The lack of flight recorders prevented the TSB from definitively concluding what caused a plane crash that killed former Alberta premier Jim Prentice and three others, but the pilot was probably disoriented, investigators say.

The Transportation Safety Board called on Transport Canada to make flight recording systems mandatory for all commercial and private business operators, as it released its report from an 18-month investigation into the crash.

Read the TSB report

The Cessna Citation jet disappeared from radar shortly after takeoff from Kelowna, B.C., on its way to the Springbank airport west of Calgary on Oct. 13, 2016.

Killed in the crash with Prentice were the pilot Jim Kruk, a retired RCMP officer; optometrist Ken Gellatly, the father-in-law of one of Prentice's three daughters; and Calgary businessman Sheldon Reid.

Investigators couldn't pinpoint the exact cause of the crash because the plane, which was built in 1974, was not equipped with a cockpit voice recorder or a flight data recorder, the TSB said. Neither is a requirement for that type of aircraft.

An overview shows crash wreckage of the Cessna Citation. (Transportation Safety Board)

"All we have is a hypothesis," TSB chair Kathy Fox said as she released the report in Calgary.

"And that simply isn't good enough."

Pilot likely had 'spatial disorientation'

The safety board says the "most plausible scenario" for the cause of the crash was that Kruk became disoriented due to a heavy workload at the controls.

There were no emergency or distress calls made, according to the TSB.

The investigation revealed that the plane's climb rate changed rapidly several times within 30 seconds just before it went down, lead investigator Beverley Harvey said.

It also deviated to the right by 20 degrees, she said.

TSB chair Kathy Fox says Transport Canada should make flight recording systems mandatory for all commercial and private business operators. (CBC)

"The most plausible scenario is that the pilot, who was likely dealing with a high workload associated with flying the aircraft alone, experienced spatial disorientation and departed from controlled flight shortly after takeoff," the TSB said in a release issued ahead of a news conference in Calgary.

The investigation determined the pilot didn't have enough recent experience flying after dark.

"The pilot, although experienced, had very little recent experience flying at night with just two night takeoffs in the past six months. This did not meet Transport Canada's requirements to carry passengers at night," said Harvey.

"Pilots who do not have sufficient night proficiency are at a greater risk of experiencing what's known as spatial disorientation."

Fox called on Transport Canada to make flight recording systems mandatory.

The board also said it has concerns about the way Transport Canada conducts oversight of private business aviation in the country.

"During the course of its investigation, the TSB found no record that the operator of this aircraft had ever been inspected by TC," the board said in a release.

"As such, TC was unaware of safety deficiencies in its flight operations, such as the failure to obtain approval for single-pilot operation of the aircraft and the pilot's lack of recent night flying experience required to carry passengers at night."

Prentice family thanks TSB

Prentice, 60, was also a former federal cabinet minister.

He became premier of Alberta in September 2014 after winning the leadership of the province's governing Progressive Conservative Party. He quit politics in May 2015 after the NDP swept the PCs from power.

The Prentice family thanked the TSB for its work on the investigation.

"While this report cannot restore what has been lost, it is our hope the learnings from this tragic event can be used to prevent similar accidents in the future," the family said in a written statement.

"We are proud of Jim's contributions to Alberta, to Canada and to public service, but he was first and foremost a loving husband, father, grandfather and sibling; we will always miss him. Our thoughts and prayers are with the other families impacted by this tragedy."

In anticipation of Wednesday's TSB report, Greg McConnell, national chairman of the Canadian Federal Pilots Association, said one change he would like to see is regular Transport Canada inspections for small aircraft such as the business jet Prentice died in.</s>Former Alberta Premier Jim Prentice, shown in this Morinville News file photo, was one of three who died in a plane crash in October of 2016. The crash was recently investigated by the Transportation Safety Board of Canada.

After an investigation into the Oct. 13, 2016 crash that killed former Alberta premier Jim Prentice, the Transportation Safety Board of Canada (TSB) is recommending the mandatory installation of lightweight flight recording systems by all commercial and private business operators not currently required to carry them.

TSB ‘s report indicates the Cessna Citation 500 privately operated by Norjet Inc. departed Kelowna Airport for Calgary/Springbank Airport with three passengers on board. Shortly after departure, the aircraft departed controlled flight, entering a steep descending turn to the right until it struck the ground. No emergency call was made. All occupants died in the crash and the force of impact and resulting fire destroyed the aircraft.

TSB could not determine the cause of the accident because there was no flight recording systems on board the aircraft. Their best assumption is the pilot experienced spatial disorientation and departed from controlled flight shortly after takeoff.

“We don’t like having to say ‘We don’t know’ when asked what caused an accident and why,” said Kathy Fox, Chair of the TSB in a release. “We want to be able to provide definitive answers—to the victims’ families, to Canada’s aviation industry, to the Canadian public. This is why we are calling today for the mandatory installation of lightweight flight recording systems on commercial and private business aircraft not currently required to carry them.”

In addition to the recommendation of mandatory flight recorders, the Board has raised concern with the way Transport Canada (TC) had conducted oversight of private business aviation in Canada.

The TSB investigation found no record the aircraft operator had ever been inspected by TC, meaning TC was unaware of a “failure to obtain approval for single-pilot operation of the aircraft and the pilot’s lack of recent night flying experience required to carry passengers at night.”

TC has said that it will conduct targeted inspections of private business operators starting this spring.

TSB say they will continue to monitor this safety issue.</s>The Transportation Safety Board says the pilot of a plane that crashed, killing former Alberta premier Jim Prentice, was probably disoriented while flying in the dark, but investigators will never know for sure because the aircraft didn’t have flight recorders.

The Cessna Citation jet went down shortly after takeoff from Kelowna, B.C., on its way to the Springbank airport west of Calgary in October 2016.

The plane took off about 9:30 p.m. and shortly after took a steep descending right turn and hit the ground from 2,580 metres above sea level.

The safety board says the “most plausible scenario” is that pilot Jim Kruk became spatially disoriented because he had a lot to do at the controls.

Kruk, a retired RCMP officer, optometrist Ken Gellatly, the father-in-law of one of Prentice’s three daughters and Calgary businessman Sheldon Reid all died with Prentice.

“The most plausible scenario is that the pilot, who was likely dealing with a high workload associated with flying the aircraft alone, experienced spatial disorientation and departed from controlled flight shortly after takeoff,” the TSB said in a release issued ahead of a news conference in Calgary.

The investigation also determined that the pilot did not have enough experience flying after dark.

“The pilot, although experienced, had very little recent experience flying at night with just two night takeoffs in the past six months. This did not meet Transport Canada’s requirements to carry passengers at night,” said senior investigator Beverley Harvey.

“Pilots who do not have sufficient night proficiency are at a greater risk of experiencing what’s known as spatial disorientation.”

Prentice was Alberta’s premier from October 2014 until his election loss the following spring when the Progressive Conservatives were kicked out by the NDP after more than 40 years in power.

His family issued a statement thanking the board for its work.

“While this report cannot restore what has been lost, it is our hope the learnings from this tragic event can be used to prevent similar accidents in the future,” it said.

“We are proud of Jim’s contributions to Alberta, to Canada and to public service, but he was first and foremost a loving husband, father, grandfather and sibling. We will always miss him.”

Harvey said the “physical illusions” that accompany disorientation while flying can occur during prolonged acceleration such as during an initial climb after takeoff.

“Even though they are erroneous, these sensations can be intense causing pilots to doubt their instruments, to incorrectly adjust controls or even put the aircraft into an accidental spiral dive.”

The lack of concrete proof as to what happened was extremely frustrating for investigators, she said.

Kathy Fox, the safety board’s chairwoman, said the plane involved in the crash was not required to have a flight data recorder. The Transportation Safety Board is recommending such recorders, as well as cockpit recorders, be required on all commercial and private business aircraft.

“We don’t like having to say we don’t know when asked what caused an accident or why,” Fox said. “We want to provide definitive answers to the victims’ families, to Canada’s aviation industry and to the Canadian public.”</s>The TSB will announce its findings and the Capital News will follow.

The wreckage of a Cessna Citation which crashed on October 13, 2016, is seen in the woods near Lake Country, B.C., in this October 15, 2016, Transportation Safety Board handout image. The aircraft crashed shortly after takeoff, killing the pilot and all three passengers aboard, including the former Alberta Premier Jim Prentice. THE CANADIAN PRESS/HO-TSB,

There is no definitive way to figure out what caused a small plane carrying former Alberta Premier Jim Prentice and three others to crash into a forested area near Kelowna.

In a Transportation Safety Board press conference held Thursday morning, however, investigators offered a theory hung on radar data and the history of the pilot.

TSB investigator Beverly Harvey, indicates that the plane took off at a high speed, and then the speed dropped back dramatically, only to increase again. It also deviated its track by 20 degrees.

What happened is keeping with a condition called spatial disorientation, where a pilot that doesn’t have a lot of nighttime flying experience suffers from physical illusions like tumbling backward.

MORE TO COME

The Transportation Safety Board of Canada (TSB) is recommending the mandatory installation of lightweight flight recording systems by all commercial and private business operators not currently required to carry them. The TSB is also concerned with Transport Canada’s reactive approach to oversight of private business aircraft operations. The details are in the investigation report (A16P0186) released today into the 2016 fatal loss of control and collision with terrain of a Cessna Citation 500 near Kelowna, British Columbia.

The investigation into the 2016 plane crash that killed four passengers, including former Alberta premier Jim Prentice, has been completed and results will be announced this morning.

The Transportation Safety Board will hold a news conference at 9 a.m. to release its investigation report on the Oct. 13 2016 crash of the Cessna Citation 500 just outside Kelowna, and the Capital News will report on its findings.

At the time of the crash RCMP Cpl. Dan Moskaluk said the Cessna Citation private business aircraft was owned by Norjet, a Calgary-based firm, and had departed Kelowna International Airport en route to Springbank, outside of Calgary.

“I know that heavy rain was felt across the Okanagan Valley but difficult to say if that was an issue in this case,” Moskaluk said.

The Transportation Safety Board released a statement at the time also, saying that there were no emergency calls or signals from the high impact crash that scattered debris over a vast space.

RCMP, with the help of a police dog, were able to get to the scene just before midnight, and received assistance from local search and rescue volunteers.

“It’s a complex scene right now and it will take some time for the investigation of the crash site to be completed,” Moskaluk said.

“The terrain is hilly and densely forested, but we were able to access the site from a nearby forest service road.”

The site of the crash was northeast of Winfield, about four kms north of Beaver Lake Road and about 18 kms north of Kelowna.

Kelowna RCMP and Lake Country RCMP detachments were alerted by the Surrey Air Traffic Control Centre that they had lost contact with a Citation jet shortly after its takeoff from Kelowna airport.

Also onboard that night were Sheldon Reid, a shareholder in Norjet, the owner of the Cessna Citation aircraft that crashed, and Jim Kruk, associated with the 83 ‘Lynx’ air cadet squadron based out of Airdrie, a rural community north of Calgary, and Calgary optometrist Kenneth Gellatly, whose son was married to Prentice’s daughter.

The men were flying home to Calgary from a late-season golf game in Kelowna when the crash occurred.

@KelownaNewsKat

kmichaels@kelownacapnews.com

Like us on Facebook and follow us on Twitter.</s>The TSB will announce its findings and the Capital News will follow.

The wreckage of a Cessna Citation which crashed on October 13, 2016, is seen in the woods near Lake Country, B.C., in this October 15, 2016, Transportation Safety Board handout image. The aircraft crashed shortly after takeoff, killing the pilot and all three passengers aboard, including the former Alberta Premier Jim Prentice. THE CANADIAN PRESS/HO-TSB,

There is no definitive way to know what caused a small plane carrying former Alberta Premier Jim Prentice and three others to crash into a forested area near Kelowna Oct. 13 2016, but investigators have constructed a “plausible scenario” hinged on a condition called spatial disorientation.

In a Transportation Safety Board press conference held Thursday morning, investigators explained they constructed the theory based on radar data, the pilot’s flight history as well as the absence of any evidence indicating mechanical failure.

TSB investigator Beverly Harvey said radar data indicates that the plane took off at a high speed appropriate for take-off, and then the speed dropped back dramatically, only to increase again. The plane deviated from its track by 20 degrees and entered a steep descending turn that ultimately ended in the crash that killed all onboard.

What happened is in line with what would happen if a pilot suffered from spatial disorientation.

“(The pilot gets a) feeling of tumbling backwards or vertigo because of the balance system in the inner ear … it can cause a pilot to push forward on controls and to turn thinking that he’s straightening out the aircraft, which is why it is so insidious,” said Kathy Fox, Chair of the TSB.

The condition can cause pilots to doubt the plane’s instruments, doubt its controls, and to put the plane into accidental spiral dive.

The pilot, said Fox, had only seven to nine hours of night flying in the last six months, which she said is not a lot for piloting a high-performance plane. In fact, it falls below industry standards of completing five take-off and landings at night over six months.

Fox stressed that while they believe their theory has merit, pilot error is not a reason they are willing to offer.

There just isn’t enough evidence to say anything conclusively as there was no flight recorder, no voice recorder, no detailed sequence of what happened in flight deck.

There are two things that she did know, however. First, that the plane was not required to have these recording devices onboard and second, that needs to change.

This accident may act as the impetus for change that could affect hundreds of aviation companies and thousands of planes.

“We don’t like having to say ‘We don’t know’ when asked what caused an accident and why,” said Fox, Chair of the TSB. “We want to be able to provide definitive answers—to the victims’ families, to Canada’s aviation industry, to the Canadian public. This is why we are calling today for the mandatory installation of lightweight flight recording systems on commercial and private business aircraft not currently required to carry them.”

The Board also raised a concern with the way Transport Canada had conducted oversight of private business aviation in Canada.

During the course of its investigation, the TSB found no record that the operator of this aircraft had ever been inspected by TC. As such, TC was unaware of safety deficiencies in its flight operations, such as the failure to obtain approval for single-pilot operation of the aircraft and the pilot’s lack of recent night flying experience required to carry passengers at night.

Since this occurrence, TC has said that it will conduct targeted inspections of private business operators starting in April 2018. Fox said the TSB will continue to monitor this safety issue.

The investigation into the 2016 plane crash that killed four passengers, including former Alberta premier Jim Prentice, has been completed and results will be announced this morning.

The Transportation Safety Board will hold a news conference at 9 a.m. to release its investigation report on the Oct. 13 2016 crash of the Cessna Citation 500 just outside Kelowna, and the Capital News will report on its findings.

At the time of the crash RCMP Cpl. Dan Moskaluk said the Cessna Citation private business aircraft was owned by Norjet, a Calgary-based firm, and had departed Kelowna International Airport en route to Springbank, outside of Calgary.

“I know that heavy rain was felt across the Okanagan Valley but difficult to say if that was an issue in this case,” Moskaluk said.

The Transportation Safety Board released a statement at the time also, saying that there were no emergency calls or signals from the high impact crash that scattered debris over a vast space.

RCMP, with the help of a police dog, were able to get to the scene just before midnight, and received assistance from local search and rescue volunteers.

“It’s a complex scene right now and it will take some time for the investigation of the crash site to be completed,” Moskaluk said.

“The terrain is hilly and densely forested, but we were able to access the site from a nearby forest service road.”

The site of the crash was northeast of Winfield, about four kms north of Beaver Lake Road and about 18 kms north of Kelowna.

Kelowna RCMP and Lake Country RCMP detachments were alerted by the Surrey Air Traffic Control Centre that they had lost contact with a Citation jet shortly after its takeoff from Kelowna airport.

Also onboard that night were Sheldon Reid, a shareholder in Norjet, the owner of the Cessna Citation aircraft that crashed, and Jim Kruk, associated with the 83 ‘Lynx’ air cadet squadron based out of Airdrie, a rural community north of Calgary, and Calgary optometrist Kenneth Gellatly, whose son was married to Prentice’s daughter.

The men were flying home to Calgary from a late-season golf game in Kelowna when the crash occurred.

@KelownaNewsKat

kmichaels@kelownacapnews.com

Like us on Facebook and follow us on Twitter.</s>Eighteen months after former Alberta premier Jim Prentice and three other men died in a fiery B.C. plane crash, federal investigators can still only hypothesize the pilot become disoriented in the dark and lost control of the Cessna Citation 500 before the aircraft entered a steep, descending turn.

Without the hindsight of a flight recorder − not a requirement for this type of aircraft – no one may ever know for sure what happened at about 9:30 p.m. on Oct. 13, 2016, as the plane set off from Kelowna to Calgary.

The pilot, Jim Kruk, had decades of experience behind the controls. But in its investigation report released on Thursday, the Transportation Safety Board says Mr. Kruk had just two night takeoffs under his belt in the six months before the crash. Transportation Canada requires pilots carrying passengers in the dark to have at least five such night takeoffs and landings in six months. That lack of up-to-date nighttime experience meant the pilot was more likely to experience “spatial disorientation,” with loss-of-control sensations including vertigo that can see pilots push down or turn controls when they think they are levelling out, TSB chairwoman Kathy Fox said.

“That’s why it’s so insidious and so dangerous.”

What is clear, however, is the independent agency in charge of investigating transportation incidents in Canada believes there are cracks in the system designed to keep private business aircraft flights safe.

“That’s not just concerning to the TSB, but it should be concerning to everyone,” Ms. Fox said, speaking to reporters in Calgary.

Mr. Prentice was the popular federal Conservative cabinet minister who went on to serve a tumultuous eight months as Alberta’s premier before his long-ruling Progressive Conservative party was voted out of office in May, 2015. Mr. Prentice was in the midst of building a postpolitical life and was returning from an Okanagan golf trip with Mr. Kruk; Calgary optometrist Ken Gellatly – the father-in-law of one of Prentice’s three daughters; and Calgary businessman Sheldon Reid. According to the TSB, the Cessna that the four men were travelling in experienced rapid changes in its rate of climb, deviated from its intended track and crashed just minutes after it left the runway. No emergency call was made.

In its investigation report, the TSB said Transport Canada should create a mandatory condition that commercial operators and private operators install flight recording systems – even for those not required to carry the devices today. The systems have become lighter and less expensive in recent years, and would give investigators a fighting chance of figuring out what went wrong after a crash.

“It’s extremely frustrating when at the end of 18 months we’ve come up with a likely scenario of spatial disorientation, but it is just that – a likely scenario,” TSB investigator-in-charge Beverley Harvey said.

Transport Canada said on Thursday the majority of the travelling public, close to 85 per cent, fly in aircraft equipped with a cockpit voice recorder, flight data recorder, or both. Only some smaller, private aircraft are not required to have the devices. Based on a past recommendation from the TSB, the federal department is consulting on the issue.

But more damning, the TSB said Transport Canada had not inspected Norjet Inc., the company that owned the plane, in the four years before the crash. It was therefore unaware that no approvals had been obtained for the single-pilot operation of the aircraft; Transport Canada was also not aware of non-compliance with maintenance inspection schedules for wing components, along with the pilot’s lack of nighttime flight experience.

The TSB said the current approach to oversight for the private business aviation sector isn’t robust enough – saying the focus on investigating only after an incident or crash heightens the risk of “another serious incident or accident involving a private operator.”

Transport Canada has told the TSB that as of this month, it will conduct “targeted” inspections of private business operations.

The TSB does the investigations into crashes but doesn’t assign blame, or criminal or civil responsibility. On Thursday, Transport Minister Marc Garneau said he takes the agency recommendations seriously.

“Departmental officials are conducting a thorough review of the report and will provide a formal response to the board within the required 90-day time frame,” Mr. Garneau said in a news release.

In a statement, Mr. Prentice’s family said while the TSB report “cannot restore what has been lost, it is our hope the learnings from this tragic event can be used to prevent similar accidents in the future.”</s>CALGARY — The Transportation Safety Board says the pilot of a plane that crashed, killing former Alberta premier Jim Prentice, was probably disoriented.

The Cessna Citation jet went down shortly after takeoff from Kelowna, B.C., on its way to the Springbank airport west of Calgary in October 2016.

The plane took off about 9:30 p.m. and shortly after took a steep descending right turn and hit the ground from 2,580 metres above sea level.

The TSB says there were no flight recorders on board the aircraft, so investigators could not definitively determine the cause of the crash.

But the safety board says the “most plausible scenario” is that pilot Jim Kruk became spatially disoriented due to a heavy workload at the controls.

Kruk, a retired RCMP officer, optometrist Ken Gellatly, the father-in-law of one of Prentice’s three daughters and Calgary businessman Sheldon Reid all died with Prentice.

“The most plausible scenario is that the pilot, who was likely dealing with a high workload associated with flying the aircraft alone, experienced spatial disorientation and departed from controlled flight shortly after takeoff,” the TSB said in a release issued ahead of a news conference in Calgary.

The investigation also determined that the pilot did not have enough recent experience flying after dark.

“The pilot, although experienced, had very little recent experience flying at night with just two night takeoffs in the past six months. This did not meet Transport Canada’s requirements to carry passengers at night,” said Beverley Harvey, senior investigator at the TSB.

“Pilots who do not have sufficient night proficiency are at a greater risk of experiencing what’s known as spatial disorientation.”

Prentice was Alberta’s premier from October 2014 until his election loss the following spring when the Progressive Conservatives were kicked out by the NDP after more than 40 years in power.

Harvey said the “physical illusions” that accompany disorientation while flying can occur during prolonged acceleration such as during an initial climb after takeoff.

“Even though they are erroneous, these sensations can be intense causing pilots to doubt their instruments, to incorrectly adjust controls or even put the aircraft into an accidental spiral dive.”

The lack of concrete proof as to what happened was extremely frustrating for investigators, she said.

Kathy Fox, the safety board’s chairwoman, said the plane involved in the crash was not required to have a flight data recorder. The Transportation Safety Board is recommending such recorders, as well as cockpit recorders, be required on all commercial and private business aircraft.

“We don’t like having to say we don’t know when asked what caused an accident or why,” Fox said. “We want to provide definitive answers to the victims’ families, to Canada’s aviation industry and to the Canadian public.”</s>CALGARY -- The Transportation Safety Board is to release a report today on the plane crash that killed former Alberta premier Jim Prentice and three other men.

The Cessna Citation jet went down shortly after takeoff from Kelowna, B.C., on its way to the Springbank airport west of Calgary in October 2016.

No distress signal was sent before the aircraft vanished from radar.

Also aboard were optometrist Ken Gellatly, the father-in-law of one of Prentice's three daughters, and Calgary businessman Sheldon Reid.

Jim Kruk, a retired RCMP officer and aviation enthusiast, was flying the plane.

The small aircraft was not required to have voice and data recorders, which the Transportation Safety Board warned would make its investigation particularly challenging.

Days after the crash, board chairwoman Kathy Fox made a renewed call for the devices to be required on small planes.

"This latest accident is another reminder of how important these recorders are," she said in a statement at the time. "If we are to get to the underlying causes of these tragic accidents, Transport Canada and the aviation industry need to take immediate action to address this outstanding safety issue."

Greg McConnell, national chairman of the Canadian Federal Pilots Association, said one change he would like to see is regular Transport Canada inspections for small aircraft such as the business jet Prentice died in.

He said it's possible the TSB may not be able to pinpoint a single cause for why the plane went down.

"Often with accidents it's never one thing, but it's a culmination of a bunch of little things," McConnell said.

"We won't know until we see the report, I guess."</s>The Transportation Safety Board can’t determine the cause of the 2016 plane crash that killed former Alberta premier Jim Prentice and three passengers because the Cessna Citation 500 did not have a flight recording system.

In its report into the Oct. 13, 2016 plane crash near Kelowna released Thursday, the TSB is recommending the mandatory installation of lightweight flight recording systems by all commercial and private business operators not currently required to carry them.

TSB chair Kathy Foxsaid that without better data, the agency can only form a hypothesis about the cause of the wreck.

But the most likely crash scenario is that pilot Jim Kruk, who was dealing with a high workload, experienced spatial disorientation and departed from controlled flight shortly after takeoff.

Kruk also did not have the recent night flying experience required by Transport Canada for carrying passengers at night.

"When a pilot is very busy, as this pilot would have been during the take-off phase ... and because of his limited recent night-flying experience and limited recent instrument-flying experience, he would be more susceptible to this phenomenon," Fox told reporters in a Calgary news conference

"What that can lead to is that the sensations can lead to a feeling of tumbling backwards or vertigo because of the balance system in the inner ear. And it can actually cause a pilot to push forward on the controls and turn, thinking he's actually levelling out ... that's why it's so insidious and so dangerous."

The TSB said it’s also concerned about a lack of oversight by Transport Canada over private business aviation, finding no record that the federal agency had inspected the operator of the aircraft, Norjet Inc.

“We don’t like having to say ‘We don’t know’ when asked what caused an accident,” said Fox.

“We want to be able to provide definitive answer ... this is why we are calling today for the mandatory installation of lightweight flight recording systems on commercial and business aircraft not currently required to carry them.”

There is no legislation requiring smaller planes to carry black boxes, despite recommendations from the safety board dating back to 1991 calling for the installation of the devices.

Shortly after the 2016 crash, Transport Minister Marc Garneau said the government would look at potential regulatory changes given that advances in technology had made such systems more cost-effective.

In a statement Thursday, Garneau said department officials were looking closely at the report and would respond within 90 days, as required.

"Transport Canada takes recommendations from the Transportation Safety Board very seriously and shares their goal of maintaining and improving the safety of Canada's transportation network."

Just minutes after taking off from Kelowna on a night instrument rules flight heading to Springbank, the plane carrying Prentice made a steep descending turn to the right until it struck the ground.

Prentice served as a federal cabinet minister in Stephen Harper’s Conservative government and premier of Alberta from 2014 to 2015.

Besides Prentice and Kruk, Dr. Ken Gellatly, the father-in-law to one of Prentice's daughters, and Calgary businessman Sheldon Reid were killed in the 2016 crash.

Prentice's family issued a statement thanking the TSB for their work.

"While this report cannot restore what has been lost, it is our hope the learnings from this tragic event can be used to prevent similar accidents in the future."</s>The Transportation Safety Board can’t determine the cause of the 2016 plane crash that killed former Alberta premier Jim Prentice and three passengers because the Cessna Citation 500 did not have a flight recording system.

In its report into the Oct. 13, 2016 plane crash released Thursday, the TSB is recommending the mandatory installation of lightweight flight recording systems by all commercial and private business operators not currently required to carry them.

Investigators say the most likely crash scenario is that the pilot Jim Kruk, who was dealing with a high workload, experienced spatial disorientation and departed from controlled flight shortly after takeoff.

Kruk also did not have the recent night flying experience required by Transport Canada for carrying passengers at night.

The TSB said it’s concerned about a lack of oversight by Transport Canada over private business aviation, finding no record that the federal agency had inspected the operator.

“We don’t like having to say ‘We don’t know’ when asked what caused an accident,” TSB chair Kathy Fox said in a news release.

“We want to be able to provide definitive answers.”

Prentice served as a federal cabinet minister in Stephen Harper’s Conservative government and premier of Alberta from 2014 to 2015.

Besides Prentice and Kruk, Ken Gellatly and Sheldon Reid died in the 2016 crash.
The Transportation Safety Board of Canada concludes pilot disorientation was the most likely cause of a plane crash that killed former Premier of Alberta Jim Prentice and three others. The TSB asks Transport Canada to mandate cockpit voice recorders and flight data recorders on all commercial and private business aircraft.