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Stawell crash

Old 8th Oct 2018, 03:21
  #41 (permalink)  
 
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Folks,
I am guilty of no more than not being pedantic enough about "self certification certification" versus what you assume as "certification", at the end of the day, these aircraft have still been "certified" to an "appropriate" mechanism.

As for the adequacy of the flight testing under the ASTM standards, I can only describe it as minimal, or "rough and ready" and in no way as extensive as a FAR 23 single engine (just to be pedantic) aircraft test requirements.

Tootle pip!!
PS: At least two imported LSA that I have inspected very closely during assembly have been real shockers, I would expect better from the average home builder.
Interestingly, CASA demanded that the incorrect assembly instructions of the manufacturer/certifier be followed to the letter, because anything else would be a "modification" not approved by the manufacturer/certifier.

PS2: Re. the Brumby, I was hoping to make the point that it was tested to well beyond the minimal required standards.

Last edited by LeadSled; 8th Oct 2018 at 03:38. Reason: PS2 added
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Old 8th Oct 2018, 11:55
  #42 (permalink)  
 
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I am guessing that Soar are confident they know what went wrong as they are still currently flying their other Bristells, so seemingly not too concerned.
Squawk 7700

I am quite confident that SOAR do not know what they are doing. Except ripping people off.
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Old 16th Oct 2018, 00:43
  #43 (permalink)  
 
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Anyone see the Moorabbin Accident on Sunday? C172 on landing, ran off end of runway into ditch
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Old 16th Oct 2018, 03:36
  #44 (permalink)  
 
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Originally Posted by sta5fhl View Post
Anyone see the Moorabbin Accident on Sunday? C172 on landing, ran off end of runway into ditch
Was VH-EWZ from Oxford went off end of 17L. Nose wheel broken off. Otherwise looked not too bad from a distance.
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Old 16th Oct 2018, 04:15
  #45 (permalink)  
 
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the old "land at 70 knots" problem
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Old 16th Oct 2018, 05:17
  #46 (permalink)  
 
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Originally Posted by Sunfish View Post
the old "land at 70 knots" problem
Is that what you did when you bent the firewall of the 172 at Moorabbin Sunfish?
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Old 16th Oct 2018, 14:01
  #47 (permalink)  
 
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Re. the Brumby, I was hoping to make the point that it was tested to well beyond the minimal required standards.
Was there any "official" report published on the cause or suspected cause of the Brumby fatal accident north of Penfield Vic where Terry Otway and his passenger died?

If I recall, media reports described the aircraft in a flat spin.
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Old 29th Jun 2020, 08:54
  #48 (permalink)  
 
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Report out.

https://www.atsb.gov.au/media/577817...-066_final.pdf

The pilotís recollection of events and what actually happened appear to differ somewhat.

Last edited by Cloudee; 29th Jun 2020 at 10:24.
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Old 29th Jun 2020, 10:30
  #49 (permalink)  
 
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[QUOTE=Cloudee;10824201 The pilotís recollection of events and what actually happened appear to differ somewhat.[/QUOTE]

yikes, wonder if they were aware of the data recording or if it was a bit of a gotcha moment.

Looking at a triple figure bank angle I can imagine some selective amnesia creep in
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Old 29th Jun 2020, 15:58
  #50 (permalink)  
 
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Read and weep. What an idiot.
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Old 29th Jun 2020, 23:52
  #51 (permalink)  
 
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Without wishing the pilot any ill-harm, I'm glad they got caught out.

Unacceptable behaviour, and it doesn't show a great understanding of performance limitations.
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Old 30th Jun 2020, 00:04
  #52 (permalink)  
 
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1. I don't understand the spin recovery method in the POH per that ATSB report:
"Unintentional spin recovery technique:
1. Throttle - idle
2. Lateral control - ailerons neutralized
3. Rudder pedals - full opposite rudder
4. Rudder pedals - neutralize rudder immediately when rotation stops
5. Longitudinal control - neutralize or push forward and recover dive."
It suggests that only after the rotation stops is the elevator moved down and then used to recover from the dive.

2. "CASAís assessment of the new flight testing data and further information supplied by the manufacturer was that it still did not confirm that the aircraft met the required ASTM standard for spin recovery." CASA still hasn't explained why they think that. I would've thought that the ATSB would've read the spin test report themselves and came to a conclusion themselves.

The method of recovery from a fully developed spin may be quite different from that in the POH intended to be used up to one turn.

"Idiot" "unacceptable behavior" I wonder if anyone had told him what he needed to know.
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Old 30th Jun 2020, 00:53
  #53 (permalink)  
 
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Possibly in another aircraft that was demonstrated as being able to meet the required standards, may have never entered the spin in the first place.

Plenty of pilots have gone to 90 degrees or more when showing off and not come close to entering a spin.
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Old 30th Jun 2020, 11:56
  #54 (permalink)  
 
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Iím not qualified to critique the spin recovery in the POH but I feel like when youíve significantly exceeded the aircraftís stated performance as was done here then the POH pretty much goes out the window.

Perhaps there are plenty of GA aircraft that could have done what was done here and not had an accident outcome. The decision to do it in this particular type though is evidently flawed. That they had decided to do it earlier at a low altitude over a mateĎs house as well.....
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Old 30th Jun 2020, 23:19
  #55 (permalink)  
 
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Originally Posted by djpil View Post
1. I don't understand the spin recovery method in the POH per that ATSB report:
"Unintentional spin recovery technique:
1. Throttle - idle
2. Lateral control - ailerons neutralized
3. Rudder pedals - full opposite rudder
4. Rudder pedals - neutralize rudder immediately when rotation stops
5. Longitudinal control - neutralize or push forward and recover dive."
It suggests that only after the rotation stops is the elevator moved down and then used to recover from the dive.
Seems to me that is different than described in the company's spin test report of August 2011/February 2020:
"In all cases the aircraft responded to control actions and immediately recovered from a spin or spiral using ďclassicď spin recovery sequence Ė full opposite rudder and elevator control push to neutral position. Just as the aircraft stops the rotation, rudder pedals were moved to neutral position." and "Recovery from the flat spin requires that engine power must be reduced to idle, full opposite rudder applied with ailerons and elevator in neutral position. It takes up to 2 turns to stop the flat spin. Once stopped, rudder pedals in neutral position, increase engine power, push stick slightly forward and recover to horizontal flight in the normal manner."

Originally Posted by Squawk7700 View Post
Possibly in another aircraft that was demonstrated as being able to meet the required standards, may have never entered the spin in the first place.
Seems to me that it meets the standards for spin recovery. I haven't seen the official stall test report.
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Old 1st Jul 2020, 00:40
  #56 (permalink)  
 
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Iíll ask Gerard next time I see him.
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Old 1st Jul 2020, 11:39
  #57 (permalink)  
 
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Iíll ask Gerard next time I see him.
Why? You're talking to an experienced aeronautical engineer, Grade 1 Flight Instructor and competition aerobatic pilot and instructor. I think he knows what he's talking about.

And Lappin will tell you that thing should never be used in a training environment.
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Old 1st Jul 2020, 11:51
  #58 (permalink)  
 
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Trespassing into aircraft engineering here, but does not having a relatively short arm between CG and rudder make rudder design and sizing more critical? Look at a C150, the rudder is at least 0.5m further aft of CG compared to a Bristell. In other words, I would have thought The tighter the coupling distance between CG and rudder/elevator, the more critical the design of those control surfaces, but what would I know? I would also expect that the shorter “wheelbase” between rudder and CG leaves less time and room for error in spin recovery.
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Old 1st Jul 2020, 12:51
  #59 (permalink)  
 
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Originally Posted by Bodie1 View Post

Why? You're talking to an experienced aeronautical engineer, Grade 1 Flight Instructor and competition aerobatic pilot and instructor. I think he knows what he's talking about.

And Lappin will tell you that thing should never be used in a training environment.


Because unless Iím mistaken, Lappin was commissioned by CASA to flight test the aircraft to assess its spinning characteristics.
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Old 2nd Jul 2020, 00:42
  #60 (permalink)  
 
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Because unless Iím mistaken, Lappin was commissioned by CASA to flight test the aircraft to assess its spinning characteristics.
Yes, every time there's a Bristell crash they call him. But he's not the only authority. And you know what he's going to tell you anyway!
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