CAQ trolley for in-flight measurements (Cabin Air Quality)

The ambient air in aircraft cabins is considered by experts to be a “sensitive aspect” because passengers are constantly (passively) exposed to it during a flight. Depending on the flight phase, passengers’ activities or the services being carried out, emissions are released into the atmosphere in different ways. Undesirable emissions can also occur for other reasons, e.g. from the bleed air (air from the combustion air stream compressed by the turbo compressor of gas turbines).

With the aid of an autonomous measurement and sampling unit developed at Fraunhofer IBP and approved by the European Aviation Safety Agency (EASA), the air inside aircraft cabins can be extracted and analyzed during actual flights. To optimize its ease of use, the entire unit has been built into a converted on-board trolley. This also enables measurements and sampling steps to be performed inconspicuously.

Before take-off, our experts load  the trolley and program it to suit the planned flight. During the flight, a sampling hose sucks in the cabin air, which is then guided inside the trolley via a branched sampling system to 36 different ports (plus four blank value ports). These contain air sample collectors for diverse emissions.

The system can be used to sample:

• typical VOCs (Volatile Organic Compounds)
• aldehydes and ketones
• odorous substances
• organyl phosphates
• amines.

Sampling times and intervals - such as specific odor events and graphs of emissions occurring during take-off and landing - can be programmed in advance or manually triggered with ease by trained crew members. At the end of the flight, the collected samples are sent directly to the analysis laboratory for identification and quantification.

In addition, the following parameters are continuously recorded during the entire flight by integrated online sensors:

• temperature
• relative humidity
• air pressure
• carbon monoxide (CO)
• carbon dioxide (CO₂)
• particle sizes and distributions, grouped in the range from 0.25 to 35 micrometers
• total VOC content (Total Volatile Organic Compounds)