Flying the H at higher altitudes
- Thread starter jwjohnson
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I just ordered the dbs and 2500 ft on a craft that is advertised at 5300ft + is not worth the 115 dollars. Hummmm.
I see your foot has been on the gas pedal
Hey, I wonder what is the best speed between turtle to rabbit that will give you the most flight time - the furthest distance away and back home.I've been flying R/C aircraft for 30 years (wow, has it really been that long?) Although the H is plenty fast enough for a multirotor camera platform, it isn't really all that fast. I've had it up to 4000' away and 400' high. I usually start getting video break-up off and on between 1000' and 1500' away but it will go much farther if you take it easy. Not sure what the best speed is for endurance but I did a hover test and still only got 17 min before the low batt alarm came on so it doesn't seem to make much difference.
PatR
Premium Pilot
For those interested, the standard temperature lapse rate is 3 degrees per thousand feet of altitude gain. If the air mass is unstable or moving against up or down slope terrain that lapse rate can increase.
At higher altitudes there is less O2 density, which impacts propeller efficiency. Propellers have to turn faster to generate the same amount of thrust they do at lower altitude. A faster turning propeller requires more battery energy to make that happen. Combine increased current draw with cold temperatures and batteries are hit with a two fold flight time impact. If descending quickly from a high altitude the propellers may not be able to arrest the descent, so a moderate descent is more appropriate.
RPM, airspeed and altitude are closely tied together. To go fast you need high RPM and at high altitudes demanding the fastest airspeed can cause the aircraft to descend because adequate lift may not be available to sustain altitude when the aircraft is being commanded to go fast. This can be seen at lower altitudes as well. All flying is a trade off in lift over weight, thrust over drag,and a balance has to be achieved for effective flight. If flying at high altitudes use some level of caution and experiment with what works safely for the altitude being flown.
The longest flight time achievable on a battery will be obtained in a generally stationary hover with GPS turned off. Nobody buys one of these things to fly that way.
At higher altitudes there is less O2 density, which impacts propeller efficiency. Propellers have to turn faster to generate the same amount of thrust they do at lower altitude. A faster turning propeller requires more battery energy to make that happen. Combine increased current draw with cold temperatures and batteries are hit with a two fold flight time impact. If descending quickly from a high altitude the propellers may not be able to arrest the descent, so a moderate descent is more appropriate.
RPM, airspeed and altitude are closely tied together. To go fast you need high RPM and at high altitudes demanding the fastest airspeed can cause the aircraft to descend because adequate lift may not be available to sustain altitude when the aircraft is being commanded to go fast. This can be seen at lower altitudes as well. All flying is a trade off in lift over weight, thrust over drag,and a balance has to be achieved for effective flight. If flying at high altitudes use some level of caution and experiment with what works safely for the altitude being flown.
The longest flight time achievable on a battery will be obtained in a generally stationary hover with GPS turned off. Nobody buys one of these things to fly that way.
The firmware has an altitude limit of 8000'. The motors will not start at that elevation. If you plan to fly at or over 8000' you need to contact Yuneec in advance to get special firmware that will allow you to start the motors.
Many people fly at higher altitudes. Yuneec is being very conservative regarding altitude because of their 6 month warranty. There are a huge number of people who purchase these as their first copter and therefor know little about the effects on the flight characteristics at altitude. This bird will fly just like any other copter as long as you know what you're doing.
Above sea level elevation and Above ground level (AGL) are entirely different. If you tried to fly 5000' AGL you would never see your H again. 400' AGL is the limit.
Can the H fly above 8000 feet or is the starting altitude locked in the firmware? Because simspeed wrote that he departed from 8500+? Iam planning a trip to the Andes and it would be really disappointing if I cannot start there...
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As I said in my previous post....I live and fly @ 8500+ with no problems other than shorter flight times. Colder temperatures will also cut flight time my max time so far is around 15 minutes per battery.
PatR
Premium Pilot
Altitude is calculated using the launch point as 0' altitude. Doesn't matter what the MSL altitude is, the 8000' limit references that spot on the ground it was launched from.
Sea level elevation does matter. There is an altimeter in the H and the ST16. Unless there was a change in the firmware, the original specs noted a max sea level altitude of 8000'. It would be best to call Yuneec to confirm if this is still the case.
PatR
Premium Pilot
Yes, there is a pressure altimeter sensor, but it references ground level pressure as a foundation pressure reference. Nowhere does the ST-16 or the telemetry show a reference to an MSL altitude. Next time you go out, note the altitude displayed on the ST-16 with the H sitting on the ground. If it referenced sea level it would display an altitude somewhere close to what it was at MSL. My area elevation is ~700' MSL but the starting altitude is usually between 0 an 12'
I understand perfectly how it operates. The question is whether the motors will start over 8000' MSL. The Q500 would not. That is based on the internal altimeter. The early specs were the same for the H, but are no longer listed. It is possible the new firmware removed the altitude limit. Only Yuneec would be able to verify.
I just returned from a weekend at a family members mountain home. The house sits at 9958' ASL. This is based on several Garmin GPS readings and on USGS maps.
My H successfully launched and flew at this altitude. It even flew as high as ~10,150' ASL. My H did not require any special firmware. It is using the current firmware available to all.
At that altitude, you could hear the motors working harder to keep it aloft. Everything reacted slower due to the thinner air. Had to be careful descending and moving in the X axis as it took it longer to slow/stop. Battery life was definitely shorter. I didn't time it, but I know based on previous flights. I played it safe and brought it back closer to me when the battery got to 14.9 volts. The motors were not any warmer/hotter than normal...
Again, the H took off and flew above 8,000' ASL with no special firmware like the Q500...
BTW, I live at about 6,000' ASL and regularly fly at this altitude with no issues. Even flying at 8,000' ASL, I've not noticed any significant differences, but at that 10k mark, handling is noticeably different.
My H successfully launched and flew at this altitude. It even flew as high as ~10,150' ASL. My H did not require any special firmware. It is using the current firmware available to all.
At that altitude, you could hear the motors working harder to keep it aloft. Everything reacted slower due to the thinner air. Had to be careful descending and moving in the X axis as it took it longer to slow/stop. Battery life was definitely shorter. I didn't time it, but I know based on previous flights. I played it safe and brought it back closer to me when the battery got to 14.9 volts. The motors were not any warmer/hotter than normal...
Again, the H took off and flew above 8,000' ASL with no special firmware like the Q500...
BTW, I live at about 6,000' ASL and regularly fly at this altitude with no issues. Even flying at 8,000' ASL, I've not noticed any significant differences, but at that 10k mark, handling is noticeably different.
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Iam really glad to hear this!!
Could you perhaps take a look which firmware you are using? Then I would double check, that I will take this firmware version with me if mine is different...just to be save
Thanks!
Could you perhaps take a look which firmware you are using? Then I would double check, that I will take this firmware version with me if mine is different...just to be save
Thanks!
Do you fly in 'turtle' speed mode when flying 8000' and above like they recommend?
(Just Curious.)
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(Just Curious.)
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