Lismore RV-12

[Bandit12]

I don't seeing it as a intentional vertical pull- up at all, you just don't do that sort of thing on a first flight..even for Wayne.

Exactly my point - 78kn is not enough of a margin to be pulling up hard, if it had been held on the deck to 100kn or more and then zoomed, perhaps that would have been a suitable explanation then. While knowing nothing more than what has been written here, I'd be thinking that either control failure or incapacitation to be more likely than showboating error.

 

 

[jakej]

There is another explanation to this accident, not nice or popular , but it is there

Matty

 

Which one ? All I see is a list of videos.

 

Jake J

 

 

[metalman]

No

 

MattyWhich one ? All I see is a list of videos.

Jake J

Not on my utube mate, there is some footage out there though, I think the ATSB might have it , we'll have to wait till a full report comes out ,

Matty

 

 

[rankamateur]

rgmwa are you building an rv12? The anti servo tab on stabilator it would operate by deflecting more as stabilator is moved ie when up stabilator is used the trim tab would also go up thereby applying aerodynamic force to return stabilator to more neutral position yes? Is it at all possible (I would think it not possible)to assemble so that it becomes a servo tab ie it goes the opposite way thereby making stabilator wanting to go full travel either up or down(would be unstable)? Just trying to think what would cause such a strong pitch up. Tom

Most sensible thing I have seen suggested on this thread was

 

maybe we need to look at pilot incapacitation at some stage?

Could have contributed to the strong pitch up.

 

Wayne was an amazing man and pilot, but he was very human just like the rest of us.

 

 

[Guest Maj Millard]

Most sensible thing I have seen suggested on this thread was

Could have contributed to the strong pitch up.

 

Wayne was an amazing man and pilot, but he was very human just like the rest of us.

Good in theory, but unfortunatly there was no evidence present from the autopsy to indicate any physical problems with the pilot...........Maj.....

 

 

[rankamateur]

Good in theory, but unfortunatly there was no evidence present from the autopsy to indicate any physical problems with the pilot...........Maj.....

I will PM you Ross, I don't think posting here will achieve anything more in this discussion.

 

 

[Bandit12]

Perhaps when the coroner's inquest is completed, someone might remember to post a link to it.

 

 

[motzartmerv]

Its not the final decision, but the data from the Dynon paints the picture. There is discussion on other forums about it being a 'zoom takeoff' with a pull out, I would find that highly unlikely on a forst flight, some of the trim data is incredibly interesting. I wont speculate, but look at that trim sheet.

 

http://www.atsb.gov.au/media/4469487/AE-2013-069_Final.pdf

 

 

[rgmwa]

According to the report the trim range was mapped on the Dynon from+1 to -1. However, the range shown on the graph is only a tiny fraction of this (from about 0 to-.03), so the actual trim movement was so small it's quite possible the trim switch wasn't touched again after being set for takeoff. Could just be seeing the response to the change in aerodynamic pressure on the tab throughout the flight.

 

rgmwa

 

 

[Roundsounds]

Just stumbled upon this report, scarily similar to Wayne’s accident. I wonder if this was reviewed / considered during the Lismore investigation?
 

RV12 accident on initial test flight.

 

Pilots report suggested runaway trim

Edited June 16 by Roundsounds

[rgmwa]

It should take 25-30 seconds for the stabilator trim to run from full up to full down, so given he stalled at only twenty feet, chances are he may have had the trim set incorrectly rather than have experienced a runaway trim. His serial number is 120185 so it's an older kit. I started building mine at the end of 2010 and mine is 120346. The Production Acceptance Procedures for the RV-12 are quite detailed and thorough, so any trim malfunction or common builder's error such as having the trim wires reversed should have been picked up either by the builder or the DAR at sign-off. I understand the Lismore 12 got to about 200 feet before he pulled up steeply.  The trim can be over-powered by the pilot, but it needs a pretty firm push/pull on the stick, and if he wasn't expecting it, he wouldn't have had much time to react. Another common cause of this type of accident in the RV-12 is forgetting to latch the canopy. His early kit would not originally have had the audible canopy latch warning that the later kits had, although he could have retro-fitted it.

 

[Roundsounds]

2 hours ago, rgmwa said:

It should take 25-30 seconds for the stabilator trim to run from full up to full down, so given he stalled at only twenty feet, chances are he may have had the trim set incorrectly rather than have experienced a runaway trim. His serial number is 120185 so it's an older kit. I started building mine at the end of 2010 and mine is 120346. The Production Acceptance Procedures for the RV-12 are quite detailed and thorough, so any trim malfunction or common builder's error such as having the trim wires reversed should have been picked up either by the builder or the DAR at sign-off. I understand the Lismore 12 got to about 200 feet before he pulled up steeply.  The trim can be over-powered by the pilot, but it needs a pretty firm push/pull on the stick, and if he wasn't expecting it, he wouldn't have had much time to react. Another common cause of this type of accident in the RV-12 is forgetting to latch the canopy. His early kit would not originally have had the audible canopy latch warning that the later kits had, although he could have retro-fitted it.

 

I did the initial test flights on an RV-6. The electric trim operated in reverse. Neither the owner / builder nor the LAME who did the dual inspection picked it up. I found it during the preflight inspection prior to the first flight. I always set trims to neutral on the first flight and don’t touch them until well above circuit height just in case. 

[Thruster88]

I find it strange the pilot of the N reg RV12 was looking at the tachometer and not the air speed indicator on the takeoff roll. Rearward stick pressure would have been building as the aircraft accelerated.  

[Roundsounds]

19 minutes ago, Thruster88 said:

I find it strange the pilot of the N reg RV12 was looking at the tachometer and not the air speed indicator on the takeoff roll. Rearward stick pressure would have been building as the aircraft accelerated.  

Whenever doing test flights I have a number pre determined parameters for a go / no go decision. The USA guy may not have done so, the takeoff roll isn’t the time to be figuring that stuff out.

The point of me posting the USA accident report was the similarity in the observed flightpath immediately after liftoff.
I’m more than a little concerned about the RV-12si fight envelope protections and the level of understanding of its functions and response to faults associated with the system. I’ve read claims by an Australian operator of the type having stall protections when they don’t. Download a copies of the POH and Autoflight systems manuals and have a read. The emergency procedures section of the POH makes for interesting reading, lots of pulling out fuses. 

Edited June 17 by Roundsounds

[facthunter]

Why would you need the RISK of having powered trim on a small plane?  Where it's used there is a brake that comes in automatically  by pulling the elevators to oppose it which is intuitive and it's non too subtle in it's action as well.. .  

[Thruster88]

John, Please take this post as it is intended, to try and figure out what happened, and not point fingers. Good pilots learn from every flight. Lets find out what happened and move forward to get you and your plane back in the air, this time longer than 3 seconds. 

Last night I decided to test fly -12 with trim fully deflected in "up and down" position. My speed was about 60-MPH (to simulate rotate speed) and I used no flaps, 1/2 flaps, and full flaps. While the -12 trim demonstrated good command over the stabilator I was able to maintain flight straight and level with one arm, and actually control the plane up and down as if to attempt to land. Granted, I was prepared and ready for the "heavy stick" and had this happened on my first flight it certainly would have been a surprise and I possible would have needed longer than 2-3 seconds to figure out what was happening. The stick does become heavy and pushing on it hard to counteract the force would seem very unnatural and unnerving, especially on the 1st flight.

The Dynon has a trim indicator gage on it that appears after calibration. What does it indicate now? Where was the trim set for take off?

 

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

 

The above is from the US forum and answers the question I have had, how much stick force in a runaway trim for an RV12.

 

I have done the same tests in the Musketeer, manual trim stabilator and RV6a electric trim conventional elevator trim tab. Scenario based training like Dan Gryder advocates, less surprising when it happens for real.

Edited June 18 by Thruster88

[skippydiesel]

Slow day in The Forum

 

 "Recreation" as in recreational pursuit  - activity done for enjoyment when one is not working. Often involves learning and maintaining/practising a skill - The word recreation is derived from re create, as in to make oneself again, in this case diffrent to your work or other activates.

Private/recreational pilots learn to fly to re create themselves, develop new skills, enjoy a challenge & the magic of flying, continue to learn & maintain/enhance the skills acquired.

 

It seems to be a very human trait, to add complexity when non is needed (electric trim/autopilot/autoflaps/CS props/ EFB/ etc etc).

I, along with many others have often commented on the over enhancement/complication of small recreational (RAA) level aircraft .

Thanks to miniaturisation & computers, small aircraft can now be equipped with systems/capabilities formally only found in airliners/military aircraft.

There is no doubt that, technology's of this kind, can enhances safety and reduce the "workload" ( eg OzRunways ) so the pilot is freed to enjoy other aspects of the flying experince BUT it is a "two edged sword"  as it also  "dumbs down" the pilot who now does not have to maintain his/her skills in planning/ meteorology/ WB/ tracking/etc. This does not bode well for the pilot, who becomes dependent on these systems, when they fail/malfunction, these small aircraft rarely have system redundancy beyond the skill/knowledge of the pilot to adapt and manage the situation.

While I support the right of an owner to fit out his/her personal magic carpet, with whatever "bling" systems they desire, I can not help but wonder at what drives such excess, after all it's supposed to be about recreation.😈

[facthunter]

Simple safe and affordable.  IF you are fitting gadgets and playing with them make sure someone is still ,managing the "SHOP". If your PAX is an air person make use of the extra pair of eyes.   Nev

[Thruster88]

Aileron/ flapperon control heim joints incorrectly installed caused this recent fatal in the USA.

 

The Junior GA Reporter

WWW.FACEBOOK.COM

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- NTSB issues the preliminary report into the fatal accident involving a Van's RV-12, N412JN, that occurred on June 6, 2024, in Auburn, Washington: On June 6, 2024, about 1159 Pacific...

 

- NTSB issues the preliminary report into the fatal accident involving a Van's RV-12, N412JN, that occurred on June 6, 2024, in Auburn, Washington:

On June 6, 2024, about 1159 Pacific daylight time, an experimental amateur built Vans Aircraft Inc. RV-12, N412JN, was substantially damaged when it was involved in an accident near Auburn, Washington. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The airplane departed Auburn Municipal Airport (S50), Auburn, Washington, for what family members of the pilot reported as a routine pleasure flight. Preliminary Automatic Dependent Surveillance-Broadcast (ADS-B) data indicated that shortly after takeoff the airplane followed a southeast track, and after reaching the eastern foothills of Mt. Rainier, performed a 180° right turn, and followed a similar track back to Auburn. As the airplane approached the airport from the east, the pilot reported over the common traffic advisory frequency (CTAF) that he was just over midfield and intended to perform a full stop landing on runway 35. Correlation between recorded CTAF audio and ADS-B data indicated that over the next 60 seconds, the airplane overflew the runway, while descending from 1,500 to 1,250 ft. It then began a left turn, and as it rolled out onto the left downwind leg, the pilot transmitted, “Pan Pan RV412JN, I just had a control failure, I’m inbound for 35, without any controls”.

Over the next 45 seconds, the airplane began a descending left turn, that witnesses described as similar to a spin or spiral dive. A west-facing security camera, located on the exterior wall of a warehouse about ¾ miles southwest of the runway 35 threshold, captured the final 3 seconds of flight. It showed the airplane come into view at the top of the frame while in a 45° descending left turn. The airplanes roll rate rapidly increased, and the airplane struck the warehouse roof inverted in a 45° nose-down attitude.

The airplane came to rest inside the reception area of the warehouse. The forward cabin sustained crush damage through to the main wing spar. The complete right, and the inboard left section of the wings remained attached to the fuselage by the main spar, and the outboard fragments of the left wing were located on the building’s roof.

The airplanes roll control system consisted of full-length flaperons, connected to tandem control sticks through a series of pushrods, torque tubes, and a centrally mounted flaperon mixer bellcrank. Examination of the wreckage revealed that the left control stick pushrod (F1264-1) was not connected to the inboard eyebolt bearing (CM-4MS) at the flaperon mixer bellcrank (see figure 1).

When compared with the airplane’s plans, the inboard eyebolts were installed such that the eyebolt stud was connected to the pushrod, and its body to the mixing bellcrank, rather than the other way around (see figure 2). In this configuration, the stud end of the eyebolt was free to rotate within the threaded inboard section of pushrod.

Construction of the airplane was completed in May 2021, and by the time of the accident it had accrued about 100 hours of flight time. The pilot was flying the airplane from the left seat. 

The wreckage has been recovered for further examination.

- Report:
https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194412/pdf

Edited June 25 by Thruster88

[rgmwa]

The plane would have been controllable using the passenger-side stick but given his low altitude he didn’t have a lot of time to try to figure out the problem.