Has this ever happened to anyone?
08-27-2009 | 02:59 PM
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From: BarranquillaAtlantico, COLOMBIA
RE: Has this ever happened to anyone?
ORIGINAL: ww2birds
Pete,
Funny you say that (as others have commented!) ...
I often make the best landing on a maiden flight, as observed above probably due to total focus. The it goes downhill for a while then seems to come back. My son spent some time as a CFI and CFII and his primary training students have the same pattern in full scale Cessnas and Pipers .. best landing during training are at/just after solo .. imagine that. Wonder if some of the military-trained guys had the same experience.
Given the description, I'd wonder about the GC location and elevator travel .. if we were talking heavy prop warbirds with the same story, I'd say too far back on the CG and/or too much elevator travel (which of course are related...).
Also, if you have many planes and switch back + forth, it takes longer to be ''in the zone'' with more than one plane at a time .. jets or otherwise.
I'll still learning too, about 2 yrs jet experience (after many many years of heavy warbird experience), and I sure know what you mean :-)
Dave
Pete,
Funny you say that (as others have commented!) ...
I often make the best landing on a maiden flight, as observed above probably due to total focus. The it goes downhill for a while then seems to come back. My son spent some time as a CFI and CFII and his primary training students have the same pattern in full scale Cessnas and Pipers .. best landing during training are at/just after solo .. imagine that. Wonder if some of the military-trained guys had the same experience.
Given the description, I'd wonder about the GC location and elevator travel .. if we were talking heavy prop warbirds with the same story, I'd say too far back on the CG and/or too much elevator travel (which of course are related...).
Also, if you have many planes and switch back + forth, it takes longer to be ''in the zone'' with more than one plane at a time .. jets or otherwise.
I'll still learning too, about 2 yrs jet experience (after many many years of heavy warbird experience), and I sure know what you mean :-)
Dave
According to Dave's comment, I remember a thread where C.G of the F-16 1/8 were discussed an Craigs's said that in a center turbine with exhaust duct set up, people that has the C.G. as factory specified, fly the Jet hanged in the elevators. In other words, a nose heavy model and even worst if you have a header tank. The result of this set up is as Dave said. Nose heavy model, fast approach with nose down attitude and the result is a very hard elevator control. (A little elevator input, and the nose barely comes up and a little more elevator input, and the nose comes up too much, so the approach pattern is not smooth and is as you sey worst every time).
It is not true that when fuel is burnt, the model becomes tail heavy because the balance is donde with fuel tanks empty, gear down and UAT full. Maybe the problem is that with tanks full, elevators trim are up (you said me that your elevators when you landed are 1/4 above neutral) and with fuel tanks empty, elevator trim should be reduced or the model will fly like tail heavy unless you land in a nose up attitude.
If you don't fly with nose up attitide as I have see in your videos, the approach and the final flare, are going to be the way you are describing.
So, try two steps or wait until my maiden and my experience with my new C.G. set up at 175 mm:
1- Try to fly your downwind , base leg and final at the slowest speed your model can fly in a nose up attitude. Don't try short final leg.
2- Try to set yor C.G. back until you can fly your jet almost with neutral elevator. When fuel are gone and you start your landing pattern, you are going to be in a nose up attitude.
My problem to get 175mm as Craig's said in his experience is that with my set up, I need to add lead strips in the tail and this is going to make my Jet heavier.
Watch this video of my first F-16 on Aug. 3, 2.008.
http://www.rcuvideos.com/video/Skyma...18-Flight-No-2
And this is the thread about C.G.
http://www.rcuniverse.com/forum/m_83...tm.htm#8375613
http://www.rcuniverse.com/forum/m_77...tm.htm#8280992
Guillermo
08-27-2009 | 08:49 PM
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From: East Providence, RI
RE: Has this ever happened to anyone?
ORIGINAL: Guillermo Ibanez
Hey Pete:
According to Dave's comment, I remember a thread where C.G of the F-16 1/8 were discussed an Craigs's said that in a center turbine with exhaust duct set up, people that has the C.G. as factory specified, fly the Jet hanged in the elevators. In other words, a nose heavy model and even worst if you have a header tank. The result of this set up is as Dave said. Nose heavy model, fast approach with nose down attitude and the result is a very hard elevator control. (A little elevator input, and the nose barely comes up and a little more elevator input, and the nose comes up too much, so the approach pattern is not smooth and is as you sey worst every time).
It is not true that when fuel is burnt, the model becomes tail heavy because the balance is donde with fuel tanks empty, gear down and UAT full. Maybe the problem is that with tanks full, elevators trim are up (you said me that your elevators when you landed are 1/4 above neutral) and with fuel tanks empty, elevator trim should be reduced or the model will fly like tail heavy unless you land in a nose up attitude.
If you don't fly with nose up attitide as I have see in your videos, the approach and the final flare, are going to be the way you are describing.
So, try two steps or wait until my maiden and my experience with my new C.G. set up at 175 mm:
1- Try to fly your downwind , base leg and final at the slowest speed your model can fly in a nose up attitude. Don't try short final leg.
2- Try to set yor C.G. back until you can fly your jet almost with neutral elevator. When fuel are gone and you start your landing pattern, you are going to be in a nose up attitude.
My problem to get 175mm as Craig's said in his experience is that with my set up, I need to add lead strips in the tail and this is going to make my Jet heavier.
Watch this video of my first F-16 on Aug. 3, 2.008.
http://www.rcuvideos.com/video/Skyma...18-Flight-No-2
And this is the thread about C.G.
http://www.rcuniverse.com/forum/m_83...tm.htm#8375613
http://www.rcuniverse.com/forum/m_77...tm.htm#8280992
Guillermo
ORIGINAL: ww2birds
Pete,
Funny you say that (as others have commented!) ...
I often make the best landing on a maiden flight, as observed above probably due to total focus. The it goes downhill for a while then seems to come back. My son spent some time as a CFI and CFII and his primary training students have the same pattern in full scale Cessnas and Pipers .. best landing during training are at/just after solo .. imagine that. Wonder if some of the military-trained guys had the same experience.
Given the description, I'd wonder about the GC location and elevator travel .. if we were talking heavy prop warbirds with the same story, I'd say too far back on the CG and/or too much elevator travel (which of course are related...).
Also, if you have many planes and switch back + forth, it takes longer to be ''in the zone'' with more than one plane at a time .. jets or otherwise.
I'll still learning too, about 2 yrs jet experience (after many many years of heavy warbird experience), and I sure know what you mean :-)
Dave
Pete,
Funny you say that (as others have commented!) ...
I often make the best landing on a maiden flight, as observed above probably due to total focus. The it goes downhill for a while then seems to come back. My son spent some time as a CFI and CFII and his primary training students have the same pattern in full scale Cessnas and Pipers .. best landing during training are at/just after solo .. imagine that. Wonder if some of the military-trained guys had the same experience.
Given the description, I'd wonder about the GC location and elevator travel .. if we were talking heavy prop warbirds with the same story, I'd say too far back on the CG and/or too much elevator travel (which of course are related...).
Also, if you have many planes and switch back + forth, it takes longer to be ''in the zone'' with more than one plane at a time .. jets or otherwise.
I'll still learning too, about 2 yrs jet experience (after many many years of heavy warbird experience), and I sure know what you mean :-)
Dave
According to Dave's comment, I remember a thread where C.G of the F-16 1/8 were discussed an Craigs's said that in a center turbine with exhaust duct set up, people that has the C.G. as factory specified, fly the Jet hanged in the elevators. In other words, a nose heavy model and even worst if you have a header tank. The result of this set up is as Dave said. Nose heavy model, fast approach with nose down attitude and the result is a very hard elevator control. (A little elevator input, and the nose barely comes up and a little more elevator input, and the nose comes up too much, so the approach pattern is not smooth and is as you sey worst every time).
It is not true that when fuel is burnt, the model becomes tail heavy because the balance is donde with fuel tanks empty, gear down and UAT full. Maybe the problem is that with tanks full, elevators trim are up (you said me that your elevators when you landed are 1/4 above neutral) and with fuel tanks empty, elevator trim should be reduced or the model will fly like tail heavy unless you land in a nose up attitude.
If you don't fly with nose up attitide as I have see in your videos, the approach and the final flare, are going to be the way you are describing.
So, try two steps or wait until my maiden and my experience with my new C.G. set up at 175 mm:
1- Try to fly your downwind , base leg and final at the slowest speed your model can fly in a nose up attitude. Don't try short final leg.
2- Try to set yor C.G. back until you can fly your jet almost with neutral elevator. When fuel are gone and you start your landing pattern, you are going to be in a nose up attitude.
My problem to get 175mm as Craig's said in his experience is that with my set up, I need to add lead strips in the tail and this is going to make my Jet heavier.
Watch this video of my first F-16 on Aug. 3, 2.008.
http://www.rcuvideos.com/video/Skyma...18-Flight-No-2
And this is the thread about C.G.
http://www.rcuniverse.com/forum/m_83...tm.htm#8375613
http://www.rcuniverse.com/forum/m_77...tm.htm#8280992
Guillermo
I have flown the model with a nose up attitude on downwind pretty slow, Once I was trimmed for it it flew high AOA very nicely with little to no back pressure on the elevator, This was a few flights ago at capitol jets. I came in nose high and had a good one there, I think I need to get back to concentrating as hard as I was my first few flights, Either that or get another refresher course from Frank..
Pete
Pete
08-27-2009 | 09:33 PM
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From: BarranquillaAtlantico, COLOMBIA
RE: Has this ever happened to anyone?
ORIGINAL: Pete737
Looks awesome with the lighting Guillermo!
I have flown the model with a nose up attitude on downwind pretty slow, Once I was trimmed for it it flew high AOA very nicely with little to no back pressure on the elevator, This was a few flights ago at capitol jets. I came in nose high and had a good one there, I think I need to get back to concentrating as hard as I was my first few flights, Either that or get another refresher course from Frank..
Pete
Pete
ORIGINAL: Guillermo Ibanez
Hey Pete:
According to Dave's comment, I remember a thread where C.G of the F-16 1/8 were discussed an Craigs's said that in a center turbine with exhaust duct set up, people that has the C.G. as factory specified, fly the Jet hanged in the elevators. In other words, a nose heavy model and even worst if you have a header tank. The result of this set up is as Dave said. Nose heavy model, fast approach with nose down attitude and the result is a very hard elevator control. (A little elevator input, and the nose barely comes up and a little more elevator input, and the nose comes up too much, so the approach pattern is not smooth and is as you sey worst every time).
It is not true that when fuel is burnt, the model becomes tail heavy because the balance is donde with fuel tanks empty, gear down and UAT full. Maybe the problem is that with tanks full, elevators trim are up (you said me that your elevators when you landed are 1/4 above neutral) and with fuel tanks empty, elevator trim should be reduced or the model will fly like tail heavy unless you land in a nose up attitude.
If you don't fly with nose up attitide as I have see in your videos, the approach and the final flare, are going to be the way you are describing.
So, try two steps or wait until my maiden and my experience with my new C.G. set up at 175 mm:
1- Try to fly your downwind , base leg and final at the slowest speed your model can fly in a nose up attitude. Don't try short final leg.
2- Try to set yor C.G. back until you can fly your jet almost with neutral elevator. When fuel are gone and you start your landing pattern, you are going to be in a nose up attitude.
My problem to get 175mm as Craig's said in his experience is that with my set up, I need to add lead strips in the tail and this is going to make my Jet heavier.
Watch this video of my first F-16 on Aug. 3, 2.008.
http://www.rcuvideos.com/video/Skyma...18-Flight-No-2
And this is the thread about C.G.
http://www.rcuniverse.com/forum/m_83...tm.htm#8375613
http://www.rcuniverse.com/forum/m_77...tm.htm#8280992
Guillermo
ORIGINAL: ww2birds
Pete,
Funny you say that (as others have commented!) ...
I often make the best landing on a maiden flight, as observed above probably due to total focus. The it goes downhill for a while then seems to come back. My son spent some time as a CFI and CFII and his primary training students have the same pattern in full scale Cessnas and Pipers .. best landing during training are at/just after solo .. imagine that. Wonder if some of the military-trained guys had the same experience.
Given the description, I'd wonder about the GC location and elevator travel .. if we were talking heavy prop warbirds with the same story, I'd say too far back on the CG and/or too much elevator travel (which of course are related...).
Also, if you have many planes and switch back + forth, it takes longer to be ''in the zone'' with more than one plane at a time .. jets or otherwise.
I'll still learning too, about 2 yrs jet experience (after many many years of heavy warbird experience), and I sure know what you mean :-)
Dave
Pete,
Funny you say that (as others have commented!) ...
I often make the best landing on a maiden flight, as observed above probably due to total focus. The it goes downhill for a while then seems to come back. My son spent some time as a CFI and CFII and his primary training students have the same pattern in full scale Cessnas and Pipers .. best landing during training are at/just after solo .. imagine that. Wonder if some of the military-trained guys had the same experience.
Given the description, I'd wonder about the GC location and elevator travel .. if we were talking heavy prop warbirds with the same story, I'd say too far back on the CG and/or too much elevator travel (which of course are related...).
Also, if you have many planes and switch back + forth, it takes longer to be ''in the zone'' with more than one plane at a time .. jets or otherwise.
I'll still learning too, about 2 yrs jet experience (after many many years of heavy warbird experience), and I sure know what you mean :-)
Dave
According to Dave's comment, I remember a thread where C.G of the F-16 1/8 were discussed an Craigs's said that in a center turbine with exhaust duct set up, people that has the C.G. as factory specified, fly the Jet hanged in the elevators. In other words, a nose heavy model and even worst if you have a header tank. The result of this set up is as Dave said. Nose heavy model, fast approach with nose down attitude and the result is a very hard elevator control. (A little elevator input, and the nose barely comes up and a little more elevator input, and the nose comes up too much, so the approach pattern is not smooth and is as you sey worst every time).
It is not true that when fuel is burnt, the model becomes tail heavy because the balance is donde with fuel tanks empty, gear down and UAT full. Maybe the problem is that with tanks full, elevators trim are up (you said me that your elevators when you landed are 1/4 above neutral) and with fuel tanks empty, elevator trim should be reduced or the model will fly like tail heavy unless you land in a nose up attitude.
If you don't fly with nose up attitide as I have see in your videos, the approach and the final flare, are going to be the way you are describing.
So, try two steps or wait until my maiden and my experience with my new C.G. set up at 175 mm:
1- Try to fly your downwind , base leg and final at the slowest speed your model can fly in a nose up attitude. Don't try short final leg.
2- Try to set yor C.G. back until you can fly your jet almost with neutral elevator. When fuel are gone and you start your landing pattern, you are going to be in a nose up attitude.
My problem to get 175mm as Craig's said in his experience is that with my set up, I need to add lead strips in the tail and this is going to make my Jet heavier.
Watch this video of my first F-16 on Aug. 3, 2.008.
http://www.rcuvideos.com/video/Skyma...18-Flight-No-2
And this is the thread about C.G.
http://www.rcuniverse.com/forum/m_83...tm.htm#8375613
http://www.rcuniverse.com/forum/m_77...tm.htm#8280992
Guillermo
I have flown the model with a nose up attitude on downwind pretty slow, Once I was trimmed for it it flew high AOA very nicely with little to no back pressure on the elevator, This was a few flights ago at capitol jets. I came in nose high and had a good one there, I think I need to get back to concentrating as hard as I was my first few flights, Either that or get another refresher course from Frank..
Pete
Pete
Lets see how will perform mine with ligths and ordinance, although my firts flights will be without ordinance. Just to be familiar first.
08-27-2009 | 10:03 PM
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From: Canyon Lake, TX
RE: Has this ever happened to anyone?
This is a well written "how to land" from the JPO knowledge bank: http://www.jetpilots.org/knowledge_bank/landings.pdf It is worth a read even if you already know how to land.
FWIW, I've had the same problem - first few landings with a new airframe are pretty good, the next 5 or 10 kinda suk. I don't know for sure why it happens, but I sometimes find myself slipping back into bad habits without realizing it. I think it helps to consciously focus on the fundamentals every second of every landing.
FWIW, I've had the same problem - first few landings with a new airframe are pretty good, the next 5 or 10 kinda suk. I don't know for sure why it happens, but I sometimes find myself slipping back into bad habits without realizing it. I think it helps to consciously focus on the fundamentals every second of every landing.
08-28-2009 | 12:05 PM
#32
RE: Has this ever happened to anyone?
Hi Guillermo
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
08-28-2009 | 03:00 PM
#33
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From: East Providence, RI
RE: Has this ever happened to anyone?
ORIGINAL: jetnuno
Hi Guillermo
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
Hi Guillermo
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
08-28-2009 | 04:47 PM
#34
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From: BarranquillaAtlantico, COLOMBIA
RE: Has this ever happened to anyone?
ORIGINAL: jetnuno
Hi Guillermo
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
Hi Guillermo
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
Not yet because my maiden is in 15 days.
My set up will be at 170 mm initially with the UAT full, gear down and front or header tank at 50%
Try this threads:
http://www.rcuniverse.com/forum/m_83...tm.htm#8375613
http://www.rcuniverse.com/forum/m_77...tm.htm#8280992
Guillermo
08-28-2009 | 04:54 PM
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RE: Has this ever happened to anyone?
ORIGINAL: Pete737
Don't you think 175 is pushing it a bit? Just asking. I've heard 190 is supposedly uncontrollable.
ORIGINAL: jetnuno
Hi Guillermo
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
Hi Guillermo
Are you flying with CG at 175mm? I went just to 160mm.
I also set-up my planes with UAT full, gear down and empty tanks, but since the fuel tanks are far away forward the CG, at take off the plane is quite nose heavy and during fliht as fuel is burnt, the CG will move back almost till it's original setting (160 mm in my case with no fuel). 175mm could be an interesting number to test. Do you know if any one tested it before with sucess?
Anyway, I still believe that the best setting will be to relocate the fuel tanks to a more neutral position and make those with less lenght and more height (valid set-up for tail mounted turbines)
Regards
Nuno
