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 9 hours ago 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 5 minutes ago by Roundsounds