Don’t spoil a good story by telling the truth
Published: 30 August, 2012
Simon Webb responds to the issues raised in the article “Flickers and Foam” by Mike Willson published in Fire and Rescue, 2ND Quarter 2012.
You may think the title is rather harsh and I would probably agree that in reality it is not actually a good story. When many dedicated people and organisations spend a lot of time and money pursuing increased safety in aviation only to have an article unnecessarily written to pick holes in their endeavours it is actually rather sad and one wonders why the effort was made writing the article rather than in establishing the facts.
To start with I will summarise the facts of the development of the new International Civil Aviation Organisation (ICAO) Level C performance standard for aviation firefighting. I will then go on to deal with the issues raised in Mike Willson’s article.
In 2005 a proposal was made to the ICAO Rescue and Fire Fighting Working Group (RFFWG) by the then Chief Officer of the UK BAA Airport Fire Service to develop a new performance standard for foam. The RFFWG accepted the challenge and a sub-group was established to oversee firstly if it was possible and secondly if it was to develop and validate the new Level C standard. The sub-group consisted of representatives from the UK, France, Canada and Holland. The technical detail was first developed and a target of 22.5% improvement of effectiveness was proposed with an application rate of 1.75 L/min/m2 for the test.
This proposal was taken back to the RFFWG and a plan to carry out testing with the aid of foam manufacturers was agreed. The UK and Canada funded the testing with the test facility, CNPP of France, selected following an open tendering process. Manufacturers were briefed and submitted some 27 samples of foam concentrate which were tested to the proposed standard in 64 live fire tests over two weeks in September 2008.
In these tests one product met the 60 second extinguishment target. The results were taken back to the RFFWG, which considered that it was worthwhile continuing with the programme and in February 2010 large scale tests were carried out in conjunction with the US Federal Aviation Administration (FAA) at Tyndall airforce base in Florida. Two tests were carried out one with a fire of 525m2 and another with 585m2. The target extinguishment time in all the fires was easily met and the average safety margin was 41%, ie the fires were extinguished much more quickly than in the equivalent small scale tests.
The results of this testing were considered by the sub-group which took advice from testing and industry experts in assessing the results and refining the test to be “fit for purpose”. This review led to the proposal for the tests to be amended to reflect aviation firefighting tactics and the critical area concept which is not to control and extinguish the fire but to control only that area of fire adjacent to the fuselage. The testing experts advised the sub-group that a more consistent method of testing would be to keep the branch static, to focus on the control of the fire, ie to allow flickers and to introduce independent accreditation of performance testing. The videos of the 64 tests were reviewed and it was clear that this proposal would indeed produce more consistent and focused results.
The amended test proposal and the introduction of the Level C standard was then taken to the ICAO RFFWG who agreed to the changes and these are currently going through the very thorough ICAO approvals process with a target date of November 2013 for them to come into force.
So turning to Mike Willson’s article, the first issue he raises is the assumption by many that the objective is to extinguish the fire. Whilst that may be the case for many other applications and tests it is not the case for aviation firefighting. ICAO is quite clear on this point – the objective is control. Mike Willson asserts that any standard requires a clear pass/fail criterion with the fire clearly out, to be of value. No – ICAO says control is the criterion. He goes on to talk of a meaningful benchmark. One of the problems with the existing test is that it allows both the branch to be moved during the test and for manufacturers to self-accredit their product which takes away any chance of a meaningful benchmark – much more of a salesman’s dream.
The article says that the changes could allow substantially inferior foam products to pass in future and that flickers present a risk of re-ignition. As I have said the primary criterion is control, and extinguishment must take place in the second minute; in addition there is the burnback test to confirm control. He asserts that the test was designed hurriedly to allow potential cost savings to be quickly realised. I have explained the history of the proposal, that it came from ARFF firefighters, as well as the time taken and the checks that have been gone through. All this information is available and has been the subject of a number of articles written by myself in journals such as this one.
Mike Willson then plays his joker card, claiming that the changes will kill people. I take great exception when a team of dedicated professionals who have steered through these changes are slurred by such comments. Such emotive language makes me question his motives.
The safety margin that the article says is of concern to firefighters has been demonstrated in the large scale fires to be 41%. On reviewing the original 64 tests the amended test would allow some five products to be classed as Level C.
Regarding the comments around the nozzle used in which Mike Willson says that foam quality from practical nozzles often falls short of UNI 86 test nozzle performance. Actually the reverse was found to be true in the large scale tests, hence the 41%.
In the article and his conclusion he makes the assertion that there could be a need for more – not less – foam. I am afraid that on this point and throughout the article he has made too many assumptions. His poor story has genuinely been “spoiled by telling the truth”.