Mooney M20J VS Bonanza V tail or F33

[Jerry Pressley]

A Beechcraft Bonanza crashed in a residential area on New York's Long Island Tuesday after the pilot declared an emergency, reporting a failed vacuum system. All three people on board are dead and the aircraft appears to have broken up in flight. The Bonanza departed Myrtle Beach, South Carolina, about 12:45 p.m., heading for Plainville, Connecticut, according to news reports. About 2:30 p.m., the pilot declared an emergency and reported a vacuum failure. According to audio from LiveATC.net, the pilot told New York Approach he was partial panel and "VFR over the top" and did not want prolonged flying in IMC to get below the clouds. After a few exchanges and receiving a vector, the pilot said, "we are IMC at this time." Later, he said, "I just lost a little bit more control here," then "we just lost more of our panel." Radar contact was lost moments later." 

[Jerry Pressley]

in-flight structural failures.

Grist for the mill was the fact that Bonanzas with regular tails seldom had structural failures. They did have just as many loss of control accidents. The difference was they were in one piece a millisecond before becoming thousands of pieces after a collision with the ground. The V-tails didn’t make it to the ground in one piece,

Investigators did find a common thread in V-tail accidents. Effective with the C35, the chord of the tail surfaces was increased by seven inches but the internal structure remained the same. As a result, the tail stabilizer is extended to 16 inches ahead of the spar on C35 and later airplanes.

In the 35, A35 and B35 the airframe failures were usually a result if the wings failing first. From the C35 on, the first failure was usually of the tail with the wings next failing in a downward direction.

It was determined from wreckage that when the airplane was operated in excess of the never exceed speed, the unsecured leading edge of the stabilizer would fail first, in an up or down direction. Even though the airplane met the certification standards, it was determined that anchoring the leading edge of the stabilizer to the fuselage at the root would minimize this and give the pilot a little extra time to recover from an overspeed condition.

[Jerry Pressley]

The V-tail has a very high rate of in-flight failures. Compared with the Model 33, which is the same aircraft with a conventional straight-tail, the V-tail has a fatal in-flight failure rate 24 times as high as the Straight tail Bonanza. In spite of this glaring statistic, Beech claimed that there was no problem with the V-tail, and for many years the public seemed to agree with Beech. However, the deaths from in-flight failures continued to mount. The V-tail Bonanza is a classic tale of a dangerous item, which because of its popularity continued to kill.

 

[Jerry Pressley]

The very first V-tail models had a tendency to fail in the wings. Within the first two years of manufacture, it became apparent to Beech that the wing structure was inadequate. Beech increased the strength of the wings, but instead of ending in-flight failures, this action simply changed the source. Now instead of the wings failing, the tail failed. In 1952 the FAA (Federal Aviation Administration) opened a study on the V-tail Bonanza. For the next twelve years the agency accumulated statistics on the airplane, particularly on in-flight break-ups, and examined possible problems with the design. Although the study found a high incidence of in-flight failure, no action was taken and in 1964, the study was closed.1

During this time period, Beech made numerous small changes to the V-tail Bonanza. Most all of the structural modifications involved the tail. Beech apparently was aware that the structural margin on the tail was inadequate, because the purpose of the modifications was to increase the strength of the tail. However, the modifications did not end the in-flight break-ups; the tails continued to fail.

When the attempts to strengthen the tail by minor structural modifications did not work, Beech and three independent aircraft parts suppliers searched for other methods of strengthening the tail. The result was a stub spar which reduced the load on the front spar once skin buckling began. After conducting tests on its stub spar design, Beech concluded that it did not result in an appreciable increase in tail strength. However, subsequent investigation by the FAA concluded that Beech did not carry their tests to the point of tail failure and therefore, did not really have any information on which to base the decision that the stub spar kit was ineffective.4

In the early 1970s it was discovered that the tab control cables to the tail on many V-tail Bonanza were in very poor condition. The cables on many planes were worn, frayed, and sometimes coated with paint. Generally, this was the result of improper maintenance and not poor design. However, in many cases the improper maintenance resulted in slack tab cables. This in turn produced an unbalanced reversible tab that drove the rudder to flutter. In addition to all the other alleged problems, the V-tail was extremely sensitive to the problems of tail flutter. The FAA issued a directive ordering all V-tail owners to inspect the tab cables of their planes.

Throughout the 1970s, people continued to die as the result of in-flight failures of the V-tail Bonanza. The families of some of these victims sued Beech Aircraft claiming that the V-tail Bonanza was an unsafe aircraft. To support their contentions, the plaintiffs hired experts to conduct independent studies of the V-tail Bonanza. Several of the studies noted irregularities with the V-tail design, but it was difficult to prove direct cause and effect for most of the accidents. Beech won most of the lawsuits.

In 1978, the FAA commissioned STI (Systems Technology Inc.) to study problems of in-flight break-up for all aircraft. STI concluded that the V-tail Bonanza had the best overall safety record of any general aviation aircraft, but had the worst record when it came to mid-air break-up. The V-tail Bonanza was twenty-four times more likely to suffer from in-flight structural failure than the Straight-tail Bonanza. The only difference between theses two models was the configuration of the tail. Beech disputed this claim and said that the V-tail was only eight times more likely than the straight-tail to suffer from in-flight failure.4

Even accepting Beech's figures, it still seemed impossible to draw any conclusion other than the one put forward by many in the aviation industry. The V-tail Bonanza was inherently more dangerous than the Straight-tail Bonanza. However, a very different conclusion was drawn by the report. Instead of citing the V-tail Bonanza as an unusually unsafe airplane, the Straight Tail Bonanza was cited as an unusually safe airplane. About the same time as the FAA study, the NTSB (National Transportation Safety Board) conducted its own study. The FAA study had examined in-flight break-up for a wide variety of aircraft. The NTSB study examined the accident history of light, single engine fixed-wing aircraft. The conclusion of this study agreed with the FAA study.4

 

 

and on and on for page after page

[Jerry Pressley]

http://www.thomaspturner.net/inflight breakups NTSB.htm

[Jerry Pressley]

look at the dates on the above list

[jaylw314]

15 minutes ago, acpartswhse said:

The V-tail has a very high rate of in-flight failures. Compared with the Model 33, which is the same aircraft with a conventional straight-tail, the V-tail has a fatal in-flight failure rate 24 times as high as the Straight tail Bonanza.

I'd be careful with quotes about relative risk increase ("24 times as high").  Risk assessment regarding rare events is best done using information about absolute risk increase ("had 12 more incidents").  Most of the time you see data about relative risk increase is when there is a lawyer trying steal money from you. 

For common incidents, e.g. occurring more than 1% of a sample, relative risk is okay to consider in risk assessment, but few interesting (or lawsuit-worthy) things happen more than 1% of the time.

 

[jetdriven]

10 minutes ago, acpartswhse said:

http://www.thomaspturner.net/inflight breakups NTSB.htm

yes, 7 of the 11 inflight breakups since the 1994 AD have been V-tails.  The other 4 were A36 models.  Most of which involved encounters with TStorms or VFR into IMC. Probably more midair collisions involving V-tails in that time frame. I think the AD fixed it, and I dont worry about V-tail airplanes coming apart, or any Bonanza from D35 and later. Yes the Mooney airframe is stronger, but its 4x as strong as it needs to be, instead of simply 2.5x.

Edited April 2, 2018 by jetdriven

[xcrmckenna]

I know nothing about Beechcrafts other than they are fast, roomie, and burn a lot of fuel. I was wondering what is the reasoning of the V tail? Was it just a marketing design, or did the plane originally benefit largely from it? Sorry to drift the thread even more.


Sent from my iPhone using Tapatalk

[flight2000]

2 hours ago, acpartswhse said:

33 and 36 you are possibly correct but the V tail is a different animal. As you know I have been into parts for most of my life and the 35 Bonanza has had more in flight breakups than anything else out there. Cherokee 6 is next in line if i remember correctly.   I have picked up a large number of V tails where the ruddervator leading edge folds under and comes off then the tail passes the fuselage and wings shed.  I said it all rides on one nut which is the lower front one.  the other three are not too important without that last one.  

Beech come up with a solution to the ruddervator leading edge folding under by putting a dinky little cuff attached to the tailcone around the leading edge. (check ir out next time you see a v tail sitting) Didn't work as they are still coming apart.  I know, I know....mine wont.  I had a friend who had a straight 35 who would come over my field at full speed and jerk the yoke back just to prove it.  His didnt.    

Sorry to cause unneeded hate and discontent but this IS a forum for this kind of discussion i believe.

It's not unneeded hate and discontent - it was wrong information or a very poorly worded comment at best. You stirred the pot, I was just correcting your bad attempt.  And since I own a Bonanza, I think I know how bolts keep the wings mated to the fuselage.  Same for the tail section. 

You said wing (see below), which last time I checked does not equal or reside in the same place as a Ruddervator on the V tail Bonanza's.  As @jetdriven already mentioned, the AD solved this problem.  Please point me to the most recent inflight failure that was aircraft induced versus PILOT induced.  Fly any aircraft into a thunderstorm or put the plane into a dive/spin beyond its design limits and things will come apart pretty quickly, regardless of design.

8 hours ago, acpartswhse said:

Did anyone ever consider the wing on the mooney is tank strong and the Bonanza rides around with all the weight depending on one nuts threads.  shear that nut and it is all over.

Cheers,

Brian

[EricJ]

44 minutes ago, xcrmckenna said:

I know nothing about Beechcrafts other than they are fast, roomie, and burn a lot of fuel. I was wondering what is the reasoning of the V tail? Was it just a marketing design, or did the plane originally benefit largely from it? Sorry to drift the thread even more.
 

For a lot of V-tail history with Bonanzas and other aircraft, the idea was to minimize drag by eliminating a tail surface.   It seems to have been figured out since that it either doesn't make much difference or isn't worth the effort.

Kinda like puck landing gear.    ...runs away...   

[Alan Fox]

3 hours ago, acpartswhse said:

A Beechcraft Bonanza crashed in a residential area on New York's Long Island Tuesday after the pilot declared an emergency, reporting a failed vacuum system. All three people on board are dead and the aircraft appears to have broken up in flight. The Bonanza departed Myrtle Beach, South Carolina, about 12:45 p.m., heading for Plainville, Connecticut, according to news reports. About 2:30 p.m., the pilot declared an emergency and reported a vacuum failure. According to audio from LiveATC.net, the pilot told New York Approach he was partial panel and "VFR over the top" and did not want prolonged flying in IMC to get below the clouds. After a few exchanges and receiving a vector, the pilot said, "we are IMC at this time." Later, he said, "I just lost a little bit more control here," then "we just lost more of our panel." Radar contact was lost moments later." 

And how was this structural...... Oh yea.... It wasnt

[flight2000]

Don't get stuck in the mud pit, I'm bailing on this discussion before I get any dirtier.  Peace out.... 

Brian

 

 

[carusoam]

Don’t bail without the learning experience...  

Step one: lose vacuum system, VMC above the clouds...

Step two: descend into the clouds... using a TC to keep the shiny side up...

Step three: Lose Control in IMC...

Step four: Spread aluminum shards all over the ground...

The entire fight lasted a few minutes at Best.

 

Learning experience... A TC bouncing around in IMC May be difficult to keep the shiny side up with.  Applies to most Mooneys...

Take-away... If your TC bounces around unusably in turbulence.  It is probably time to get it OH’d or aided by an electric AI back-up device.  Applies to some Mooneys with worn TCs...

You certainly don’t want to descend into IMC with only a TC that is un-follow-able...

 

looking back on this one, the IR pilot had some opportunity to avoid going into the IMC To make sure everything was working as he needed...

Finding VMC conditions that day wasn’t that far away...

 

The tragedy would be not learning from this experience...

I haven’t reviewed the tape in a long time.  The detail may be amiss, but the gist is the important part...

The Mooney is a strong bird.  When a pilot flies into thunderstorms or icing conditions or VFR into IMC or in this case faulty or unfollowable instruments,  his plane, will be in one piece until it hits the ground.

Probably not enough to make a difference. Let’s say, it’s a good idea to avoid this list...

Check your TC while flying.  I did some IR training in an older bird, partial panel with a bouncing TC needle... that was a learning experience...

Best regards,

-a-

 

[jetdriven]

ditch the T/C and get a real second AI.  its a few hundred dollars, but gives you real pitch and bank, cheaply.  We did this 5 years ago.  worth the money.

[ArtVandelay]

ditch the T/C and get a real second AI.  its a few hundred dollars, but gives you real pitch and bank, cheaply.  We did this 5 years ago.  worth the money.

I thought the advantage of t/c was they don’t tumble unlike a mechanical AI?

[Alan Fox]

46 minutes ago, teejayevans said:

I thought the advantage of t/c was they don’t tumble unlike a mechanical AI?

Yea , but they also have stops after about 30 degrees of bank , past that , they don't work ,   Better to have at least one electric AI , or DG ,   At least the DG can keep the shiny side up....

[jetdriven]

And they only represent bank, not s direct indication.   And they do not give any pitch information.  J read that FAA Advisory circular and they were right, transport aircraft have no turn coordinator.