Beech V35 Midair Breakup

Doc Holliday said:
So why didn't Beech include the straight tail (Debonair) into the AD? How many Debonairs have broken up compared to the V tail?
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I'm sure you'll attempt to correct me.....but we are discussing the post AD aircraft....that had an inflight break up.

If your memory is that short.....I can repost the pictures. ;)
 
Checkout_my_Six said:
I'm sure you'll attempt to correct me.....but we are discussing the post AD aircraft....that had an inflight break up.

If your memory is that short.....I can repost the pictures. ;)
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That’s ok, you’re just deflecting because you simply can’t answer it. :rolleyes:

Wash, Rinse, Repeat. ;)
 
Checkout_my_Six said:
It will break up also....given similar flight conditions. ;)
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Statistics prove that wrong. IIRC, from the Aviation Consumer expose on it, there were a couple of hundred V-tail break ups and less than five straight tail break ups.
 
Checkout_my_Six said:
Any aircraft that exceeds structural limits will break a part....ask Scott Crossfield.
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Actually, when the V-tails broke up in flight, it was the failure of the ruddervator. The straight tails do not have a ruddervator.
 
Kristin said:
Statistics prove that wrong. IIRC, from the Aviation Consumer expose on it, there were a couple of hundred V-tail break ups and less than five straight tail break ups.
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let's see your references. I believe those were prior to the AD.
 
Kristin said:
Actually, when the V-tails broke up in flight, it was the failure of the ruddervator. The straight tails do not have a ruddervator.
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Is there a statistical analysis on this before and after the AD? I'd like to see the data....
 
Checkout_my_Six said:
let's see your references. I believe those were prior to the AD.
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Aviation Consumer Used Aircraft Guide, Third Edition.

"What makes the V-tail's high record of in-flight breakup all the more ironic is the very low breakup rate of the straight-tail 35 and 36 models, which are essentially identical to the 35 except for the tail. The V-tail's breakup rate, according to one study, is 24 times higher than the straight tail."

From the book:
1716485399034.png
This edition was copyrighted 1989, though the Bonanza article might stem from the earlier edition in 1981 or the actual magazine article, published earlier.

It may pre-date the AD. However, what catches my attention is that the piece doesn't solely attribute the problem to structural issues.

"Any airplane will fall apart in the air if pushed far enough beyond its airspeed or g-load limits, and Bonanzas don't usually break up unless pushed past their limits. The question is, why do the pilots of older V-tails allow their craft to exceed speed and load limits so much more often than pilots of other planes?

"The answer, we believe, may lie in the handling qualities of the V-tail Bonanzas."

The article then notes that the V-tails are very light ailerons and pitch control, have and low lateral and pitch stability, and exhibit high spiral divergence. Also notes that the V-tails have a relatively narrow CG range..."Some models have 30 pounds of lead in the nose to counter the balance problem."

Ron Wanttaja
 
Doc Holliday said:
So why didn't Beech include the straight tail (Debonair) into the AD? How many Debonairs have broken up compared to the V tail?
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Perhaps because when Debonairs break up after exceeding structural limits, a different structure is involved.
BWTFDIK.
 
wanttaja said:
Aviation Consumer Used Aircraft Guide, Third Edition.

"What makes the V-tail's high record of in-flight breakup all the more ironic is the very low breakup rate of the straight-tail 35 and 36 models, which are essentially identical to the 35 except for the tail. The V-tail's breakup rate, according to one study, is 24 times higher than the straight tail."

From the book:
View attachment 129060
This edition was copyrighted 1989, though the Bonanza article might stem from the earlier edition in 1981 or the actual magazine article, published earlier.

It may pre-date the AD. However, what catches my attention is that the piece doesn't solely attribute the problem to structural issues.

"Any airplane will fall apart in the air if pushed far enough beyond its airspeed or g-load limits, and Bonanzas don't usually break up unless pushed past their limits. The question is, why do the pilots of older V-tails allow their craft to exceed speed and load limits so much more often than pilots of other planes?

"The answer, we believe, may lie in the handling qualities of the V-tail Bonanzas."

The article then notes that the V-tails are very light ailerons and pitch control, have and low lateral and pitch stability, and exhibit high spiral divergence. Also notes that the V-tails have a relatively narrow CG range..."Some models have 30 pounds of lead in the nose to counter the balance problem."

Ron Wanttaja
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Note the footnote.....Thru 1979. Those are mostly prior to the tail stiffening AD. ;)

See the Collins article for more.... https://airfactsjournal.com/2016/06/airframe-failure-not-just-v-tails/
 
Checkout_my_Six said:
Note the footnote.....Thru 1979. Those are mostly prior to the tail stiffening AD. ;)
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Note, though the items I quoted about how AC felt that stability, sensitivity, and CG issues may be associated with the failures. Doubt the tail stiffening AD affected those.

Ron Wanttaja
 
wanttaja said:
Note, though the items I quoted about how AC felt that stability, sensitivity, and CG issues may be associated with the failures. Doubt the tail stiffening AD affected those.

Ron Wanttaja
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Meh....maybe. I'm a sub-par pilot and think it might take a bit to lose it in my Bo. Maybe some disorientation could do it I suppose. Thankfully I have a functional autopilot to hep me out. It's probably the easiest plane I've ever flown.
;)
 
Checkout_my_Six said:
Meh....maybe. I'm a sub-par pilot and think it might take a bit to lose it in my Bo. Maybe some disorientation could do it I suppose. Thankfully I have a functional autopilot to hep me out. It's probably the easiest plane I've ever flown.
;)
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First slice of cheese : “I’m a subpar pilot”

Second slice: “Maybe disorientation could do it I suppose”

Third slice: “I have an autopilot to help me out”

Fourth slice: “It’s the easiest plane I’ve ever flown”
 
Doc Holliday said:
First slice of cheese : “I’m a subpar pilot”

Second slice: “Maybe disorientation could do it I suppose”

Third slice: “I have an autopilot to help me out”

Fourth slice: “It’s the easiest plane I’ve ever flown”
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Nails it...... :yes:
 
robin ardoin said:
I know the family well. He practiced with a friend of mine in BR and his younger brother and father are referrals to my practice. Tragic loss. :(
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Robin, I read somewhere (probably AvWeb) that he'd only had the Bo since January. Do you know what he was flying before? Could inexperience with a higher performance plane be a factor?
 
Pinecone said:
Most were overstressed.

Many times by flying into thunderstorms. More of a indictment of the type of people flying them, not the actual aircraft. That's why they were called Fork Tailed Doctor Killers.
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Bonanzas were never doctor killers. Doctors were Bonanza killers.
 
Half Fast said:
Robin, I read somewhere (probably AvWeb) that he'd only had the Bo since January. Do you know what he was flying before? Could inexperience with a higher performance plane be a factor?
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I don’t know. I have not spoken to his brother or father since the accident. Funeral is tomorrow and will be a very sad event laying 3 family members to rest. They were enroute to pick up another sibling. Could have been even more tragic if it happened on the return flight.
 
wanttaja said:
Aviation Consumer Used Aircraft Guide, Third Edition.

"What makes the V-tail's high record of in-flight breakup all the more ironic is the very low breakup rate of the straight-tail 35 and 36 models, which are essentially identical to the 35 except for the tail. The V-tail's breakup rate, according to one study, is 24 times higher than the straight tail."
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I don't think the author of "Aviation Consumer User Aircraft Guide" understands the meaning of the word "ironic". The stats they're quoting aren't either humorous or unexpected.
 
Checkout_my_Six said:
let's see your references. I believe those were prior to the AD.
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They were prior to the AD. It was an article in Aviation Consumer, circa 1984. I am not a subscriber, so don't have access to their archive, but perhaps you can look it up. I was in Mike Smith's shop a few times in 1984 while work was being done to beef up the ruddervators. Smith clearly identified what the issue was, and had examples. The ruddervators would fail in torsion under higher loading because the center of pressure was significantly forward of the main spar. It only became an issue with the C model in about 1951 was the chord of the ruddervator was increased, without significant change to the torsion box structure. The Mike Smith stub spar and the Beech cuff did the same thing, by alleviating the torsion load by transferring stress from the leading edge to the empennage. I am sure if you Google you can come up with written references with the precise statistics. After 40 years, my recall of exact numbers is imperfect, but I was around the issue enough to have the gist of the thing.
 
Is there a way to tell what the max G factor is for an aircraft? My new fancy panel has a G meter and I’ve seen 1.3 on the display.
 
Jamie Kirk said:
Is there a way to tell what the max G factor is for an aircraft? My new fancy panel has a G meter and I’ve seen 1.3 on the display.
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Normal category aircraft must have a design load limit of at least +3.8G. Utility category is +4.4G. Aerobatic category is+6G. Negative G limits are less.
 
All that after 40 years is pretty impressive in my book.

Kristin said:
They were prior to the AD. It was an article in Aviation Consumer, circa 1984. I am not a subscriber, so don't have access to their archive, but perhaps you can look it up. I was in Mike Smith's shop a few times in 1984 while work was being done to beef up the ruddervators. Smith clearly identified what the issue was, and had examples. The ruddervators would fail in torsion under higher loading because the center of pressure was significantly forward of the main spar. It only became an issue with the C model in about 1951 was the chord of the ruddervator was increased, without significant change to the torsion box structure. The Mike Smith stub spar and the Beech cuff did the same thing, by alleviating the torsion load by transferring stress from the leading edge to the empennage. I am sure if you Google you can come up with written references with the precise statistics. After 40 years, my recall of exact numbers is imperfect, but I was around the issue enough to have the gist of the thing.
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Ed Haywood said:
Normal category aircraft must have a design load limit of at least +3.8G. Utility category is +4.4G. Aerobatic category is+6G. Negative G limits are less.
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Wow. I was getting bounced around pretty good and was seeing 1.4 and I was worried. I could not imagine turbulence at 3+ and how that would feel.
 
Jamie Kirk said:
Wow. I was getting bounced around pretty good and was seeing 1.4 and I was worried. I could not imagine turbulence at 3+ and how that would feel.
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Typical loop requires 3.5. If you have never done an acro/UPRT flight, it is a useful experience to learn the physical sensations of different G forces.
 

I found the part about the precise balancing of the ruddervators- even after painting- interesting.
 
The supposition being what? That the V-tail somehow takes substantially less time to Vne compared to their conventional tail variant? Meh. I contend that delta, just like everything in this overhyped lawnmower space, is just not significant enough to have made the difference as to whether this gentleman loses control upon encountering inadvertent IMC, or lives through the unusual attitude.

In short, the V-tail, much like the T-tails in Pipers, were more of a stupid marketing gimmick than a design choice of transformative performance difference. They're just not that significant. Heck you have people on here debating the bottom to the top cruise speed differences for a given horsepower rating within a class of make/models of less than 15 knots, and they act like the slowest is an outright indignity. It's just fanboi nonsense of little import.

Would I saddle myself with old timey ruddervator equipped Bo in 2024? Heck naw. But not for the reasons the scaredy cats imply. Concern for said tail feathers somehow separating when inside the certified envelope is absolutely not one of them.

Then again, I'm the SGOTI who used to own a 'widow maker' with a spar bolt AD on it which I emphatically refused to comply with. So don't take my advice on any of this; my apathy toward my own self-preservation is apparently pathological. /s :rolleyes:

Occam's Razor: The good doctor lost control of an otherwise airworthy airplane in an upset attitude and oversped it. The mechanism of structural failure is a red herring in this context.
 
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