Helicopter Pilot Heat Stress
Thread Starter
Join Date: Jan 2005
Location: Australia
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Helicopter Pilot Heat Stress
We are trying to formulate some guidelines for our pilots when operating on very hot or very humid days, re: hydration, fatigue, effects of heat stress on cognitive skill levels etc. I know there has been some work done by the military for fighters but is there any helo research? Do other operators have heat policies? Do pilots feel heat stressed on 35+ degree C days? I think this is an issue that is being overlooked but as usual we just get in and do it but man is hot!! in the glasshouse some days!
Thanks for your thoughts,
Cuppa Joe
Thanks for your thoughts,
Cuppa Joe
I think the major factor is aclimatisation - when I have been on examining visits to heli units in the Middle and Far East for two week stints, I found it very difficult to cope with the feelings of fatique. After a month into a 6 month stint in Belize (+35 and vicious humidity) I realized that those feelings had gone. Apart from that, sleeping in A/C accom helps the body's core temperature to keep low(ish) and loads of water - if you don't need a pee every couple of hours, you're not drinking enough!
Join Date: Feb 2005
Location: In my box!
Posts: 135
Likes: 0
Received 0 Likes
on
0 Posts
Hi,
I found that operating in Hot climates did fatigue crews a lot quicker. Plenty of fluids were a norm and at least a week of acclimatisation with very little flying. I have had instances where I couldn’t see the instruments on start up because the sweat was pouring down my face, but once the fan got going it made it a lot more pleasant. I also wore a fridge suit a few times (like a set of thermals that has vein’s of ice water pumped around it). And the dog’s bo**ox it was aswell. But a rule of thumb was add 5 to 10 degrees to the outside temp then another 5 degrees for the temp inside your helmet and that was the conditions on start up!!!!! One word HOT.
I found that operating in Hot climates did fatigue crews a lot quicker. Plenty of fluids were a norm and at least a week of acclimatisation with very little flying. I have had instances where I couldn’t see the instruments on start up because the sweat was pouring down my face, but once the fan got going it made it a lot more pleasant. I also wore a fridge suit a few times (like a set of thermals that has vein’s of ice water pumped around it). And the dog’s bo**ox it was aswell. But a rule of thumb was add 5 to 10 degrees to the outside temp then another 5 degrees for the temp inside your helmet and that was the conditions on start up!!!!! One word HOT.
Join Date: Jun 2003
Location: yeovil
Posts: 87
Likes: 0
Received 0 Likes
on
0 Posts
Heat Stress & Fridge Suits
FYI, there's a whole bunch of research done by IAM in the early 90s. Unfortunately not (apparently) in public domain.
Seems daft there's no formal guidance (e.g. H&SE), given the habit of bolting a greenhouse to the front of the airframe, then dressing in overalls before sitting in the sun.
In unpublished work
, IAM found mid-summer Germany was enough to terminally fry the pilot
in less than 2 hours for some workloads, even after acclimatisation
. Best answer was the liquid cooled (15 deg) suit, with an attached cooling skull cap worn under the helmet
, which also supresses sweat. Pipes, plumbing, escape and cooler weight were all reasons why this isn't done now. That and looking a prat queueing at ATC with that lot on.
Perhaps an opening sunroof would help, given the big cooling fan on top (Brylcreme might be needed
).
Nimby
Seems daft there's no formal guidance (e.g. H&SE), given the habit of bolting a greenhouse to the front of the airframe, then dressing in overalls before sitting in the sun.
In unpublished work
, IAM found mid-summer Germany was enough to terminally fry the pilot in less than 2 hours for some workloads, even after acclimatisation. Best answer was the liquid cooled (15 deg) suit, with an attached cooling skull cap worn under the helmet, which also supresses sweat. Pipes, plumbing, escape and cooler weight were all reasons why this isn't done now. That and looking a prat queueing at ATC with that lot on.Perhaps an opening sunroof would help, given the big cooling fan on top (Brylcreme might be needed
).Nimby
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,576
Received 425 Likes
on
224 Posts
Crews were getting very fatigued in Belize in the early 1980s; I took part in an RAF heli pilot heat stress survey. I flew with a medic in the left seat; he took my temperature every 10 minutes and before and after every landing.
The looks on some soldiers faces, as they spotted the thermometer in my mouth while they filed past the cockpit to emplane, was a real picture
The outcome was that I was operating with a body temperature of well over 100 degrees F. It was urgently recommended that the aircraft (Pumas) were fitted with a fan of some sort in the cockpit. Of course, this was regarded with the normal level of priority given to the well-being of helicopter crews........... i.e. none, at least nothing had changed by the time I became a civvie some 14 years later.
I wonder if Puma helicopters, over 25 years later, have been improved in this respect, given the location of their present deployments?
The looks on some soldiers faces, as they spotted the thermometer in my mouth while they filed past the cockpit to emplane, was a real picture
The outcome was that I was operating with a body temperature of well over 100 degrees F. It was urgently recommended that the aircraft (Pumas) were fitted with a fan of some sort in the cockpit. Of course, this was regarded with the normal level of priority given to the well-being of helicopter crews........... i.e. none, at least nothing had changed by the time I became a civvie some 14 years later.
I wonder if Puma helicopters, over 25 years later, have been improved in this respect, given the location of their present deployments?
For some reason a techie brought a min-max thermometer along on one of our border detachments in Oman in the early 80s. Popped it under my (green) flying helmet on the seat of my Huey after landing and left it there for an hour late one morning. Around midday I went back to check - it had reached 88 deg Celsius.
Once I'd seen some Oz troops using Camelbaks in the late 90s I bought one and kept it strapped to the back of my 212 seat in Borneo. Our doc said that if you feel thirsty you are already 5% dehydrated. Just make sure you train your bladder to last as long as the a/c fuel tank does - see Oldbeefers comments earlier
Once I'd seen some Oz troops using Camelbaks in the late 90s I bought one and kept it strapped to the back of my 212 seat in Borneo. Our doc said that if you feel thirsty you are already 5% dehydrated. Just make sure you train your bladder to last as long as the a/c fuel tank does - see Oldbeefers comments earlier
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,576
Received 425 Likes
on
224 Posts
Not In My Back Y..passage!
Let me guess... Navy, eh
Let me guess... Navy, eh
Join Date: Jun 2006
Location: London
Age: 64
Posts: 100
Likes: 0
Received 0 Likes
on
0 Posts
Makiwa,
You are the one who needs to get real!
The conditions in which you operate will affect the way you operate.
If you don't care about the service or safety you give to your employer or passengers then carry on with the macho bravado bulls**t.
Those professional pilots who do have an interest in flying as safely and efficiently as possible will be very interested in this valid thread.
Wind your neck in and keep you infantile comments to yourself.
LM
You are the one who needs to get real!
The conditions in which you operate will affect the way you operate.
If you don't care about the service or safety you give to your employer or passengers then carry on with the macho bravado bulls**t.
Those professional pilots who do have an interest in flying as safely and efficiently as possible will be very interested in this valid thread.
Wind your neck in and keep you infantile comments to yourself.
LM
Join Date: May 2006
Location: Canada
Posts: 67
Likes: 0
Received 0 Likes
on
0 Posts
There was a study done in the late 80s on fixed wing drivers. I believe that it was undertaken on the behalf of an insurance company. All that I recall was that there was an optimum core temperature range and that even for someone that was supposedly well adjusted to one extreme or the other, the performance levels were measurably diminished. I only recall this because I believed that after having operated for some time in ambient temps of 35-45C that I was just as proficient as at 25C. I was wrong. Problem solving and reaction times were measured. I would guess that having your head cooking inside a brain bucket in a greenhouse wouldn’t make things any better. I took to wearing a cotton baseball cap with a wet sponge beneath it and keeping as many of the vents pointed at me as possible.
Join Date: Jun 2002
Location: Florida/Sandbox/UK
Posts: 324
Likes: 0
Received 0 Likes
on
0 Posts
Ouch, somebody seems to have touched a raw nerve! Maybe a large Cognac will help.
Cupajo,
There have been some surveys done on this but all solutions that involve technology are very expensive and in the civilian world, usually prohibitively expensive.
I operated in Kuwait for several years where the summer temperatures got to 50 deg C on a regular basis. It was a dry heat and not as tiring as hot and humid, nonetheless, very hot. Unless absolutely essential, I stopped the pilots flying in temperatures above 45 deg C. Aircraft were kept inside until the last possible moment to minimise the time sitting on the ramp getting heatsoaked. Pilots spent the minimum amount of time outside before getting airborne. Two pilots at those temps, both rested and watered. Lots of water on board in case of a breakdown. All fairly common sense stuff that I am sure you know.
I now operate in Florida where the temperatures are lower but humidity is high and the discomfort is pretty much the same as in the Middle East. I now have my own operation and cannot justify high cost solutions, therefore, I have to apply all the common sense I can in order to minimise fatigue. Not always easy but that's why I love being a helicopter pilot.
I guess it comes down to how much you are prepared to spend and, of course, the aircraft you fly and the function you perform in your operation. There are some very good and light air conditioners available, otherwise, I'm afraid it really just comes down to awareness and there are several good points made on this thread already.
Cupajo,
There have been some surveys done on this but all solutions that involve technology are very expensive and in the civilian world, usually prohibitively expensive.
I operated in Kuwait for several years where the summer temperatures got to 50 deg C on a regular basis. It was a dry heat and not as tiring as hot and humid, nonetheless, very hot. Unless absolutely essential, I stopped the pilots flying in temperatures above 45 deg C. Aircraft were kept inside until the last possible moment to minimise the time sitting on the ramp getting heatsoaked. Pilots spent the minimum amount of time outside before getting airborne. Two pilots at those temps, both rested and watered. Lots of water on board in case of a breakdown. All fairly common sense stuff that I am sure you know.
I now operate in Florida where the temperatures are lower but humidity is high and the discomfort is pretty much the same as in the Middle East. I now have my own operation and cannot justify high cost solutions, therefore, I have to apply all the common sense I can in order to minimise fatigue. Not always easy but that's why I love being a helicopter pilot.
I guess it comes down to how much you are prepared to spend and, of course, the aircraft you fly and the function you perform in your operation. There are some very good and light air conditioners available, otherwise, I'm afraid it really just comes down to awareness and there are several good points made on this thread already.
I remember being told by some RAN guys about a helicopter heat stress trial they'd taken part in, about mid-eighties as I recall.
The thermometers were in fact rectal - not a pleasant thought, but I'm sure they did it for their country and the expansion of scientific knowledge (not to mention the expansion of bodily orifices...)
The thermometers were in fact rectal - not a pleasant thought, but I'm sure they did it for their country and the expansion of scientific knowledge (not to mention the expansion of bodily orifices...
)
Thread Starter
Join Date: Jan 2005
Location: Australia
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Thank you all for your thoughts,
I have been sent some interesting stuff, it seams the Australian Navy and the Royal Air Force Sea King guys have done some work that suggests a caution when operating above 37.5 C, it suggests restrictions on ground idle time and also recomends extended recovery periods between flights.(up to 2 hours in some cases) It also defines an extreme danger period above 45 C ambient where all but non essential flights be avoided (I know which flights my boss thinks are essential - you guessed it!) Other research also shows that aclimitization is very important as is dehydration, physiological studies show it is difficult for a person sweating profusely to rehydrate during the period of sweating - so drink before and after the flight. Heat stress appears to effect different people in different ways, quite clearly some "cope" better than others. The research and anecdotal evidence does suggest a reduction in skills at higher temps and an increase in fatigue related to the lenth of time exposed (this more how it effects me personally, I don't feel particually stressed during the hot flight but am more knackered at the end of the day) I think that if there is a factor (that can be mitigated) that can adversley effect our performance (and therefore our obligations to passengers and crew) then as professionals we should at least consider it. It may be as simple as a water cooler in the crew rest area or a complex risk matrix that cancels flights above a certain temp, I thinks its probably somewhere in between, thanks again for the responses, I appreciate it,
Joe.
I have been sent some interesting stuff, it seams the Australian Navy and the Royal Air Force Sea King guys have done some work that suggests a caution when operating above 37.5 C, it suggests restrictions on ground idle time and also recomends extended recovery periods between flights.(up to 2 hours in some cases) It also defines an extreme danger period above 45 C ambient where all but non essential flights be avoided (I know which flights my boss thinks are essential - you guessed it!) Other research also shows that aclimitization is very important as is dehydration, physiological studies show it is difficult for a person sweating profusely to rehydrate during the period of sweating - so drink before and after the flight. Heat stress appears to effect different people in different ways, quite clearly some "cope" better than others. The research and anecdotal evidence does suggest a reduction in skills at higher temps and an increase in fatigue related to the lenth of time exposed (this more how it effects me personally, I don't feel particually stressed during the hot flight but am more knackered at the end of the day) I think that if there is a factor (that can be mitigated) that can adversley effect our performance (and therefore our obligations to passengers and crew) then as professionals we should at least consider it. It may be as simple as a water cooler in the crew rest area or a complex risk matrix that cancels flights above a certain temp, I thinks its probably somewhere in between, thanks again for the responses, I appreciate it,
Joe.
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,576
Received 425 Likes
on
224 Posts
Makiwa, A question - How do you know how stressed folk are?
As far as being rude is concerned, I suggest you read both your posts again; it's not surprising that some folk take exception and retaliate.
Despite that, I'm sure your 120 hard men colleagues find you a pleasure to work with.
Meanwhile, I'm going for a lie down - it's a little warm this morning and I hate it when I perspire.
As far as being rude is concerned, I suggest you read both your posts again; it's not surprising that some folk take exception and retaliate.
Despite that, I'm sure your 120 hard men colleagues find you a pleasure to work with.
Meanwhile, I'm going for a lie down - it's a little warm this morning and I hate it when I perspire.
Hovering AND talking
Join Date: Feb 2003
Location: Propping up bars in the Lands of D H Lawrence and Bishop Bonner
Age: 59
Posts: 5,705
Likes: 0
Received 0 Likes
on
0 Posts
Makiwa, well good for you!
Actually, how would you know? That's the trouble with stress; it can be quite insidious. Maybe your reaction to the "softies" here is a result of the stress under which you are placed and no doubt your blood pressure is fluctuating.
Again, how would you know - perhaps you are being a little subjective? And not a little aggressive. Maybe you can't handle it and an inability to cope with the stress is manifesting itself in this agression. Care to revisit your HPL studies?
Cheers
Whirls
I have never felt as "stressed"
I am not alone in my ability to handle the conditions
Cheers
Whirls
Join Date: Jul 2001
Location: ...in view of the 'Southern Cross' ...
Posts: 1,383
Received 0 Likes
on
0 Posts
Whirls ....
I do know in fact that Makiwa does know what he is talking about .... the fact is we do operate in rather uncomfortable conditions during a middle eastern summer .... however we ARE used to it and are conditioned ... which is a very different situation to those who might not be!
I also think Makiwa might just be having a not too subtle "dig" at those he might percieve to be whingeing about the "tough" conditions that they have chosen to work in.
His final words "Hydrate or Die" ... so very true!
Cheers
I do know in fact that Makiwa does know what he is talking about .... the fact is we do operate in rather uncomfortable conditions during a middle eastern summer .... however we ARE used to it and are conditioned ... which is a very different situation to those who might not be!
I also think Makiwa might just be having a not too subtle "dig" at those he might percieve to be whingeing about the "tough" conditions that they have chosen to work in.
His final words "Hydrate or Die" ... so very true!
Cheers
Avoid imitations
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 14,576
Received 425 Likes
on
224 Posts
An important point is that once you are acclimatised it's not such a big problem; It's certainly a different ball game when you aren't.
I took it that the original question reflected this problem, presumably for inexperienced pilots perhaps meeting the conditions for possibly the first time.
As part of a deployable military oufit in the late 70s and 80s, we used to go from three months at 95 -100F and 95-100% humidity in Central America to well below freezing in the Central European winter, so we had quite a lot of acclimatisation to do.
I personally always find a hot climate takes longer to get used to. Sometimes in the Far East, the S-76's "Windscreen Hot" (overheat) captions were on as soon as we switched on the aircraft battery; it's been a while since I worked out there but I think they come on at +50C.
Yes, even "soft" pilots acclimatise, but everyone is different. We routinely wore Nomex flying suits, roll-neck long sleeved shirts, long socks, boots, gloves, helmets and underarm deodorant.. On the less hot days we used to wear a Nomex jacket too.
To acclimatise more quickly, my advice is to stay out of over-airconditioned rooms, if possible. Just try to stay in the shade with a breeze going. Keep hydrated by steadily sipping water, not gulping it down - an over-full bladder only adds to the discomfort. I used to run about 15-20 miles a week in my far east days, so I certainly got used to the climate. Air-con is nice to sleep in, but it's also noisy. I preferred to sleep under a ceiling fan (she was nice, that See Ling Fan).
I took it that the original question reflected this problem, presumably for inexperienced pilots perhaps meeting the conditions for possibly the first time.
As part of a deployable military oufit in the late 70s and 80s, we used to go from three months at 95 -100F and 95-100% humidity in Central America to well below freezing in the Central European winter, so we had quite a lot of acclimatisation to do.
I personally always find a hot climate takes longer to get used to. Sometimes in the Far East, the S-76's "Windscreen Hot" (overheat) captions were on as soon as we switched on the aircraft battery; it's been a while since I worked out there but I think they come on at +50C.
Yes, even "soft" pilots acclimatise, but everyone is different. We routinely wore Nomex flying suits, roll-neck long sleeved shirts, long socks, boots, gloves, helmets and underarm deodorant.. On the less hot days we used to wear a Nomex jacket too.
To acclimatise more quickly, my advice is to stay out of over-airconditioned rooms, if possible. Just try to stay in the shade with a breeze going. Keep hydrated by steadily sipping water, not gulping it down - an over-full bladder only adds to the discomfort. I used to run about 15-20 miles a week in my far east days, so I certainly got used to the climate. Air-con is nice to sleep in, but it's also noisy. I preferred to sleep under a ceiling fan (she was nice, that See Ling Fan).
Last edited by ShyTorque; 8th Jun 2007 at 15:23. Reason: grammar