HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jul 06, 2012, 09:46 PM
Registered User
Joined Jul 2012
1 Posts
Discussion
high altitude

i live at 8600 feet altitude, and have purchased 2 different small remote control helicopters. there wasn't enough air pressure for either of them to get more than a few inches off the ground. does anyone have any experience of what would fly at high altitude?
stevef24 is offline Find More Posts by stevef24
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 06, 2012, 10:06 PM
Registered User
wlee1017's Avatar
Joined Jul 2011
1,389 Posts
Quote:
Originally Posted by stevef24 View Post
i live at 8600 feet altitude, and have purchased 2 different small remote control helicopters. there wasn't enough air pressure for either of them to get more than a few inches off the ground. does anyone have any experience of what would fly at high altitude?
what 2 small rc heli you have?
wlee1017 is offline Find More Posts by wlee1017
Reply With Quote
Old Jul 07, 2012, 05:03 AM
mutski
Fairbanks, AK
Joined Jan 2011
1,151 Posts
Make sure your batteries are good. It wouldn't hurt to try a new battery.
mutski is offline Find More Posts by mutski
Reply With Quote
Old Jul 07, 2012, 10:35 AM
Rocket Programmer
jasmine2501's Avatar
United States, AZ, Mesa
Joined Jul 2007
25,386 Posts
The Walmart toys won't fly at this altitude, but hobby quality helicopters will be ok. High performance helicopters do very well. So like, your Trex 450 and so on. But, those are hard to fly and require training or you will crash it and they don't crash well.
jasmine2501 is offline Find More Posts by jasmine2501
Reply With Quote
Old Jul 09, 2012, 03:11 AM
Registered User
Joined May 2012
27 Posts
Three factors influence the performance of helicopters at high altitudes.
1) Thinner Air
2) Decreased Power
3) High Winds
mushia is offline Find More Posts by mushia
Reply With Quote
Old Jul 09, 2012, 03:14 AM
Registered User
United States, CO, Colorado Springs
Joined May 2012
65 Posts
I can tell you from experience that not all cheap micro helis are the same, not even the same model! I have flown 4 different V911's, and they all flew a LOT differently. My first one I was lucky to get a 2 minute flight out of. I too chalked this up to the high altitude I'm at (6,600'). My second V911 though was a different story. I easily got 5 minute flights out of it and it flew much better as well. The third one came with what I assume was a defective board as it was almost uncontrollable, while the fourth flew as good as the second one.

Needless to say, I was happy to know that the altitude was not the problem, just bad quality helis. I should also mention that my 450 heli flies great at this altitude and I easily get 7 minute flights out of it. My advice is to try a V911. Actually, try at least two!
kbohip is offline Find More Posts by kbohip
Reply With Quote
Old Jul 09, 2012, 04:52 AM
A man with too many toys
United States
Joined Feb 2001
17,544 Posts
Quote:
Originally Posted by stevef24 View Post
i live at 8600 feet altitude, and have purchased 2 different small remote control helicopters. there wasn't enough air pressure for either of them to get more than a few inches off the ground. does anyone have any experience of what would fly at high altitude?
Since the air presser is lower the blades need to turn faster to have the same lift and motor load. Usually a 1 tooth larger pinion will do the trick on most helicopters.

The alternative solution is a higher voltage battery but make sure that the electronics can handle that before you try more voltage.

RC Man is offline Find More Posts by RC Man
Reply With Quote
Old Jul 16, 2012, 02:32 AM
Registered User
Joined Jul 2012
2 Posts
I have known a lot of folks having problems flying small helis at greater than 6000 ft, the helis just won't get off the ground or out of ground effect mode. The basic problem is lift. There are a few basic factors in generating lift, in simple terms: speed (or rpm), angle of attack (pitch), surface area, and air density. Air density changes with the altitude. If everything stays the same except the altitude, at 8600 ft ASL you will have about 77% of the lift as at sea level.

Quick table of altitude ASL and % of lift compared to sea level:
500 ft = 98.6%
1000 = 97.1%
1500 = 95.7%
2000 = 94.3%
2500 = 92.9%
3000 = 91.5%
3500 = 90.2%
4000 = 88.8%
4500 = 87.5%
5000 = 86.2%
5500 = 84.9%
6000 = 83.6%
6500 = 82.3%
7000 = 81.0%
7500 = 79.8%
8000 = 78.6%
8500 = 77.4%

The only ways to compensate for the decrease in air density is to increase pitch, increase speed (rpm), or increase surface area.
OdinsBeard is offline Find More Posts by OdinsBeard
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Question High altitude flight.? squigg Aerial Photography 14 May 10, 2012 08:07 PM
Help! Indoor Micro Heli for High Altitude!!!??? Rslayer Micro Helis 14 Apr 03, 2012 12:33 AM
Discussion High Altitude Balloon project/pictures MkFn Aerial Photography 3 Mar 21, 2012 05:59 PM
Discussion high altitude with dlg rct Hand Launch 17 Mar 12, 2012 12:17 PM
The High Altitude Slug Project - A cheap high altitude UAV! phatmonkey UAV - Unmanned Aerial Vehicles 11 Nov 13, 2005 05:16 AM