How high could an rc Jet fly?
12-26-2013, 12:40 PM
#28
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King Air C90GT climb performance from Flying Magazine
http://www.flyingmag.com/pilot-repor...echcraft-c90gt
I'm not a turbine pilot but does anyone have any performance numbers on their model jet?
Paul
Immediately after takeoff the C90GT climbed steadily at 2,200 fpm and held near that rate up to 15,000 feet, and then maintained an 1,800 to 2,000 fpm climb through 18,000 feet. We were still going up at 1,500 fpm when I leveled at 25,000 feet just 15 minutes after takeoff
I'm not a turbine pilot but does anyone have any performance numbers on their model jet?
Paul
12-26-2013, 01:03 PM
#29
King Air C90GT climb performance from Flying Magazine
http://www.flyingmag.com/pilot-repor...echcraft-c90gt
I'm not a turbine pilot but does anyone have any performance numbers on their model jet?
Paul
http://www.flyingmag.com/pilot-repor...echcraft-c90gt
I'm not a turbine pilot but does anyone have any performance numbers on their model jet?
Paul
12-26-2013, 01:19 PM
#30
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ama says 400 feet for rc are you jet men able to go over whar the ama says and rui n it for everyone one reason clubs dont like jets>> so you might hit a jet plane with 300 people in it and they all die???????????
12-26-2013, 01:27 PM
#32
This is interesting! I think the right sportjet could possibly top this! Although 7900fpm is respectable, it's only 10 degrees up & shows a negative trend on the tape. A 2 to 1 power to weight on a good sportjet & I'm guessing it could top this by a bit..(but totally a guess though, could be talking outta my ars..lol)
12-26-2013, 01:27 PM
#33
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my club dont allow jets which is good some and i say some jet flyers make it hard to find a place to fly>>> each state the jet flyers schould get a field of there own that way you wont screw the other fields up
12-26-2013, 01:31 PM
#34
Originally Posted by [email protected]
ama says 400 feet for rc are you jet men able to go over whar the ama says and rui n it for everyone one reason clubs dont like jets>> so you might hit a jet plane with 300 people in it and they all die???????????
12-26-2013, 02:09 PM
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12-26-2013, 02:33 PM
#36
Would it really be -45 deg C at 30,000 feet? I have jumped out of an airplane at 14,000 ft and it wasn't very cold at all. It was cooler than on the ground though. Obviously, it was summer time.
If I had to guess, I would say your radio range would be the limit as to how high you could fly. Assuming you are on the ground. I had been told years ago that the FM radios were good for about 1000 meters or around 5/8 of a mile. Not sure about the 2.4 radios.
Terry
If I had to guess, I would say your radio range would be the limit as to how high you could fly. Assuming you are on the ground. I had been told years ago that the FM radios were good for about 1000 meters or around 5/8 of a mile. Not sure about the 2.4 radios.
Terry
- EFP
- ZFP
- RNS
- SVR
- MAR
- REC
=== State Collectives for OH ===
WINDS ALOFT FORECASTS DATA BASED ON 261800Z <---- Dec 26 1013 @ 1800Zulu = 2pm VALID 271800Z FOR USE 1200-0000Z.
TEMPS NEG ABV 24000 FEET CLE CMH
3000 2718 2625
6000 2828-06 2729-03
9000 2933-09 2831-08
12000 2938-13 2836-12 <--- 12000 over CLE 290@38KT -13 C
18000 2940-24 2842-24
24000 2944-37 2847-37
30000 285350 267148 <----Winds over Cleavlend at FL300 280 degrees
@ 53 Knots-50C
34000 276252 267551 Yes it's cold up there
39000 276751 267251
45000 267854
53000 266860
Last edited by HoundDog; 12-26-2013 at 02:43 PM.
12-26-2013, 02:56 PM
#37
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Also fly a Global Express, also certified to 51,000. we go to 47,000 regularly on long trips but I have only been to 49,000 once.
To answer some earlier questions. Temperature reduces on average 2 degrees C per thousand feet. (Environmental Lapse rate) Until it reaches the Tropopause where it remains constant at -57C
If you had a model this high for any period of time the cold would cause issues with fuel (Jet fuel freezes at -47C) and I can't imagine the servos being happy at this temp.
Like Dieselman1220 said, most aircraft designed to fly that high have fuel heaters of some type.
2.4Ghz is good up to 3500-4000 meters line of sight so 10,000 feet would not be an issue. Seeing your plane might be the issue. Departing some airports we double back over the airport at 10,000 or above.. even Boeing 737s sitting on the ground look tiny from that height…..
https://www.youtube.com/watch?v=PhOKlP6Psn8 https://www.youtube.com/watch?v=Pxyly9rUcOs
Last edited by Rob2160; 12-26-2013 at 03:06 PM.
12-26-2013, 03:20 PM
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Originally Posted by [email protected]
ama says 400 feet for rc are you jet men able to go over whar the ama says and rui n it for everyone one reason clubs dont like jets>> so you might hit a jet plane with 300 people in it and they all die???????????
7.2.1 Unless approval has been obtained beforehand, model aircraft should only be flown
(a) when the weather is suitable;
(b) clear of the movement areas or runways of an aerodrome;
(c) below 400ft above ground level unless:
(i) clear of controlled airspace, and
(ii) further than 3 nautical miles from any aerodrome:
(d) within sight of the operator at all times;
(e) well clear of populous areas;
(f) at least 30m clear of persons, vessels, vehicles or structures.
Last edited by Rob2160; 12-26-2013 at 03:24 PM.
12-26-2013, 03:40 PM
#39
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In the 1960's, Maynard Hill set an altitude of around 26000 feet with an internal combustion R/C model, and I think that still stands today. He also set records for endurance and distance. Here is a link: http://www.rchalloffame.org/Exhibits...t05/index.html
12-26-2013, 05:31 PM
#40
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I don't think fuel temps will be the major issue.
None of the full sized airliners I work on be it either Airbus or Boeing heat the fuel stored in the wings in any way shape or form. The wings cool soak and stay at that temp for the duration of the flight, so potentially 10+ hours.
Fuel/oil heat exchangers are normally fitted at the engines. They are there to primarily cool the oil more than to heat the fuel. The warmer fuel will atomize better and will also greatly reduce the chance of any trapped water floating in the fuel from blocking the fuel metering system or fuel nozzles. If it was your major concern then don't use JETA-1, and get some JP-11 fuel. the military uses some stronger (and far more carcinogenic ) anti-freeze additives in their fuel.
Having radio connection can be overcome to a large extent with the UHF 433mhz systems used in FPV guys have flown over 20km away from themselves. Servos and radio gear at -47 would be a far greater issue...
Thanks
dave
None of the full sized airliners I work on be it either Airbus or Boeing heat the fuel stored in the wings in any way shape or form. The wings cool soak and stay at that temp for the duration of the flight, so potentially 10+ hours.
Fuel/oil heat exchangers are normally fitted at the engines. They are there to primarily cool the oil more than to heat the fuel. The warmer fuel will atomize better and will also greatly reduce the chance of any trapped water floating in the fuel from blocking the fuel metering system or fuel nozzles. If it was your major concern then don't use JETA-1, and get some JP-11 fuel. the military uses some stronger (and far more carcinogenic ) anti-freeze additives in their fuel.
Having radio connection can be overcome to a large extent with the UHF 433mhz systems used in FPV guys have flown over 20km away from themselves. Servos and radio gear at -47 would be a far greater issue...
Thanks
dave
Last edited by ticketec; 12-26-2013 at 05:47 PM.
12-26-2013, 07:34 PM
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I don't think fuel temps will be the major issue.
None of the full sized airliners I work on be it either Airbus or Boeing heat the fuel stored in the wings in any way shape or form. The wings cool soak and stay at that temp for the duration of the flight, so potentially 10+ hours.
Fuel/oil heat exchangers are normally fitted at the engines. They are there to primarily cool the oil more than to heat the fuel. The warmer fuel will atomize better and will also greatly reduce the chance of any trapped water floating in the fuel from blocking the fuel metering system or fuel nozzles. If it was your major concern then don't use JETA-1, and get some JP-11 fuel. the military uses some stronger (and far more carcinogenic ) anti-freeze additives in their fuel.
Having radio connection can be overcome to a large extent with the UHF 433mhz systems used in FPV guys have flown over 20km away from themselves. Servos and radio gear at -47 would be a far greater issue...
Thanks
dave
None of the full sized airliners I work on be it either Airbus or Boeing heat the fuel stored in the wings in any way shape or form. The wings cool soak and stay at that temp for the duration of the flight, so potentially 10+ hours.
Fuel/oil heat exchangers are normally fitted at the engines. They are there to primarily cool the oil more than to heat the fuel. The warmer fuel will atomize better and will also greatly reduce the chance of any trapped water floating in the fuel from blocking the fuel metering system or fuel nozzles. If it was your major concern then don't use JETA-1, and get some JP-11 fuel. the military uses some stronger (and far more carcinogenic ) anti-freeze additives in their fuel.
Having radio connection can be overcome to a large extent with the UHF 433mhz systems used in FPV guys have flown over 20km away from themselves. Servos and radio gear at -47 would be a far greater issue...
Thanks
dave
It takes many hours to cool that much fuel and with cruising speeds around Mach 0.80 and above you get temp increases on the airframe due to Mach Temp rise. (Ram rise) So it is unlikely the fuel will ever get cold enough to freeze.
Many corporate jets can climb straight to 41,000 and then step climb up from there.
Last edited by Rob2160; 12-26-2013 at 08:01 PM.
12-26-2013, 09:21 PM
#44
lots of interesting info and theories here... The magenta is our selected vertical speed set at 5000. the autopilot pitched up to 7900FPM to keep from over speeding as our VMO is 330 KIAS. In this cold weather at mid to light weights its not uncommon for us to maintain a steady 5000FPM climb from 12,000 or so up to the mid 20s at 300 KIAS
12-27-2013, 01:50 AM
#46
Never heard of any jet having fuel heaters, FOHE, yes, but they are designed to prevent ice crystals resulting from water in the fuel (there's usually just a trace) freezing and blocking engine fuel components, particularly filters, (And cooling the engine oil as Ticketec said) !)
The only Boeing procedure I know of to raise fuel temperature is to descend to a lower level ! Fuel freeze point is at least -47, usually -57, trop. temperature -56 and lowest OAT I have ever seen was -70 at FL390 over northern Russia on flight from Soeul to LHR. Highest TAT , actually nose probe, PLUS 127 at FL600 no fuel freezing problems there !
The best information I have ever read on this subject is in the accident report into the BA 777 crash at LHR. A lot of new knowledge was discovered by the UK AAIB, Boeing and Rolls Royce, who redesigned the FOHEs. based on the findings. Every fullsize, jet pilot should read it, particularly those who operate at high altitudes.
Just google it for a very succinct summary of that lengthy report.
Interesting subject.
David
The only Boeing procedure I know of to raise fuel temperature is to descend to a lower level ! Fuel freeze point is at least -47, usually -57, trop. temperature -56 and lowest OAT I have ever seen was -70 at FL390 over northern Russia on flight from Soeul to LHR. Highest TAT , actually nose probe, PLUS 127 at FL600 no fuel freezing problems there !
The best information I have ever read on this subject is in the accident report into the BA 777 crash at LHR. A lot of new knowledge was discovered by the UK AAIB, Boeing and Rolls Royce, who redesigned the FOHEs. based on the findings. Every fullsize, jet pilot should read it, particularly those who operate at high altitudes.
Just google it for a very succinct summary of that lengthy report.
Interesting subject.
David
Last edited by David Gladwin; 12-27-2013 at 03:15 AM.
12-27-2013, 04:42 AM
#48
Originally Posted by [email protected]
ama says 400 feet for rc are you jet men able to go over whar the ama says and rui n it for everyone one reason clubs dont like jets>> so you might hit a jet plane with 300 people in it and they all die???????????
12-27-2013, 12:13 PM
#50
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i believe the old AM radios were pretty much unlimited in vertical range.I don't believe Maynard Hill used any special radios when he set altitude records 17,000 + ft. But my old memory brain files could be corrupted by now