Airplane breaks up in Flight - Second Crash in 5 months

[FireLight]

The following article is about a recent tragedy in Alberta. For the second time in 5 months members of an engineering company were killed in a crash which took the lives of several of the principles of the company.

http://www.theglobeandmail.com/servlet/story/RTGAM.20080329.wplanecrash0329/BNStory/National/home

EDMONTON — The family of an Alberta engineering company president grieved privately Saturday over his death in a plane crash investigators say was caused when the single-engine aircraft fell apart in mid-air.

But it's still unclear what caused the breakup. That will be for the Transportation Safety Board to determine once the wreckage is retrieved, board spokesman John Cottreau said.

“There are some pieces strewn over a three-kilometre-long debris field and they're looking for those pieces,” Mr. Cottreau said from Ottawa.

“They're going to pull together all the pieces that they can recover [and] they're going to bring them to our office in Edmonton, where they're going to do a more detailed examination to focus on what might have initiated the event that led to the in-flight breakup.”

In the first crash, the 3 year old granddaughter of the company founder survived in the wreckage due to being in a car seat.

It is the second air tragedy for the Williams family in five months. Mr. Williams's father, Allen, who founded the company, died in a crash near Golden, B.C., in October, although his three-year-old granddaughter miraculously survived.

Rescuers found her hanging upside down from a car seat that had been belted into the aircraft by her grandfather.

The company's chief financial officer, Steve Sutton, also died in that crash.

[FireLight]

Updates:
http://www.theglobeandmail.com/servlet/story/RTGAM.20080402.wmalibu02/BNStory/National/
http://www.theglobeandmail.com/servlet/story/RTGAM.20080402.wmalibu02/BNStory/National/

When Reagan Williams lined up for takeoff at Edmonton City Centre Airport last Friday, there was no hint of what was to come just over half an hour later. Mr. Williams, the owner of a successful engineering company, was at the controls of a Piper PA-46 Malibu, a sleek six-seater. Although it was originally built in 1989, Mr. Williams's aircraft had been renovated by a company called Jetprop, which installed state-of-the-art computerized instruments and a powerful gas turbine engine that allowed it to cruise as high as 27,000 feet.

"A beautiful airplane," one pilot said.

Mr. Williams was off the ground shortly after 7:30 a.m., en route to a meeting in Winnipeg. He was carrying four passengers, including two of his firm's top executives. By 8:15 a.m., they were all dead, and the once-beautiful Piper was a twisted trail of wreckage, scattered over a four-kilometre radius near Wainwright, about 200 kilometres east of Edmonton.

Almost immediately, investigators could see that they were dealing with an aviation rarity - a structural failure that ripped the plane apart in the air. The wings and tail of Mr. Williams's plane were located several kilometres away from the mangled fuselage.

Image from Globe and Mail
Nose of Plane is on the right
<IMG SRC=http://www.jetphotos.net/user-uploads/ADWilliamsCrash080402.jpg>

The aircraft is amazingly intact considering that the articles say that it lost the wings and tail.

Given this, the sheer G-forces of impact resulted in the 5 deaths. :sad: It would be difficult to know how they must of felt, plummeting from 27,000 feet and at some point knowing that there would be minimal hope of survival.

Additional images and stories here:
http://www.nationalpost.com/news/canada/story.html?id=409808
http://www.ctv.ca/servlet/ArticleNews/story/CTVNews/20080328/plane_crash_080328/20080329?hub=TopStories

[Gabriel]

Why does 'a beautiful airplane' break up in the sky?

Nobody said that the break-up was the cause of the accident.
For example, it could have been a loss of control in a perfectly flyable airplane with the airplane breaking up in the subsequent dive.

The loss of control could have been (just examples) spacial disorientation, or hypoxia.

What's strange is the cracked top of the fuselage. Was it an explosive decompression high there? Or a job of the rescue team?

[Airfoilsguy]

Two planes from the same company mysteriously crash in a short period of time. Both with bigwigs in them. Anyone else thinking revenge or sabotage?


As for the cut top, that looks like rescue. The doors are smashed so I don't see any other way in other then the can opener.

[FireLight]

As for the cut top, that looks like rescue. The doors are smashed so I don't see any other way in other then the can opener.

These photos show the aircraft more or less before they used the "can opener"

<IMG SRC=http://www.jetphotos.net/user-uploads/ADwilliams080328.jpg>
<IMG SRC=http://www.jetphotos.net/user-uploads/ADwilliams080329.jpg>


Two planes from the same company mysteriously crash in a short period of time. Both with bigwigs in them. Anyone else thinking revenge or sabotage?

I suppose revenge/sabotauge is a possibility, but it sounds similar to a number of other crashes with the PA-46.
* Entry into bad weather
* Bad weather either causes instrument problems, or they encounter instrument problems.
* They lose orientation and aircraft starts to dive.
* Aircraft exceeds VNE
* Aircraft exceeds structural limits
* Parts of the plane come off and the plane goes out of control
* Plane crashes

Last Friday's crash fit a pattern only too familiar to investigators examining PA-46 in-flight failures. After lifting off in Edmonton, Mr. Williams's airplane climbed to just over 27,000 feet and cruised southeast at more than 450 kilometres per hour. About 25 minutes into the flight, Mr. Williams told air traffic controllers that he was experiencing trouble with his autopilot and a gyroscope that supplied critical information to his flight instruments.

A few minutes later, Mr. Williams's airplane started turning to the right and descending in what became an increasingly steep dive. According to a radar track of the doomed flight, the PA-46 may have plunged up to 10,000 feet in a single minute. As the dive continued, the airplane apparently exceeded its maximum speed, known as velocity never exceed, or VNE, ripping off the wings and tail due to aerodynamic overload.
Instead, they pinned the accidents on a combination of pilot error and omissions in the airplane's operating manual, which did not warn pilots of the need to turn on a device called a pitot heater when flying into icing conditions. Without the heater on, ice could block the opening that supplied information to the airplane's airspeed indicator, leading to confusion on the part of the pilot or problems with the autopilot system.

[kukkudrill]

What's odd is that the fuselage is remarkably intact for a plane which hit the ground at high speed. Could those stub wings have moderated the path of its descent?

[Gabriel]

What's odd is that the fuselage is remarkably intact for a plane which hit the ground at high speed. Could those stub wings have moderated the path of its descent?
If it fell flat, the remaining of the wings plus the bottom of the fuselage would have retarded the descent. But even if it was not so slow, an aircraft hitting flat with no ferward speed woud not leave a lot of visible damage on the upper side of the fuselage. The load of the upper part, which is not very heavy, would be evenly distributed along the walls and from there to the bottom and the the ground. The engine would stop itself against the ground and the passangers would crush the seats that would crush the bottom of the fuselage leving no visible damage on the upper part.

The vetical load on the passangers would be, however, unsurvibable. Just to make a mental example, say that the speed of the vertical flat fall was 60kts (31m/s), that the distance between the bottom of the fuselage and the upper side of the seat cushion, before the crash, was 15in (0.38m), and that that that distance after the crash (crushed) was reduced to 5in (0,13m), what means that the distance available to descelerate the fall was 10in (0,25m). Even further, say that the design was so ideal (and unrealistically impossible) that it provided a constant desceleration while crushing those 10 inches. The constant desceleration that makes you go from 60kts to 0kts in 10in is 190g.

A frotal crash at a much slower speed would leave a lot more of visible damage, since the load of the inertia of all the weight of the plane (except the engine), including the passangers, would be transferred through the crossection. And since there is more distance to descelerate forward, it woud be more survibable too (destruction is a measure of energy absorbed by the the structure rather than its occupants).

[bob12312357]

CIf it fell flat, the remaining of the wings plus the bottom of the fuselage would have retarded the descent. But even if it was not so slow, an aircraft hitting flat with no ferward speed woud not leave a lot of visible damage on the upper side of the fuselage. The load of the upper part, which is not very heavy, would be evenly distributed along the walls and from there to the bottom and the the ground. The engine would stop itself against the ground and the passangers would crush the seats that would crush the bottom of the fuselage leving no visible damage on the upper part.

The vetical load on the passangers would be, however, unsurvibable. Just to make a mental example, say that the speed of the vertical flat fall was 60kts (31m/s), that the distance between the bottom of the fuselage and the upper side of the seat cushion, before the crash, was 15in (0.38m), and that that that distance after the crash (crushed) was reduced to 5in (0,13m), what means that the distance available to descelerate the fall was 10in (0,25m). Even further, say that the design was so ideal (and unrealistically impossible) that it provided a constant desceleration while crushing those 10 inches. The constant desceleration that makes you go from 60kts to 0kts in 10in is 190g.

A frotal crash at a much slower speed would leave a lot more of visible damage, since the load of the inertia of all the weight of the plane (except the engine), including the passangers, would be transferred through the crossection. And since there is more distance to descelerate forward, it woud be more survibable too (destruction is a measure of energy absorbed by the the structure rather than its occupants).Cool explanation as i was wondering pretty much the same thing. On another note,I've yet to fly or fly in a plane short of a jet where the wind noise,or an odd amount of down trim didn't at least make you aware you were speeding up. Even with the pitot inoperable, a known cruise setting and trim would have allowed the plane to remain level,and at roughly estimatable airspeed. ATC could then have helped him down. Just weird that such a simple problem causes crashes like those thousands of times a year and will continue to. Can't blame the plane in 4 outta 5.

[FireLight]

Gabriel - thanks for the calculations. Given that you calculate impact around 190 G's, it clarifies why they weren't able to survive the crash, even with the aircraft remarkably intact.

G forces that humans can withstand - depends on direction and duration of forces and other factors specific to the impact. {UK Health and Safety study}

9G = typical limit of maintaining consciousness for pressure suited jet pilot when forces maintained for extended time.
up to 20G = some risk of injury. Typical limit for ejection seats.
up to 40G = likely survivable, but risk of moderate injury
over 40G = increasing risk of severe injuries. Short duration of large impact forces allows for greater risk of survival. 75G's could be survivable, and even 100G's in some circumstances, although dying would also be highly likely especially if medical assistance wasn't available immediately.

As a note; It is estimated that the accident Princess Diana died in was at around 70 G's, and her head experienced 100 G's. At this deceleration the pulmonary artery was torn from her heart. :sad:

The vetical load on the passangers would be, however, unsurvibable. Just to make a mental example, say that the speed of the vertical flat fall was 60kts (31m/s), that the distance between the bottom of the fuselage and the upper side of the seat cushion, before the crash, was 15in (0.38m), and that that that distance after the crash (crushed) was reduced to 5in (0,13m), what means that the distance available to descelerate the fall was 10in (0,25m). Even further, say that the design was so ideal (and unrealistically impossible) that it provided a constant desceleration while crushing those 10 inches. The constant desceleration that makes you go from 60kts to 0kts in 10in is 190g.

[Gabriel]

On another note,I've yet to fly or fly in a plane short of a jet where the wind noise,or an odd amount of down trim didn't at least make you aware you were speeding up. Even with the pitot inoperable, a known cruise setting and trim would have allowed the plane to remain level,and at roughly estimatable airspeed. ATC could then have helped him down. Just weird that such a simple problem causes crashes like those thousands of times a year and will continue to. Can't blame the plane in 4 outta 5.
The wind noise is a cue even in large jets. However, several accidents have happened as a result of a faulty airspeed indication.

But more frequent than that is spacial disorientation. In that case you can have a perfect airpseed indication and be fully aware that you are going too fast, but you don't know how to recover since that would involve a pull up and you don't know where is up. Pulling the yoke dosn't work if you are banked nearly or past vertical.

[Gabriel]

Gabriel - thanks for the calculations. Given that you calculate impact around 190 G's, it clarifies why they weren't able to survive the crash, even with the aircraft remarkably intact.

G forces that humans can withstand - depends on direction and duration of forces and other factors specific to the impact. {UK Health and Safety study}

9G = typical limit of maintaining consciousness for pressure suited jet pilot when forces maintained for extended time.
up to 20G = some risk of injury. Typical limit for ejection seats.
up to 40G = likely survivable, but risk of moderate injury
over 40G = increasing risk of severe injuries. Short duration of large impact forces allows for greater risk of survival. 75G's could be survivable, and even 100G's in some circumstances, although dying would also be highly likely especially if medical assistance wasn't available immediately.

As a note; It is estimated that the accident Princess Diana died in was at around 70 G's, and her head experienced 100 G's. At this deceleration the pulmonary artery was torn from her heart. :sad:
A sort of disclaimer: I didn't intend to estimate any acceleration in any actual accident. The numbers I used as input data were just some numbers I judged "reasonable". In this particualr crash the acceleration could have been much higher or lower depending on several factors.

On another note, you already mentioned that direction is a factor on survability, and it's a major one. Seated in a seat, the vertical/downward acceleration is not the best scenario, since all the weight of the torso and head is supported by the lower part of the spine which has a small crossection an is in the middle of a critical system if damaged. Permaenet incapacitation is very likely if you survive. Horizontal acceleration is much more survivable at higher Gs because the force is distributed in a large zone of the body. The most surviable ditrection is horizontal facing back. "My" numbers for "very likely to survive with no permanent injury" (always very short duration) were 40Gs horizontal facing forward (provided a good restrain system) and 20 Gs vertical. I don't have numbers but I understand that spine compresion is the main cause of permanent injury and death in GA airplane crashes (and even more in helicopters).

[FireLight]

Gabriel; your disclaimer is understood. (I'm an engineer.) I know that there are a large number of factors that you wouldn't be able to calculate well without information regarding the actual parameters of the descent, crash and structure of the aircraft. Nevertheless, an estimate of 190G's +/- versus survivable limits for humans shows how low the likelihood of survivability would have been.

Thanks also for the clarification regarding the importance of direction of impact and adequate restraints. I understand that an ejection seat with a 20G limit has a potential of causing injury due to spinal compression. Clearly worth the risk though - versus hanging around with the aircraft.

Question: would passengers have a greater chance of survival if the seats in the aircraft all faced backwards?

A sort of disclaimer: I didn't intend to estimate any acceleration in any actual accident. The numbers I used as input data were just some numbers I judged "reasonable". In this particualr crash the acceleration could have been much higher or lower depending on several factors.

On another note, you already mentioned that direction is a factor on survability, and it's a major one. Seated in a seat, the vertical/downward acceleration is not the best scenario, since all the weight of the torso and head is supported by the lower part of the spine which has a small crossection an is in the middle of a critical system if damaged. Permaenet incapacitation is very likely if you survive. Horizontal acceleration is much more survivable at higher Gs because the force is distributed in a large zone of the body. The most surviable ditrection is horizontal facing back. "My" numbers for "very likely to survive with no permanent injury" (always very short duration) were 40Gs horizontal facing forward (provided a good restrain system) and 20 Gs vertical. I don't have numbers but I understand that spine compresion is the main cause of permanent injury and death in GA airplane crashes (and even more in helicopters).

[Uncle Jay]

This whole deal reeks of set up. I bet any amount of money the pax were killed off site, the fuselage transported to the scene on a truck and placed there.

How come no bent propeller ? How come no trees knocked down to each side like in a flat spin ? If it wanst spinning, then how did it remain horizlntal ? it would have nosed in without the wings.

[FireLight]

This whole deal reeks of set up. I bet any amount of money the pax were killed off site, the fuselage transported to the scene on a truck and placed there.

How come no bent propeller ? How come no trees knocked down to each side like in a flat spin ? If it wanst spinning, then how did it remain horizlntal ? it would have nosed in without the wings.

What is this; X-files? ;)

If the incident wasn't so similar to a large number of other Piper Malibu PA-46 crashes then sure, I'd be more suspicious. Or maybe I'm not paranoid enough? :skeptic:

But then - if the conspirators knew about all the other incidents and made it look like the aircraft came apart in mid-air ....

Who would stand to gain from this?

And a radio station said the TSB hasn't completely ruled out the possibility that an explosive was on the plane. (although they don't have any evidence that there was any sort of explosion on the plane.)

It all makes sense to me now. :roll:

[Gabriel]

This whole deal reeks of set up. I bet any amount of money the pax were killed off site, the fuselage transported to the scene on a truck and placed there.

1- How come no bent propeller?
2- How come no trees knocked down to each side like in a flat spin?
3- If it wanst spinning, then how did it remain horizlntal?
4- it would have nosed in without the wings.
1- Fuel gone with the wings. If the prop doesn't turn then it doens't bend.
2- Maybe it was not a flat spin, or maybe it was but the rotation speed was slow compared to the fall speed.
3- It could have just crashed belly down. Maybe it was faling chaotically and happened to crash more or less horizontal.
4- Not without a tail, which might have been lost during the fall too.

[Gabriel]

Question: would passengers have a greater chance of survival if the seats in the aircraft all faced backwards?
Certainly. It's a proven fact. However, it would require stronger seats and supporting structure (floor included) to withstand higher loads. That means more empty weight for the same MTOW, and that means:
The aircraft is more expensive.
All trips will consume more fuel for the same ayload.
A flight with max payload will have a shorter range (less weight allowable for fuel).
A flight with full fuel will have less payload (passangers or freight).

And of course they wouldn't have helped in this crash. Only in frontal crashes (horizontal desceleration).

[FireLight]

Certainly. It's a proven fact. However, it would require stronger seats and supporting structure (floor included) to withstand higher loads. That means more empty weight for the same MTOW, and that means:
The aircraft is more expensive.
All trips will consume more fuel for the same ayload.
A flight with max payload will have a shorter range (less weight allowable for fuel).
A flight with full fuel will have less payload (passangers or freight).

And of course they wouldn't have helped in this crash. Only in frontal crashes (horizontal desceleration).

Thanks for the explanation Gabriel. Makes a lot of sense.

So, forward facing seats would take the load at the point where the seatbelt is connected, which is relatively low down. Rearward facing seats would effectively take the impact load higher up the back of the seat, therefore substantially increasing the (structural) moment on the seat structure. Therefore requiring stronger seats and floor. Therefore ...

Tough tradeoff on increasing safety versus passenger loads. However, if you reduce the odds on planes crashing, the tradeoff is perhaps not too bad. In any event it's the one we live with every time we fly.

[Gabriel]

So, forward facing seats would take the load at the point where the seatbelt is connected, which is relatively low down. Rearward facing seats would effectively take the impact load higher up the back of the seat, therefore substantially increasing the (structural) moment on the seat structure. Therefore requiring stronger seats and floor.
Hmmm, I had not thought it that way, but it's true, however:

The full effectiviness of forward facing seats (those 40Gs) is achived with 5 points restrain systems (harnesses), in which case the load is not taken low like with the lap strap only.

But what I had in mind was that the fact a rearward facing seat increases survibability is that the body is able to resist higher accelerations (what means higher loads) in that position. It doesn't make any sense to put a seat in a position where the body would be able to resist higher loads if the seat itself cannot resist those higher loads, and that's what makes the seat and supporting structure heavier.