Investigations of EASA
The European Aviation Security Agency is Europe's supreme supervisory and licensing authority for aviation and is based in Cologne. According to their specifications (e.g. EASA CS 25.831 and 25.832, pp. 127 f or in the original pagination: 1-D 29 f) „it must be ensured that no ‚dangerous substances’ may be contained in the breathing air during a flight“. In addition, construction regulation 25.1309 stipulates, that sensors must be installed to enable the crew to don oxygen masks in an emergency. So far, only the cockpit is equipped with oxygen cylinders, crew and passengers are not. The oxygen masks, part of the emergency demo before each departure, which are only automatically deployed in case of a rapid decompression emergency case, provide a mix of cabin air and oxygen.
Because across the board prevention is not prelevant, EASA commissioned two studies in 2013. On some flights, the contractors were to measure whether the cabin air contains "dangerous substances" in dangerous doses.
An appropriate approach in such situations if you want to avoid any changes to remedy an inherently awkward situation, are these two options:
Method 1: The permissible limit values are increased. Prof. Helmut VALENTIN, for example, successfully proposed this in the field of mercury. And that is how it was handled. (cf. The Erlangen VALENTIN School).
Method 2: You simply cannot find problematic values. All you have to do is use the appropriate method. For example, measure something that is not important at all.
This study is that important to EASA that they a) tender two studies, and b) invest a total amount of around €500,000 in order to be able to communicate in the future, official clarity to just over 500 million people.
Converted to per member state (investment) that amounts to just under 18,000 Euro. In terms of population size in the 28 countries, Germany accounted for 80,000 Euro of the total cost. The importance EASA attaches to this problem can be clearly seen from this scale.
And so, the results are not too surprising.
The study, which investigated the toxicity of the chemical substances in engine oil, states: It concluded that neuroactive products are present, but that their concentration in the presence of an intact lung barrier is too low to be a major concern for neuronal function.
It was carried out by a Dutch team.
The study, which tested cabin air quality on a total of 61 test flights, states: "The results show, that the cabin/cockpit air quality is similar or better than what is observed in normal indoor environments (offices, schools, kinder gardens or dwellings). No occupational exposure limits and guidelines were exceeded."
This study comes from Germany. It was also carried out by a team: the Fraunhofer Institute for Toxicology and Experimental Medicine and the MHH in Hannover. Their responsible "Project Manager": Wolfgang ROSENBERGER (now, that has of course been changed, read below).
61 test flights are few. One could speak of a statistical zero-relevance. If you take a closer look at the figures, such as the one of the ex-pilot "MK", who was signed off as unfit to fly because of a serious fume event (see: „Once a pilot - never again a pilot“ - actually in German only), it turns out that, additionally, they often used the same aircraft from Lufthansa and Condor.
On which - for example the consequences of (not) leaking labyrinth seals - were measured on return flights. To use different planes (or flights) would have made more sense than return flights on the same aircraft, but in view of the much too small sample it doesn't really matter anymore.
The fact, that even during 8 test flights with the Boeing 787, the so-called Dreamliner, which does not ventilate its cabin air with bleed air from the engines, low pollutant levels could also be measured due to the presence of flame retardants in the interior cabin infrastructure, is no argument for the fact that the bleed air principle would therefore not be less dangerous or harmless.
Ultimately, one did not measure what one would have to measure if one wanted to get to the bottom of the problem. With a statistical probability of a serious fume event of 1:2000 you simply have to make more effort.
And it would make sense to compare such substances in the cabin air simultaneously with what can be detected immediately afterwards in the "biological material", i.e. in blood and urine. And then to compare this - as epidemiologists would - with the data of an uncontaminated control group. Not just once. Several times.
But this is not the approach of the VALENTIN school in Erlangen. And the aviation business does not want it.
And this also explains the standstill in this problem: who has an interest in it and why.