Are probable cause reports issued by the NTSB accurate and correct as to what happened? Or can they be incorrect and biased?
NTSB accident report accuracy?
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ClimbnSink
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Greg
With all the clamoring to not speculate until the official report is in I don't see how they could be anything but perfect.
Non Compos Mentis
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Non Compos Mentis
Were they written by a human?
TUPilot
Pre-takeoff checklist
Obviously human error is also possible. I also tend to believe that while large, high profile accidents (airline crashes, etc.) tend to be highly scrutinized by multiple experts, the NTSB simply does not have the manpower and resources to do an exhaustive investigation in all cases. Thus I imagine many probable causes are simply the best guess they could come up with given limited information and time. Pilots and lawyers can make their lives tough!
Oh yeah. I know of a banner pickup crash following an engine failure at the worst time and the "NTSB" report did not involve any actual investigating by the NTSB. They were never onsite. Local FAA "investigator" phoned it in to the NTSB. FAA cited "pilot's failure to maintain adequate airspeed". Crash pics showed no damage to one prop blade. Not sure how you can bury one prop blade in the dirt, and leave the second blade untouched if the engine was running. Report made no mention of engine failure.
I know of another accident where the wreckage was taken to a junkyard and destroyed before any actual analysis could be done. Then the report that was issued stated mechanical findings that would be impossible to ascertain after the airplane was crushed up in a junkyard.
Take a look at this video:
https://www.youtube.com/watch?v=jjRPY4_XKy0
Had the video not existed, I'm almost certain that the NTSB would have cited 'Pilot's failure to maintain airspeed which resulted in a stall' or some such wording. As it was, they took a look at the video and determined that shifting winds made it impossible for the Bonanza to accelerate and climb out.
Unfortunately, I don't have an NTSB link for the report. But it sure makes me wonder, how many other 'Pilot's failure to...' reports actually had something else going on?
https://www.youtube.com/watch?v=jjRPY4_XKy0
Had the video not existed, I'm almost certain that the NTSB would have cited 'Pilot's failure to maintain airspeed which resulted in a stall' or some such wording. As it was, they took a look at the video and determined that shifting winds made it impossible for the Bonanza to accelerate and climb out.
Unfortunately, I don't have an NTSB link for the report. But it sure makes me wonder, how many other 'Pilot's failure to...' reports actually had something else going on?
poadeleted20
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"Probable cause" means just that -- the consensus of the experts involved in the investigation as to what probably caused the accident. Nothing more, nothing less.
The next question is why do you want to know? The NTSB conclusion is only usable for contribution to air safety. It's not admissible in a liability action (the lawyers will have to present the evidence and provide their own expert witnesses to make conclusions from that).
Has the NTSB been wrong? Yep, even on major investigations. Have they changed their mind or expressed conflicting possible answers. Yes, that too.
Has the NTSB been wrong? Yep, even on major investigations. Have they changed their mind or expressed conflicting possible answers. Yes, that too.
The reason I want to know is just because I look through accident reports once in a while and try to learn something from them and I just wondered how accurate they are, as to why something happened, and if it really happened the way they say it did.
MauleSkinner
Touchdown! Greaser!
Are the probable cause guessers sometimes wrong? Absolutely.
Can we learn things from a probable cause report that is wrong, even if we don't know it to be wrong? Absolutely.
Can we learn things from a probable cause report that is wrong, even if we don't know it to be wrong? Absolutely.
petrolero
Pattern Altitude
I recently attended a meeting with an NTSB investigator. He said that they usually only travel to fatalities and that the investigators themselves typically write the prelim and factual reports but that the probable cause determination comes from the actual Board itself.
I have mainly been impressed with the factual accuracy of the reports and the way they examine events from multiple angles (weather, systems, flight data, voice, forensics, etc.) before arriving at a probable cause.
If anyone is looking for perfection in this world, well, have fun! Perfection is not the standard. The alternative is the standard.
But the NTSB's methods are as scientific and reasoned as anything I've ever seen from a government agency.
I have mainly been impressed with the factual accuracy of the reports and the way they examine events from multiple angles (weather, systems, flight data, voice, forensics, etc.) before arriving at a probable cause.
If anyone is looking for perfection in this world, well, have fun! Perfection is not the standard. The alternative is the standard.
But the NTSB's methods are as scientific and reasoned as anything I've ever seen from a government agency.
poadeleted20
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It's sufficiently reliable for the purpose of learning how to avoid the same thing happening to you.
If you happen to be on the Red Board, look up Jeff King's posts. He talks about his engine out landing in a Wal-Mart parking lot and subsequent challenges with the NTSB to "get it right".
Turningfinal
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You're spot on. I was an intern for the NTSB years ago and that's how it was done then, and I assume to this day.
Normally, if you see an accident report with "FA" somewhere in the title, it's a field investigation and an NTSB investigator was sent to the scene. This is usually the kind of investigation involving fatalities, a high profile accident, or there's concern of a major safety issue involved in the accident.
"LA" is a more limited investigation and and investigator may or may not have traveled there, but an FAA representative was involved. An engine failure due to reasons not immediately obvious (fuel exhaustion, etc.) would be one such example.
"CA" is the most basic type of investigation, and we usually talked with the FAA rep and the pilot over the phone. Usually these were the fairly obvious cases, such as substantial damage caused by a hard landing, ground loop, etc.
The preliminary report was generally written the day we received notification of the accident. Just a basic paragraph giving the easy stuff we could gather (aircraft type, location, weather conditions, etc.)
After gathering everything we could from the pilot (via their 6120 & phone), FAA inspector, and the scene (if it was a field investigation), we'd compile the factual report along with our best guess at probable cause & contributing factors. That was submitted and reviewed by the Board - most times they would accept the investigators PC/CF but there were quite a few times I saw changes occur.
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I will let you know when the NTSB releases the probable cause of the fatal I witnessed and helped investigate..
Turningfinal
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I worked with Todd Fox, the NTSB IIC. That investigation was based on information provided to him by the FAA inspectors. Unfortunately, when they don't do a field investigation, there's not much else to go by. That's more of a case of the FAA getting it right versus the NTSB.
Good to know. And to be clear, I wasn't trying to say who was right -- simply that that was the only example I knew of where someone had first hand knowledge of the process and wrote about it.
Neal Howard
Cleared for Takeoff
A good friend of mine died in a crash of his experimental KR-2 attempting the impossible turnback. The first report claimed fuel exhaustion as the major cause of loss of power. They later amended the report to state that loss of engine power was due to undetermined cause. I *know* the cause was failure of the electronic ignition system on the Subaru engine because it had shut down a couple times before the fatal crash and my friend had successfully turned back to the airport and dead-sticked it to successful landings on the runway. The NTSB originally had guessed that it was fuel starvation based solely on not finding any fuel in the shattered remains of the header tank, but a fuel receipt from the airport showed that he had just put ample fuel into the tank just before the fateful flight and the impact shattered the fiberglass fuel tank so badly that the several gallons of fuel that were in it were scattered all over the ground due to the impact. They did not take any dirt samples around the crash site, but later examination of the engine did show fuel still present in the injector lines.
My friend had replaced every part of the electronic ignition system except for the main control board which I told him was failing when it heated up and he didn't believe me. He was an A&P mechanic too. I still get sick to my stomach every time I think about it. I helped to pick up the broken shards of his airplane and load them onto a flatbed trailer in the field where he died. There was not much left of it. The whole fiberglass structure shattered into small pieces except for the empenage and the engine. I hate the KR planes. I think every one of them should be chopped up with a chainsaw before they kill someone else.
My friend had replaced every part of the electronic ignition system except for the main control board which I told him was failing when it heated up and he didn't believe me. He was an A&P mechanic too. I still get sick to my stomach every time I think about it. I helped to pick up the broken shards of his airplane and load them onto a flatbed trailer in the field where he died. There was not much left of it. The whole fiberglass structure shattered into small pieces except for the empenage and the engine. I hate the KR planes. I think every one of them should be chopped up with a chainsaw before they kill someone else.
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Snaproll
Filing Flight Plan
Sometimes NTSB gets it right - sometimes wrong... Have seen too many "wrong" reports where NTSB didn't bother following up, didn't interview all parties, and came up with "guesses" instead of facts. Guess they are just as efficient as the rest of the government......
Turningfinal
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Turningfinal
Unfortunately, if the NTSB can't prove scientifically or with almost absolute certainty that it was the ignition that failed, it's speculation. They're not going to include that. So you're stuck with engine failure for undetermined reasons.
Additionally, if it was an experimental aircraft with an experimental motor, they're not going to spend the same amount of time on that accident as they would on a certified aircraft.
Witmo
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Looks more like the engine either wasn't developing enough power or the aircraft was overloaded or it was hot/ high density altitude or some combination of the three. The tree tops looked like the winds were very light so I don't know how someone would surmise that shifting winds caused the airplane to fail to climb out of ground effect.
I had the exact opposite experience.....
http://www.pilotsofamerica.com/forum/showthread.php?t=63468&highlight=sad+day+jackson+hole
Witmo
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Tim
Here's the NTSB probable cause link:
http://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20070910X01354&key=1
I used to live in Cameron Park (same place as the 2007 accident) and was there when a very similar accident occurred in the 80's. There was also a news crew there filming and got the accident on tape. The lesson to be taken from these two accidents is never take off from an airport that has a news crew filming.
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Here's an AOPA article I found for it. I'd forgotten that it was 100 lbs. over gross, which didn't help:
http://www.aopa.org/Pilot-Resources...rts/Film-crew-captures-density-altitude-crash
petrolero
Pattern Altitude
The NTSB does an admirable job for the most part. But there are some accidents that just defy explanation.
I have been following this accident since the day it happened (Easter weekend 2013) and there is still no probable cause. There's not even a factual report available. Just prelim.
It just makes very little sense to me why there hasn't been more released on this. From the news reports and photo it seems like it would be a typical "Pilot's failure to maintain control" but that wouldn't take 1.5 years to come up with. I still scratch my head about how this accident could have been caused. Should have been easy enough for the NTSB to test the usual culprits - spinning prop? fuel? controls? Dusk VMC... nothing odd there. He was near Castle Rock, CO which is not in the mountains.
http://castlerocknewspress.net/stories/Plane-crash-kills-one-on-Douglas-County-ranch,116218
I have been following this accident since the day it happened (Easter weekend 2013) and there is still no probable cause. There's not even a factual report available. Just prelim.
It just makes very little sense to me why there hasn't been more released on this. From the news reports and photo it seems like it would be a typical "Pilot's failure to maintain control" but that wouldn't take 1.5 years to come up with. I still scratch my head about how this accident could have been caused. Should have been easy enough for the NTSB to test the usual culprits - spinning prop? fuel? controls? Dusk VMC... nothing odd there. He was near Castle Rock, CO which is not in the mountains.
http://castlerocknewspress.net/stories/Plane-crash-kills-one-on-Douglas-County-ranch,116218
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olasek
Pattern Altitude
I don't see how they can be biased but there is always a chance some could be incorrect. Nobody is perfect, no investigator was there when it happened. Hence they are only 'probable' causes.
ggroves
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Titanium
Yup. A friend of mine bought a Subaru conversion (not Egg, the other one in WA/OR..the name escapes me) for a Glastar. Disaster. He could NEVER get it to run properly. Even flew the owner out here to work on the electronics. Miraculously, he found someone who swapped a Lyc O-320 for it, and avoided a $20K+ nightmare.
Edit - NSI was the company.
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Shepherd
Final Approach
Ten(ish?) years ago I was the sole witness to, and the first person on the scene of a fatal crash involving a Cessna 172. I witnessed the last 8 minutes of the event. The plane was descending. The engine was fine. The plane made a turn toward a closed airport, realized the runways were blocked off (it is now a flea market), turned back towards the highway, descending, tried to line up for a landing, shut off the engine, then drifted to the side and settled into the trees. I was there in less than 2 minutes. Damage was minimal, but the pilot was dead. (From the autopsy report issued later) He had apparently suffered a heart attack. He knew he was in trouble and tried to set down on the road but died before he could set it down.
I gave a complete statement, in writing to the police and the NTSB. The NTSB findings concluded "loss of situational awareness, while trying to land on other than an approved airport." They never even mentioned that he was dead before he hit the trees.
I'm convinced that the NTSB has some agenda and needs statistics to prove some point. I just can't figure out what it is.
It gets a little weirder.
The pilot was one of my flight instructors starting when I was 14. He and I flew together in the Civil Air Patrol for 5 years, before I went into the Air Force. On his worst day he was still better than 99.99% of the pilots flying. If he was breathing, he would have nailed that landing on the road.
I gave a complete statement, in writing to the police and the NTSB. The NTSB findings concluded "loss of situational awareness, while trying to land on other than an approved airport." They never even mentioned that he was dead before he hit the trees.
I'm convinced that the NTSB has some agenda and needs statistics to prove some point. I just can't figure out what it is.
It gets a little weirder.
The pilot was one of my flight instructors starting when I was 14. He and I flew together in the Civil Air Patrol for 5 years, before I went into the Air Force. On his worst day he was still better than 99.99% of the pilots flying. If he was breathing, he would have nailed that landing on the road.
Turningfinal
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Turningfinal
Link to accident report?
jnmeade
Cleared for Takeoff
I have nothing but opinion, but that is that if the cause is given as weather, mechanical or something such, it may be fairly close, but the NTSB is bound and determined to come up with a probable cause and will will accept the first and most obvious explanation and stop there. Pilot error is fully acceptable and in absence of anything more definitive is going to be assigned. The NTSB is bound and determined to not consider multiple factors in an accident incident if at all possible to avoid.
I view their results as having a wide range of error outside of the obvious ones.
My experience and my opinion.
I view their results as having a wide range of error outside of the obvious ones.
My experience and my opinion.
Also, without posting a new thread, I notice that on some of the NTSB reports some causes of accidents appear to be engine failure by what happened, however in the NTSB report it says something like "The postaccident examination revealed no evidence of mechanical malfunctions or failures that would have precluded normal engine operation." So the pilot had engine trouble or reported engine trouble which caused an accident but reports say the above, why is this?
To word it differently, the pilot says he has engine troubles which caused an accident but when the NTSB comes to investigate they don't find any abnormalities, why is this?
To word it differently, the pilot says he has engine troubles which caused an accident but when the NTSB comes to investigate they don't find any abnormalities, why is this?
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wanttaja
En-Route
Carburetor icing. Vapor lock. Partial blockage of a fuel line dislodged by the accident. Pilot with fuel valve on empty tank who lies about it. Engine type in which the NTSB investigators have no expertise. Wreck so severe that major portions of the engine are destroyed. Or post-crash fire doing the same thing. Or disinclination to do an in-depth analysis due to time or budget limitations.
A fairly large percentage of accidents are attributed to engine failure for undetermined causes. Nine percent of homebuilt accidents end up in that category, about six percent of Cessna 172/210 accidents.
Ron Wanttaja
Neal Howard
Cleared for Takeoff
My friend's KR2 had an NSI Subaru on it too. When it ran, it ran good, but would suddenly quit and wouldn't fire up again until the electronic ignition cooled off.
ggroves
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Titanium
Yep. Same symptoms. My friend was really spooked by it. Sorry about your friend.
I have heard of similar issues with the NSI and the Eggen subi's.....
Easily fixed..... The base engine is bulletproof... The add on components are what gives up the ghost......
Remove ALL sensors , computers and EFI stuff...
Install a good quality ignition like MSD or Mallory and use crank triggers to fire the plugs....
Install a Air Flow Performance mechanical fuel injection system...
Motor and plane will run for decades without any hiccups...
....