CTSW Down

[procharger]

2 fatal in 05N  Pitt County  NC . Anybody heard anything?

[FlyingMonkey]

http://www.kathrynsreport.com/2021/05/accident-occurred-may-22-2021-at-south.html

Accident pilot was Alan Stancill and passenger was his wife Susan.  Very sad, prayers are with the family & friends. 

[cdarza]

Rest in Peace.  

[Bill3558]

Very disturbing. Stall spin?

My wife recently started flying with me again after 35 years. She likes taking a crew car to lunch at different places. I need to understand what happened here. 

[GrassStripFlyBoy]

The FAA report will reach a conclusion, most always there is a chain of events that lead to the final outcome.  ie - running out of fuel, mechanical issues, weather, pilot error - the usual likely list.

Sad situation for sure.  And also hard to see the fleet taking the toll it has the past few weeks, this is 3rd total loss of airframe in a mater of weeks.

 

[Jim Meade]

(I don't know why this thread is in this forum rather than INCIDENTS.)

(This post is major thread drift, so maybe I should have started a new thread, but it is triggered by one of the comments in the thread so starting a new thread would lose context.)

Accident reports are NTSB, not FAA, responsibility.

The NTSB will likely come up with a "broken link" in the the "chain of events" and will be able to assess and allocate blame on some person or component.  It is very satisfying to say, "she done it".  Sadly, it often does not deter the something from happening again.  This observation applies to many - perhaps most - NTSB reports.  Prof Nancy Leveson of MIT leads an effort to take a different look at accident analysis with the idea of changing the system so the accident doesn't happen again.  

Here are some excerpts from an analyses of a UPS crash at Birmingham in 2013.

http://sunnyday.mit.edu/UPS-CAST-Final.pdf

"Traditionally, accidents have been thought of as resulting from a chain of failure events, each event directly related to the event that precedes it in the chain. For example, the baggage door is not completely closed, the aircraft climbs to a level where unequal pressure between the cargo compartment and the passenger cabin causes the cabin floor to collapse, the cables to the control surfaces (which run through the floor) are severed, the pilots cannot control the aircraft, and the plane crashes. The biggest problem with such a chain-of-events model is what it omits. For example, why did the design of the baggage door closure mechanism made it difficult to determine whether it was effectively sealed? Why did the pilots not detect that the door was not shut correctly? Why did the engineers create a design with a single point failure mode by running all the cables through the cabin floor? Why did the FAA certification process allow such designs to be used? And so on. While these additional factors can be included in accident investigation and analysis, there is no structured process for making sure that “systemic” causal factors are not missed."

"In STAMP, accidents are treated as more complex processes than simple chains of failure events. The focus is not simply on the events that led to the accident, but why those events occurred."

"The goal of accident analysis should be not to identify someone to blame (in practice this is usually the flight crew) because they did not satisfy their particular role in preventing a hazard such as CFIT but to identify all the flaws in the safety controls that allowed the events to occur, to understand why each of these controls was not effective, and to learn how to strengthen the controls and the design of the safety control system in general to prevent similar losses from occurring in the future."

"The National Transportation Safety Board determined that “the probable cause of this accident was the flight crew’s continuation of an unstabilized approach and their failure to monitor the aircraft’s altitude during the approach, which led to an inadvertent descent below the minimum approach altitude and subsequently into terrain [AAR-1402-2]"

"CAST tries to avoid hindsight bias by assuming that the humans involved (absent any contradictory information) were trying to do the right thing and did not purposely engage in behavior that they thought would lead to an accident. After an accident, it is easy to see where people went wrong, to determine what they should have done or not done, to judge people for missing a piece of information that turned out to be critical, and to blame them for not foreseeing or preventing the consequences [Dekker, 2017]. Before the event, such insight is difficult and, usually, impossible. The Clapham Junction railway accident in Britain concluded: “There is almost no human action or decision that cannot be made to look flawed and less than sensible in the misleading light of hindsight” [Hidden 1990]. CAST attempts to eliminate hindsight bias as much as possible from accident analysis. Simply listing what people did wrong provides very little useful information about how to eliminate or mitigate that behavior."

The cited work is almost 100 pages and gets a bit dense.  It's bottom line is that we can explain accidents in very simple terms but we can prevent accidents only if we take a much broader approach to the system failure.  Why was the work on the longer, closed runway not done during a slack arrival time, like 0200 rather than 0600?  Why was there no ILS on the shorter runway?  Why did crew challenge and response break down?  And many more.  These factors were not in a direct line of a chain of events, but if any of them had been changed the accident may well not have happened.

I have very little confidence that NTSB reports do anything except assign blame, and I'm not confident they do that accurately.  Three CTSW accidents in recent weeks?  Totally unrelated?  Who knows.  We'll never know from the NTSB.

 

 

[GrassStripFlyBoy]

22 minutes ago, Jim Meade said:

Totally unrelated?  Who knows.

Two of the three will be clearly known.

[Jim Meade]

1 minute ago, GrassStripFlyBoy said:

Two of the three will be clearly known.

MIT's point is that unless one analyzes the entire situation it's unlikely anything other than a "blame" conclusion will be reached.  When I asked if they are totally unrelated I was addressing it from the MIT perspective of analyzing the entire circumstances, rather than the NTSB approach of finding someone to blame.  I should have been clearer in my statement.

[GrassStripFlyBoy]

Jim - I get it...  And I go back to my industries process of having to ask "why" 5 times to reach true root cause of problems.  That may not transfer to aviation accident investigations, but does speak to it's rarely the first, or second, or even the third chain in an event that is where the problems (and lessons learned) lie.

 

[John Vance]

Unfortunately, it looks like the same old story.  According to the news people, it began with an attempted landing.  From the video, it appears that they landed on the runway but either aborted after touching down or were attempting a touch & go, and during the attempted climb-out, didn’t or couldn’t maintain airspeed (power loss?), ending with a stall & spin entry from about 100 ft.  

https://www.cbs17.com/news/north-carolina-news/video-shows-nc-plane-leave-runway-then-dip-in-crash-that-killed-couple/

[John Vance]

If you haven’t seen Dan Gryder’s videos on minimum maneuvering speed, this is worth a look.  He’s had several friends succumb to stall/spin accidents and this is his reaction:

https://www.youtube.com/results?search_query=dan+gryder

[Bill3558]

I suspect he was climbing out with 15-30 degrees flaps and just moved the switch to zero without releasing back pressure. 
Instant stall.

My heart goes out to the family.  They seem like nice people. 

 

 

[andyb]

On 5/25/2021 at 5:50 PM, Bill3558 said:

I suspect he was climbing out with 15-30 degrees flaps and just moved the switch to zero without releasing back pressure. 
Instant stall.

My heart goes out to the family.  They seem like nice people. 

 

 

I'm assuming the comment about a stall coming from not releasing back pressure while reducing flaps refers to shortly after a bounce or immediately after rotation.

In a normal routine of takeoff, transitioning from 15 to 0 degrees, then 0 to -6, at an appropriate altitude, slight backpressure is sometimes needed to sustain the climb when flaps are retracted.  If the AOA and airspeed are normal, it's not an issue.

Andy

[andyb]

Just looked at the video.  Looks more like a go-around than a touch-and-go. 

Under those circumstances, if they retracted flaps (don't know if they did), that would have bad consequences.

Sadly, there was a similar accident last week with a Cirrus.  I've had plenty of bounce go-arounds in both the Cirrus, as well as the CT, especially when first learning to land them.  Both planes have plenty of power to gain altitude after a bounce, but using pitch to maintain a safe airspeed is critically important.  More often than not, upon slowly applying power, the combination of a bounce and the power makes the plane want to pitch up, which needs to be counteracted with forward pressure on the stick.

Andy

[John Vance]

It’s difficult to tell from the video, but it looks like he might have been very close to the left edge of the runway and may have decided to go around for that reason.  It doesn’t appear that a high flap setting was used.

[Roger Lee]

It is hard to tell from the video, but looks like a turning stall.

[GrassStripFlyBoy]

26 minutes ago, Roger Lee said:

looks like a turning stall.

That was my first impression, wing starts to dip and natural reaction is to yank opp stick.  Rudder is not always front of mind for control. 

When I was working slow edge of envelop / stalls to develop skill on lower approach speeds, I kept feet in the game bigtime and remain aware of that in my continuing skill work.  I'm even thinking more of buying a premium slip indicator and put on panel, a real one with a ball in the tube.

Watching STOL competition fails, many fall victim to not staying coordinated or respecting gusting winds, and trash some lovely airplanes dropping wings in from just off the deck.

I'd sure like to go up to altitude and crank a hard rudder for an intentional spin entry, but have played by the regs.  I think training has done a disservice to pilots by only requiring the recognition with onset of conditions and never experience the event.  I loved spinning the old 150.

[okent]

Darrell I agree.  I feel fortunate to do spin training in a DA20.  Valuable.

[Madhatter]

Again, an issue I found years ago and reported it several times. A static leak in a ctsw will give you a 10 kt error in indicated airspeed. My leak came from a case leak in the airspeed indicator.  The handling of the plane was very noticable when I picked it up in Tulsa. You can't just tighten fittings and assume the static is tight, plastic fittings are notorious for leaks when old. When I had my certified avionics repair shop I found the most vfr aircraft had static leaks when I went to ifr certify them. The CT is one of the worst when it comes to how much error occurs. It takes about 10 min to check. If you cruise at 120 or 130 indicated you either have a bad indicator or a static leak, period.

This is easy and cheap to do and it may save you from a stall spin.

 

[GrassStripFlyBoy]

This situation is still odd from the perspective a classic stall spin occurs power off, turning downwind to crosswind, or turning final.  Having power on in a CT, it will darn near hang on the prop.  Makes me wonder things such as was the landing attempted on downwind runway, realized things were not right, then in go around the tailwind component was stronger above the trees.  

[andyb]

17 hours ago, Roger Lee said:

It is hard to tell from the video, but looks like a turning stall.

I think that's entirely possible.  When I looked at the video, I thought the left turn was due to the left wing dipping in the stall-spin, but hard to tell for sure.

If it was an intentional turn that soon and that low, then that would be way too early to initiate the turn, I believe, especially coming from the bounce on the runway.

With any of the scenarios that are being considered here, all of which I believe are plausible, I think that after the bounce, applying power gradually, pitching to assure sufficient airspeed and not exceeding critical AOA, then once stabilized retracting flaps if necessary and then initiating the crosswind turn, would be the course of action to avoid the very sad outcome of the flight.

Andy

[Duane Jefts]

Another plane down. Folks on board OK.

https://www.staradvertiser.com/2022/01/15/breaking-news/2-men-injured-in-plane-crash-near-hana-airport/

[GrassStripFlyBoy]

Glanced at the comments, someone referenced rescue cut things to assist removing the passengers, still - that looks like a rather hard lick to break the fuse at the rear bulkhead.  Hope all recover well.

[Jim Meade]

http://www.kathrynsreport.com/search?q=ctls+maui

 

[Bill3558]

I wonder if he considered pulling the chute. Worked for me. Glad it worked out.