Mt Erebus accident.

[gulfairs]

The local news media is again full of "expert opinions" as to who, what, why, and how did this terrible accident occur.
I was in the air in another DC10 at the time of the accident, and by a quirk of fate was not on board NZP, even though I had involved with both Lucas and Cassin on roster swaps prior to the accident.
The enquiry and accident reports on this prang are all full of lies deception, holier than thou statements that are so much a distortion of the truth, it is as hard as picking fly dirt out of pepper to get a complete truthful and accurate story of events prior to and indeed after the accident.
Blame has been afforded on the CEO of ANZ at the time, how he is to blame is still a mistry to me.
Capt Collins was the victim of a series of tragic mistakes and mis information.
Some of the previous captains( not all) flew in VMC conditions and flew low level up to Mc Murdo sounds.
Most of these Captains deny this but photgraphs from previous flight passengers show this to be a fact.
MSA was and still is 16000 ft, but it was allowed to be ignored if the Met conditions were OK for VFR type flying at a lower level.
Collins took this loop hole in the accepted practices.
Unfortunately Collins did not know that previous to his flight the computer generated flight plan had moved the Position of Mc Murdo by some 26 miles.
Collins had, prior to the flight used a flight plan printout that was issued by the Route briefing unit which DID NOT SHOW the new revised turning point at McMurdo.
Collins would have been confident that he had a clear VFR route to Mc Murdo,but ANZ administration had seen that he was short of current info.
Admittedly one of the crew, Casin and or Lucas would have cross checked that the printed format was the same as the format in the CDU, but I and most other pilots of the time did tend to skip along tracks a bit quickly because of time constraints.
To Deviate to Illustrate the point I was on a AKL HNL flight one night and the aircraft did a 180 degree turn at the transition of the date line. which took several minutes to clear.
I had enterered a longtitude with an East instead of a West at the date line transition.(This was not picked up in the xcheck of the CDU/Flightplan)
Capt Jim Collins was not to blame, for the accident even though some of the bottom lines state Pilot error.
Should it be able to get the whole truth out in the open a lot of egotistical short arsed pilots would have a little more than egg on their faces.

I add as a Post script ,I flew with every member of the crew on that flight in the previous six weeks, Collins was a good pilot to fly with, Casin was good But not tough enough to challenge a captain, Lucas was tough enough but he was back in the cabin at the time.
I did see a hand written transcript of the voice recorder that commenced with "You are wrong, stick it up your arse." Bang door slammed( ostensibly from Lucas). thence the rest of the 30 minutes of tape recording.
The real bottom line is a case of money.
Should the airline be in error the compensation claims are limitless, should the pilot be in error the claims are limited to US$40,000.00.
We are back to the big boys cheating again! and the small players paying as usual.
Little cog in big wheel.

[HEATHROW DIRECTOR]

My family and I were within a hair's breadth of being on that flight and hearing the sad news that evening on a TV in Tauranga shook us to the core.

The arguments will continue, but in my book the crew were in error. If they were in true "visual" conditions they should have seen the dangers; it's no good arguing about waypoints being moved. They were ultimately responsible for the safety of the aeroplane and it went pear-shaped. Sorry if that upsets anyone... 30+ years later I still get the shivers thinking about it.

[BOAC]

If they were in true "visual" conditions they should have seen the dangers; - there was an excellent reconstruction (?TV?) film made (I saw it on one of DanAir's early CRM courses in the late 80's). We all agreed after watching the 'similar' flights up the sound in the same weather that we could not see the mountain in what was apparently 'true' visual' visual flight conditions. If anyone has a link to the production I would recommend those who have an 'interest' or position on this accident should watch it. An excellent 'Swiss Cheese' example with failures at all levels.

[henry crun]

"You are wrong, stick it up your arse." sounds like the sort of remark Brick would make if he was sure the other person was in error.

[Tagron]

The NZALPA website www.erebus.co.nz (http://www.pprune.org/www.erebus.co.nz) is essential reading for anyone with an interest in this accident.

Here can be found the original Chippindale and Mahon reports in full. They are lengthy documents, scanned and presented as a series of PDFs which makes them not the easiest of reading. Time and perseverance are essential.

One would have hoped that the words of reconciliation by Rob Fyfe (Air New Zealand CEO) at the thirtieth anniversary might have healed the wounds caused in no small part by previous ANZ management. Evidently not - it appears there will always be differing views on where responsibility and blame begin and end, and passions are too strong.

If there can be a simple summary of a complex situation, I would endorse BOAC's post #3: -
An excellent 'Swiss Cheese' example with failures at all levels.

[Groundloop]

it's no good arguing about waypoints being moved.


I don't often disagree with you, HD, but I do this time.

Because the crew were not told the waypoint had been moved they thought they were somewhere else. They did not expect to see a mountain directly in front of them - and, because of the whiteout conditions, they didn't! This gave them the impression they were flying in VMC - because they saw what they expected to see based on the flightpath they had previously plotted on their charts!

[PLovett]

Isn't the real issue that the crew descended below LSALT without a positive identification of their position?

They descended because they thought they were over McMurdo Sound based on the aforementioned navigational change and a misidentification of some coastline. However, in the virtual whiteout conditions that prevailed that was a dangerous assumption.

IIRC the SOP prevailing for the flights was that they were not to descend below the LSALT unless they were in visual conditions and had positively identified their position.

[Fantome]

The causes of this accident are far more complex than what a cursory look at the evidence would at first produce in the way of assumptions. The material pertinent to the first investigation, the Mahon enquiry, the input of experts such as Gordon Vette, all must be reviewed closely, before holding forth with an opinion.

In which regard, it becomes manifestly clear, on consideration in particular of the testimony of the captains who had crewed earlier flights of identical character, (except that they returned of course in one piece), in addition to the erroneous INS data that the company gave Captain Collins, that he did not stuff up due to any lack of airmanship. The primary fault lay in the carelessness of the company. Further to that the training section was found negligent in the conduct of their briefing sessions, which, though designed to cover every conceivable aspect of these special flights into potentially hazardous conditions, did not in fact for a first timer such as Jim Collins, give him adequate preliminary exposure.

History is too full of cases of commanders held culpable on false or unsafe grounds, then hounded, even to the grave, later to be exonerated by those who'd smelled a rat and would not rest till they'd uncovered the truth of the matter.

[prospector]

Fantome ,

" In which regard, it becomes manifestly clear,"

I would agree with that statement but for entirely different reasons. Here is the first one.

The requirements for descent were very clearly laid out, very explicit, and for the reason that the lack of Antarctic experience of the Air New Zealand crews was well known. The required conditions were as follows.

Delete all reference in briefing dated 23/10/79. Note the only let-down procedure available is VMC below FL160 to 6,000ft as follows:

1.. Vis 20 km plus.

2. No snow shower in area.

3. Avoid My Erebus by operating in an arc from 120'Grid through 360'Grid to 270'grid from McMurdo field, within 20 nm of TACAN CH 29

4. Descent to be Co ordinated with local radar control as they may have other traffic in the area.

The reported weather at McMurdo base was well below that required for the approved descent procedure. That is why they invented their own.

Not one of the required mandatory requirements for descent was met. They did talk to the radar operator, but they were never identified on the radar.
At no time did they have a DME lockon to TACAN channel 29.
At no time were they in the required arc from TACAN Ch 29 for the approved descent.

The argument that the waypoint had been changed would have had no such serious repercussions if these mandatory requirements had been complied with.


But, even if the aircraft was where the crew thought it was, in the weather conditions that they considered were good enough for a VMC descent, why was it that nobody twigged that they were on the wrong side of Beaufort Island, a very distinctive Island that was visible, it showed in photo's recovered from the wreckage.

If they were so certain of their position during this descent why was it that Mulgrew, the tour guide, and supposed expert on things local for this trip told the passengers less than 4 minutes from impact

" I still can't see very much at the moment, keep you informed soon as I see something that gives me a clue as to where we are"

Even if they were where they thought they were,they were within 25 miles of a 13,000 odd ft mountain and they had never sighted it even once.

And the simplest confirmation of the lot, they had a lat/long readout from the INS that was exceedingly accurate, but at no time was this readout put on a chart before descent was commenced.

Previous flight had descended below the altitudes laid down, but they had all been identified, and position confirmed by McMurdo radar, and in the conditions they had Mt Erebus could be see from 100 miles or more.

This from Bob Thomson who had been down to Antarctica some 75 times, and some 50 times on the flight deck of aircraft approaching from the North. He was the usual commentator on Air New Zealand flights to the ice.

Taken from John Kings New Zealand Tragedies, Aviation.

"The captain didn't give any attention to problems that he might have around there. These people were taking a Sunday drive. When I heard the transcript of the CVR I fell out of my chair. Most of the times Mulgrew had been there he had gone in by sea, and all his travel from Scott Base was to the South. Hardly anybody ever went into Lewis Bay.
Had they orbited Ross Island they would have seen the the cloud. If a pilot is unsure of his position he always goes up, never down. The co-pilot of flight 901 never opened his flight bag to look up the co-ordinates. I always had a chart in the cockpit and checked the latitude and longtitude readout, but the crew of the fatal flight never referred to it."

And that sums it up, as to the cause of the accident.

PS "the input of experts such as Gordon Vette," How many trips to the ice does it require to be termed an expert??? How many trips to the ice had Gordon Vette carried out??

[gulfairs]

" I always had a chart in the cockpit and checked the latitude and longtitude readout, but the crew of the fatal flight never referred to it."

In those days we were overawed in the accuracy of the triplex INS compared to the nearly correct doppler that was still used on the DC8.
After loading a flight plan into the computer, if it wasn't aleady loaded as a route as a 'from via to format', one rarely if ever cross checked the CDU waypoints with the printed edition at hand.
It wasn't until we operated the steam driven, cable operted switch, B747-200 was the stage by stage cross checked; and that was because the 747 INS was almost clockwork, as well we had all had our arses kicked after the horse got out( so to speak)
A.G Vette's redition of mind set, visual accurity ,seeing what you expected even it it did not quite fit theses, is probably closer to the truth than most pilots would or will admit.
It certainly was not Morry Davis's fault that the accident took place, but the brains in Flight route planning/flight planning do really have to look at them selves and try and be honest about the pre 901 events.
Jim Collins and crew were victims of a system that was run by a bunch of men who did suffer from alto ego, particularly if one challenged them over any point in navigation ,operation and performance.
Air New Zealand broke more rules in performance operation because of cost in useable dollars than most people would ever believe.
Another incident was discovered by a very poor take off performance at Hong Kong one evening, due to a power plant change in allowable limits, the aircraft then increased in mauw for take off but the new limits on the engines were not applied because it woudl shorten the hot section overhaule life.
I succeeded in getting 5(five) consecutive route checks because I challenged aircrew management over this issue and we were technically taking off over weight.
Such was the thinking in those days.
In fact I retired 5 years early over a disputed take of performance in a steam driven aircraft out of LGW again because it would increase operating costs if we did it according to the manufacturer's specifications.
I could write on but Have diverted a little from Poor old Jim Collins case.
He was not at fault---Air New Zealand flight management was.
I flew on after leaving Air NZ, working in Europe, Ireland NZ and self employed,.
I make the unreserved statement that.
In all my working life, Air New Zealand LTd stand head and shoulders above the rest as being the WORST employer I ever worked for.

Now go back and look again at the Mahone report, Impact Erebus, and other publications on that accident and the route cause is obvious.

GR

[prospector]

" Now go back and look again at the Mahone report, Impact Erebus, and other publications on that accident and the route cause is obvious."

Yes, the cause certainly is obvious.

Mahons publication,containing what one would expect it to contain, is actually titled "Verdict on Erebus".

Gordon Vettes publication is entitled "Impact Erebus"

There are many other publications and reports on this accident, many by Pilots with many years of experience in airline flying, and very few of them agree with Mahons findings, which is not suprising as he had absolutely no aviation experience or expertise.

His findings were admittedly of value in the aftermath of the accident, the political sheenanigans, the shortcomings of some of Air New Zealand's operational staff, but his knowledge of cockpit behaviour in large, or for that matter, any aircraft, as he accused the Chief Accident inspector of, was non existant.

All this happened after the accident, if the mandatory descent requirements were adhered to, even one of them, then the accident would not have happened.

[Fantome]

There you have it . . . . same again for the second course. . . . two diametrically opposed opinions . . . one from seemingly a lounge chair expert, (apologies, if this is insulting to an expert witness), and one from a former Air NZ skipper, possibly jaundiced by clashes with management. Over and over, there have been a steam of often predictable, unreconcilable opinions, bruited back and forth, a great many of them resistant to substantiation.

The precise origins of the campaign to maintain and never let up on the vilification of Jim Collins are not particularly obvious. My suspicion is that the Ron Chippendale camp would not in a million years be able, or want to be able, to take a broad and reasoned view, subjecting every scintilla of evidence to dispassionate review. Those who claim this has been done and that such would be an exercise in futility are wrong. . . . more than wrong . . . they are as deluded as the world's most benighted ostrich.

[prospector]

"The precise origins of the campaign to maintain and never let up on the vilification of Jim Collins are not particularly obvious."

Come now, lets try and stick to fact. Nobody started the ball rolling (again) on this subject to vilify Jim Collins, Paul Holmes started it to vilify Ron Chippendale.

If you wish to refer to "lounge chair experts", how about starting with that person??

[chris lz]

A key question for me has not been resolved to my complete satisfaction. I'm hoping someone here can answer it, as I am not a pilot. I believe absolute key to Vette's position is his view that INS is as reliable as ground based aides. Is (or was) this justified, given the conditions at the time? I know some have answered "yes," and others "no." If the answer is "no," then why not? My common sense speculation has been that INS is less reliable for precisely the kind of mistake that was actually made in the last minute change of coordinates.

Thanks


[edit: changed "unreliable" to "less reliable"]

[wiggy]

chris

An INS is telling you where it "thinks" you are because it knows where you started off ( that's if you aligned it properly) and has integrated every single acceleration you've made since brake release.
Any error in the above processes, (e.g. in measuring the accelerations) will result in a mismatch between where the INS "thinks" you are and where you really are in the world.

It was not unknown, in the days of flying around with a single 1960s build INS to see mismatches of tens of miles between the calculated position and your real position...the modern kit is much better, a good ADIRU or IRS position might only be adrift by a couple of miles after a long flight. Even so if you let down on raw INS alone (highly unusual these days of GPS but....) you are letting down on a "theoretical" position. FWIW some companies (most?all?) forbid letting down on the basis of a raw INS position, so I guess you can draw your own conclusion..

ALL IMHO as an end user, not as a INS techie.

[DozyWannabe]

Having been hooked on the subject since I saw the TVNZ docudrama on the BBC when I was off sick from school in 1990 (and in fact managed to stretch out my infirmity by an extra day so I could see the final part), as an outside observer there were several forces at play in the aftermath of the accident.

Chippindale was an old-school "by-the-book" pilot of military extraction and post-WWII vintage, and everything he said indicates it was inconceivable to him that anyone other than the Captain should take responsibility for a crash that was caused by anything other than mechanical failure or extreme weather. By all accounts a great pilot and a good man, even if you disagree with his conclusions he should not be vilified for them. His occasionally slightly exotic interpretations of what was said on the CVR are not so easy to defend, but I suspect he genuinely believed that he was right. I wonder if the "handwritten" transcript that bbg's original post refers to might have been his - I distinctly remember that the controversial phrase "Bit thick here, eh Bert?"* was handwritten over the top of the NTSB's "indecipherable" marks at that particular timestamp. The problem with Chippindale's approach is that he was not a line pilot at the time, and he had no reason to believe that ANZ's corporate culture was any less stringent than the military culture he knew well. While later in life he acknowledged that the rules governing the sightseeing flights had not been followed in the past, he seemed to consider those incidents at the discretion of the pilots involved, and looking deeper into it was not warranted.

From what I've read and conversations I've had, in the cut-throat world of aviation in the '70s the truth was that rules were being bent, if not outright ignored, almost routinely. Most of the Kiwis I've spoken to over the years have advanced the opinion that Muldoon was running the country like his own personal fiefdom even as it increased in stature over the years, and as far as he was concerned his mate Morrie [Davis, then-CEO of ANZ] was still the man to run the national flag carrier, having seen it grow from a small operation in the Tasman days to the multi-million dollar operation it had become by the late '70s. A lot of ANZ's pioneer spirit was admirable on the surface, and indeed they followed through on the Antarctic flights to start with - rules were put in place, including the one Chippindale referred to regarding minimum altitudes, and no-one was allowed to command an Antarctic sightseeing flight until they had first been down there for familiarisation. These rules stayed in place for some time, but something went awry between that time and the Collins flight, and an "all mates together" attitude from the top down was not sufficient to stop it happening.

To begin with, the requirement for any commander of an Antarctic flight to first be taken on a familiarisation trip was dropped, whether because of the human tendency to grow complacent as new ventures become routine or more controversially, commercial pressure (ANZ pioneered Antarctic flights, but the larger Australian airlines were beginning to offer similar packages) we can only speculate. The fact remains that even by the '70s, Antarctica was still a risky proposition in aviation terms - sector whiteout was known about, but something rarely experienced on the line and the haste with which aviation in Antarctica went from being something that involved small aircraft loaded with survival gear to fully-laden widebodies with full onboard service and passengers in mufti definitely began to look foolhardy with 20/20 hindsight.

The breakdown in communication between ANZ's Navigation section and flight operations was also something that should not have been tolerated. A culture that allowed the Chief Navigator to make a mistake when programming the navigation computer because he did not perform the third "re-check" of his data is bad enough, but to compound that mistake by correcting it the night before the next flight was due to leave and *not informing operations that he had done so* quite rightly beggars belief, and Mahon was absolutely right to censure both the Chief Navigator and the company that allowed him to do so.

The fallout following the Mahon report is legendary, and the subsequent finding that he had overstepped his bounds - not by explicitly stating his belief that he had been lied to, but by saying that the lies were orchestrated from the top down - was later spun by Muldoon as an exoneration of ANZ and Morrie Davis (which it clearly wasn't). The tragedy there was that the careers of both Mahon and Davis - both pioneers in their field and very capable men - never recovered from these events.

Whether one subscribes to Chippindale's or Mahon's interpretation of the accident (or indeed weigh up the pros and cons of both), the fact remains that ANZ's corporate culture (and aviation safety knowledge globally) received a much-needed overhaul because of the information that Mahon brought to light, and for that the man deserves to be applauded.


* - When Mahon went to Washington with the CVR tapes, an equally credible alternative was "This is Cape Bird", which would completely reverse the conclusions Chippindale drew - but ultimately the equipment was not able at that time to make it any more clear. I wonder what modern audio technology would make of it?

[chris lz]

"This is Cape Bird" I assume was made after the aircraft had descended below 6,000 ft?

My question is, was it safe to rely on INS for this very descent? The view has been expressed that Collins and his crew should have positively identified the terrain before descending, or else wait for corroboration from ground instruments. That's the piece I'm trying to get a definitive answer on.

[Biggles78]

The arguments will continue, but in my book the crew were in error. If they were in true "visual" conditions they should have seen the dangers; it's no good arguing about waypoints being moved. They were ultimately responsible for the safety of the aeroplane and it went pear-shaped. Sorry if that upsets anyone... 30+ years later I still get the shivers thinking about it.
I agreed the same at the time, during the Royal Commission and still now. At that time the 1953 Civil Aviation Regulations, Reg 51 stated "The Pilot in Command is responsible for the safety of the passangers, crew and aircraft". Collins was the Pilot in Command and the majority of the blame rests on his shoulders irrespective of the orchistrated litiney of lies by ANZ, it was HIS responsibility to check the waypoints that were input into the INS.

HD, I share your shivers. I was a PPL at that time waiting at NZCH for the DC10 to land and refuel before heading back to Auckland. It was a long cold night and it didn't take long before we worked out it had exceeded it's flight time and had run out of go-juice.

Collins has to share the majority of the blame but that doesn't say other may have been blameless. Again it is a case of the swiss cheese syndrome; take away one factor and it may never have happened. I remember a C130 flew the same route but 500 fet higher and it cleared the summit. How many seconds earlier if TOGA had been applied would we now not be discussing this issue. It was a sad day for the whole country. What followed was also no better.

I would also like to make it very clear that I in no way am trying to impeach the integrity of Captain Vette and his role in the subsequent Commission. I met him briefly (picked up the Tech Crew when I was driving taxis while saving for my C Cat) and from discussions with ANZ flight crew who knew him, he was a man of honour and intergrity. I believe he was protecting/defending his pilots from the ANZ management skulduggery that took place after the event. Captain Collins was responsible for checking the Flight Plan and using an old school atlas was really not the way to do that. That was not a professional at work on this ocassion and added to the swiss cheese slices.

Mahon uncovered the ANZ management involvement and the attempted coverup or at least the distortion of events and the political involvement. However he failed to take into account Reg 51 and the responsibility of the PinC in this Regulation.

This tragedy was a long time ago. Lessons were learned from this (like they are from every accident). I hope AF447 and other tragic incidents are not going to suffer the same repeated regurgitation that TE901 is being put through.

[DozyWannabe]

"This is Cape Bird" I assume was made after the aircraft had descended below 6,000 ft?

Yes, it was during the "below cloud" phase of the flight - shortly before the crash. Crucially, if "This is Cape Bird" was what was said, it gives the lie to Chippindale and Thompson's assertions that the crew were not checking their progress against a map and contradicts Chippindale's belief that they were in cloud.

My question is, was it safe to rely on INS for this very descent? The view has been expressed that Collins and his crew should have positively identified the terrain before descending, or else wait for corroboration from ground instruments. That's the piece I'm trying to get a definitive answer on.

It was safe as long as the aircraft was following Chief Navigator Hewitt's "erroneous" co-ordinates, which were actually safer than the original path he plotted to the TACAN south of Ross Island. It was ANZ's practice to brief the next two Antarctic crews in advance, meaning that a period of time of four weeks would elapse before the second crew made the flight they were being briefed on. Captain Collins and Captain Simpson's crews attended the same briefing, and both received the same briefing materials which showed the route down McMurdo Sound - not just the publicity material, but a photocopied chart based on data from the navigation computer ostensibly from the navigation section. However, Hewitt testified that he had never seen that chart prior to the inquiry. On his flight, Simpson noticed that there was a discrepancy of 26 miles between where the McMurdo co-ordinates were plotted and where he could clearly see the station to the east and duly reported this to the nav section. Hewitt claimed that he believed he was correcting a .2 degree error, from the McMurdo NDB co-ordinates themselves to the TACAN as originally specified when the Antarctic flights began, but he failed to take into account his original typing error, turning a 2 mile discrepancy into a 26-mile discrepancy.

The chart showing the route down McMurdo Sound, and the INS co-ordinates following that route had by this time been in the system for a year - all the line pilots flying to Antarctica believed that the route change was deliberate, and that henceforth they would be flying down McMurdo Sound. All the evidence indicates that Collins' briefing materials showed the same thing (although ANZ's later conduct made sure that it could never be proven conclusively). If Hewitt had spotted the magnitude of his error and informed ops, the crash wouldn't have happened - in fact the flight probably would have been postponed while they sorted the error out. Likewise, if Hewitt had waited until after the Collins flight to make the correction, the next briefings would have been done with the new material and it's possible no-one would have been the wiser.

As for the conditions at the time, a lot of myth has grown up around that over the years - Chippindale went to his grave believing they were in cloud at the time, even though the photos recovered show visibility of 40 miles plus right up until the point of impact. But as Captain Vette's research showed, there was more to it than that.

At that time the 1953 Civil Aviation Regulations, Reg 51 stated "The Pilot in Command is responsible for the safety of the passangers, crew and aircraft".

Ah, but in 1953 it was technically impossible to send a jet full of people to Antarctica and back, and here we get back to an age-old problem of the reality on the ground overtaking the regulations. In 1953 (and for a decade to come or more), any Empire or Commonwealth operation would be carrying a full-time navigator on board and they'd be plotting the routes manually against charts every step of the way, informing the PIC if there were any changes. By 1979, nav section were desk jockeys working at computer terminals.

Collins was the Pilot in Command and the majority of the blame rests on his shoulders irrespective of the orchistrated litiney of lies by ANZ, it was HIS responsibility to check the waypoints that were input into the INS.

...

Captain Collins was responsible for checking the Flight Plan and using an old school atlas was really not the way to do that. That was not a professional at work on this ocassion and added to the swiss cheese slices.

All evidence suggests that he was not using the atlas for his primary route planning - he had the McMurdo route ostensibly given to him by nav section in his briefing materials along with a black-and-white photocopy of the chart. It looks like the purpose the atlas served was to cross-check the co-ordinates he was given at the briefing, and if he'd been informed that the co-ordinates had changed even slightly the following morning, there's no reason to suggest he wouldn't have checked them for a fourth time and discovered the error - in fact Captain Vette seems certain that he would have, having known him for two decades or more.

TVNZ's "Erebus : The Aftermath" docudrama has been removed from YouTube, which is a shame. However, NZALPA recently uploaded Captain Vette's "Impact Erebus" documentary in it's entirety - it goes even further than the Mahon report in places in terms of demonstrating the false visual perceptions, and mentions a couple of factors that the docudrama did not, which I consider very important - namely:


The transponder indicator light on the flight deck indicated coding during the descent and approach to Erebus, giving the crew the impression that McMurdo were tracking them on radar and had them in the right position.
The flight plan filed with McMurdo had the co-ordinates for the McMurdo waypoint removed and replaced with the term "MCMURDO" - the only time this had happened in the entire time ANZ had been flying down there.


It also says that the briefing on whiteout given to all ANZ crews was inappropriate for aviation, instead being based on the effects of what are commonly known as snowblindness - the dangers of a low overcast obscuring high ground and possibly (although Mahon was not convinced) presenting a false horizon were never covered - this was Mahon's "malevolent trick of the polar light".

Part one is here:

Impact Erebus Part 1 - YouTube

To answer the question chris_lz is asking regarding "positively identif[ying] terrain", a combination of the features of McMurdo Sound versus Lewis Bay shows that it would indeed be easy to mistake one for the other were Erebus to be obscured. Cape Tennyson is approximately the same distance and azimuth from the track over Erebus as Cape Bird is from the track down McMurdo Sound. The cliffs to the west of McMurdo Sound (Cape Bernacchi) are three times further from the McMurdo track than Cape Bird is from the Erebus track. However, in a coincidence that demonstrated just how much the crew had going against them that day, the Cape Bernacchi cliffs are approximately three times larger than those of Cape Bird, meaning that they would appear from the flight deck to be much the same - certainly Peter Mulgrew never seemed to notice, so what chance did Captain Collins have?

Much seems to be made of Captain Vette's motivation to clear his friend's name, but he himself says that was only a minor part of it - what bothered him was that as far as he was concerned Captain Collins was probably the most cautious and conscientious pilot he knew, and he reasoned that whatever had happened in Antarctica to allow Jim Collins to fly into a mountain, given the kind of pilot Collins was - Vette didn't think much of anyone's chances, including his own, if faced with that kind of situation.

[chris lz]

DozyWannabe (http://www.pprune.org/members/54871-dozywannabe) :

It was safe as long as the aircraft was following Chief Navigator Hewitt's "erroneous" co-ordinates, which were actually safer than the original path he plotted to the TACAN south of Ross Island.

But in a sense, isn't that precisely why INS is not as reliable as ground aides? They can be inadvertently misprogrammed. The crew themselves can mistakenly punch in a wrong coordinate. If you've never been to destination before, wouldn't it also be prudent to check the programmed coordinates you've just entered and make sure they match the actual coordinates for the McMurdo Sound route?

I'm aware the Lewis Bay track and the expected route down McMurdo Sound would have appeared similar. But before the letdown commenced, could the crew really be 100% certain of their position by visual means alone?

Thanks

Chris

[DozyWannabe]

But in a sense, isn't that precisely why INS is not as reliable as ground aides? They can be inadvertently misprogrammed. The crew themselves can mistakenly punch in a wrong coordinate. If you've never been to destination before, wouldn't it also be prudent to check the programmed coordinates you've just entered and make sure they match the actual coordinates for the McMurdo Sound route?

This is where things get murky, thanks to the actions of certain contemporary ANZ management people and the US radar station staff. If Collins was true to form he would have checked and re-checked the co-ordinates on his ops sheet against what was in the AINS system before takeoff and found no discrepancy. The rest of the story would be found in his little A6 ring binder. This was recovered from the site by police and sealed in an evidence bag by Inspector Gilpin, noting that it contained "numerous pages of legible technical writing and figures that indicated they related to the flying of aircraft. We recognised that this could be of importance to any investigation into the crash, and I sealed and secured it in a bag before it was returned to McMurdo". The NZCAA officials were not there yet, so it wound up in the hands of Chief Pilot Gemmell, and was never seen again in its intact state publicly, instead turning up at the 1981 inquiry with all its pages removed.

True to his meticulous nature, Collins performed all the cross-checking at home the previous night, which can only lead to the conclusion that contained in that book was proof that he was certain they were going down McMurdo Sound and not over Erebus. This would have rendered ANZ's case at the inquiry null and void, because it relied entirely on the idea that the nav track had *always* run over Erebus, and it was the McMurdo track that was an aberration. Hewitt's navigation change was input to the computer at approximately 1:40AM the morning of the flight, and nobody told Collins or any of his crew. At his preflight briefing he had every right to believe that the co-ordinates he had fastidiously plotted before retiring the night before and the ones he now held in his hand, and would later cross-check as he input the co-ordinates into AIMS, were one and the same.


I'm aware the Lewis Bay track and the expected route down McMurdo Sound would have appeared similar. But before the letdown commenced, could the crew really be 100% certain of their position by visual means alone?

Up until the crash flight, it was all they had. The southernmost waypoint in all previous INS-navigated Antarctic flights was to a point just west of the Dailey Islands and had no navaid (because it was, as it turns out, a typo rather than an actual fix), and the NDB at McMurdo, which was the secondary navaid fix, had been withdrawn in 1978. And forget "similar" - unless you were intimately familiar with the area, in certain conditions they would have appeared nigh-on identical. Prospector likes to talk about Beaufort Island being on the wrong side, but looking at the let-down tracks, it's possible they would have emerged from cloud south of the island - photos exist of the island taken from within the passenger cabin, but there is no proof that it would have been visible from the flight deck. In any case they were taking a visual fix from Cape Tennyson, thinking it was Cape Royds, and Cape Bird, thinking it was Cape Bernacchi.

Hewitt selected the new navaid fix in 1978, which would be the TACAN south of Ross Island, but because of the typo, none of the crews ever knew that was the intent - they simply entered the co-ordinates and assumed that the new route was designed to follow the military track. To my mind it looks like Hewitt simply entered the co-ordinates into the computer from his data sheet - did not re-check them against a map as he was entering them, and forgot about it entirely until Captain Simpson reported the 26 mile discrepancy three weeks before the Collins flight. After making the correction, Hewitt made no attempt to contact the computer section to confirm that it had been updated, and likewise the computer section did not confirm with nav section that the work had been done. Again, to my mind very unprofessional behaviour.

The only major concern from the confirmed voices on the CVR seems to be that Mac Central was out of radio contact in the last few minutes of the flight - however the transponder was coding, indicating that the crew believed that they were being tracked on radar. The radar tapes that covered the last four minutes and change leading up to the crash had been erased, and Mahon got a very frosty reception from the US base when he visited and made it known he was aware of this.

I want to make it clear that even though I think Vette and Mahon's investigations were more in-depth and the conclusions more correct than those of Chippindale, this does not invalidate entirely the work that Chippindale did, and I don't think he was any less than scrupulously honest about what he believed. The problem as I see it is that the information Chippindale had to work from was tightly controlled by ANZ, and that most of what he had to work with was only the material that ANZ wanted him to see. The only major fault I see in Chippindale's methodology was inviting Captain Gemmell to participate in his re-write of the CVR transcript, and indeed, revising the content of the CVR transcript from what was agreed in Washington in the first place. I'm sure that had he known that Captains Gemmell and Crosby were engaged in the obtaining and destruction of evidence from Collins' and Cassin's files - even clearing material from their homes without the knowledge or permission of their families, he would not have been so sanguine about their involvement in his investigation.

[IGh]

From Dozy, just above, commenting on the INVESTIGATION PROCESS:"... I think Vette and Mahon's investigations were more in-depth and the conclusions more correct than those of Chippindale ... scrupulously honest ... The problem ... the information Chippindale had ... was tightly controlled by ANZ ... was only the material that ANZ wanted him to see. The only major fault I see in Chippindale's methodology was inviting Captain Gemmell to participate..."
Dozy -- NICE, there should be a forum for such critique of the mishap-"investigator", constructive additions to too-limited investigations. [Maybe I'll go back over the years and tack these investigator-errs into an organized compilation: investigating-the-investigator, or expanding the focus of an investigation.]

This mishap- INVESTIGATION(s) [NZCAA & Royal Commission's] turned out much better than some others of that same year 1979: The Royal Commission PROCESS seems much better than the UNCHALLENGED product from the USA-system, where the USA's NTSB is legally the SOLE judge of their past investigative-product (never any critical oversight from any Royal Commission).

The NTSB might consider a PETITION from the French BEA (eg, ATR72 at Roselawn), but will mostly ignore any domestic-petition that contradicts the USA's big manufacturer (eg, the NTSB's endorsement of the "Boeing Scenario" in AAR81-8 while the direct evidence and the surviving crew told the Board otherwise). Boeing created data, analysis, simulator-runs, insisting that the NTSB agree that the direct evidence ranked lower than Boeing's created "evidence". [That investigation described in AAR81-8 was the longest most expensive investigation in the then history of the NTSB, & the B727 was then the best selling product of the USA's biggest exporter.] http://www.pprune.org/safety-crm-qa-emergency-response-planning/372186-your-opinion-old-controversial-accident.html

Dozy -- thanks for those comments on the investigative-process: the USA's "independent" Safety Board concept, over the past forty years, seems mostly to produce an "investigative product" of lesser quality. Where as the public's option of the NZ- Royal Commission might force the investigator [NZCAA] toward a more complete, better quality product; & reduce subtle bias in evidence-rejection (eg, Chippendale's exclusion of Vette's HF-components).

[chris lz]

Wiggy:


Any error in the above processes, (e.g. in measuring the accelerations) will result in a mismatch between where the INS "thinks" you are and where you really are in the world.




In practical terms, in 1979 on a DC-10, is it reasonable then to suppose that this type of error was far more likely than a failure of a ground based navigation aide? I'm thinking the answer is "yes." But then I have heard from one pilot that AINS is "much more accurate" than what a typical ground based aide would predict for a plane's exact position. Maybe this is true also?

[DozyWannabe]

In practical terms, in 1979 on a DC-10, is it reasonable then to suppose that this type of error was far more likely than a failure of a ground based navigation aide? I'm thinking the answer is "yes." But then I have heard from one pilot that AINS is "much more accurate" than what a typical ground based aide would predict for a plane's exact position. Maybe this is true also?

The problem as this applies to the Erebus crash is that on each Antarctic flight using it the AINS had been completely accurate every single time. The reason ANZ tried so hard to muddy the waters was because their navigation section had mis-keyed the fix in the first place and left it that way for over a year, even to the extent that the charts presented to the pilots at briefing showed the "incorrect" route - this left them vulnerable to accusations of incompetence in the first instance. Correcting the route to the TACAN in the middle of the night without notifying the crew who had been briefed on the previous route and were due to leave in the morning could, in the hands of a lawyer, open them to accusations of gross negligence in trying to cover up their earlier incompetence - hence the all-out effort to destroy all evidence that showed the McMurdo Sound track had been the accepted route for a year.

Regarding ground navaids, the McMurdo NDB had been gone since 1978 - all there was in the area was the TACAN, which - while it had been the intended waypoint as far as nav section's seniors were concerned since the NDB was decommissioned - was never on the route supplied to the pilots between 1978 and 1979, nor was it's existence briefed. If crews had known about it, the only purpose it could serve would be to provide a fix after they had made the left turn south of Ross Island, because to use it as a direct fix during their south-westerly track would have taken them straight over, or indeed into the side of, Erebus - which at low level would have been a major safety hazard, and at high level would have contradicted the whole purpose of the flight, which was sightseeing.

@IGh - Ironically it was the global response to the Mahon report that made accident investigation what it is today. I disagree that the NTSB's independence harms the quality of it's output, however, and I know the "'Hoot' Gibson" incident, of which you are talking, fairly well. It wasn't just Boeing who advanced that particular theory though, the truth is that a lot of line pilots knew about the use of CB's to pop the slats in cruise - my suspicion is that the NTSB and the FAA had been looking for an opportunity to end the practice for a long time and for better or worse used that incident to do so. To discuss it further here would be taking the thread off-topic however.

[henry crun]

DozyWannabe: Referring to the Tacan you said "the only purpose it could serve would be to provide a fix after they had made the left turn south of Ross Island".

My understanding was that civil aircraft could interrogate the DME part of Tacan but not the direction indicating part.

If I am correct they could not have obtained a fix from it.

[IGh]

DozyW -- re'your's on that 1979 B727 case "... line pilots knew about the use of CB's to pop the slats in cruise ... the NTSB and the FAA ... looking for an opportunity to end the practice..."

From inside, there never were any B727pilots who had done that "pop the slats" at Crz FL390: On Oct'2 1980, in Seattle, aboard the company's ship E209, TBC did the purported C/B drill -- it didn't work; TBC tried various methods, using various Circuit Breakers, eventually finding other combinations of C/Bs. Similarly, at the operator TWA, no pilots had done it -- never heard of it (but those second-hand rumors live-on). The IIC [Dean Kampshore] admitted this later, during deposition.

Re' INS into McMurdo, I had flown into McMurdo the during the Oct'78 re-supply, landing on the "ice". Just as we had done, ANZ also forced their INS's into "Grid" mode while south of 60S. These ANZ-guys had been given some extra training on INS & its weaknesses [the err-rate curve after 5-hours shoots up exponentially].

Re' the NDB, MacJob's _AD_ [Vol2, pg73, mid], contrary to the ANZ briefing, the McMurdo NDB was actually still operative during Nov'79 mishap.

[DozyWannabe]

Re' the NDB, MacJob's _AD_ [Vol2, pg73, mid], contrary to the ANZ briefing, the McMurdo NDB was actually still operative during Nov'79 mishap.

That's interesting. I wonder why they'd have told ANZ that it had been withdrawn - although it might be that it had been officially withdrawn while still technically operative. I read that the US base weren't particularly happy about the sightseeing flights.

[Tagron]

Chris lz

The accuracy of a triple-INS installation may be very good, but it is not perfect. Over the course of a six-hour flight it would not be unusual to see an error in the region of 1 - 3 nautical miles, and greater on exceptional occasions. The error is likely to be cumulative, i.e. the longer the flight the larger the error. It can only be identified by comparison with a known fix point, so poor fixing performance (as opposed to a system malfunction) may not be immediately apparent to the crew. For these reasons Flight Management Systems navigational computations used radio navaid fixing, principally DME/DME, to update the INS-generated position.

In the case of the Antarctic flight no such updating would have been available, so the crew were relying on raw INS data.. For the en route navigation this would have been entirely satisfactory - the ANZ experience of operating DC10s over the Pacific and North Atlantic would have told them that. As wiggy has suggested most if not all companies would prohibit descent below MSA based solely on INS position, for the above reasons plus the risk of inaccurate data entry. But that is for a descent in IMC.

The principal requirement for a VMC descent below MSA is that safe terrain clearance must be maintained by visual means throughout the descent. Provided that requirement is met then there can be no objection to the use of INS. Whether to fly the direct INS track or to use the INS data to assist situational awareness while following a different track would depend on the circumstances at the time. Note these are general comments about VMC descents as I do not know how the requirements were specified in the ANZ SOPs of the time.

The visual misidentification was a fatal error. That was an opportunity to verify INS accuracy beyond doubt. Had the visual position been correctly identified the crew would surely have realised there was something seriously amiss with their INS position and maintained altitude to await a corroborative fix. As it was, confirmation bias seemed to set in. The INS could not be so wrong. A 27 nm error in their INS performance was quite contrary to their experience

henry crun

I agree with you. To the best of my knowledge civilian aircraft can only use the DME function of TACAN, not the bearing information.

[chris lz]

Tagron:


The principal requirement for a VMC descent below MSA is that safe terrain clearance must be maintained by visual means throughout the descent.


But isn't it also a basic requirement than in VMC, a visual letdown below MSA first requires a positive visual confirmation of one's exact position? I was under the impression the crew was only able to form a visual confirmation (in their minds at least) after they had descended below the cloud layer and could see the terrain to the left of their track, most of which (including Erebus) was not visible at 16,000 ft. (My memory could be wrong here.)

[DozyWannabe]

The visual misidentification was a fatal error. That was an opportunity to verify INS accuracy beyond doubt. Had the visual position been correctly identified the crew would surely have realised there was something seriously amiss with their INS position and maintained altitude to await a corroborative fix. As it was, confirmation bias seemed to set in. The INS could not be so wrong. A 27 nm error in their INS performance was quite contrary to their experience.

Regarding visual misidentification - I highly recommend watching the complete "Impact Erebus" video if you have not already seen it, as it demonstrates the optical illusions involved in a very useful and understandable way. The phenomenon of whiteout as it was briefed to the ANZ pilots was actually the wrong kind of whiteout - the type caused by refractions from powdery snow low to the ground, as opposed to the type which trapped Captain Collins and his crew, which can affect almost any altitude below overcast cloud. It was an error, no question about it, but it was an error capable of affecting even pilots who know the area well - with the fog bank (well below them) obscuring the end of the bay and the foot of Erebus, the only visible difference between the cliffs of Lewis Bay and those of McMurdo Sound would be the way the cliffs in the latter fan out in the distance - at 1,500ft that would have been extremely difficult to spot.

But isn't it also a basic requirement than in VMC, a visual letdown below MSA first requires a positive visual confirmation of one's exact position? I was under the impression the crew was only able to form a visual confirmation (in their minds at least) after they had descended below the cloud layer and could see the terrain to the left of their track, most of which (including Erebus) was not visible at 16,000 ft. (My memory could be wrong here.)

The full overcast affected only the immediate area of Ross Island itself. North of Ross Island, the cloud was patchy and there were more than enough gaps to make a visual let-down viable (as you can see from the passenger photos). The problem was not that the crew could only form visual confirmation once under the cloud at the point of let-down, it was that once down, Lewis Bay and McMurdo Sound were almost indistinguishable from one another from the point-of-view of the flight deck in the conditions they encountered. Once they had reached the level Mac Central had invited them to descend to, the only clue that something was wrong was that they could no longer communicate with Mac Central via radio.

The question that bothers me is that if the radar let-down was completely above board from Mac Central's end, why did they erase the radar tapes?

[chris lz]

The full overcast affected only the immediate area of Ross Island itself. North of Ross Island, the cloud was patchy and there were more than enough gaps to make a visual let-down viable. . .


But again, while in VMC, isn't confirmation of position required before one passes below MSA?

[henry crun]

After reading Mahon's book I got the strong impression he believed that because the DC10 was within the theoretical coverage of McMurdo radar it would have been displayed.

Did anyone else feel the same way ?

[DozyWannabe]

The reason they thought they were being tracked on radar was because the transponder was coding at the time.

@chris lz - I'll have to defer on that one, but Vette and Mahon both concluded that no rules were broken as far as the crew were concerned.

[Dream Land]

Leave the tours, to tour pilots!

[stepwilk]

To the best of my knowledge civilian aircraft can only use the DME function of TACAN, not the bearing information.

Aren't TACANs typically co-located with VORs?

[DozyWannabe]

Leave the tours, to tour pilots!

Well, as I said in my earlier post, when ANZ started the Antarctic flights they did their homework - researched the limits of INS (as IGh says, enforcing GRID mode) - which is partially why the course was manually navigated until 1978, and included in the protocol two directives - that each flight should carry two Captains, a First Officer and two Flight Engineers, and that in order to command an Antarctic flight, a prior familiarisation trip was mandatory. Between 1977 and 1979 both those directives were dropped, in favour of a Captain, two F/Os and two F/Es, and losing the familiarisation requirement. Whether this was down to the flights becoming routine, cost-cutting or other factors will never be known. I have my suspicions however - at the time ANZ appeared to be a successful multi-million dollar flag carrier, but under the surface it was almost entirely reliant on government subsidy following the National acquisition. Qantas was about to start offering their own Antarctic flights, which would have eaten into ANZ's market share considerably.

Aren't TACANs typically co-located with VORs?

Typically? If you say so. In the vicinity of the southernmost active volcano in the world? It certainly doesn't look like it at the time. Remember that the only flights down there prior to the mid-70s were military flights supplying McMurdo and Scott Base.

[Dream Land]

Well I think it's a very complicated accident, I don't want to criticize anyone based on my YouTube knowledge of the accident, but with my knowledge of scud running, Alaska and the Grand Canyon, I am well aware of what it involves.

Anytime a pilot drops through a hole and descends to 1500 foot above the ground, should know exactly what he's doing, doesn't matter whether it's a Cessna 206 or a DC-10. And seeing lights on your transponder blinking shouldn't lead anyone to assume they are within radar control, especially an experienced aviator. Tragic.

[DozyWannabe]

Anytime a pilot drops through a hole and descends to 1500 foot above the ground, should know exactly what he's doing, doesn't matter whether it's a Cessna 206 or a DC-10.

That would appear to be the crux of the problem in that they thought they did, thanks to a combination of the INS programming not matching their briefing, and weather conditions that were little-understood at the time making where they were headed look to all intents and purposes identical to where they thought they were headed.

And seeing lights on your transponder blinking shouldn't lead anyone to assume they are within radar control, especially an experienced aviator. Tragic.

It was the blinking transponder in combination with the invitation to descend which gave them that impression. Again, if Mac Central didn't make a c*ck-up, why erase the tapes?

[chris lz]

all intents and purposes identical to where they thought they were headed


That's what Vette claims in his book, but I am not necessarily convinced. They see land where they expect to see land, according to Vette, and that in his mind translates to a "positive fix."

Consider some interesting comments from the crew which I would guess you have already read:

Mulgrew to passengers 4 min before impact: "I still can't see very much at the moment. I'll keep you informed as soon as I can see something that gives me a clue to where we are [emphasis added]."

FE 3 min before impact "Where's Erebus in relation to us at the moment?"

Mulgrew 3 min before impact: "Yes- - - no, no, I really don't know." [(this is not a response to the FE's question quoted above)].

Mulgrew 1 min 40 sec before impact "I reckon Bird's through here and Ross Island there. Erebus should be here."

Mulgrew 50 sec before impact "Looks like the edge of Ross Island there."

These remarks no doubt are subject to a wide degree of interpretation, and I would agree with Vette none of them shows anything so blatant as that the crew feels lost or confused. But I can't help thinking they don't convey the sense of "positive fixes" either. Vette calls the view from the aircraft cockpit a "visual counterfeit" of the McMurdo Sound track. But how much so? I would think that any track where there is terrain to your left and to your right would have more than a minute posibility of being taken by a flight crew for what they think should be there. Vette describes walls of clouds rising above them on either side, and clouds and fog below them, obscuring much of the landscape. Given this, I'm wondering if "doesn't contradict what they expect to see" is really the equivalent of a positive identification.

[IGh]

Observation from several slots earlier, re' ANZ's perception:"... they thought they were being tracked on radar was because the transponder was coding at the time...."
The crews flying into McMurdo (annual resupply) were TRAINED to mostly disregard any position information offered by the local Navy-guys staffing McMurdo_radar. Also, due to repeated arrival-CFIT mishaps [turbojets while in radar-contact] during the mid-1970's, the TERRAIN-threat was a BIG training-lesson for any crew flying with a North American operator. An old-fashioned Pro-Navigator was aboard each heavy-jet landing at McMurdo, charts-out, constant challenging of any position-fix [mostly disregarding any info' from McMurdo-radar].

I recall flying downwind at McMurdo, with the ICE Rwy insight, and the only visual "horizon" were those ICE-CLIFFs at some un- certain distance, with the higher terrain obscured by low cloud.

[DozyWannabe]

Vette describes walls of clouds rising above them on either side

Does he? I'll admit to not having seen that. It certainly doesn't correlate with his submissions to the inquiry. There was an overcast around Ross Island above them and a fog bank at the base of Erebus (which under most conditions would have been further out into the bay). The let-down was performed in the patchy cloud north of Ross Island.

Vette calls the view from the aircraft cockpit a "visual counterfeit" of the McMurdo Sound track. But how much so? I would think that any track where there is terrain to your left and to your right would have more than a minute posibility of being taken by a flight crew for what they think should be there.

Vette's submissions are here:

http://www.erebus.co.nz/Portals/4/Documents/Reports/Mahon/Whiteout%20Phenomenon.pdf#page=7

Lewis Bay on the left, McMurdo Sound on the right. Top images show how they would appear on a clear day, middle images with some overcast and the lower images with sector whiteout due to the weather conditions as they were on the day.

Given this, I'm wondering if "doesn't contradict what they expect to see" is really the equivalent of a positive identification.

It was the best they had given the information supplied.

[HEATHROW DIRECTOR]

<<TRAINED to mostly disregard any position information offered by the local Navy-guys staffing McMurdo_radar>>

An interesting and remarkable statement. Why should the radar be unreliable or is it due to high ground and reduced low cover? Otherwise I'd take radar any day against a guy with a chinagraph and a spin wheel.

[IGh]

Comment just earlier -- "... interesting and remarkable statement. Why should the radar be unreliable..."

Skepticism --> Maybe not that the 'radar was unreliable.' -- Mostly I filed such cases under the label "CFIT", but many of these could be more accurately filed as "involving ATC-Crew mis-communication" [read the link at bottom for an exemplar of fatal mis-comm'].

At the time, when nearing McMurdo, check-in & other radio-comm, you quickly felt that things just weren't "normal": McMurdo local controllers weren't the same as at SFO nor Oakland-Oceanic (not FAA, not USAF, nor NZCAA).

But the big ARRIVAL-CFIT training lessons were unmistakable during the 1970's: since the advent of Enhanced-GPWS it might be difficult for todays' pilots & controllers to comprehend that we regularly drove big turbojets into small peaks WHILE IN RADAR CONTACT.

Those "fatals" led to repeated training-sessions for all pilots, and extra training for the annual DeepFreeze. For us, then, a big lesson was that TWA B727 that impacted that tiny hill while on arrival at Washington DC's Dullus Int'l / 1Dec74 (pilot hurrying to get below cloud while descending through a turbulent cloud-layer). Then, for those MAC-pilots, they had the recent lesson of a MAC-crew [with a senior- CHECKAIRMEN professional Navigator] impacting a peak in the Olympic range while descending into McChord (near Tacoma) / 20Mar75: HistoryLink.org- the Free Online Encyclopedia of Washington State History (http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=8562)

[India Four Two]

Aren't TACANs typically co-located with VORs?

stepwilk,

Typically (at least in the US), yes, but not all VORs are also TACANS. In your neck of the woods, the closest VOR/DME (TACAN sets can receive the DME range but no azimuth) is KINGSTON and the closest VORTAC is SPARTA (Azimuth and range for both VOR and TACAN receivers).

Stand-alone TACAN beacons are quite common at military airfields in the UK. In this case a civil aircraft can receive the DME range information only.