Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Morten
FLYER Club Member  FLYER Club Member
#1854834
Jonzarno wrote:I use one of these:
https://smile.amazon.co.uk/FORENSICS-Vehicle-Aircraft-Monoxide-Detector-BLACK/dp/B076S6KBP2.
It’s very compact and works well.

That seems a good product - but is it not the same as the one described by @patowalker from LAS at almost half the Amazon price:
patowalker wrote: https://www.aircraftspruce.com/catalog/ ... -22019.php
Paste the Aircraft Spruce part number in the LAS Aerospace search box and it will show the UK price: £96.53.
Red LED warning at 9ppm and buzzer at 25ppm.
?
It's rare to see aviation specific sites being cheaper than Amazon for the same thing, but no need to fill Bezos' pockets any more than necessary :thumright:
#1854836
Amazon pricing depends on the seller, current listing is from I & O Store I think at that figure (£156). Also, Brexit has changed things at the border. We got ours (via Amazon but direct from Forensics in USA) at £118 delivered last January. Probably best to go direct to Forensics and order there or from LAS. There can be an import customs charge added by the local delivery company but there is no way of knowing until it arrives.

The unit is tiny so easy to place anywhere suitable in the cockpit. It has an on/off button so if the alarm becomes distracting can easily be disable, this is one of the features that attracted me to it instead of the domestic ones which, whilst cheaper, I don't think can be easily turned off in flight.

It is very sensitive and responds immediately to presence of CO. Although it is prompting us to investigate our aircraft for CO leakage into the cockpit, the alarms have quite low trigger thresholds at 9ppm for the light and 25ppm for the buzzer. Maybe that's a good thing though.
Last edited by MartinC on Thu Jun 24, 2021 3:30 pm, edited 1 time in total.
#1854841
I'd say not, as its a dangerous distraction.

Your employer is allowed to have you in 35ppm for 8 hours a day, every day, and you're not going to notice any difference, so a brief spike above 25ppm causing an alarm is an un-necessary distraction.

The WHO analysis of scientific studies (with the numbers quoted above) are for zero impairment when doing moderate exercise (so don't apply to pilots) to keep COHb level of 2.5% is not exceeded. In comparison, a smoker will have COHb levels of at least 5%.

Many people, such as those work work in transport / sit in traffic will commonly work in higher background ppm levels, depending on how close they sit to the car in front. Normal background levels in an urban environment near a road are likely around 17ppm.

I don't know why you would pay £100 extra for something which
- isn't certified to any standard
- has an easily blocked sensor on the back
- is temperature sensitive (doesn't compensate for temperature, then will shut off at 50DegC)
- shouldn't be left in a vehicle (according to its instructions)
- shouldn't be in direct sunlight, but must be visible to pilot
- requires 3 minutes warm up time in fresh air before its used
- needs installed not near an air vent
- is only accurate to +-15%
- you need to import
Shoestring Flyer liked this
#1854887
I would be a little suspicious of what employers are 'allowed' to inflict on you at law. You only have to look at mining, asbestos, chemicals, farming etc., to see that employment laws tend to play catch up.

I certainly accept that this has to be viewed with some sensible perspective against the risks of encountering CO low levels in other normal activities (driving, living in cities, using gas appliances ....). That is why I asked the question of whether it is realistic to try and get CO levels down to zero in an old aircraft. We all have to consider our own priorities, flying generally is not itself without risk.

As regards our choice of the American unit, primarily the *lack* of relevant product review and the apparent lack of reasonably priced detectors (i.e. sub-£500 panel mount etc.) intended for aviation use. The question of CO danger in aircraft seems only recently to have taken on serious importance by the aviating community. Certification could be a bit of a red herring though. The models most are using are 'certified' to a standard that only applies to use in a household setting, often not sounding an alarm for an hour+ before they trigger at low levels (50ppm).

We wanted something that responded quicker than that. We may have gone for one that is too sensitive for our requirements, but we can replace it with a household Fireangel later if it proves unsuitable, they are pretty inexpensive after all. My main concern is what happens when the Fireangel goes off with a piercing wail at 3000ft - I don't think you can turn it off ! Now that's distracting.

The Forensics unit has an on/off button (another thing we looked for), although the buzzer is not particularly loud and not really audible in a noisy cockpit. In our recent flight tests, the light and buzzer was sounding continuously at one point, not really an issue. It is placed in a position that the ppm display is clearly visible (central footwell console in front of our flap lever) for easy monitoring. Away from air vents, but probably close to the point of entry of exhaust gases in our case.

Not sure about the question of blocking the sensor vent, the unit comes with a plastic case-holder mount which holds the unit away from the surface, so don't think masking is likely. Also makes it easy to remove from the holder and take out of the aircraft if required.
By riverrock
FLYER Club Member  FLYER Club Member
#1854906
Fire Angel has a "Silence" button which stops the alarm for 3 minutes as long as the level is below 200ppm, then it re-evaluates. 3 minutes should be enough time to make a change in your circumstances (vents, canopy, heater etc).

Level wise, above 200ppm, you would expect a headache (etc) in about 2 hours.

https://www.fireangel.co.uk/co-9d-manual/
#1934746
Paul_Sengupta wrote:But do get one with an LCD readout of the levels so you can look and check exactly what they are.

Some start showing levels at different amounts (some start at 10, some at 50, etc) so get one which starts reading at 10 if you can.

This is poor advice about a 10 ppm alarm

I have been using a certified device for approx 8 years. They have to be disposed of every 2 or 3 years depending on the model and once switched on cannot be switched off.
I started buying the model which gives an initial alarm at 35ppm and i would say during blocks to on blocks I am likely to have one alarm taxing and an alarm on final is not unusual.

It has picked up a couple of pin hole heater duct problems which were reported and fixed.

The device has a further 200 ppm alarm which is audibly and visually different. I have never had this alarm.

One year i was sent the version with a 30 ppm initial alarm and i set it working before i realised the supplier’s mistake. I was kind enough to accept that everyone can make mistakes but i had to put up with a noticeable increase of alarms for the next two years so please don’t buy anything which alarms at 10ppm, it’s a waste of money.

Also i note that in the CAA trial there are people reporting no alarms, their devices are no better than the cheap disks.

I fly a PA28-181
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By russp
FLYER Club Member  FLYER Club Member
#1934757
SGS66 wrote:
Also i note that in the CAA trial there are people reporting no alarms, their devices are no better than the cheap disks.

I fly a PA28-181


I have an aviation specific CO meter (Aithre AX) that's wired into my AFIS with user configurable alarm levels. Dont think Ive ever seen it over 15 ppm on the ground and never above low single digits in flight. It's never tripped the alarm (I think the yellow range is 40 and the red over 100). Is it also no better than the cheap disc as I was one of those that reported no alarms? Seems like a very broad statement?
#1934759
The reason for the price rises on Amazon for the FireAngel type devices is that they've recently become mandatory in all private rented accommodation - with a requirement to have a device in each room where a gas, oil or solid fuel burning appliance is located. Hence lots of demand.

Hopefully they'll return to normal pricing once that's passed.