insurance rates go down, I would assume? do you think passengers feel more safe if a charter company would hangar there a/c VS's one that does not? more comfortable to work on as far as mechanics go, etc, yes? any others?

So that it doesn't sit outside. Outside means wetness, hotness, coldness, animalness, dirtness, rustness, etc. None of which is helpful to the longterm upkeep of a machine.

Corrosion, paint. Protects from hail damage. The aircraft stays cleaner longer. Etc. The same reasons you'd put your car in a garage.

Dont forget windness!

No need to wipe the wings before a flight, no need to clean bird crap off it, less need to see if there is a bird's nest in the static port, no need to tie it down, less chance of the canopy perspex crazing in sunlight, no need to lock it up, probably less chance of water contamination in the fuel, no need to carry an oxygen bottle half a mile up an airfield to where the aircraft is tied down. Disadvantage is that you sometimes have to get the thing sitting on one of those 'wheel it sideways affairs' where the tires sit in a ring off the ground (no idea what they are called LOL, manuevering dolly perhaps?) so that you can shove it sideways into the back corner of the hangar, and of course, have to get all the other aeroplanes out to be able to get yours out if you do that. Al

Ultraviolet light from the sun is going to make the paint deteriorate. Paints have gotten more UV resistant over the years, but if the plane is only out in the sun when it's flying, that's going to be a lot less UV than if it sits on the ramp all day, every day. Here in New England, it's cold at night in the winter. Crankcase oil gets much thicker and engines are harder to start. (Do airplanes use synthetic oil?)

thanks for all of these..now the tough part, writing the algorithm that would effect passengers.. I would think passengers would choose a charter company that hangars it planes over another that wouldn't, considering everything else is equal. The non hangared charter company would compete by offering lower prices, etc..

99.9% of passengers wouldn't care. Nearly all the airlines in the world only have hangars for maintenance. At FBOs the only time airplanes go in hangars is when it is going to snow. Hangar rates can cost up to $1000 a day for something like a GV.

Some real good points why to hangar an aircraft. Elements are harsh particularly (as mentioned) the sun and the temp extremes (cold temps a killer on batteries and as said the congealing of the oil). There’s nothing like starting an aircraft on a sub-freezing morning that has been hangared in a heated hangar all night!

No need to wipe the wings before a flight, no need to clean bird crap off it, less need to see if there is a bird's nest in the static port,

Hmmm... you mean Al, bird's nest in the cowl? Yes, less chance of that but still always check for any obstructions in the cowling. More like wasps (mud daubers or such) in the pitot tube / little buggers in the static port. As far as cleaning off the wings... you mean for frost? Yes... no way will I go flying before removing ALL the frost from the wings. Absolutely amazing how a “little” frost will destroy much of the lift ability of a wing. One only need look at a car that always remains outside and one that remains "always hangared" to see the huge difference and toll the Wx takes. It was actually because of A&P schooling that I decided when I purchased my F-250HD (gas engine) to have it come with heater plugs in the engine block... always the thing stays garaged when I can. If by some chance I leave it outside with temps in the 40s or below… drag out an extension cord and plug it in. After nearly 14 years it looks (and runs) “like new”.

Here in New England, it's cold at night in the winter. Crankcase oil gets much thicker and engines are harder to start. (Do airplanes use synthetic oil?)

Well "they used to"... Geoff may have some experience with this depending how long he's had his Baron. Back in the late 80s, when I was finishing my A&P / Flight schooling at Purdue, Mobil came out with a synthetic that was I think was used in Burt Rutan's "Voyager". It was quite the boon product for some (short) years and I remember when I turned wrenches at a local airport, we had a number of customers who used Mobil Av 1. I remember it had TCM approval (Teledyne-Continental... don't remember Lycoming ever putting any approval on it)... and it was actually STC'd by the FAA. By the mid-90s it had become the bane of many owners and had been pulled from the market... there was a big lawsuit... apparently it was responsible for causing major sludge build-up in various places thruout the engine. Some blamed it on owners not heeding Mobil's instructions... like using on engines w/o filters. If you want to read more in-depth about the whys and wherefores of the Mobil AV 1 problem, and basics about how aircraft engines are different than auto engines... here's a very good article I found: http://www.avweb.com...s/182891-1.html I decided to check Shell's offerings and almost right away saw this: "AeroShell Oil Diesel 10W-40 is unique in being the only fully synthetic engine oil available in General Aviation" (so there is your answer) http://www.shell.com...on_engine_oils/ From what we used to sell (if I remember correctly) AeroShell 15w50 was very popular (semi-synthetic). It had the combined the "slickness" of a synthetic in an AD type oil (ashless dispersant... just google if interested). So for now, a semi-synthetic is as close as one will get. Unless you are operating a turbine / diesel powered aircraft.

Some of that stuff I noted relates to when I fly gliders, so some of it is more critical because of the way things can be detrimental to lift with a glider. Wet wings seriously affect performance on a glider, so I usually run an old windscreen wiper blade along them if they've been rained on, in order to dry them off, even a lot of squashed bugs on the leading edge can affect lift quite a bit, to the extent that some gliders have built-in wing wiping systems that can be used in flight. The pitot tube is normally buried in a recess on the nose of a glider, and the recess is often wide enough for a bird to nest in it on some types, so that is worth a look. I normally pop the palm of my hand against it and have someone watch to see if the ASI needle moves. Gliders are usually flown in close proximity to other gliders too, so generally speaking there is far more collision danger than when flying powered aicraft, thus it is not a bad idea to wipe every single dead bug or smear off the canopy as well, so you don't mistake an aircraft coming at you for a dead bug on the windscreen. I've had several colleagues killed in glider collisions over the years, and I don't intend to join them just yet, nor intend to test the functionality of my parachute, as such, I'm a big advocate of keeping a good lookout! Al

Aha, ok thanks Al for the clarification / information about gliders. :) I also was a stickler about the “windscreen” being absolutely spotless before flight. I too would keep my head on the proverbial swivel and expected my students to do the same . Rob

Re Al's old sig. What about snakes on a plane? More chance of a snake making a home in the wheel well when it is parked outside.

Never mind snakes, I should think finding a wasp in the cockpit after take-off would be a bit of a problem. I guess you could keep a can of bug-spray in there just in case though..

Never mind snakes, I should think finding a wasp in the cockpit after take-off would be a bit of a problem. I guess you could keep a can of bug-spray in there just in case though..

That happens all the time. We had a couple bumble bees in the cockpit the other day when we were waiting for passengers. Those things are juicy when you smash them!