Originally Posted by
Radgirl
Sorry for my multiple posts, but the issue of virus transmission is important.
Masks are the most important method of mitigating transmission. Some studies suggest they reduce it by 70%, more than hand washing and spatial separation. Obviously most cabs are fairly leaky and there is good air circulation. Equally the incidence of the virus needs to be considered, as well as the risk to the instructor and student in terms of age, ethnicity and comorbidty. However many professional pilots and cabin crew are successfully using and working with masks. The reusable masks are easy to use because they do not need professional fit testing. I wear mine for 6 hours at a time and I am happy to answer PMs about various models and how to don / doff / test. CO2 retention is a new one on me and I cannot understand the physiology. The dead space created by a mask is insignificant, rebreathing is insignificant. Altitude should not increase CO2........S-Works please do send me any papers you have on that as I am genuinely interested.
Each person has to be comfortable with the precautions on their flight and S-Works' second paragraph is spot on. However it is not true to say masks and gloves are pointless.
Please see the attached link for starters on CO2 retention in surgical settings. Its shows clear reduction in O2 saturation and CO2 retention.
http://scielo.isciii.es/pdf/neuro/v19n2/3.pdf
There have already been auto accidents attributed to people wearing masks for long periods of time in vehicles and suffering from impairment due to Co2 retention. As a commercial diver specialising in rebreather systems I can give you chapter and verse on CO2 retention. Or you could just buy my books and make me some money.....
Altitude does not increase CO2 retention, the side effect of CO2 retention is a reduction in O2 saturation levels and as the the altitude increases the partial pressure of O2 decreases which further exasperates the problem. Please read my chapter in European Instrument Pilot on the use of O2 in aviation for further reference on the effects of CO2 and reduced partial pressure of O2 on cognitive function.
Mask are a way of mitigating transmission by people who have the virus. However those people have no place being in the cockpit in a training environment in the first place and as a result we have put preventative measures in place that should prevent people with infection even getting airside. Mask are not needed in this environment and serve no real purpose and there is still no real evidence they are of any use outside a medical setting....