I usually fly in Maine (on the coat) so field elevation is about 100ft. I'm on vacation now in easter Colorado and flying out here (about 4100ft). I've noticed the plane seems a little sluggish here in Colorado (it flys GREAT in Maine), and the engine runs rougher (want's to sputter and quit more at idle). I do have the needle valve set for this altitude. I'm not worried about running the engine at a higher idle because I have steady 5 - 8 knot headwind all the time, so the plane is not too fast at touchdown (if anything I need more power). I'm flying a Sig LT-40 with a O.S. LA .40 using a 10x6 prop.

Just wondering if anyone else is familiar with this, and any recommendations to improve the engine performance.

I lived in southern CA at 1500 ft. Moved to Prescott, AZ. It is 5300 ft. here. It took a little getting used to flying at a higher altitude. I notice it more with the 1/2 A and 1/8 A stuff. I use 15% nitro for the big ones and min. 25% for the small ones. They run very good, just don't have as much power as they do at a lower altitude. You might check the idle mixture adjustment on your engines, this also would be affected.

I took a couple of planes out to Denver a year ago and found the same thing. My engines were running fine, but I just couldn't get the pull out of them. I wonder if a higher pitch prop is called for? I didn't really do anything with mine because I wasn't out there that long, but would have asked someone who is familiar with the conditions if I were staying longer.

More Power!!! I typically fly around 1,000-2,000 feet, but I have flown in Denver (5,000 feet) and at the Santa Fe (7,500 feet.) Talk about sucking air. At high altitides everything is against you. Lower air density so less lift and control, higher stall speed, less bite on props, and engines run at reduced power. Props, nitro, etc will effect usable power somewhat, but what you really need to boost power is more engine displacement. Cheers.

I don't know about the rest of you but I'm just impressed with the dedication it must take to be able to take your plane with you on vacation. Transporting, having a place to fly, time and understanding people who went with you on vacation............I have to stop, a tear just came to my eye.

Wasn't really that hard transporting. Just built a carrier for the back of my truck for the wing and plane, put all the luggage below. As for a place to fly, my in-laws have a farm, just cut a runway and presto!!! My father-in-law was really excited to hear I was bringing my plane. I did have the idea of putting on bigger engine on my plane, but I'm only here for a week, so not really worth the expense. Next time I may go for a different prop, see if that helps.

Sorry to make you cry there Damon. I have a pickup with a cap on the back (see picture). I just loaded up a couple and took them with me. Actually, we were just going back to visit my parents, so it was home to me. I got a chance to have my nephew watch and he had a ball. Dedication really had nothing to do with it. Just thinking about sitting around the house and talking about the relatives was all the motivation that I needed.

No problem my plane goes every where with, where I go it goes.

YEAH! welcome to colorado! up here we tend to go for bigger props to compensate the thinner atmosphere... um.. that's all i wanted to say lol.

Bigger engines and higher nitro is the best way to get around the problem. For the higher altitudes I need to lean the idle mixture a little bit to get the engine to run right. A lot of times we have to void the manufacturers warranty to get a plane to fly like it would at sea level. The fields that I regular are between 4200 and 7200 feet with density altitudes usually between 7,000 and 10,000 feet. That is up to a 25% power loss over sea level power. Not to mention the stall speed is increased, so you have to watch landing speeds. It's not bad when you get used to it.


Check this web site out:

http://wahiduddin.net/calc/calc_hp_dp.htm

To find the information needed go to www.weather.com and type in your zip code.

At my location I currently have 17% less power than that of standard conditions and we have 12 degrees to go to hit the high for the day. So were a 40 would go, put a 46. Replace a 46 with a 50-61. Replace a 90 with a 120.

I just bought a 4 wheeler and wish I would have bought the one with fuel injection. I have been running it between 4,000 and 10,000 feet and it doesn't run well at the higher altitudes because the carbs are jetted for the lower altitude.