Kenn Borek Antarctic Cause/Speculation Thread

[captcrunch2013]

I'm just going to throw this out there, no disrespect to the crew. Could they have been doing some sight-seeing and at the last minute realized they were too close to Mount Elizabeth? My closest call in the mountains came on a CAVOK day.

If I was flying that leg, I would have had several video cameras running plus taking turns to take big meg pictures.

These particular mountains and the winds make for some of the the riskiest flying around, several posters have
questioned why they were not flying higher and thats a good question.,

There are two scenarios, one VFR and one IFR assuming it was IMC at the time or became IMC as they approached
abeam apparently of the mountain.

Either way mountain wave is one probable cause with
a host of other factors.

Were they up late the night before? Is anyone going to talk? not likely
What were their duty hours?

The cargo didn't leak, the controls didn't freeze, the autopilot raises some questions
and it could have played a role, with a sudden disconnection.

Bob did make a lot of use of an autopilot.

Right now, the most probable cause is a loss of control due to mountain wave
in VMC and or IMC conditions at the time.

[Gear Jerker]

I'm not sure a heavily-loaded Twin Otter could climb back up 4200 feet in that period of time. It seems more likely to me that the sat tracking system had an error, which I've seen hundreds of times.

Thank you Diadem for that information. I was of the belief that the sat tracking systems were more reliable than that. You did though indirectly support my point about the climb back from 8800 to 13000 feet as it was noted that they were climbing at 140 Kts. There didnt seem to be any "urgency" in their climb back to 13000 or wouldnt they have went for Best rate or Best angle of climb? At 140 Kts (if we can believe these numbers) it would be a casual cruise climb at best in a DHC6, so why the lack of urgency in the climb back up if they were able to see rocks sneaking up on them?

PS... Cat, I sincerely hope you are correct and the answers will be in the CVR.

*Edit* Thanks for the PM Changes in Latitudes and I replied as well. Alls well.

Also possible that their IAS was more like a Vx or Vy while their G/S was 140, if they had a good tailwind component?

[Diadem]

Were they up late the night before? Is anyone going to talk? not likely
What were their duty hours?

The cargo didn't leak, the controls didn't freeze, the autopilot raises some questions
and it could have played a role, with a sudden disconnection.

Bob did make a lot of use of an autopilot.

Right now, the most probable cause is a loss of control due to mountain wave
in VMC and or IMC conditions at the time.

On what are you basing these assertions? How do you know the cargo didn't leak and the controls didn't freeze? The only info that's been released is the location and altitude of the aircraft leading up to the crash, and we don't even know how accurate that data is. You're making a lot of strong claims based on absolutely no evidence whatsoever. I don't know what your experience was flying with Bob, but I never saw him use autopilot, not once.

[loopy]

I'm just going to throw this out there, no disrespect to the crew. Could they have been doing some sight-seeing and at the last minute realized they were too close to Mount Elizabeth? My closest call in the mountains came on a CAVOK day.

If I was flying that leg, I would have had several video cameras running plus taking turns to take big meg pictures.

These particular mountains and the winds make for some of the the riskiest flying around, several posters have
questioned why they were not flying higher and thats a good question.,

There are two scenarios, one VFR and one IFR assuming it was IMC at the time or became IMC as they approached
abeam apparently of the mountain.

Either way mountain wave is one probable cause with
a host of other factors.

Were they up late the night before? Is anyone going to talk? not likely
What were their duty hours?

The cargo didn't leak, the controls didn't freeze, the autopilot raises some questions
and it could have played a role, with a sudden disconnection.

Bob did make a lot of use of an autopilot.

Right now, the most probable cause is a loss of control due to mountain wave
in VMC and or IMC conditions at the time.

I'm pretty sure that most twin otters do not have autopilots. Can anyone comment on the Borek fleet? Are you sure Bob did not mean the copilot when referencing the use of the autopilot?

[Rowdy]

A few of the borek twins have autopilots. Not many though. I cant for the life of me remember if KBC had one or not. Knowing Bob, those comments may have been made in jest, especially after hand flying on a ferry trip for how many hours

A whole lot of speculation without much in the ways of fact at this point. Even the information from the sat tracker is speculative. They are not 100% perfect. It would also require a look at their actual track over the ground for this segment to see what was going on. Whether or not they had altered course, where they had started to cross that range etc. Unfortunately we are not privy to that information.

Also, for those commenting about them possibly sightseeing, I highly doubt it, based on where the aircraft came to rest and the extent of the impact.

Lets hope some more solid facts come to light, so many of us can seek some closure to such a terrible event.

[ethan]

Ya, sorry. I think I was just caught up in what was already presented and interpreted your comments as "you wouldn't understand because the rules we fly by don't apply down there." Sounded like the physical laws are somehow violated in Antarctica.

I haven't flown below 60S, but I do fly and I have spent over five cumulative years in Antarctica including multiple winters and learned about Antarctic weather by sharing workspace with the Met department. My interpretation of those comments, heavily coloured by my experience of course, is not that the physical laws don't apply on the Ice, it's that there are physical realities there that you can't possibly understand or predict if you haven't seen it first hand - _summer_ temps and winds and visibilities on a regular basis that would be on the evening news if they happened in the lower 48.

The first time you disembark an early summer flight to Pole when it's -54C outside is an experience that will definitely take your breath away.

[arctic navigator]

What's the SE service ceiling on the twin otter? One stove down combined with some mountain wave/downdraft could very well have been enough to push them below the peak's. Having met Bob a couple times and reading everything he's posted on here I have a very hard time believing they were not in some serious trouble leading up to this.

[co-joe]

I'm just going to throw this out there, no disrespect to the crew. Could they have been doing some sight-seeing and at the last minute realized they were too close to Mount Elizabeth? My closest call in the mountains came on a CAVOK day.

I seem to remember that years ago KBA lost an otter just that way. The crew was sight seeing too close to a very large ice berg and got caught in some kind of shear or downdraft that they couldn't outclimb. SRP told me that story years ago and I don't know anything first hand. If a berg can cause it, a 14 700' moutain has the potential to.



WRT mountain wave and associated downdraft, my understanding is that if one is strong enough (as could easily have been the case here with 90 KT peak level winds) that a downdraft can cause an uncontrollable descent. Furthermore, I thought I'd learned that if enough air is descending at once, the pressure immediately around the aircraft wouldn't appreciably change and so the barometric altimeter wouldn't show a descent or the reading would be delayed enough that the crew could be at an enormous and possibly fatal disadvantage. Especially if you factor in either IMC, or whiteout VMC, and all the other factors of aircraft performance.

This could explain the sudden dip in altitude and the preoccupation with returning to minimum no O2 altitude while in very high terrain. The distraction caused by a shear or downdraft like this could lead to a loss of situational awareness which could result in that early course change. If so the CVR will be a big help.

I've experienced severe CAT in a jet stream that made the King Air 350 nothing more than a helpless feather in the wind. I can't imagine the shears possible at 13000' with 90kt winds that close to a 14 700'peak.


I really want to see a photo of Mt Elizabeth. I've spent a great deal of time looking for one and have only come up with pictures of mountains in the Antarctic with no names. Does anyone have one they would share or a link to one they can point out for me. Thank you.

[captcrunch2013]

cojoe, thanks for the post.
I'll admit to screwing up on assuming use of an autopilot as
don't know if the otta had an ap or not.
I'll stand by what I said, Bob did make use of an autopilot
or more often than not a cojoe who he let fly more often than not.ll

Another question raised that was a good one was
we don't know the accuracy of the skytrac reporting.

I'd like to hear from others about the accuracy of the reporting.

The more I think about that data, the more I'm left wondering about
its reliability.

What errors have been observed.

Obviously, there are people who are privy to the flight plan and its route
but they are not talking yet.

I'll bet he planed around the mountain, thru the scenic pass,
mountain wave effects with a loss of control.

Now, this route was flown before,
can anyone tell us what routes
were previously used?

[MUSKEG]

Co-joe. Just google Mount Elizabeth

[stallie]

It might have been clear to others, but I've just realized that the news image of the screenshot with the pen pointing is actually not of the Beardmore Glacier and the accident flight. The flight track is of an aircft heading down the Koelitz Glacier adjacent to the dry valleys near McMurdo.

[CpnCrunch]

There have been quite a few accidents where extremely high time and skilled pilots ploughed into mountains while sightseeing too close (Steve Fossett, Sparky, etc). A member of this forum did something similar and survived. I hesitate to post this, because I don't want to imply Bob screwed up in the same way. These speculation forums are more about discussing possible scenarios to remind the rest of us to be careful. If pilots like Sparky and Fossett (who are more skilled and experienced at mountain flying than any of us here) can get caught out in the moutains on nice days, I think the lesson to be learned is that you really need to avoid flying too close to the rocks. A lot of mountain training still tells you to fly 100ft from the side of valleys, tops of ridges, etc. (including an article I just read in last month's AOPA) which seems dubious in my opinion.

[Diadem]

I seem to remember that years ago KBA lost an otter just that way. The crew was sight seeing too close to a very large ice berg and got caught in some kind of shear or downdraft that they couldn't outclimb. SRP told me that story years ago and I don't know anything first hand. If a berg can cause it, a 14 700' moutain has the potential to.

http://aviation-safety.net/database/rec ... 19941124-2 It wasn't actually sight-seeing, they were departing Rothera on a ferry flight to Terra Nova, coincidentally. There was a large iceberg sitting off the end of the runway, and the aircraft was estimated to weigh 18500 lbs. They had a ferry permit to go above 12500, but I believe the max weight on the permit is 17000 or 17500. Either way, it was too heavy to climb over the iceberg, they stalled, crashed, and burned.

[Cat Driver]

I don't think using Sparky Imeson as a benchmark for how to fly in the mountains is the best example we can find because he managed to crash twice in about two years in the mountains...the last and final time he was .. running in really bad weather.

If pilots like Sparky and Fossett (who are more skilled and experienced at mountain flying than any of us here)

Are you sure they were more skilled and experienced than " Any of us here " ?

[CpnCrunch]

I don't think using Sparky Imeson as a benchmark for how to fly in the mountains is the best example we can find because he managed to crash twice in about two years in the mountains...the last and final time he was .. running in really bad weather.

If pilots like Sparky and Fossett (who are more skilled and experienced at mountain flying than any of us here)

Are you sure they were more skilled and experienced than " Any of us here " ?

I guess I should have said "most of us here"

PS, when are you going to write your book?

[cncpc]

I don't think using Sparky Imeson as a benchmark for how to fly in the mountains is the best example we can find because he managed to crash twice in about two years in the mountains...the last and final time he was .. running in really bad weather.

If pilots like Sparky and Fossett (who are more skilled and experienced at mountain flying than any of us here)

Are you sure they were more skilled and experienced than " Any of us here " ?

I guess I should have said "most of us here"

PS, when are you going to write your book?

Not meaning to belabor the point, but Steve Fossett was a very rich guy who dabbled in aviation. I think most of us here probably knew more about mountain flying than he did. No issue with Sparky Imeson, though.

[Cat Driver]

PS, when are you going to write your book?

Probably never mainly because I really don't have any desire to.

The reason I made the comment regarding Sparky is to point out to the younger generations here that like everything else in life we have to examine " all " the facts surrounding what we read.

Just because someone can build a great story and pontificate on how to do something does not make their writing all that valuable..

Humans evolved ( or were made in Gods image out of clay ) whatever process you feel is more logical as creatures that walk around on the ground, unlike birds we were not designed to fly.

And therein begins a slippery slope wherein people get fixated on the thrill of actually being able to leave the ground and fly......

...unfortunately we do not have the DNA of a bird and flying is an unnatural environment that we were not born to do, like learning to walk.

We are really only in the embryo stage of learning to fly as a species and therefore must be careful just accepting what someone else claims is the best way or only way to survive in an environment were were not designed to be in.

If you read these aviation forums a lot it can get really difficult to separate the wheat from the chaff so to speak.

For me when I read some of the long debates about the physics and mathematical calculations that can be found in the Mensa circle jerk discussions that ebb and flow on this site I get really fearful about how ignorant I really am and wonder how in hell I ever lasted this long.

Best explanation I can come up with is the more I learned about surviving each flight was learning when to say no to a flight or part thereof.

In other words I take pride in knowing what I can't do.......not what I can do.

[mbav8r]

Cat, I don't often agree with you and have been critical of your post
in the past, however very eloquently put, especially the last part. Maybe
You should write a book

[Cat Driver]

Cat, I don't often agree with you and have been critical of your post
in the past,

Have you thought about why you were critical?

Maybe it is more a difference in how we perceive aviation than a difference in how we physically fly?

Maybe our perceptions are shaded by the environment we learned in more than anything else?

however very eloquently put, especially the last part.

Thanks, that is truly a compliment coming from someone that normally disagrees with me.

Maybe You should write a book .

Naw I do O.K. right here where occasionally I get the gratification of writhing something that people grasp in real time.

And I am convinced this discussion would be approved of by Bob and his crew because we are truly mystified at what happened to them.

Maybe in some small way this process will help us cope with another unexpected loss to our family.

[scot]

Well, I don't often pitch in with these discussions, but I'm going to today.
For anyone unfamiliar with the iceberg accident, scroll back up a few posts to Diadem's, and click on the aviation-safety link. This happened in 1994; there wasn't much in the way of internet forums then.
They had already done a day of flying by the time they got to Rothera. Would that have been a good place to call it a day and get a night's sleep? You bet.
Was there pressure from management to get that plane south? I'm sure there was.
And sometimes pilots put pressure upon themselves; it's that sort of a job.
To paraphrase Cat Driver, sometimes you have to know when to say no.
I'm sort of aiming this post at the younger pilots out there, say under 25. Don't be afraid to tell management where to stick it; it can be your life on the line. Fatigue can be a killer.

To make this clear, I'm not saying any of this applies to the case of the KBC crew. Bob had been around the block enough times to make his own mind up. They will all be sadly missed.

[Cat Driver]

When I think back on the long road behind me and look at the risks I accepted to get a trip done I am left with the feeling that fate has to be a factor in survival at least part of the time.

Reading about the practice of loading an airplane way, way over its maximum certified take off weight to ferry long distances is a case in point.

Even though the regulator issues an overweight flight permit we know that if we lose an engine before we burn off the excess weight we are not going to be able to maintain flight.

Yet we do it even knowing the very high risk involved, losing an engine is only one danger as there is always the strutuctural failure risk should we encounter severe turbulence......which was always in the back of my mind flying in the ITCZ.

I retired when I knew deep down that if I kept rolling the dice eventually the wrong numbers would come up.

[GyvAir]

I see the 1994 crash being referenced on this thread. For those interested, here are links to the accident investigation report and report addendum:

http://www.aaib.gov.uk/cms_resources.cf ... 002-95.pdf
http://www.aaib.gov.uk/cms_resources.cf ... 001-96.pdf

[crazy_aviator]

Reading the 1994 crash, it looks like the pilots were rolling the dice with 90% of the numbers missing. No need for buck rogers, seat of the pants flying like this when lives are at stake ! Sadly, pilots are simply NOT enginerring absolute types, they are "creative" artsy types.( left brain-right brain) Most accidents result from pilot error, however, some are foolish pilot error like the 1994 crash.

[Lost Lake]

I don;t wish to speculate. It is said it is better to say nothing and be thought of as ignorant, than to speak and prove you are ignorant. Bob was my trainer on the twin.

There are a few questions that come to mind in dealing with this accident.

Firstly, the terrain. Bob was at 13,000 ft. What was the height of the mountain on the other side. How far away was it. What was the AGL through the valley.

It was reported that the ground speed was 140 kt, indicating almost 0 head wind. What was the wind direction and speed in relation to his flight path. What was the altimiter setting at the points of departure and arrival.

When these questions are answered, it may give a little more insight into what happened.

To Bob and crew, I am so sorry, RIP.

[2550]

I wont speculate on the recent accident for the same reasons as lost lake. Also, this whole thing has made it too easy for me to imagine how horrible it would be to be recovering inhospital, or to be a family member of someone who has died in a crash, and read even some of the milder things said on these forums.

The report on the 1994 crash seems not much more than speculation to me. Determining weight from ground roll? And passing judgement on a crew without even laying hands on the wreckage? I understand the difficulties involved, but the report and subsequent discussion should take into account that nobody knows for sure what happened during that short flight.
Lessons can be learned anyway: overloaded ferry flights shouldnt be taken casualy, have a sleep if you just flew 7 hours across the southern ocean, turn out of trouble early if you have the choice.

But before we pass judment on the crew as being fools and buck rodger types, we should realize that we dont really know, and we wernt there. Learn, speculate, but dont judge and name call.