Incident: British Airways A320 near London on Oct 1st 2021, fumes in cockpit

[Manual Pitch Trim]

It is time for Airbus to make some safety modifications or put sensors-detectors on the A320 is it not ? Regarding fumes events

“A British Airways Airbus A320-200, registration G-EUYO performing flight BA-2678 from London Heathrow,EN (UK) to Dubrovnik (Croatia), was climbing through about FL200 when the crew experienced fumes in the cockpit. Subsequently the crew began to feel unwell and donned their oxygen masks. When the aircraft subsequently climbed through about FL320 the crew decided to return to London for an automatic landing. The aircraft landed safely on Heathrow's runway 27R about one hour after departure.

The AAIB reported the occurrence, which did not cause any injuries and no damage, was rated a serious incident and is being investigated. Climbing through FL200 the crew noticed fumes in the cockpit and subsequently began to feel unwell, donned their oxygen masks and returned to Heathrow for an automatic landing.” Aviation Herald

[DaveReidUK]

Is there evidence of a history of such events involving the A320 family ?

[Manual Pitch Trim]

The A320 is one of the safest airplanes in the history of aviation, and very well engineered.

The maintenance troubleshooting is very complex, to find the source. Might be a small quantity of oil in the bearings, at times....(?)

Please Go to the aviation herald and search “A320 fumes” if you are interested.

[Less Hair]

Filling the engine oil reservoir above max seems to be related to some events.

[gcal]

Filling oil above max is not good for any engine.

[Less Hair]

True but in this case oil fumes and their nasty ingredients might get into the cabin air system.

[Jaf4fa]

Is it just me, but why did it take 12,000ft to stop the climb when you are already on oxygen?

[Consol]

Is there evidence of a history of such events involving the A320 family ?

The extract fans have a bit of a history in that regard.

[sycamore]

Jaf, if you get fumes,you don`t wait until you feel `unwell`,get on oxygen and get down,PDQ....

[Locked door]

The crew went on O2 because of the quality of the air in the cabin, not because of the pressure. “Getting down” is irrelevant, the cabin altitude was always below 10,000ft.

Presumably they donned O2, performed some robust decision making, came up with a plan and executed it in a timely manner without rushing.

[Lookleft]

I subscribe to the Flight Safety daily emails and anecdotally there is an Airbus fumes or smoke event somewhere in the world several times a week.

[DaveReidUK]

Lookleft

Out of interest, for the A320 family what proportion of the events are IAE vs CFM vs PW ?

[Atlantic Explorer]

Jaf4fa

Thanks, glad it wasn’t just me thinking that!

[wiggy]

What’s your thinking behind stopping the climb?

[richardthethird]

Maybe the fact the crew were already on oxygen isn’t significant enough to turn back?! What’s the bloody point in continuing the climb?

[wiggy]

I refer you to locked door’s comment upthread…..

If you are established in the climb in busy airspace, what is the immediate priority, changing the flight path or protecting yourself from possibly noxious fumes?

[Lookleft]

Out of interest, for the A320 family what proportion of the events are IAE vs CFM vs PW ?

TBH I don't look at the engines, possibly they are not even mentioned.

[Locked door]

Ref continuing the climb, the SFF checklist may well fix the problem, if you come steaming down while running the checklist and subsequently fix the issue you’ll need to divert due to lack of fuel and you’ll look a bit silly explaining that to atc, the pax and management.

The best practice is to calmly run the SFF checklist, then if necessary calmly do some decision making and then if necessary calmly initiate a diversion.

Hetting into a panicky rush reduces safety and helps no one.

[richardthethird]

Come on, really - the SFF checklist might fix the problem?! If I'd been on oxygen, running that checklist there is no way I would be considering continuing - even if the fumes did appear to stop. And as for stopping the climb, hardly labour intensive. Something is clearly not right with the aircraft, take it back for the engineers to fiddle with. If management wanted to ask questions in that scenario then quite frankly I'd be considering a new employer. Hardly an everyday occurence!

Bloody Nigels.

[snooky]

This is the long running scandal that one day will be exposed as aviations biggest hide. There is a petition and much news at https://www.change.org/p/stop-contaminated-cabin-air-in-aircraft/u/29705025?cs_tk=Ah9QWxpPu8p-EGQGbGEAAXicyyvNyQEABF8BvN0Xb28IwUVFE1alq5UlFyo%3D&utm_campaign=0c93e0bffe9549a992f114470dba6524&utm_content=initial_v0_5_0&utm_medium=email&utm_source=petition_update&utm_term=cs

[Roj approved]

I agree 3rd Dick,

Once you start running the Fumes checklist, that is game over for that aircraft and crew in my company.

We have had a significant number of events in the past, leading to a change in the shutdown procedure for the APU/Batteries at last flight of the day, to try to avoid the “wet sock” smell on start up the next day.

Once “fumes” are reported or detected, MASKS ON, PUSH TO LEVEL, RUN Checklist, get on the ground in a timely manner, it may be the precursor to a greater emergency.

[richardthethird]

Thanks, Roj. Eminently sensible.

[pattern_is_full]

Since procedures do change sometimes, is this still an accurate rendering of the Airbus ECAM/QRH procedures for SMOKE/FUMES/AVNCS SMOKE? In order?

SMOKE/FUMES/AVNCS SMOKE

LAND ASAP

APPLY IMMEDIATELY
VENT EXTRACT.....OVRD
CAB FANS..............OFF
GALLEYS...............OFF
SIGNS....................ON
CKPT/CAB COM....ESTABLISH

• IF REQUIRED:
CREW OXY MASKS...ON/100%/EMERG
• IF SMOKE SOURCE IMMEDIATELY OBVIOUS, ACCESSIBLE AND EXTINGUISHABLE
FAULTY EQPT......ISOLATE
• IF SMOKE SOURCE NOT IMMEDIATELY ISOLATED
DIVERSION...........INITIATE
DESCENT..............INITIATE

....etc.

What is the understood time frame for "immediately obvious" and "immediately isolated?"

What is Airbus's recommendation if any doubt exists regarding the last two items? Is it.......?
DIVERSION...........INITIATE
DESCENT..............INITIATE

What is the Airbus recommendation for troubleshooting? Is it.........?
"Once the diversion is initiated, the troubleshooting may be carried on in an attempt to identify and fight the origin of the smoke."

[safetypee]

p_i_f
See page 11, and those preceding it; and after.

https://www.dropbox.com/s/bhpin7se6mea6vj/Airmanship%20Professionalism%20in%20Flight.ppt?dl=0

A glib response, … , but with thought, it’s the day job; to know, interpret, judge, apply, according to each situation, context, and objective.

Our, individual understanding at that time, place, and need.

[Atlantic Explorer]

richardthethird

Exactly. I’m quite bewildered at the apparent train of thought of continuing climb with a fume event in the hope or chance that the checklist might fix the issue. Nobody is saying they should have initiated a rapid decent but at the very least level off to deal with the issue.

If I had to end up on oxygen at the initial part of a flight, there’s no way the aircraft is going anywhere other than back to the hangar!

[Jwscud]

Maybe if you are (for arguments sake) at FL100 cleared to FL350 and you are presented with a problem, that doesn’t require an immediate level off, the lowest workload thing to do is to continue to follow your clearance while working the problem?

Deciding to level off, and negotiate a different clearance takes you away from focussing on the technical issue you’re presented with particularly with the communication challenges inherent in Darth Vader mode!

[Manual Pitch Trim]

found From the GCAQE website


“A newly published study has identified increases in Ultrafine Particle (UFP) concentrations in aircraft cabins associated with normal aircraft engine and Auxiliary Power Unit (APU) operation. These results correlate with times when engine and APU oil seals are known to be less effective, enabling oil to leak into the aircraft flight deck and passenger cabins. The concentrations reached in the passenger cabins exceeded those taken in other ground-based environments. These results support that UFP exposures in aircraft cabins during normal flight are associated with adverse health consequences for long serving aircrew and some passengers.
The airline industry has focussed on occasional oil system failure events and exposure to individual substances. However, this study for the first time makes the clear link between the aircraft design factor that enables oil and other fumes to enter the aircraft air supply in normal operation and exposure to UFPs. This enables a complex mixture of chemicals associated with oil fumes to attach to the surface of the UFPs, cross the blood brain barrier and thereby enter the brain. UFPs have been raised as a causative factor in the emergence of Aerotoxic Syndrome.” GCAQE

[Vokes55]

Given that the report says “climbing through FL320” suggests they did stop the climb once other, more important tasks had been completed. One assumes this happened over the channel in the climb out - a very busy piece of airspace with aircraft climbing and descending through all levels on an FIR boundary.

Quite why every tiny detail has to be scrutinised in a way akin to petty phallus waving, I’ve no idea. They diagnosed the problem, ran the procedures and returned for a safe landing. Job done. The aircraft was never in danger continuing the climb.

[Gizm0]

wiggy

Totally agree with this and similar comments. There are so many armchair pilots here with a lack of "real time" flt ops who then spout forth nonsense is one of the reasons that has driven so many professional contributors away from PPRuNe. If you can't comment sensibly or just don't know about the subject then keep quiet!
The aircraft was not in any immediate danger. The cabin pressure was being maintained below 10000ft. The FMC was, presumably, programmed to climb and then level-off without further pilot input. To initiate an immediate level-off would have required a pilot to take his/her attention away from the issue at hand (probably both pilots to some degree) to communicate with ATC - in a busy environment - then re-programme the system. As it was the most sensible course of action was let the aircraft fly itself - safely - while the crew address the problem using the appropriate checklist. Exactly what they did and what one would hope all professional, experienced, pilots would do.

[DaveReidUK]

Vokes55

Yes, Avherald appear to have interpreted the ADS-B data correctly on this occasion - maximum altitude reached was just over FL320, at which point the aircraft turned back soon after crossing the Belgian coast.

[neilki]

Lookleft

We had a (thankfully minor) fume even the other day; during pushback. A new 32N LEAP.
Engine start valve fault (like that never happens!!...) followed by a face full of the most awful body oder smell. It was a physical kick in the face smell; I certainly now understand how disorientating and aggressive these events can be. In flight this would have been very distressing.

[Airbanda]

Referred to the AAIB will look into it with their usual thoroughness.

Let's see what they say about 'similar incidents' and the crew's actions.

[Manual Pitch Trim]

Mr Gizmo, how do you define “ immediate danger”?

interested im your( -our )risk analisis with your knowledge as there was a risk of both pilots beiing incapacitated if they did not put their masks on or not?
Lets see what the investigators find ...(?)

“If you can't comment sensibly or just don't know about the subject then keep quiet!”
‘The aircraft was not in any immediate danger.” ?? You wrote.
The crew was in danger if they had not put on their masks right?

From the aviation herald
“Subsequently the crew began to feel unwell and donned their oxygen masks. When the aircraft subsequently climbed through about FL320 the crew decided to return to London for an automatic landing. “

[Roj approved]

Jwscud

A "PAN PAN" or "MAYDAY" for the Americans, "Declaring Emergency" should solve the level off and communication workload problem. (I don't work in Europe or the US, but in Australia it'll work)

[Gizm0]

Hi MPT

Well we really do need to know quite a bit more about "the fumes" and how potent / noticeable they were. Just because you become aware of "an unpleasant whiff" does not necessarily mean you have to (or should) take immediate action! Most of us at some stage have experienced the "smelly socks" odour - especially on the first flight of the day. Doesn't mean that you should automatically put on masks. De-icing fluid mistakenly sprayed into or near [run-off] the APU inlet can also result in odours / fumes (unlikely in this case). I am sure that the AAIB will establish at what stage the crew felt that this was actually "an issue that requires action" - and why. As I have said before on this forum: "we weren't there"! However for the purposes of this debate I am assuming that particular point was reached when the crew began to feel unwell and not before. You asked for my reasoning in not immediately levelling / descending / diverting the aircraft - it was thus:

Normally the first course of action in an in-flight emergency is the checklist. In the case here [fumes] this is normally accomplished by "memory items" and then "follow-up actions". In the case of <fumes in the cockpit> then the item that is very, very close to the top of the memory checklist is "don masks & establish communication" (inter pilot initially). Then the rest of the checklist can be followed. One common theme of CRM is "keep the workload as low as practical". By following, at least initially, the original flight path the crew accomplished this. That is the point that many on PPRuNe seem to take issue with. Had there been a loss of pressure that would be very different but, again, that is covered in the "memory items" and I'm sure would have been actioned if required.

Another poster said 'just declare an emergency' and then basically do what you want (my italics). Whilst true this can result in a number of other issues & potential problems. To whit: ATC will need to contact & reroute other aircraft (this was very busy airspace). They are almost certainly also going to contact the subject aircraft with queries such as "confirm ABC is squawking 7700"; and "what is the nature of your emergency" plus the famous "what are your intentions". All of these require crew responses and thought trains that distract from the matter in hand. Yes these comms can indeed be ignored for a while but that further increases workload & ATC anxiety / workload.

The aircraft was flying just fine - albeit with a possible cabin air problem but not a loss of air. The crew, once masked up, were also just fine. Thus the aircraft was in no immediate danger. Follow the checklist which will, almost certainly, end with you having to divert or at least RTB. Just as this, professional, crew did.

[red9]

BA wont be hearing anything from the AAIB

[Bergerie1]

Thank you GizmO,

Having once been in a smoke incident a long time ago where the captain rushed into unnecessarily rapid action I can only agree with your analysis. Slow and calm deliberation is the only way to deal with an event like this.

[DaveReidUK]

red9

Avherald reports that the AAIB are investigating the event (classed as a Serious Incident)?

If true, then there is no reason why a report won't be issued in the normal way, for the benefit of BA and the wider industry, most likely in one of the AAIB's Monthly Bulletins.

The investigation report may or may not be accompanied by one or more Safety Recommendations directed at BA, though that looks unlikely.

[Avionista]

This aircraft has INTERNATIONAL AERO ENGINE V2527-A5 and, although by no means conclusive, a check on A320 fume events listed in AV Herald suggests the IAE engines are more prone to this problem.

[Manual Pitch Trim]

Hello Gizmo,

good points, common sense, right.👍

I agree as long as you/we get the Oxygen masks on right away. Dont wait.
My humble opinion is cockpit VOC sensors should be installed, as they are on DHL 757 aircraft.

putting forth a scenario here...
If the crew did not smell the fumes, which can happen with Formaldehyde and other VOCs and poor sense of smell and then became incapacitated then the crew would be in danger, thus the aircraft.

[BewareOfTheSharklets]

There's a fantastic video from a Spirit Captain about their mitigation procedures for fume events. It's a few years old but was made in the aftermath of another Spirit Captain dying a month or so after an extreme fumes event.

https://www.youtube.com/watch?v=5sSz-03i8PY

[hans brinker]

He was in my new hire class. Very funny, always joking. After that event, a different person.

[FlightDetent]

From the other apex of the pendulum, let's make sure not to forget Swissair 111.

Even if the crew couldn't had saved that day, the 'thorough methodic professionalism' A.K.A. negligent leniency rightfully sent shockwaves through safety and training teams worldwide. Somehow UPS6 did not get the message.

Borrowing this one from #37 (in wider agreement but to underscore the point): (one other day) the captain rushed into unnecessarily rapid action I can only agree with your analysis. Slow and calm deliberation is the only way to deal with an event like this. Not quite, measured and proficient should not be slow. Investigation report on G-VIIO explains.

The airspace DVR-KOK has the most professional ATC that ever existed in the whole universe known to man. Claiming that stopping a climb there complicates things is a stretch, the same applies for the cockpit work behind it.

Sure there's no need for a dramatic first word out, before the situation is understood. An adjustment to CLB clearance does not fall into the 'Aviate' / 'Safe flight path' category here, nor takes precedence over the troubleshooting items of the C/L. However, any (implied) suggestion that a continuous climb of 8 minutes during a smoke event is evidence of procedures being executed properly does not pass.

I have no opinion on the crew's actions. Was not there and might had done the same.

[Less Hair]

Masks on early seems to be some good advice.

[Manual Pitch Trim]

its time for cabin fumes sensors to be installed on A320s

aviation herald

“Accident: Allegiant A319 enroute on Dec 13th 2021, fumes injure flight attendant.


“An Allegiant Airbus A319-100, registration N318NV performing flight G4-33 from Las Vegas,NV to Bozeman,MT (USA), was enroute about 20 minutes into the flight, when a flight attendant noticed a strong, thick foul locker room smell near seat rows 7-12 and began to feel burning sensations in chest, eyes and nose. Other flight attendants confirmed smelling some odour, however, did not report to be affected. Headache, dizziness and shortness of breath followed. The flight attendant walked to the back of the cabin worrying she might faint, at the back of the cabin her fingers and arms cramped, she lost feel of her legs, and needed to be laid onto the floor, a collegue administered oxygen. Medical personnel on board was called out, three passengers came to provide first aid, however, because of the cramps had trouble to remove the clothing and connect a defibrillator with the medics suspecting she was tachycardiac. While the flight crew accelerated approach and landing to Bozeman, the passengers prepared for a landing with the flight attendant on the floor, with 3 of them holding her on the floor throughout the landing. The aircraft landed without further incident about 75 minutes after departure from Las Vegas, emergency services came on board, cut open the flight attendant's clothes, connected an automatic external defibrillator (AED), diagnosed acute supraventricular tachycardia, used a wheelchair to get the flight attendant off the aircraft, then put her onto a stretcher and took her to the hospital.“

[snooky]

found From the GCAQE website


“A newly published study has identified increases in Ultrafine Particle (UFP) concentrations in aircraft cabins associated with normal aircraft engine and Auxiliary Power Unit (APU) operation. These results correlate with times when engine and APU oil seals are known to be less effective, enabling oil to leak into the aircraft flight deck and passenger cabins. The concentrations reached in the passenger cabins exceeded those taken in other ground-based environments. These results support that UFP exposures in aircraft cabins during normal flight are associated with adverse health consequences for long serving aircrew and some passengers.
The airline industry has focussed on occasional oil system failure events and exposure to individual substances. However, this study for the first time makes the clear link between the aircraft design factor that enables oil and other fumes to enter the aircraft air supply in normal operation and exposure to UFPs. This enables a complex mixture of chemicals associated with oil fumes to attach to the surface of the UFPs, cross the blood brain barrier and thereby enter the brain. UFPs have been raised as a causative factor in the emergence of Aerotoxic Syndrome.” GCAQE


An excellent post. As one seriously crippled and otherwise affected by these fumes it really is time that this should be exposed. It is basically a design fault in that the seals will inevitably leak and expose crews to regular small doses which over time accumulate.
There is a pprune thread on this important issue which was moved to a less prominent part of the site. If you’d care to read it here’s a link. https://www.pprune.org/safety-crm-qa-emergency-response-planning/506344-toxic-cabin-air.html

[Manual Pitch Trim]

“Alaska Airlines has confirmed that two of its flight attendants were sent to the hospital after they started to feel unwell when they breathed in a ‘strong chemical smell’ on a flight from Seattle to San Jose on Friday.

The two flight attendants were in the rear galley of the aircraft and none of the other crew or passengers was affected, a spokesperson for the airline said. There were 44 passengers onboard, along with three other flight attendants and two pilots.

Alaska Airlines flight AS338 was approaching San Jose at around 10 am on Friday when the flight attendants at the back of the aircraft started to feel unwell. An ambulance responded to the incident and after being evaluated on the plane, the pair were transported to a local hospital for further checks.

The Association of Flight Attendants (AFA-CWA) which represents crewmembers at Alaska Airlines recommends that flight attendants who are exposed to a ‘smoke, odor or fume’ event record their symptoms and get checked out by a medical professional as quickly as possible.

Alaska Airlines said the Airbus A320 aircraft involved in Friday’s incident had been temporarily removed from service for engineering checks. An onward flight from San Jose to Portland was cancelled on Friday but the 11-year-old aircraft is expected to return to Seattle on a revenue service later on Saturday.“

[Manual Pitch Trim]

Incident: Easyjet Europe A320 at London on Feb 3rd 2022, fumes on approach, cabin pressure issues
By Simon Hradecky, created Saturday, Feb 5th 2022 17:50Z, last updated Saturday, Feb 5th 2022 17:50ZAn Easyjet Europe Airbus A320-200, registration OE-ICU performing flight U2-8418 from Lyon (France) to London Gatwick,EN (UK), was on approach to Gatwick descending through about 6000 feet, the crew was slowing the aircraft and extending the first flaps, the crew noticed a very strong odour of wet socks on board, the flight crew donned their oxygen masks. Descending through about 2000 feet the cabin altitude began to rise rapidly through 5000 feet prompting the crew to perform a manual depressurization of the aircraft. The aircraft landed on Gatwick's runway 26L about 10 minutes after the first detection of the fumes. The crew remained on oxygen until after arriving at the stand as the fumes persisted, the aircraft was finally ventilated on the stand with doors and cockpit windows open and the APU shut down.

The crew went for medical checks.

The aircraft is still on the ground in Gatwick about 47 hours after landing.

[DaveReidUK]

Descending through about 2000 feet the cabin altitude began to rise rapidly through 5000 feet

That sounds a tad unlikely in an era where outflow valves and PRVs no longer get gummed up by nicotine ...

[Manual Pitch Trim]

Aviation Herald

“A Swiss International Airlines Airbus A320-200, registration HB-IJL performing flight LX-2802 from Zurich to Geneva (Switzerland) with 56 people on board, had been enroute at FL170 and was descending towards Geneva when the crew donned their oxygen masks and reported fumes on board. The aircraft continued for a safe landing on Geneva's runway 22.

The crew went for medical checks after landing.@

[Manual Pitch Trim]

https://sepla.es/en/sepla-calls-on-aircraft-manufacturers-to-take-steps-to-make-air-travel-safer/Sepla is today calling for contaminated air warning systems to be installed in the cockpit as a matter of priority and for effective bleed air filtration systems to be installed on aircraft. Companies specialized are known to have developed filtration solutions for the Airbus A320 series of aircraft which frequently has such events. However, Airbus are not supporting the important introduction of this much needed technology.

[fdr]

When it gets miserable in the cockpit and it isn't from last nights curry, a few things are supposed to happen. One of those is a checklist thingy, which starts with some suggestions.

that's enough on that bit.

------

fumes in the cockpit is not trivial, it may be given a bit of a low priority, but that isn't always a good thing in the real world. Way back, a crew that were with bone domes and masks on normal ended up with smoke in the cockpit, one crew member got to emergency in about 4 seconds, the other one had to be helped, and while on 100/emergency he was out for the count. There is an immediate action that should be followed, and at least one of the drivers needs to go on ASAP. Have had more than my share of cockpit smoke, on B767 B747 B744 and B777, and a few military aircraft, and none of them are much fun, although one got close to being amusing, The day the Capt left his glasses in Scotland and then left his spares in the hotel happened to be the day the classic B747 ended up with a full dose of smoke in the cockpit, in low viz and snow. Would have been OK but he left his seeing eye dog with his mother in Scotland too. Lost both packs on a B773. and that blew shrapnel all around the belly. Doing the smoke checklist, the FO could not see the EICAS, and could not identify where the right switches were in the overhead. Easy to find, if you whack across at the guys left ear, go up vertically about 18", they are up there. It was thick enough that the vision would not allow looking at both the window and the gauges, which would not be a problem had the APLT stayed happy in it's job.

Prefer engine failures, fires, or control problems over smoke or fire. When someone indicates they are fighting flames it's interesting how fast you can age.


Since procedures do change sometimes, is this still an accurate rendering of the Airbus ECAM/QRH procedures for SMOKE/FUMES/AVNCS SMOKE? In order?

SMOKE/FUMES/AVNCS SMOKE

LAND ASAP

APPLY IMMEDIATELY
VENT EXTRACT.....OVRD
CAB FANS..............OFF
GALLEYS...............OFF
SIGNS....................ON
CKPT/CAB COM....ESTABLISH

• IF REQUIRED:
CREW OXY MASKS...ON/100%/EMERG
• IF SMOKE SOURCE IMMEDIATELY OBVIOUS, ACCESSIBLE AND EXTINGUISHABLE
FAULTY EQPT......ISOLATE
• IF SMOKE SOURCE NOT IMMEDIATELY ISOLATED
DIVERSION...........INITIATE
DESCENT..............INITIATE

....etc.

What is the understood time frame for "immediately obvious" and "immediately isolated?"

What is Airbus's recommendation if any doubt exists regarding the last two items? Is it.......?
DIVERSION...........INITIATE
DESCENT..............INITIATE

What is the Airbus recommendation for troubleshooting? Is it.........?
"Once the diversion is initiated, the troubleshooting may be carried on in an attempt to identify and fight the origin of the smoke."

[MechEngr]

I can understand how filtration systems would help, both particle and activated charcoal, similar to what is used for chem and biowarfare. The trick with filters is to ensure they get replaced when required / before they are too contaminated to function correctly.

What is unclear to me is how one might make a general purpose "cabin fumes sensor" as there are hardly any universal detection methods. The common ones for CO and some combustible gasses each require entirely different surface chemistries and processing to make the detection. I suppose one could find a sensor for a particular sort of chemical that is used on the plane, but there is a reason there aren't robots replacing sniffer dogs any time soon. And if that chemical is partly combusted then one would need sensors for each of the possible combustion products. Perhaps it's time to reintroduce canaries into the working environment.

[MechEngr]

I can understand how filtration systems would help, both particle and activated charcoal, similar to what is used for chem and biowarfare. The trick with filters is to ensure they get replaced when required / before they are too contaminated to function correctly.

What is unclear to me is how one might make a general purpose "cabin fumes sensor" as there are hardly any universal detection methods. The common ones for CO and some combustible gasses each require entirely different surface chemistries and processing to make the detection. I suppose one could find a sensor for a particular sort of chemical that is used on the plane, but there is a reason there aren't robots replacing sniffer dogs any time soon. And if that chemical is partly combusted then one would need sensors for each of the possible combustion products. Perhaps it's time to reintroduce canaries into the working environment.

[Manual Pitch Trim]

Funny canaries in the coal mine, not funny for safety and those who have become ill.


Ultrafine fine particle detectors look like the best option…


The thing is the sensors need to developed and the installation of ultrafine particle detectors should be really mandated by EASA and the FAA, to develop reliable sensors and have indications in the cockpit. Boeing and Airbus prefer to have sensors for maintenance only at the moment. From my point of view we pilots need to write our unions and the authorities on this issue. As the manufacturers and airlines fear lawsuits,etc theres a reluctance to admit the problem and advance safety in this issue.

Also..

“ several chemicals have been identified as having potential as markers for oil contamination.
60

“Potential marker chemicals representative of bleed air contamination
Chemical Potential
Formaldehyde Good
Acetaldehyde Good
Carbon Monoxide Fair
TVOC Fair
Carbon Dioxide Good
*Note: Good as a discriminator but not for primary detection
Various methods can be used to detect these gasses. These methods can be divided into four broad categories: 1) electro-chemical sensors, 2) metal oxide sensors, 3) photo ionization detectors, and 4) spectrometers.
The electrochemical sensors and the metal oxide sensors are relatively inexpensive and can be designed to target a variety of specific compounds. They have the potential for detecting low concentrations. Multiple sensors can be combined and tuned to detect specific substances. Some disadvantages include a tendency to drift over time, poisoning of the sensing medium, and slow recovery after exposure. Various measures may be employed such as cleaning cycles and calibration to address these concerns.”


Have a look this FAA document


https://rosap.ntl.bts.gov/view/dot/62770/dot_62770_DS1.pdf

“The purpose of this project was to provide a data-driven process to identify sensing technology with good potential for detecting bleed air contamination from engine oil, hydraulic fluid, or deicing fluid. Reports from major aircraft cabin air studies were reviewed to identify the range of constituents that can be expected in cabin air, especially as they pertain to the aforementioned contaminants and their potential markers. One of the projects was the National Aeronautics and Space Administration Vehicle Integrated Propulsion Research (NASA-VIPR) project where controlled amounts of engine oil were injected into the engine compressor of a C-17 transport aircraft and the resulting contaminants in the bleed air measured. Three additional cabin air quality studies conducted on revenue flights were reviewed. These three studies provide data for a combined total of 249 flights on a variety of makes and models of aircraft. These studies provide adequate documentation of typical aircraft cabin air. Information from this review was used to identify potential markers of the bleed air contaminants. Additionally, collaboration was established with several technical committees from the Society of Automotive Engineers (SAE), American Society of Heating, Air-Conditioning and Refrigerating Engineers (ASHRAE), and American Society for Testing and Materials (ASTM) and with project personnel from the prior European Union Aviation Safety Administration (EASA)-funded cabin air study. Key objectives of the project were to identify sensors and sensing technology with potential for detection of one or more of the three aforementioned bleed air contaminants and to develop a plan for test stand engine experiments to evaluate the sensors with controlled amounts of the three contaminants. Sensors and instruments were identified and a test plan was developed. Additionally, through the collaboration with ASHRAE 1830 and the support of the industry working group, many of the experiments identified in the test plan were completed. The analysis of the data from these experiments is ongoing and will be reported in the ASHRAE 1830 project report. However, preliminary assessment of the sensing technology has been possible”.