NTSB Report Contains Key Information On High-Profile Accident

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The tragic double-fatal crash of a high-performance airplane could potentially have easily been avoided, according to one of the top experts in the field. The National Transportation Safety Board has released its preliminary report (text available here on the Aviation Safety Network) on the Dec. 7 crash of a 1965 Beechcraft 35-C33 Debonair that killed YouTube personality Jenny Blalock, 45, the pilot, and her 78-year-old father James Blalock. The flight began at the aircraft’s home base at Knoxville Downtown Airport (KDKX), Knoxville, Tennessee, and was headed for Saline Country Regional Airport (KSUZ), Benton, Arkansas, for an avionics upgrade. Weather was clear with light winds throughout the planned route of flight.

In YouTube videos in the weeks before the accident, Jenny Blalock had recorded her efforts to experiment with and understand the Debonair’s Century 2000 autopilot. Notably, the videos show that the aircraft was not equipped with electric trim, so she needed to learn that trim adjustments to coordinate with the autopilot required manual actuation.

Flight data shows that a little over an hour into the flight, the aircraft began a series of altitude fluctuations, culminating in a steep descent that showed a descent rate of as high as almost 12,000 feet per minute and a groundspeed of 228 knots. Witnesses said the airplane appeared to be in a steep, steady dive right up to impact in a wooded area. No one on the ground was injured.

The NTSB preliminary report reveals that examination of the wreckage showed the elevator trim was set to a 5-degree nose-down setting. Tom Turner, executive director of the American Bonanza Society (ABS) and longtime instructor, told AVweb in an email: “A 5-degree down-nose trim would be enough force to cause a rapid, startling and dramatic downward pitch movement. Depending on the specific autopilot installation, manually moving the trim to this position might have been enough to disengage the autopilot, handing the radically out-of-trim airplane to the pilot unexpectedly. However [it was that] the autopilot disengaged (assuming it was engaged at the beginning of the accident sequence), if not aggressively corrected by the pilot such a trim setting would have set off a series of pitch oscillations that may have unfolded as those described in the preliminary accident report.”

While her flight experience is not confirmed, Jenny Blalock posted on social media on Sept. 12 that she “hit over 400 hours!” and that she expected to be completing instrument training “soon” to “broaden my aviation horizon!”

Turner’s response to AVweb concluded with: “a good instructor’s checkout should have included the steps to recover from a radically out-of-trim condition. I stress this procedure in transition and recurring training and emphasize it to ABS’s Beechcraft Pilot Proficiency Program instructors and students.

“If in fact this crash developed from an autopilot disengagement or a manually set elevator trim, it was tragic in the classic sense in that it did not have to happen.”

Mark Phelps
Mark Phelps is a senior editor at AVweb. He is an instrument rated private pilot and former owner of a Grumman American AA1B and a V-tail Bonanza.

36 COMMENTS

  1. A pilot with minimal aviation experience would be better served focusing resources (time and money) on things other than GoPros, makeup, posing for the camera, and editing videos. These things would include additional instruction on how to use a particular autopilot — which could potentially have led to a realization that an approved modification to said device was advisable. Definitely a tragedy that did not have to happen.

    • Pilots should be disheveled and dressed in flannel. Smelling of avgas, WD40 and PB Blaster. Any contact with the outside world should be met with grunts and huffs.

      The only appropriate technologies are lighted airways, stopwatch, compass and an E6B. Only paper maps covered in coffee stains and mustard are appropriate navigational publications.

      Pictures and heaven forbid video, are avoided at all cost least peons get the idea that piloting an aircraft is possible.

      • Despite your sarcastic reply – it does appear that she focused on the wrong things (i.e. shooting videos and social media standing versus adequate training and focusing on flying the airplane).

      • Why the arrogant sarcasm? It adds nothing to the discussion, but it does amply display your own supercilious ignorance.

        • -It adds nothing to the discussion-

          My sarcasm adds just as much to the discussion as “would be better served focusing resources (time and money) on things other than GoPros, makeup, posing for the camera, and editing videos.”

          According to the OP, maybe if Blalock wore just a little less lipstick, she’d be alive today.

          Hitting record on a GoPro doesn’t crash airplanes. Stopping by the barber shop doesn’t crash airplanes.

          Does any other pilot focus resources on other things? Job? Family? Going to the gym?

          • What I get from this incident is that she should have spent more time aviating. A descent rate of 12,000 feet/minute was left unchecked? I was a longtime skydiver and exiting at 12,500 feet was a little over a minute of freefall and she didn’t sorta notice?

      • Robert, while all of her most recent videos have now been taken down, prior to that I watched over a dozen of them. It was very obvious that she was very concerned and preoccupied with the documentation of learning to fly, rather than just learning to fly. And when I say “learning”, it also was obvious she bought a plane well outside her abilities, yet didn’t seem to understand some of the basics. For instance, she didn’t even know how to turn her instrument panel lights after 5 months of ownership. Yes, we all get distracted as you pointed out, but stacking more of them into the mix is just an accident waiting to happen, as this incident shows. Lastly, one female instructor at our location made a very good observation. In her experience, male CFIs take it easier on woman students. Watching her videos, I really was in dismay that she had over 400 hours, because she exhibited behaviors of a pilot who had less than a 100. Sadly, I think the training system failed her, as I think it fails many pilots in GA. The take away? Take it seriously because flying is dangerous, so dont stack your distractions, try and minimize the risks, and know your avionics/plane inside and out.

        • “ Sadly, I think the training system failed her, as I think it fails many pilots in GA.”

          I agree.

          Pilots are taught to keep the greasy side down, but very little time is given towards basic avionics and their limitations. Better not be caught following the magenta line, that’s just poor pilotage. Don’t worry about the difference between attitude hold and altitude hold, because if you touch the autopilot during the check ride, be ready to recite the entire operators manual by rote to the DPE.

          We’ll spend an hour of ground school going over a mechanical E6B, never to be used after a check ride but not 15 minutes of avionics integration and assimilation.

    • It’s the catch 22. Chances are she was able to afford the plane, the time off, and the gas to fly around making videos was because of the YouTube channel.

  2. On my bonanza, normal trim is set at 3 degrees. I find it hard to fathom that 5 degrees would cause this accident.

    • All our planes are different so without CG or WB, it’s all speculation, but, seems very plausible to me in my F-33. 5 degrees down makes a very large difference in my plane. My trim is usually around 0 -2 degrees up because my CG is 79-80.5 with full fuel and 2 normal sized front seaters. I even keep 75 lbs. of ballast in the rear compartment with just front seats occupied. When I flew yesterday, I did a quick test. We trimmed level at 6k AGL at 146 TAS, and then moved the wheel to 5 down. My wife was pulling back hard on yoke for a count of 5 before we retrimmed. She was straining to keep it level, and this was without increased forces in a dive, while being ready for it to happen, rather than a surprise when an autopilot kicks off.

  3. From the report: “about 5° of trim tab deflection in the nose down direction. ” That says 5 degrees of trim tab deflection. That’s pretty close to neutral, and is close to the center of the green takeoff range on the V35B in our hangar. The internet should keep an open mind and let this investigation play out. I just don’t see any smoking guns yet.

    • And, same on our B55 which has a more similar system to the Debonair. 5 degree nose down “deflection” of the trim tab is almost dead center in the green takeoff band. Someone with a Debonair could confirm.

  4. Isn’t the green band nose up, not nose down? The POH calls for nose up trim, as much as 3 degrees, before takeoff if only the front seats are occupied. My Bonanza experience is that small trim adjustments make a dramatic difference. The C2000 autopilot, even without electric trim, is pretty straight forward.

  5. It’s a tragic outcome for an unfortunate trend where people are exploiting social media platforms to become ‘stars’ in their pursuits of interest, regardless of their skill levels and expertise.

  6. When I was experimenting with the auto pilot in the 182, I did it in straight and level flight over Iowa. On a clear day. I am VFR.

    I didn’t post it to social media. Nor did I go any further. I thought the auto pilot to be sloppy, lagging, and certainly not precise.

    She should done this with an instructor.

  7. I had a runaway trim happen in an Aerostar once. The Aerostar has electric elevator trim and does not have a manual trim wheel. The only way to see what the trim is doing is to watch the tiny trim tab gauge.

    I was flying straight and level in cruise in good weather with the Century 4 autopilot engaged. With no warning the airplane bunted down so hard the tops of my legs were bruised from flying up and hitting the bottom of the instrument panel.

    My initial reaction was a mid air but i immediately pushed and held the yoke autopilot/trim disconnect button and pulled on the yoke which was almost immovable. I then checked the trim and realized it was full nose down. The normal trim switch did not work but the alternate system did and I was able to regain level flight without exceeding a limitation.

    The aircraft got an overload inspection for the negative Gee and the avionics tech found a short in a wire to the elevator trim servo.

    This was a significant emotional event. The autopilot held the airplane against the running down trim until it hit its limit at which point the airplane was trimmed very nose down so when the autopilot did the uncommanded disconnect the airplane violently pitched down, The startle factor was significant.

    Know your autopilot because soon or later it will try to kill you.

    • WOW, Scary experience! Thanks for sharing as it helps those of us who havn’t experienced it better understand how it could be much more jarring than we likely realized.

  8. Interesting — not unlike what happened to the Challenger 300 crew in New England back in March. Through a series of errors, they got the autopilot holding the nose hard down against too much nose up stab trim, and when the autopilot was disengaged (due to another erroneous crew action), the airplane went through a series of nose up/down oscillations which max’d out at 4+ positive and 2.6 negative g’s — in an airplane with +2.6/-1.0 g limits. An unrestrained passenger was killed by impact with the ceiling and floor.

    As David G suggested above, you have to know your systems, and you shouldn’t be experimenting with them in flight unless you graduated from Edwards, Pax River, or Mojave.

  9. This tragedy highlights the need for a pilot with a new autopilot installation to get a thorough checkout from a CFI who is experienced in operating THAT PARTICULAR MODEL OF AUTOPILOT in THAT PARTICULAR MODEL OF AIRPLANE rather than trying to figure it out on their own.

    • Good grief…no. There are those of us who are perfectly capable learning how to use an autopilot without an instructor. Please don’t confuse those of us who can from those who can’t.

      • Will, I infer that this is your second consecutive general castigation of “teachers that cannot do”.

        Have you had a negative experience in your learning that has caused your negative yiew of teachers?

        Jack Woodhead

  10. Many years ago part of my job was doing test work for an avionics shop. A customer brought in a C or F33, can’t remember which with a Century 4 autopilot with the complaint that the airplane would unexpectedly pitch down. I was able to duplicate the fault, which the trim indicator for the autopilot was showing. The root of the fault was an autopilot servo that had failed in one direction, it would work in the up direction but not down, and the trim was trying to hold against a progressively stronger force from the servo. Eventually the trim would overcome the available force from the clutch in the pitch servo and the clutch would release, the airplane then pitched down. On a low ILS the pitch down would have been severe enough to cause a crash before the pilot could respond. I don’t know how similar the C IV is to the Century 2000, but since it was a servo failure such a fault might cause problems with any autopilot. You would think an experienced pilot, even if not totally familiar with that autopilot, would turn the beast off and hand fly until a fault was resolved, but that is not always the case. I also flew a Cessna 425 which had a similar though less dramatic fault, in that it would trim off slightly, causing the airplane to pitch down slightly when the autopilot was disengaged by the pilot, though it operated well enough in flight except for that.

  11. I don’t fly any Beech aircraft, so I don’t know if my comment will be at all relevant.

    In his Youtube discussion of this accident, blancolirio says it was the trim tab itself that was 5 degrees up (i.e., forcing down elevator); it was not the indicator on the cockpit trim wheel that was indicating 5 degrees down.

    https://www.youtube.com/watch?v=66z726rQNxc

    • Correct. He also noted that 5 degrees was 50% of full down trim spec of 10 degrees. Not drastic, but enough to pitch down with considerable force if she allowed the airspeed to climb.

  12. Friend of mine with a Baron headed down the runway to takeoff. Got to where he usually rotated. Pulled back and nothing, nose wheel stuck to the runway, harder pull, nothing. Throttled back and stopped just prior to running off the end. He was hasty and forgot to set the trim. Somehow it was in full nose down. He had never before realized how much force full trim can cause. His fault of course. But as he told the story, I paid attention.

  13. I’d like to fill in some details of my interview with Mark Phelps that were omitted to maintain a reasonable word count for his story.

    The C33’s elevator trim tab range, per the Type Certificate Data Sheet, is from 10 degrees up to 21 degrees down. Given that, a five degree deflection down is not near the extreme.

    A downward tab deflection would create an up elevator condition. In normal cruise in a C33 the elevator would be in a neutral to slightly down position. The cockpit trim indicator is in units (not precisely degrees of tab deflection), and the normal takeoff range is from 0 (streamlined) to 3 units up depending on the CG distribution. In normal cruise a C33 indicates 0 to maybe 2 units down, again depending on load distribution.

    The trim is operated by a large trim wheel near the pilot’s right knee. It’s easily reachable and moveable in flight from the pilot’s seat. Like most Beech Pilot’s Operating Handbooks, the C33 POH has a checklist for unscheduled elevator trim movement, I.e., trim runaway, which calls for turning off the electric trim, manually establishing an attitude with the pilot’s yoke, and trimming off the pressures manually. From there you have perfectly normal control and trim use, just no electric trim or autopilot function.

    The accident airplane reportedly had no electric trim (the autopilot indicates the need for trim changes and the pilot inputs trim). Still, transition training should include discussion of all emergency procedures and the pilot should have been taught, and therefore been aware, of the appropriate response if found in an out-of-trim condition. Establish an attitude and trim off the pressures. I’ve had a trim runaway in a Bonanza myself and it is dramatic but very controllable.

    Assuming the facts known to date about this crash fully describe what happened, if in fact the pilot encountered an autopilot problem her response should have been to aggressively control the pitch and trim off the pressures. It should have been a trained, almost automatic response.

    If the situation was as described and the pilot did not respond, well that’s what might have resulted in a flight path as described by the NTSB, and why I say this tragedy should never have happened.

    • Thanks for the clarification, Tom. For those who aren’t familiar with Tom Turner; as the long-time executive director of the American Bonanza Society, he is one of the – if not THE – most expert and experienced Bonanza instructors in the industry today.

  14. Sad story, but still laughing at so many supposed pilots not understanding nose up vs nose down trim settings.

  15. A note from the inside as Jenny’s Pilot briefer, meteorologist, and friend. An element of truth is in every comment here, and the collective tells the story.
    Jenny was notoriously ambitious, owned a commercial and residential construction company, and could afford a more advanced plane, true. Flying was a way to reach goals, inspire others, and expand her business. If youtube was a revenue stream, she was interested. AND, Flying was serious business. She followed protocol daily, observed procedure, and took preflight as serious as anyone. Everything done was done the right way. “Youtuber” is a byproduct, and not an accurate portrayal. As a meteorologist and Pilot, I knew everything that could kill you FIRST. Updrafts, downdrafts, hail, icing, “flaps”, lubricants, abrasions…I was a grad student on the Space shuttle Challenger O-Ring investigation with Dr Eric Smith at Florida State U.
    Sometimes Great people are simply not pessimistic enough to realize that doing the right thing doesn’t matter when fate intervenes. Imagine being in a pitch that sent you into the roof, knocked you out, and trying to recover. Auto-pilot for us means shifting from a position, stretching and moving your body and wrist…pacing for a long flight. Jenny was 100% fighting an unforeseen force during the whole flight (as mentioned) due to inexperience. She wouldn’t in a million years miss a response from Memphis, much less not respond. There was an issue to solve, something serious, then, critically, and at the worst time…the Dive.
    Lipstick didn’t doom that flight.

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