Cranbrook Heli Crash (2008) [Speculation & Commentary]

[Widow]

A new thread, to keep speculation and commentary away from those greiving.

From today's Globe and Mail:

CRANBROOK, B.C.: CRASH CAUSE OF FOUR DEATHS PROBED

Doomed copter was flying lower than allowed
'My first reaction is, what it's doing is illegal,' witness says. 'My second reaction was, the pilot's in trouble'
ROBERT MATAS AND ANNA MEHLER PAPERNY

May 15, 2008

VANCOUVER, CRANBROOK, B.C. -- The Bell helicopter that crashed Tuesday in a residential area of Cranbrook, killing four people, may have been flying lower than permitted under federal safety rules for several minutes before suddenly dropping to the ground.

Transport Canada regulations would have required the helicopter to remain 300 metres above the highest point in the residential area in which the helicopter was flying, Rod Nelson, a spokesman, said yesterday in an interview.

But witnesses to the crash say the helicopter appeared to be hovering at about 120 metres before suddenly falling from the sky, skidding for several metres and then bursting into flames.

Mr. Nelson said the flight could drop below 300 metres with special authorization. However, the helicopter, which B.C. Hydro had hired for routine surveying of power lines, was not required to fly lower than allowed under federal regulations, a B.C. Hydro spokesman said.

"There's no need for them to be close [to the ground] because they realize they're in a populated area," Ted Olynyk said. "There's no need for them to hover."

Cranbrook resident Norm Magee said he saw the helicopter circling a nearby Catholic church at about the height of a telephone pole. The helicopter dipped as if to land and then bobbed back up again. "My first reaction [when it was circling] is, what it's doing is illegal," he said. "My second reaction was, the pilot's in trouble."

The helicopter rose briefly "in a normal helicopter ascent," Mr. Magee said. He lost sight of the aircraft but then saw the helicopter whizzing past his car in a dive.

Then, shortly after 1 p.m., the helicopter fell from the sky. The pilot, Edward Heeb, 57, hydro power-line technicians Dirk Bentley Rozenboom 45, and Robert William Lehmann, 37, who were in the helicopter, and 23-year-old student Isaiah Otieno, who was crossing the street, died in the crash.

Yesterday, investigators began their exhaustive look into the cause of the accident, but with little more to work on than charred sections of the tail rotor. Much of the helicopter had gone up in flames.

Officials from Transport Canada and Bighorn Helicopter Inc. declined to comment on circumstances that may have contributed to the disaster. "I cannot comment on the accident itself at this point. It's all speculation," Mr. Nelson said. "We have no idea what caused this," Bighorn spokesman Murray Whyte said. "The regulations are followed to the letter."

So far, no one has pointed to anything that would require an immediate grounding of Bell 206B helicopters. However, Transport Canada will monitor the investigation "so we can take immediate safety action if necessary," Mr. Nelson said.

B.C. Hydro, however, was not waiting for the results of the investigation before responding. The public utility suspended its helicopter operations until further notice and announced a review of its process for selecting helicopter services.

The power-line technicians were beginning a check on transmission lines between Cranbrook and Moyie, about 30 kilometres to the southwest. The transmission lines throughout the hydro system are checked twice a year. Airborne crews look for broken or torn insulation.

Bighorn Helicopters, which has been used by B.C. Hydro for 10 years, has a valid air operating certificate. An audit of the company last November discovered no significant problems with operations or maintenance. Helicopters of a different model operated by the company were involved in non-fatal accidents in 1998 and 2002. Federal investigations did not identify any ongoing safety concerns, Mr. Nelson said.

The investigation into the cause of the accident will be conducted by the Transportation Safety Board of Canada. Bill Yearwood, the safety board's regional manager, cautioned against ascribing too much significance to whether or not the helicopter was flying lower than permitted by the regulations. Flying low may violate the rule, but that does not mean it caused the accident, he said.

He also said the helicopter had a reputation as being reliable and has been used around the world for several years. "It's been a workhorse for 40 years," he said. "The aircraft has proven itself."

I find Yearwoods comment interesting ... I can think of several cases where the presumption of an error (human/pilot) led to the construction of a theory around which investigations were based, instead of investigating for cause despite said presumption of error.

Do Heli's require a black box?

[Airtids]

Widow,

No black box required.

Heli's can and do operate at altitudes lower than the CARs in 604 prescribe, and are legal to do so under 702 aerial work.

Built-up Area and Aerial Work Zone

702.22 (1) For the purposes of subsection 602.13(1), a person may conduct a take-off, approach or landing in an aircraft within a built-up area of a city or town at a place other than an airport, heliport or a military aerodrome, if the person
(amended 2007/06/30; previous version)

(a) has an authorization from the Minister or is authorized to do so in an air operator certificate; and

(b) complies with the Commercial Air Service Standards.

(2) For the purposes of paragraph 602.15(2)(a), a person may operate an aircraft over a built-up area at altitudes and distances less than those specified in paragraph 602.14(2)(a), if the person

(a) has an authorization from the Minister or is authorized to do so in an air operator certificate; and

(b) complies with the Commercial Air Service Standards.

(3) For the purposes of subsection 602.16(2), a person may operate a helicopter that is carrying a helicopter Class B, C or D external load over a built-up area or in an aerial work zone, if the person

(a) has an authorization from the Minister or is authorized to do so in an air operator certificate; and

(b) complies with the Commercial Air Service Standards.

Tids

[CID]

I find Yearwoods comment interesting ... I can think of several cases where the presumption of an error (human/pilot) led to the construction of a theory around which investigations were based, instead of investigating for cause despite said presumption of error.

You work with what you've got. In the absense of cold hard facts, presumptions are often made in accident investigations. As far as your "black box" question, I wasn't sure if you were asking if the CARS required them or if they should require them. This type of helicopter isn't required to carry one.

If the question was "should they" I'd say no. Statistically, the operation of this type has proven to be quite safe. The 206 was once touted as the safest aircraft in the world. I don't think the cost of equiping them with flight recorders would be the wisest investment.

[tincanflyer]

widow's at it again= stir that pot!

[Widow]

So, BC Hydro's contract did not require the heli "to fly lower than allowed under federal regulations", but that does not mean that the service provider did not have the "special authorization". I would think that there could be several reasons why the hydro workers might have wanted to have a closer look. If they didn't want their workers flying low, I wonder if they had told their workers. Other news indicates that Worksafe BC is involved in the investigation (unlike our accident), and I would think that this would be a part of their investigation. Has BC Hydro jumped the gun?

CID, I think you know that my comment was meant to reflect that I feel those presumptions of error often lead to inadequate investigations. Mr. Yearwood's comments would indicate to me that they will not begin with the presumption that this accident resulted from an error.

As for the black box question, I just wondered if they were required. We've had cost and related discussions before.

[The Mole]

Hmmm. The public has no idea, nor does the media. There just grabbing the best sounding rumor.

Last year we had to inspect our longranger because a concerned citizen called transport canada. Apparently he knows what a helicopter sounds like, and ours was broken.

[GilletteNorth]

I assume your comment
Widow:

I find Yearwoods comment interesting ... I can think of several cases where the presumption of an error (human/pilot) led to the construction of a theory around which investigations were based, instead of investigating for cause despite said presumption of error.

refers to this comment
Bill Yearwood:

He also said the helicopter had a reputation as being reliable and has been used around the world for several years. "It's been a workhorse for 40 years," he said. "The aircraft has proven itself."

Instead of automatically thinking a TSB regional manager is making statements showing a presumption of human error prior to investigating an accident, maybe you could consider he might be trying to assure the public that aircraft normally are quite safe to operate and shouldn't fear them dropping from the skies in droves any time soon.

You highlighted the text

Yearwood, the safety board's regional manager, cautioned against ascribing too much significance to whether or not the helicopter was flying lower than permitted by the regulations. Flying low may violate the rule, but that does not mean it caused the accident, he said.

Why? It's a perfectly logical and correct statement. Flying at 120 meters instead of the prescribed 150 meters will not automatically cause an accident. I'm sure Hedley can tell you how low flying is a matter of risk assessment.

[Widow]

No, I highlighted the comment I was referring to. I didn't say I disagreed, but that I found it "interesting". I thought I made it clear why. I think it is a good decision not to begin an investigation with a theory based on presumed error.

[CID]

CID, I think you know that my comment was meant to reflect that I feel those presumptions of error often lead to inadequate investigations.

Um...that's the nature of making presumptions.

Mr. Yearwood's comments would indicate to me that they will not begin with the presumption that this accident resulted from an error.

Are you talking about "pilot error"? Nobody in their right mind begins an investigation into an accident using a "presumption of error" as a basis. Actually never mind. I re-read your post and it's giving me a headache.

[Widow]

Really? In that case, would you kindly explain why, in our accident, the wreckage was not taken by the TSB for thorough examination after it was recovered in July 2005 and NEVER has been? Before it was recovered, the TSB wrote a letter to the coroner clearly outlining the presumption that errors had led to the accident. After the accident, they added less than a page of information to include some "as-recovered" visual conditions, some of which is inaccurate.

Oh, sorry, you already answered ...

Nobody in their right mind begins an investigation into an accident using a "presumption of error" as a basis.

[GilletteNorth]

Bill Yearwood, the safety board's regional manager, cautioned against ascribing too much significance to whether or not the helicopter was flying lower than permitted by the regulations. Flying low may violate the rule, but that does not mean it caused the accident, he said.

I read this and I don't see what the presumption is that will lead to an investigation being incorrectly started, sorry. I really am trying to see what it is.

[Mitch Cronin]

I think the problem here is there was a presumption of other knowledge on Widow's behalf... She's presumed interested readers will know of the circumstances of her husband's death, and the "investigation -or lack thereof, that followed. ...ie. there's sarcasm, or at least a loud "Hmmmmmmmmm!?" in that "interesting" comment, or so I reckon....

[Mitch Cronin]

By the way.... since we can comment here without risk of offence to loved ones... Man!*%*! .....snuffed out by a hellicopter while you're minding your own business crossing the street!.... I guess that fella's number was up!

[Widow]

Mr. Yearwood's comments would indicate to me that they will not begin with the presumption that this accident resulted from an error.

as opposed to

several cases where the presumption of an error (human/pilot) led to the construction of a theory around which investigations were based, instead of investigating for cause despite said presumption of error.

I was making a positive comment, not a negative one. Were you looking for what you expected to find me saying, instead of reading what I said?

[V2-OMG!]

Isn't the nature of accident investigation to investigate those presumptions, then come to a conclusion based on deduction???

[BoostedNihilist]

Isn't the nature of accident investigation to investigate those presumptions, then come to a conclusion based on deduction???

no. a presumption with no facts is as good as a shot in the dark.. very not how an investigation is properly conducted.

first, gather facts
then, interpret facts
then, deduce causation based on facts
then, the deduction becomes a presumption

Just because it has the prefix 'pre' does not mean that it is the first step in the process.

presumption as a primary investigative technique has no place in any investigation.

for the record (thank you dictionary.com)

pre·sump·tion Audio Help /prɪˈzʌmpʃən/ Pronunciation Key - Show Spelled Pronunciation[pri-zuhmp-shuhn] Pronunciation Key - Show IPA Pronunciation
–noun
1. the act of presuming.
2. assumption of something as true.
3. belief on reasonable grounds or probable evidence.
4. something that is presumed; an assumption.
5. a ground or reason for presuming or believing.
6. Law. an inference required or permitted by law as to the existence of one fact from proof of the existence of other facts.
7. an assumption, often not fully established, that is taken for granted in some piece of reasoning.
8. unwarrantable, unbecoming, or impertinent boldness.

in regards to the above bold highlighted text.

It is very important in any fact based investigation or experiment to view the facts and make a deduction based on the established facts. Working off of a presumption and 'finding' (or bending) facts that support your forgone conclusion is akin to doing an experiment and looking only for evidence that supports your predetermined solution.

This leads to all kinds of sad episodes, from wrongful convictions, to roofs on shopping malls caving in.

[V2-OMG!]

Boosted N, thanks for that commentary.

Now that I have had a chance to think about it, I agree with your criminal law analogy.
An a/c accident should begin with a presumption of human, mechanical, and environmental innocence until proven otherwise.

[KAFUFO]

So I was recently reading the fine print on my life insurance policy and it is void if I die in an aircraft acident unless I am a fare paying passenger on a regularly schedualed flight.

Does this mean the guy walking across the street has voided his insurance?

[canwhitewolf]

I'm wondeing why no one is speculating this possibility...a Birdstrike ingestion to the engine and loss of power..

insuffecient power to climb and too low for a good autorotation while looking for place to set it down, ran out of altitude speed and power to get it down safely

is it possible in that situation? seems so to me

general birdstrikes


Rotary-wing operations are particularly challenging because:
The majority of helicopter flight operations are conducted at very low altitudes,typically below 500 ft AGL.
The pilot’s concentration is focused on maintaining terrain clearance whilecompleting the assigned task; there is little or no time available to watch for birds.
Even during the cruise phase of flight, most helicopters remain close tothe ground.
Helicopter operating speeds are generally lower than fixed-wing aircraft, butbird-strike certification standards—even for Transport Category helicopters—are not stringent (see Chapter 5).
Helicopters are more of a disturbance to bird colonies than fixed-wingairplanes; strike risk is therefore increased when birds are flushed into the air.
There is significant risk of birds penetrating the windshield and causing seriousinjury and incapacitation.

http://www.tc.gc.ca/civilaviation/Aerod ... pter11.htm

[Ogee]

Well, it didn't take a bird strike in the windshield. That is known and the thing was moving just above translation for most of its observed flight.

Into the intake? Not known.

All the indications are that this helicopter suffered a power loss for some reason and the pilot had to auto as best he could.

I'll be posting in a while with what I know that kind of supports that simple statement.

[sky's the limit]

The intakes on 206's, and most other helis for that matter, are not open to direct air, there's usually a screen at the very least, but many have particle separators, or at this time of year out West, even reverse scoops(snow deflectors) installed. So the likely hood of a bird causing it to flame out would be rather slim imho. Of course anything is possible I guess.

It's going to be very interesting to see what the findings are, there sure wasn't much to work with after the fire.

stl

[Ogee]

Okay, I'm going to try and summarize some of the facts that I have been able to gather while assisting a major Canadian newspaper in writing about this incident and hopefully avoiding the kind of media inaccuracy that many on here correctly get so wound up about.

I went to Cranbrook Thursday, two days after the crash.

I spoke to a number of witnesses. For this post, I refer only to three witness reports, those of Witness A, Witness B, and Witness C.

I took some photographs. I cranked up Google Earth and tried to get something that might be of use to people here in understanding what seems to have gone on and, although I am a heli pilot, allow people much more expert than I to perhaps enlighten us all.

First of all, let's see if I can get the Google thing on here.



The red lines with arrowheads show a general path that this machine had gone over three or four times according to Witness A. I am estimating the eastern leg as no one knows how far east the machine went every time it passed over the Catholic Church. But the 14th Avenue and 10th Avenue lines are very accurate.

14th Avenue runs north south and dips into a small valley which has 10th Street as its lowest point. So on either side of 10th, 14th is uphill/downhill. I would say that if you are two blocks either north or south of 10th, you may be 150 feet higher than 10th itself.

On the final pass, Witness A observed the machine to pass east to west right in front of him parallel and just north of 10th. It was below his height and very low. This time it did not turn south on 14th, but proceeded across 14th at the height of the residential power line you will see in the next picture. Looked to be about 30 feet to me. It appeared to slow at the power line, then lifted up a bit and passed just over the line. It then disappeared out of sight and there was immediately a bunch of smoke visible.

Witness C was driving north on 14th in his car from his home around 18th Street. He first saw the helicopter moving slowly about 10 feet above the roof of the Catholic Church and then disappearing out of sight to the east. At one point it appeared to dip down to land in that open area there, then bobbed up again and went east.

As he drove down the hill, right where his little yellow spot is, he saw the helicopter moving east to west, but this time at what he described as a much higher speed and with a descent angle at what he estimated to be 45 degrees. He did not note any type of stop near the power lines and the machine went out of site behind that corner building and then there was smoke and a second later he was on the scene.

Witness C was about 15 yards from the impact site, watching the helicopter. Her point of view is represented in this next photo...



The helicopter was coming directly at her. She says there was a powerful gust of wind as it came to 14th and it visibly rocked the machine, with the tail dropping. She could clearly see the pilot and the front seat passenger. Suddenly the helicopter dove towards her, with the pilot maneuvering around the tall tree and coming right over the topped tree (the shorter one at left). She said there was no sound either of engine or rotor. Most interestingly she said that as the machine passed over the first house, that the rotor blades were no longer a blur and she could clearly identify each blade without blur. She did not see if the helicopter flared as she turned her face away when it was obvious that it was going to impact.

Now referring back to the top photo...

The pinkish short lines and the pink circle show the path and the place where it is at issue whether the helicopter slowed there and the tail dropped.

It would seem that in the sort of transparent pink block to the right of the pink circle, some sort of power loss occured and the pilot began as best he could to set up some kind of auto.

I think that's a pretty accurate account of what people saw. I'm not going to throw in my two bits worth of speculation until we see what people here have to say, especially people who may be expert helicopter pilots. But in the mix are compressor stall, some other problem, and running out of rotor rpm.

There is also some discrepancy with the account of BC Hydro as to what these folks were doing. BC Hydro says they were off to the country side to look at lines between Cranbrook and Moyie substations. Their behavior of very low level flight along pretty well residential power lines is not consistent with the BC Hydro explanation.

There is a report from a reliable witness who was flying circuits at Cranbrook airport earlier that morning. He heard the pilot call in and say he was doing power line inspections in the city and was down below treetop level.

Anyways, I hope this helps a bit in understanding this awful accident.

[Widow]

Image is displaying nicely ogee.

[Ogee]

I gotta resize that second one. Gimme a sec.

[Single-Engine IFR]

Witness C was about 15 yards from the impact site, watching the helicopter. Her point of view is represented in this next photo...

I think you probably mean Witness B

Regards,

SEI