I often go flying with my dad who co-owns an SR20 G3 and the one thing I have trouble with is how warm it gets in the cockpit at cruising altitude. I have very limited experience with GA planes and I know most don't have air conditioning because of the additional weight it entails and, from what I know, would only be useful on the ground and not at altitude. The ventilation in his Cirrus is fan powered but the air entering the plane seems much warmer than the ambient air. We could be cruising with an OAT of 26 but the temp inside the plane becomes unbearably warm even with the fan cranked up to its highest speed. Relief only comes when cracking the doors open while taxiing. My dad doesn't seem to be too bothered by it, probably because he's focused on flying, but as a passenger there's no way I'll go up in that thing if it's warmer than 90 F outside. So is this a typical experience in GA planes not equipped with A/C? I just assumed that A/C would be unnecessary at cruising altitude but not so in this SR20. I've tried in vain to man-up on warm flights but invariably I get drowsy from the heat and pass out :D

Some cockpits can be real sun traps, this is especially the case on the gliders I tend to fly, since they have a 'blown canopy' like a fighter plane, so I can at least relate what I've found to be some useful solutions to try...Get yourself a 'beanie jungle type hat' if you are finding the heat hard to take, and make sure it is one that is very lightweight material, with some vents. Most military surplus type shops will have them cheap and will often have 'tropical' ones which are light enough to not retain heat in your head, but with a brim that can shade your eyes (it is the strong sunlight in your eyes and on your forehead that often contributes to drowsiness). That's the reason you see a lot of glider pilots wearing them, since glider flights often involve many hours exposed to strong sunlight from above, and the plexiglass canopy seems to make matters worse, in acting a bit like a greenhouse.When I started flying gliders, baseball caps were the headgear of choice to stop that kind of thing, but these are very much frowned upon now unless you flip them backwards (you can actually see that I have done that on my avatar picture). Baseball caps are frowned upon, particularly in the gliding fraternity, since the peak can restrict upward visibility, and restricted upwards visibility can be a collision hazard when thermalling. There is certainly a lot less chance of a collision in a powered GA aircraft, since they are rarely close up to other aircraft like a glider is when thermalling, but they can still interfere with your upward vision when flying VFR, which is not a safe practice, so they are still not a great choice for powered flight either. You may not be flying the plane, but you can still keep a lookout and contribute to safety, so that's worth considering.You should also take plenty to drink. It's easy to get dehydrated in a cockpit and that will also make you feel grim. A good alternative to water is an 'isotonic energy drink' of the kind athletes are always banging on about. They do a lot to replace fluids you'll lose in high temperatures and stop you feeling drowsy. I know pilots who have not done this and have then fallen asleep at the controls because of being in the strong sunlight. Fortunately they have woken up and found themselves drifting around in a circle because they were lucky enough to have had the plane well trimmed at the time. Had that not been the case, they'd not have been around to tell the tale.Avoiding alcohol the day before a flight is not a bad idea either (if you do drink that is), although I know a few pilots who erroneously claim that a few whiffs of the cockpit oxygen on the ground before a flight will blow out a hangover. It's true that does make you feel better for a short time, but it is false to claim it really works, and of course not every GA has the need to carry oxygen equipment!Another thing that can contribute to drowsiness is the drone of the engine (never a problem in a glider of course). The engine note can be a bit hypnotic in cruise if you are in something that is not too loud, so a decent headset with active noise attenuation can be a help, although if you fly without a headset, you might want to try some earplugs of the kind shooters use (they are not exactly a great aid to conversation in the cockpit, but can be useful to combat the problem).With a lot of aircraft you can crack open the DV (direct vision) panel if it has one, which does make things a bit noisier, but it can introduce cool air into the cockpit. Don't do that without first mentioning you are going to do so to the pilot though, because it is usually smart to secure loose objects in the cockpit beforehand in case a chart or something gets blown about in the cockpit.You are correct in thinking that being a passenger makes the fact that you have no task add to the problem, so you might want to see about following the flight on a chart and marking out some reporting or turn points, so you scan about for them and mark your progress with a pencil on the chart. It's quite a good challenge to do that and it will keep you occupied. It could also potentially assist the pilot, so it will not be a waste of time doing so. You could take this a stage further by getting hold of an E6B 'flight computer' (basically that's a circular slide rule, in case you are not familiar with them). They are used to calculate drift offset, fuel consumption and all kinds of things like that, and you will find most pilot supply shops will sell you a cheap 'student' version for not much money. If you are interested in flying and navigation you would find it a good challenge to use one and it will also improve your mathematics skills, as well as being handy if you should ever want to do the PPL written exams for an IFR rating. most pilots can show you how to use one, and many 'student' versions come with an instruction book on how to do so.Anyway, there are a few things to try.Al

Jeese Alan! That was quite a reply! The only hot and sweaty times for me in the plane are climb and descent. During the summer around here we typically see 85-95F weather. At an altitude of 6,000-10,000' feet though, it's quite bearable! This past week on a day trip to the North Carolina coast, it was 90F on the ground but 65 up at 8,000'. The descent into Ocean Isle Airport was pretty toasty though, had sweat on the forehead!