Baby FTDK
Wally - What model was the V-tail that you flew?
My understanding is that early model V-tails have smaller ruddavators (?) than later models and therefore had a greater tendancy to tail wag. Sorry, I can't tell you what year they put the larger tail on it.
My experience with FTDKs is limited to 3 aircraft - all with the larger tail.
VH-CFK, in which I did my endorsement in about 1975 with Barry Hempel. I think it was a V35A. VH-FWE, ex Stanbroke Pastoral Co - a V35A, and my current steed, which is a V35B.
I don't find the tail-wagging to be a significant issue. There are a couple of reasons for this.
1) I mostly fly by myself or with front seat pax only. The aeroplane wags around an axis between the two front seat so is not nearly as disturbing as it is for back seat pax.
2) I generally fly as high as possible - where is is usually smooth.
3) If I am in turbulence I usually hand fly, unless I am in hard core IMC when I generally let George do the work and just put up with the wagging.
2 axis autopilots generally fight the tail wag and make the problem much worse, so V-tail pilots soon learn the nack to damping out the tail-wag while hand flying and do it automatically without having to think about it.
I am told that a yaw-damper will eliminate the tail wag as an issue, but I have never flown a V-tail that had a yaw-damper fitted.
Most people think the tail-wagging is the result of not having a vertical fin, but it is actually a characteristic of the airframe design - largely I think because of the forward position of the wing. The BE36 wags its tail in turbulence, as does the straight tail BE33 - but the 35 does it best. Barons, which are essentially twin engine Bonanzas, also tail wag in turbulence - but not to the same extent.
Cheers
Dr
My understanding is that early model V-tails have smaller ruddavators (?) than later models and therefore had a greater tendancy to tail wag. Sorry, I can't tell you what year they put the larger tail on it.
My experience with FTDKs is limited to 3 aircraft - all with the larger tail.
VH-CFK, in which I did my endorsement in about 1975 with Barry Hempel. I think it was a V35A. VH-FWE, ex Stanbroke Pastoral Co - a V35A, and my current steed, which is a V35B.
I don't find the tail-wagging to be a significant issue. There are a couple of reasons for this.
1) I mostly fly by myself or with front seat pax only. The aeroplane wags around an axis between the two front seat so is not nearly as disturbing as it is for back seat pax.
2) I generally fly as high as possible - where is is usually smooth.
3) If I am in turbulence I usually hand fly, unless I am in hard core IMC when I generally let George do the work and just put up with the wagging.
2 axis autopilots generally fight the tail wag and make the problem much worse, so V-tail pilots soon learn the nack to damping out the tail-wag while hand flying and do it automatically without having to think about it.
I am told that a yaw-damper will eliminate the tail wag as an issue, but I have never flown a V-tail that had a yaw-damper fitted.
Most people think the tail-wagging is the result of not having a vertical fin, but it is actually a characteristic of the airframe design - largely I think because of the forward position of the wing. The BE36 wags its tail in turbulence, as does the straight tail BE33 - but the 35 does it best. Barons, which are essentially twin engine Bonanzas, also tail wag in turbulence - but not to the same extent.
Cheers
Dr
Last edited by ForkTailedDrKiller; 21st Dec 2007 at 03:34.
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Capt Wally "I used to trim out a slight left or right rudder inbalance & it seemed to keep it more stable"
How did you trim out to get a rudder imbalance? I assume you did it by holding down a bit of rudder, or are there some V tail Bonanza models with a rudder trim?
XXGOLDXX "Half a tail, wheels in the wrong place, wings in the wrong place...."
Far riskier than even Peter Fanelli's post
typical utterances from Cessna drivers with Beech Envy.
I do however enjoy drinking your PPrune name.
I'll think of you when I have one or two this evening
How did you trim out to get a rudder imbalance? I assume you did it by holding down a bit of rudder, or are there some V tail Bonanza models with a rudder trim?
XXGOLDXX "Half a tail, wheels in the wrong place, wings in the wrong place...."
Far riskier than even Peter Fanelli's post
typical utterances from Cessna drivers with Beech Envy.
I do however enjoy drinking your PPrune name.
I'll think of you when I have one or two this evening
My understanding is that early model V-tails have smaller ruddavators (?)
Most people think the tail-wagging is the result of not having a vertical fin, but it is actually a characteristic of the airframe design - largely I think because of the forward position of the wing. The BE36 wags its tail in turbulence, as does the straight tail BE33 - but the 35 does it best.
I am told that a yaw-damper will eliminate the tail wag as an issue, but I have never flown a V-tail that had a yaw-damper fitted.
GB - "I think the control surfaces on the V-tail have always been the same size"
"The oringinal V-tail on the 35 to B35 had a dihedral angle of 30 degrees, a chord at the root of about 42 inches, and a chord at the tip of about 31.5 inches. All Bonanza ruddervators and horizontal stabilizers have about the same span - 68 inches. Starting with the C35, all subsequent V-tails had a dihedral of 33 degrees and root and tip chords of about 50.5 and 35.5 inches, respectively."
"Geometrically, though perhaps not aerodynamically, the V-tails can be "projected" to give their vertical and horizontal "equivalent areas". This means, for instance, that if we placed an old V-tail directly below a distant light source and traced the tail's shadow on a horizontal plane, we could measure the horizontal component of the V-tail. The area of this shadow would be the "equivalent horizontal tail area". Similarly, a light from the side would cast a shadow on a vertical plane (paralleling the longitudinal axis), and the area of this shadow would be half the "equivalent vertical tail area". (It is half, since there are two tail members.) Table 1 gives the data for the various tails.
Table 1 - Equivalent Areas
Old V-tail: Horizontal tail - 31.9; Vertical tail - 18.4
New V-tail: Horizontal tail - 36.4; Vertical tail - 23.6"
Ref: "Flying the Bonanza", 2nd Ed 1977, by John C Eckalbar [ISBN 0-9616544-3-0]
Dr
"The oringinal V-tail on the 35 to B35 had a dihedral angle of 30 degrees, a chord at the root of about 42 inches, and a chord at the tip of about 31.5 inches. All Bonanza ruddervators and horizontal stabilizers have about the same span - 68 inches. Starting with the C35, all subsequent V-tails had a dihedral of 33 degrees and root and tip chords of about 50.5 and 35.5 inches, respectively."
"Geometrically, though perhaps not aerodynamically, the V-tails can be "projected" to give their vertical and horizontal "equivalent areas". This means, for instance, that if we placed an old V-tail directly below a distant light source and traced the tail's shadow on a horizontal plane, we could measure the horizontal component of the V-tail. The area of this shadow would be the "equivalent horizontal tail area". Similarly, a light from the side would cast a shadow on a vertical plane (paralleling the longitudinal axis), and the area of this shadow would be half the "equivalent vertical tail area". (It is half, since there are two tail members.) Table 1 gives the data for the various tails.
Table 1 - Equivalent Areas
Old V-tail: Horizontal tail - 31.9; Vertical tail - 18.4
New V-tail: Horizontal tail - 36.4; Vertical tail - 23.6"
Ref: "Flying the Bonanza", 2nd Ed 1977, by John C Eckalbar [ISBN 0-9616544-3-0]
Dr
Table 1 - Equivalent Areas
Old V-tail: Horizontal tail - 31.9; Vertical tail - 18.4
New V-tail: Horizontal tail - 36.4; Vertical tail - 23.6"
Old V-tail: Horizontal tail - 31.9; Vertical tail - 18.4
New V-tail: Horizontal tail - 36.4; Vertical tail - 23.6"
Total tail surface area increased on later V-tails, but did the control surface (the wiggly bits) area increase? One just has to know these things.
GB, according to Eckalbar, the 33 and the 36 have a vertical fin of similar area - about 15.3 sq ft (cf 18.4 / 23.6 above).
As for the "wiggly bits", don't know about the Bonanza's - but mine seems to be getting smaller as the years progress!
Dr
As for the "wiggly bits", don't know about the Bonanza's - but mine seems to be getting smaller as the years progress!
Dr
As for the "wiggly bits", don't know about the Bonanza's - but mine seems to be getting smaller as the years progress!
Last edited by gassed budgie; 21st Dec 2007 at 23:23.
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...........tnxs FTDK & to the others with a very comprehensive knowledge base for info and 'waggled' their tails into this Bo habbit
FTDK I am not sure what model it was that I flew years ago & the rego escapes me at the moment. (perhaps VH-CFH?). All planes 'wag' thier tails to some degree (hence the strakes on a lot of higher performance machines) mainly 'cause the medium that the machines fly in is compressable (air) not like water where any rudder has a far more effient way of keeping the 'ship' straight.
Hi "Beach King" ( I assume you too fly the BE20) you have a good point there about what method I used to trim the rudder for out of balance flt.I can't recall now how I did it but I do recall (perhaps a bending of any metal adjustable trim tab)that the rudder pedals are in fact deliberately offset to compensate for perhaps that & to assist in spin recovery, am racking my poor brain here now with that lot. So I asked if it could be checked when next it went in for a 100 hrly.. It seemed to fix the problem whatever they did a little but obviously not completely.
I know the L35/36 (std model, not modified) that I fly has yaw damper restrictions as in they have to be avail for flt (no go item) so the problem of tail wagging will always be there in any A/C to some degree. If I kick out the yaw damper (part of the auto flt system) to early in the flair (it's a req on some types of auto pilots in the Lear's)the ship wags itself around esspecially in x winds quite a bit. It's the one function that just after T/Off is required to be selected after the U/C.
Still an interesting subject.
Capt Wally
FTDK I am not sure what model it was that I flew years ago & the rego escapes me at the moment. (perhaps VH-CFH?). All planes 'wag' thier tails to some degree (hence the strakes on a lot of higher performance machines) mainly 'cause the medium that the machines fly in is compressable (air) not like water where any rudder has a far more effient way of keeping the 'ship' straight.
Hi "Beach King" ( I assume you too fly the BE20) you have a good point there about what method I used to trim the rudder for out of balance flt.I can't recall now how I did it but I do recall (perhaps a bending of any metal adjustable trim tab)that the rudder pedals are in fact deliberately offset to compensate for perhaps that & to assist in spin recovery, am racking my poor brain here now with that lot. So I asked if it could be checked when next it went in for a 100 hrly.
. It seemed to fix the problem whatever they did a little but obviously not completely.I know the L35/36 (std model, not modified) that I fly has yaw damper restrictions as in they have to be avail for flt (no go item) so the problem of tail wagging will always be there in any A/C to some degree. If I kick out the yaw damper (part of the auto flt system) to early in the flair (it's a req on some types of auto pilots in the Lear's)the ship wags itself around esspecially in x winds quite a bit. It's the one function that just after T/Off is required to be selected after the U/C.
Still an interesting subject.
Capt Wally
