Accident Report Summary

[Big Ed]

One thing I like to do is learn how other people manage to kill themselves and destroy their aircraft, lest it happen to me. The NTSB Database is a great resource for that. Plug in your aircraft type, dump the data, and start reading.

Since I'm buying a Super D, I downloaded and skimmed all the accident reports for the 8KCAB. The raw data is posted here if you want to review, with links for each accident report.

Below is a summary of all reports where the aircraft was destroyed and/or someone was killed.

Cause	Acro	Non-Acro	Total
Low Alt Maneuver	23	6	29
Unknown	9	3	12
Pilot Error	3	8	11
Engine	0	8	8
Structural	2	0	2
Mid Air Collision	2	1	3
Other Mechanical	1	1	2
Total	40	27	67

Some quick observations:

1. The single largest killer of Decathlon pilots is low level aerobatics. A few were airshow maneuvers, but most were simply someone initiating a spin at 1000 AGL and thinking they could recover, or trying a slow roll at 100 feet above the runway. Several more were low passes gone wrong. If you want to stay alive in your Decathlon, set a conservative minimum altitude and STAY ABOVE THE HARD DECK. I personally do not go below 3000 AGL during acro.
2. There were numerous stall/spin accidents associated with engine out on takeoff or landing. The symmetrical airfoil of the Decathlon is probably a factor there. Keep the speed up if you lose your engine. It won't glide like a Citabria.
3. There is only 1 documented instance of an unrecovered spin with otherwise sufficient altitude, and that was an inverted spin by an "instructor" with very little time in type. There are ZERO documented instances of unrecovered upright spins.
4. There are only 2 documented instances of structural failure not due to pilot error. One was a strut attach fitting that failed. The other was a seat back that broke during pullout, causing the pilot to fall backwards and presumably over-G the aircraft. There are ZERO documented instances of spar failure, wood or metal, caused by the spar failing to withstand the rated load. One structural failure is counted in the Pilot Error category because the pilot initiated a Split S to exit a roll with a very high entry speed and full power.
5. Pilot Error is a bit of a catchall for various flying or judgement mistakes: one flight into IMC, one flight into downdrafts in the mountains, a botched banner tow pickup, a few stall/spin accidents in the pattern, etc.
6. Of the unknown causes, several more were probably low level aerobatics. It is likely that low altitude maneuver accounts for more than 50% of Decathlon deaths.

 

[Bob Turner]

My only comment is on the spin deal - our recent fatality is not classed as a spin. The debris field was roughly the size of a Citabria, and the flight was spin instruction. I don't know what column they will put it in, but I am open to what would cause such a small impact footprint other than an unrecovered spin.

But thanks! This is good information.

 

[Big Ed]

Are you talking about the accident that happened 2 years ago to the 7KCAB out of El Cajon?

 

[Bob Turner]

Was it really that long ago?

 

[Big Ed]

Bob, here is the NTSB preliminary report:

On August 22, 2018, about 1615 Pacific daylight time, a Champion 7KCAB airplane, N1682G, impacted wooded terrain, about 8 miles northwest of Descanso, California. The certified flight instructor (CFI) and commercial pilot receiving instruction were fatally injured; the airplane sustained substantial damage to both wings and fuselage. The airplane was registered to Three Points Partners and operated by the CFI under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight. The local flight departed Gillespie Field Airport (SEE), El Cajon, California at 1601.

Information provided by family members of both pilots revealed that the purpose of the flight was for spin training as part of the commercial pilot's training to become a flight instructor. The CFI operated two Champion airplanes, providing spin training and tailwheel endorsements.

Review of radar data provided by the Federal Aviation Administration identified a primary radar target depart SEE and proceed in a northeasterly heading, climbing to about 3,200 ft above ground level (agl) across areas of rising terrain. The target continued on a northeasterly heading, at a level altitude, before radar contact was lost near the accident site. Throughout the last few minutes of the target track, altitudes varied between 2,000 to 2,400 ft agl.

Examination of the accident site revealed that the airplane impacted terrain on a heading of about 112° magnetic. The wreckage debris path was about 120 ft in length and contained all major structural components of the airplane. Hydraulic deformation was evident on both wing fuel tanks, which were breached. Residual fuel was noted within several engine fuel supply lines.

A few observations:

1. The length of the debris field indicates they were not in a spin at impact.
2. 2000'-2500' AGL is pretty low for spin training, IMO, even in a Citabria.
3. Lat-Long and wreckage heading (red arrow on map) shows they collided with sharply rising terrain.

At the risk of foolish speculation, I see two likely scenarios:

A. They were doing spins over the valley to the west, and did not anticipate that their recovery would put them in a high speed dive towards the high ground to the east.

B. They flew too far into a box canyon and were unable to turn out.

Either way, this does not appear to be an unrecovered spin.

 

[Bob Turner]

If you hit a hillside of about 45 degree slope in a spin, how long do you think your debris field would be? Conversely, if you hit it head on, how long?

The PIC was a well respected expert. He knew that country, and would not have placed himself in a box canyon. And an engine failure scenario is possible, but if it started at 2000' agl, I am quite sure it would have been successful. The terrain is rough, but 2000' gives you options.

As far as spin entry altitude is concerned, yes, a multi-turn spin from 2000' is a bit dicey.

I wasn't there. I have no idea what happened. I think they got into something unrecoverable.

 

[Big Ed]

If you hit a hillside of about 45 degree slope in a spin, how long do you think your debris field would be?

If you hit a 45 degree slope in a spin, the direction of the debris field will be DOWN the slope. Their debris field was UP the slope. Consistent with a pullout.

 

[Bob Turner]

Okay. No unrecoverable spin mode. I am still not doing multiple turn spins.

 

[Bartman]

sharply rising terrain just off their position makes A seem plausible. not one to speculate either but there it is.

 

[Big Ed]

That's entirely at your discretion, and not on my agenda to dispute. The only reason I posted the accident report was that there may be a useful learning point. When doing spins, it is not enough to have sufficient altitude under you. You also need to ensure you have enough altitude laterally to pull out of a post-spin dive in any direction. A quarter rotation could make the difference between recovering comfortably in the valley and smacking into a mountain. Perhaps someone 20 years from now reads this discussion and realises that they need to add another 1K in altitude in their practice area. That's my sole intent in this discussion.

 

[Bartman]

gotcha and thanks for the explanation though none was needed.

 

[Big Ed]

gotcha and thanks for the explanation though none was needed.

I was talking to Bob. I think he feels I'm still trying to talk him into six-turn spins.

 

[Bartman]

I was talking to Bob. I think he feels I'm still trying to talk him into six-turn spins.

only six? c'mon Bob!

 

[Bob Turner]

Have never done more than three. I meant to check Rick Stovall's book today, but got busy with fabric repairs and flying. 90 degrees and humid - California boys do not do well in New Jersey weather.

 

[aftCG]

Okay, first off a thanks to Big Ed for starting this thread and providing the links. As Ed correctly pointed out in a different thread, the numbers he posts are for the 8 series.
Disclaimer: The following is not a rant but it will probably read like one. I am actually quite interested in the study for the same reason as Ed. Also, my sincere apology to anyone in these accidents or their family members. I mean no disrespect with my arm chair observations.

An conclusion I have arrived at is that sometimes accidents end up in the wrong "buckets" which we sort things into. For example, low altitude maneuvering is easy to think of as some jack wagon hot dogging the tree tops for his friends or water skiing. Low passes are often frowned upon and I bring them up because as a war bird operator I can occasionally be found doing them (where years ago I would have been horrified). I'm going to do my own search for those later but I'll argue that 200 knots down the runway is safer than a poorly executed go around any day. With the T-6 I can turn that low pass into pattern altitude with a hard tug and still be above minimum maneuvering speed.

But back to the subject, I think a lot of accidents bucketed as "low altitude maneuvering" are poorly executed take off, approach, go around, etc. It is highly likely to be someone landing way long (floating) and not rejecting the landing soon enough, or a high density altitude situation where the plane just doesn't clear the obstacles and the pilot response ends up spinning the plane near the ground.

I just did a quick plug in of 7ECA and wow there are many. First one at the top of the list is, what do you know, "low altitude operation" but when you read the description it says the pilot took off and was caught by wind gusts at tree top level, was tossed around and hit some power lines.

Yet the very next one is categorized as "collision during takeoff/landing". Reading that one the student pilot in the front floated way down the runway, rejected the landing and executed a maximum performance climb, then hit the two trees that the instructor had briefed the student on (but couldn't see from the back seat).

Those two right off the top of the list are both from 2020 and sure sound like pretty much the same accident (scratching for altitude and hitting stuff).
Some ground loops, bird strikes, etc. Okay time to re-filter to find the fatal ones.

That takes us back to Moss Hill, TX on 9/2016. Was in fact low altitude aerobatics that ended badly, sounds like he spun it in to the river. Oh lookie, toxicology report shows cocaine and meth in the pilot's bloodstream. Pilot had a logbook entry for spin awareness but no training for aerobatics.

Another fatal following engine failure, another hit an occupied riding lawn mower on the runway. There's two guys that died searching for moose and cranking it around tight. Got a guy who died hand propping with the throttle open.

I see a stall/spin accident but in the description it says they flew into a box canyon (San Jose, CA in 2009) and they attempted a climbing left turn. So yes, ultimately they spun the plane but they were really dead before they started the turn.

See how the bucketing can be subjective and not very consistent? And for the low altitude stunt guys how is that not straight up pilot error? Certainly the canyon turn was.

So if the engine fails and the pilot spins in, and later on a fueling issue is found (starvation, selector, carb ice, wrong fuel, water/debris) is it:
a) pilot error
b) low altitude maneuvering
c) engine failure
d) accident during takeoff and landing

A dude landed way long, rejected the landing, had sun in his eyes and hit a cattle fence. One guy who was making low passes and crashed shortly after but no direct witness. His wife said it was completely silent for several seconds after he flew over but before she heard the crash. Some gaps in the discussion but let's put that in the low altitude idiot category anyway.

I'm going to download that database later and play with it. Of course I'll have to expand 7ECA to include 7GCAA and 7GCBC just to be honest.

For now though I have my filter to include all data for 7ECA, fatal, and include the words "structural failure" in the word string field. One example from December 1986 (back when having your caps lock stuck on was considered good form). Says the low time pilot was chasing coyotes and maneuvering tightly while chasing one. Looking now I see it says "no structural failure was noted."

So I changed "structural failure" to "spar". I find the guy who hit the lawn mower, the "low altitude idiot" from above, and an accident in Pine Mountain, GA where weather was 400 BKN, 1200 OVC with 1/4 mile visibility.

It's going to take some digging (no pun intended) but I don't see that wood spar wings are falling off Citabrias.

Sure seems like basic airmanship is lacking though. Huh. That's odd.

 

[Bob Turner]

I read about 3 way back when. I think they were all Scouts, and the wings had histories of hitting fenceposts or something. No idea where I read it - had to do with the AD generation.

 

[aftCG]

Got this I'm my feed today

General Aviation Accident Bulletin

AVweb's General Aviation Accident Bulletin is taken from the pages of our sister publication, Aviation Safety magazine. All the reports listed here are

www.avweb.com

Two collapsed gear issues and two cases that support my statement that people lack the skills to handle the plane under pressure. Proximity to the nearest planet is just the judge and jury. With sufficient altitude those people would have just scared themselves.

130 knots on final, long "float" and 100 knot touch down, go around with speed brakes deployed.

The description of the incident with the 210 reads like exceeding AoA under pressure.

I'm starting to groan when I read about "stick and rudder skills", like they're an add on rating