Investigators who arrived at the crash site today on the Magdalen Islands, where a small aircraft went down killing all seven people on board, say preliminary clues show the plane's engines were working and it appears the plane crashed on its approach.

"Based on our first observations, we see the engines had power," said André Turenne, a Transportation Safety Board of Canada technical investigator, speaking in French.

The plane went down about three kilometres from the airport, killing all seven people on board, including Jean Lapierre, political commentator and former Liberal federal cabinet minister.

Plane Crash 20160329

Jean Lapierre and his wife, Nicole Beaulieu, were killed Tuesday when a plane crashed on Quebec's Îles-de-la-Madeleine. They were on their way to a funeral for Lapierre's father. (Paul Chiasson/Canadian Press)

Lapierre was killed along with his wife, sister and two brothers. The family was travelling to the funeral of Lapierre's father, who died last Friday at the age of 83.

The aircraft's pilot and co-pilot also died in the crash.

The plane went down while attempting to land in freezing fog and rain.

It crashed as it approached an airfield near Havre-aux-Maisons around 11:40 a.m. AT Tuesday, about three kilometres from the airport.

"This appears to be, at this time, an approach and landing accident, and that is an issue that is of concern to the TSB and we have that on our watch list," Turenne said.

"The phase of flight that is of concern to the TSB, and other investigation agencies around the world, is the approach and landing phase. There are quite a lot of accidents that occur in the approach and landing phase, so we will look in detail at that."

The TSB is leading the joint investigation. It is working with about 20 investigators from the provincial police, and also the Canadian Coast Guard, which is taking aerial photos of the wreckage.

'Fog is a factor'

"Fog is a factor, and we will take the data that was given to the pilot before the flight, and if the conditions deteriorated during the flight while approaching the Magdalen Islands," said Turenne.

Andre Turenne

André Turenne, a TSB techincal investigator, says the team "will leave no stone unturned" in its investigation into the fatal plane crash. (CBC)

The TSB's team of six investigators arrived around noon, and spent all afternoon examining the wreckage.

Investigators said the type of aircraft involved in the crash, which was an American-registered 1982 Mitsubishi MU-2B-60 with the tail number N246W, is not equipped with a black box.

But they hope to recover its GPS in the wreckage.

"With the GPS, we will be able to get the flight path until the impact, and we'll be able to answer questions such as: What was the speed on the approach? At what moment did the pilot turn?  Where was he? Was he aware of his position?" Turenne said.

Criminal investigation also underway

About 20 Sûreté du Québec investigators arrived on site around 8 a.m.

"Our role is to ensure that there are no criminal elements involved here," said SQ spokeswoman Martine Asselin. "It'll take a few days to establish if anything is criminal. We need to trace back the last 24 hours of people's lives before they died."

Asselin said that when officers arrived on site this morning, the bodies of the victims were still there. Officers set up a one-kilometre square perimeter around the crash site.

"With images we saw yesterday, we could see that the weather conditions were rough. Was this a factor in this case? It is still too soon to know," Asselin said.

Officers have already met with some witnesses, she said.

The Quebec coroner will investigate to determine the probable cause of death for the seven victims. The report is expected to be publicly released in the coming months.

Investigating Magdalen Islands plane crash2:00

A family in mourning

Pascal Gosselin

Pascal Gosselin was an experienced pilot. (Magazine Aviation)

The family of Pascal  Gosselin, the pilot who was killed during the crash, said they are devastated and looking for answers.

Gosselin's loved ones released a statement Wednesday saying they were at "a loss for words to describe their immeasurable loss."

Fabrice Labourel

Co-pilot Fabrice Labourel was also killed in the crash. Gosselin had asked him to accompany him because of the difficult weather conditions. (CPAQ Aero)

"It's hard to explain the inexplicable," the statement read. "At this very moment everyone is waiting on answers that unfortunately won't come today."

His co-pilot and friend Fabrice Labourel was also killed during the crash. Gosselin, an experienced pilot, had asked him to accompany him on the trip due to tough weather conditions.

Funeral service delayed

André Leblanc, the owner of the Leblanc funeral home in the Magdalen Islands, told Radio-Canada that the funeral for Lapierre's father is on hold.

The wake and funeral for Raymond Lapierre were supposed to take place on Friday but have been delayed.

With files from CBC's Jay Turnbull, Marika Wheeler