Bonanza V-tail Aerodynamics

[Please Hire Me]

Why is the V-tail Bonanza known as the "Doctor Killer?" Does it have something to do with directional control near stalling speed? I would think that tail can't be too effective at slow speeds. Can anyone explain this concept?

 

[El Cid Av8or]

I think it was due to early-model design problems that led to control failure. Another reason they were "doctor killers" is because only doctors could afford them.

 

[jetdriven]

a bonanza will cruise right near the yellow arc and some will cruise in the yellow arc. A moment of inattention will have you exceeding the limits and could overstress the aircraft. Most often involves a low time instrument pilot losing control in the soup with accompanied inflight airframe overstress and the other big one is encounters with thunderstorms.
The V-tail in my mind hasnt been cured as there have been documented cases of V-tail ruddervators being within hinge mass-balance limits, the aircraft within weight and balance limits and properly (airspeed and g-loading) flown that have experienced control surface flutter. I saw a picture of one of these and the whole fuselage just in front of the stabilizer wrinkled like a beach towel.
The sequence is like this, the ruddervator flutters and tears itself from the aircraft along with the stabilizer. this sets up a sympathetic vibration that causes the other side of the tail to go also. then the aircraft violently pitches over "tuck under" causing the wing to fail in a negative overload. the the fuselage pitchpoles end over end until striking the ground. hell of a way to go.
I still fly them. other than the fact they "fishtail" in turbulence (a baron will too) they fly very nicely, although the elevator effort is more like a cessna 150 than an A-36. this aggravates the tendency to overstress the plane.

 

[ceo_of_the_sofa]

wow...nevar knew this...thanks

 

[Huck]

Also, the tail will flutter first, as opposed to the normal tendency for aircraft wings to rip off first.

The tail failure is in torsion on the fuselage, so the wreckage often has a severed tail structure laying nearby. Hence the suspicions of the tail.

I owned a '58 J model once, and miss the hell out of it. 150 kts on 13.5 gph.....

My nomination for the next "Doctor Killer" is the Citation Jet. I've seen and read about some goofy stuff with owner/pilots on that one.

 

[Timebuilder]

I flew the V-tial in IMC and never had a flutter. The model I flew had a yaw damper, and went fast as blazes!

I always was told that it's called the fork-tailed doctor killer because MD's are very confident and wealthy individuals, and are used to doing what they want, when they want to. They get into an area that is outside their professional expertise, ie: flying, and they don't have the skill set to deal with all of the performance the Bonanza is capable of providing. My doc friends have told me that his is a typical midset among their colleagues.

 

[njcapt]

My absolute favorite airplane while training was the V35 Bonanza. I flew one, I think it was a 1970, quite a bit over long distances - including in some hard IFR.

The big problem with the V tail was that it was a sexy airplane for rich folks, which could be flown by low time pilots. If taken lightly, it could really bite you. If the pitch was lowered only two degrees, it would pick up something like one or two knots per second. When added to a cruise speed already in the yellow arc, the airspeed could get past red line before the inexperienced pilot cold identify the situation. There wasn't enough of a change in the slipstream noise to clue the pilot in, and when they did notice the discrepancy a common reaction was to yank back on the yoke - massively overloading the aircraft. If they failed to catch the problem the tail would flutter and leave the airframe as described by the other posters. Game over, man.

 

[sstearns2]

......

The main problem with the V-tails originally was that the main spar in the tail was located pretty far back along the chord and there was nothing attaching the leading edge of the tail to the fuselage. This lead to the leading edge of the tail flexing around excessively in flight and causeing a lot of problems. Many years ago an AD came out the required that a cuff be rivited to the fuselage to hold the leading edge of the tail in place. All the V-tails should have this mod.

The V-tails still have a stigma associated with them and that is reflected in their prices.

The V-tail and straight tail have exactly the same performance with the same engine, but the straight tail is much more expensive now.

Scott

 

[jetdriven]

one more thing on valuation. The V-35B's had a CG range of TWO INCHES and even with two adults front and one adult in the rear seat it often was outside of the rear envelope at landing. Fuel is stored in front of the spar in the wing and the CG moves aft as it burns. Often you have to choose between overgross or outside the aft limit. I'd choose the former.
I dont think the F33A have this problem. I know the A36 has a very wide CG range.
1947 and 1948 "straight" 35's have no tail cuff and as a result have an AD speed restriction of 140 MPH indicated (125 KIAS). These straight 35's had a narrower chord on the tail stabilizers. They also had no shear webbing in the wing spar. Webbing connects the upper and lower spars in an I-beam fashion and prevent wing twist. The A35 recieved a beefed up tail with more chord.
I flew a 1947 straight 35 once (serial # D-500 something) and it flies more like a 160 mph 150 than a V-35B. It really is a light airplane. I think the V-36B tooped out at 3200# where the 1947 model was like 2600.

 

[bobbysamd]

VTail Bonanzas

I remember riding as a pax in the back seat of a V Tail. We were flying in low level turbulence. The airplane really gimbals on its vertical axis in turb. I was probably seated aft of the CG. I nearly got sick.

I have maybe 195 hours instructing in A36 Bonanzas, including instructing primary students. Good training experience for them if they've never flown anything else. Just be sure that they keep the wings level with rudder or else the airplane tends to break sharply and tuck a wing. Quite unlike Cessna or Piper. Night stall training in A36s at Mesa did not delight me.

 

[bart]

Doctor Killers?

Here is the official List of Doctor Killers:

Saratoga
Seneca
Bonanza V Series
Baron
Malibu
Meridian
310
340

Add any airplane here where one who has more money than experience and good judgement can buy oneand go kill themselves with it.

My question is: Did a benign piece of metal kill the doctor, or did the doctor manipulate that piece of metal in such a way as to have a fatal outcome?

Keep giving the V-Tail a bad name, maybe you will drive the values down enough where I can afford one again.

 

[Timebuilder]

My question is: Did a benign piece of metal kill the doctor, or did the doctor manipulate that piece of metal in such a way as to have a fatal outcome?

I'd say the latter.

Keep giving the V-Tail a bad name, maybe you will drive the values down enough where I can afford one again.

Now you're talking. It's one of my favorite airplanes.

Bobby, did the Bonanza that made you ill have the factory yaw damper? I've found that it keeps lunches down in the back.

 

[JCJ]

I have been told that the lawyers are actually worse than the doctors

jcj (pilot and doctor)

 

[utahpilot]

http://www.ntsb.gov/ntsb/brief.asp?ev_id=20021202X05541&key=1

the link is the report for an accident that killed a very well known and respected surgeon, Dr. Hershey, just last month. He was involved in lots of local and international charities, including Operation Smile.

I was talking to one of our higher ups who knew Dr. Hershey. He said that he had previously geared up his Bonanza at least twice. Apparantley he was not very proficient in his piloting, and unfortunatley it cost him his life.

 

[bobbysamd]

V-tail yaw damper & lawyer-pilots

Originally posted by Timebuilder Bobby, did the Bonanza that made you ill have the factory yaw damper? I've found that it keeps lunches down in the back.

No idea. I just remember that the flight that day was yaw city.

Many of the attorneys I've known and worked for are extremely intense. Very driven and mission-oriented. They want results. They may be anal about the details of your work but don't want to hear about the nuts and bolts of how it wound up on their desks. Attorneys I've known have tended to be very demanding. They always seem to want, want, want. They also believe that they are invulnerable in many ways. They survive court and deadline gaffes and still make things work. I've never flown with a lawyer-pilot, but, I suspect that for these reasons they pay little attention to the details that make up a flight. Hence, they fall victim to one of the ADM Hazardous Thought Attitudes, invulnerability. Also, many attorneys don't feel they have to follow the rules, i.e. anti-authority.

On the other hand, many attorneys are extremely bright and quick studies, and, so, they take to piloting quickly. One attorney I have met owns his own King Air and flies it everywhere. I suspect that this man is an excellent pilot.

 

[wingnutt]

cool thread! ive always wondered why the stigma surrounding the Bonanzas...even after 700+ hours in 'em

the only problem i had was in the V-tails with the turbulence fishtailing, especially after burning off 1/2 tank of fuel and a few hundred pounds of freight...ugh