bit they reckon you'll stop on? The bit you reckon you'll stop on?
Sounds like a DC3/B17 procedure to me...dampen sparks when avgas is in the equation. Personally I'd prefer the tenders full and the foam directed where it is needed, when it is needed.
Which bit would they foam? The touchdown zone? The stop end? All the 3000m runway? The bit they reckon you'll stop on? The bit you reckon you'll stop on?
Sounds like a DC3/B17 procedure to me...dampen sparks when avgas is in the equation. Personally I'd prefer the tenders full and the foam directed where it is needed, when it is needed.
I concur with what has been already said here by av8boy and Agaricus bisporus and I throw my €0.02 in the discussion from an ARFF point of view.
A number of factors explain why most ARFF departments are not able to foam the runway.
Just to give some approximate figures (taken from ICAO Airport Services Manual Part 1, Rescue and Fire Fighting, Third Edition - 1990), 4 liters of water are needed for foaming each squared meter of runway plus 3% or 6% of that amount in foam (depending on the foam type used).
In case of nose wheel failure, the Manual suggests foaming a 450m X 8m strip (3600 sq m), which takes 14400 liters of water and about 432 (3%) or 864 (6%) liters of foam.
The belly-landing of a 4-engined airliners requires a 900m X 23m strip (20700 sq m), which takes 82800 liters of water and about 2484 (3%) or 4968 (6%) liters of foam.
These resources should be added to the firefighting water/foam amounts required for each airport ICAO category/FAA Index. As a comparison, the water needed in case of a 4-engined aircraft belly-landing is 257% (365%) of the required amount for firefighting at a ICAO Category 10 (FAA Index E) airport.
The ARFF apparatus commonly available at major airports is not effective in runway foaming. There is the need for specialized vehicles, as those in service for example in Athens , Ankara or Geneve.
Runway foaming requires protein foam, which is thick enough to give an effective blanket. This type of foam is not commonly in use at ARFF departments. The type available, Aqueous Film Forming Foam (AFFF), is much better for firefighting but it can not be used for runway foaming.
As av8boy said, ICAO Airport Services Manual in paragraph 15.2.1 lists 4 theoretical benefits from foaming of runway:
1-Reduction in aircraft damage
2-Reduction in deceleration forces
3-Reduction in friction spark hazard
4-Reduction in fuel spill fire hazard
but the analysis in paragraph 15.2.2 debunks each of them.
Some interesting facts given when discussing #3:
-aluminium alloys don't give friction sparks capable of igniting fuel vapours
-magnesium and steel friction sparks ignite fuel vapours but are effectively suppressed by runway foaming
-titanium friction sparks ignite fuel vapours and are not effectively suppressed by runway foaming
In conclusion, I wouldn't be surprised if the next edition of ICAO Airport Services Manual Part 1 will not include Chapter 15. Runway foaming has been practically discontinued in most countries and in my opinion it will soon be history.
A number of factors explain why most ARFF departments are not able to foam the runway.
Just to give some approximate figures (taken from ICAO Airport Services Manual Part 1, Rescue and Fire Fighting, Third Edition - 1990), 4 liters of water are needed for foaming each squared meter of runway plus 3% or 6% of that amount in foam (depending on the foam type used).
In case of nose wheel failure, the Manual suggests foaming a 450m X 8m strip (3600 sq m), which takes 14400 liters of water and about 432 (3%) or 864 (6%) liters of foam.
The belly-landing of a 4-engined airliners requires a 900m X 23m strip (20700 sq m), which takes 82800 liters of water and about 2484 (3%) or 4968 (6%) liters of foam.
These resources should be added to the firefighting water/foam amounts required for each airport ICAO category/FAA Index. As a comparison, the water needed in case of a 4-engined aircraft belly-landing is 257% (365%) of the required amount for firefighting at a ICAO Category 10 (FAA Index E) airport.
The ARFF apparatus commonly available at major airports is not effective in runway foaming. There is the need for specialized vehicles, as those in service for example in Athens , Ankara or Geneve.
Runway foaming requires protein foam, which is thick enough to give an effective blanket. This type of foam is not commonly in use at ARFF departments. The type available, Aqueous Film Forming Foam (AFFF), is much better for firefighting but it can not be used for runway foaming.
As av8boy said, ICAO Airport Services Manual in paragraph 15.2.1 lists 4 theoretical benefits from foaming of runway:
1-Reduction in aircraft damage
2-Reduction in deceleration forces
3-Reduction in friction spark hazard
4-Reduction in fuel spill fire hazard
but the analysis in paragraph 15.2.2 debunks each of them.
Some interesting facts given when discussing #3:
-aluminium alloys don't give friction sparks capable of igniting fuel vapours
-magnesium and steel friction sparks ignite fuel vapours but are effectively suppressed by runway foaming
-titanium friction sparks ignite fuel vapours and are not effectively suppressed by runway foaming
In conclusion, I wouldn't be surprised if the next edition of ICAO Airport Services Manual Part 1 will not include Chapter 15. Runway foaming has been practically discontinued in most countries and in my opinion it will soon be history.
Thread Starter
Join Date: Jan 2001
Location: Dirty Sands
Age: 62
Posts: 125
Likes: 0
Received 0 Likes
on
0 Posts
Thank you gentlemen for your valuable input.
I suppose the question is settled and shall keep your comments had I ever have to justify my decision to an inquiry board.
I remember a fireman explaining that all runway foaming ever did was to help on a "psychological" level, I can see now he was right.
As a side note, I remember a MD87 landing at Geneva, Switzerland some years ago, with its nose gear in the well, came to halt with hardly a scratch and they did have the runway foamed.
I suppose the question is settled and shall keep your comments had I ever have to justify my decision to an inquiry board.
I remember a fireman explaining that all runway foaming ever did was to help on a "psychological" level, I can see now he was right.
As a side note, I remember a MD87 landing at Geneva, Switzerland some years ago, with its nose gear in the well, came to halt with hardly a scratch and they did have the runway foamed.
Join Date: Mar 2000
Location: Arizona USA
Posts: 8,571
Likes: 0
Received 0 Likes
on
0 Posts
Called up the local airport fire service where I keep my private aircraft, and asked 'em if they would consider foaming the runway, if requested.
The answer was a very firm no.
The general consenus was that it provided little, if any, benefit.
And...the same shortcomings as mentioned here.
This particular airport has nearly one thousand private aircraft based, with many high dollar business jets as regular daily visitors.
The fire service appears to be second to none...response time two minutes, day or night.
The answer was a very firm no.
The general consenus was that it provided little, if any, benefit.
And...the same shortcomings as mentioned here.
This particular airport has nearly one thousand private aircraft based, with many high dollar business jets as regular daily visitors.
The fire service appears to be second to none...response time two minutes, day or night.
Join Date: Jun 2001
Location: New Zealand
Age: 62
Posts: 98
Likes: 0
Received 0 Likes
on
0 Posts
Kia Ora, Te Rangi.
Have seen this done at Ardmore for A Beechcraft Duchess landing at night with nosewheel jammed up and having discovered the fault, unable to retract mains. Metropolitan Fire Brigade jumped at the chance to foam the runway, in conditions which were less than ideal (poor hydrant pressure). The middle section of runway 21 was foamed and the aircraft landed normally, until the nose dropped and brought the aircraft to a halt prior to the foamed area.
It took another 4 hours to hose the foam off the runway, but Ted was pleased because he got his grass fertilised for nothing.
I believe the foam is rather corrosive, and this may be another reason to keep it in the firetrucks until it is definitely required.
Have seen this done at Ardmore for A Beechcraft Duchess landing at night with nosewheel jammed up and having discovered the fault, unable to retract mains. Metropolitan Fire Brigade jumped at the chance to foam the runway, in conditions which were less than ideal (poor hydrant pressure). The middle section of runway 21 was foamed and the aircraft landed normally, until the nose dropped and brought the aircraft to a halt prior to the foamed area.
It took another 4 hours to hose the foam off the runway, but Ted was pleased because he got his grass fertilised for nothing.
I believe the foam is rather corrosive, and this may be another reason to keep it in the firetrucks until it is definitely required.
