Andreas Lubitz is seen in an image taken from Facebook.
Andreas Lubitz is seen in an image taken from Facebook.
PHOTO: from facebook
Now playing
01:57
Who was Andreas Lubitz?
SEYNE, FRANCE - MARCH 26:  In this handout image provided by French Interior Ministry, the Rescue workers and gendarmerie continue their search operation near the site of the Germanwings plane crash near the French Alps on March 26, 2015 in La Seyne les Alpes, France. Germanwings flight 4U9525 from Barcelona to Duesseldorf  has crashed in Southern French Alps. All 150 passengers and crew are thought to have died. (Photo by Francis Pellier MI DICOM/Ministere de l
SEYNE, FRANCE - MARCH 26: In this handout image provided by French Interior Ministry, the Rescue workers and gendarmerie continue their search operation near the site of the Germanwings plane crash near the French Alps on March 26, 2015 in La Seyne les Alpes, France. Germanwings flight 4U9525 from Barcelona to Duesseldorf has crashed in Southern French Alps. All 150 passengers and crew are thought to have died. (Photo by Francis Pellier MI DICOM/Ministere de l'Interieur/Getty Images)
PHOTO: Francis Pellier MI DICOM/Ministere de l'Interieur/Getty Images
Now playing
02:04
Report: Prior flight was 'practice' for co-pilot
lead dnt marsh germanwings final moments cell video_00000403.jpg
lead dnt marsh germanwings final moments cell video_00000403.jpg
Now playing
02:00
Reports: Cell phone video shows Germanwings' final moments
Caption:FRANKFURT, GERMANY - MARCH 14:(EXCLUSIVE COVERAGE)(EDITOR
Caption:FRANKFURT, GERMANY - MARCH 14:(EXCLUSIVE COVERAGE)(EDITOR'S NOTE: This photo is available exclusively through Getty Images except in Germany) In this photo released today, co-pilot of Germanwings flight 4U9525 Andreas Lubitz participates in the Frankfurt City Half-Marathon on March 14, 2010 in Frankfurt, Germany. Lubitz is suspected of having deliberately piloted Germanwings flight 4U 9525 into a mountain in southern France on March 24, 2015 and killing all 150 people on board, including himself, in the worst air disaster in Europe in recent history. (Photo by Getty Images)
PHOTO: Getty Images
Now playing
03:46
What effects do heavy antidepressants have on patient?
Andreas Lubitz is seen in an image taken from Facebook.
Andreas Lubitz is seen in an image taken from Facebook.
PHOTO: from facebook
Now playing
04:51
How can airlines detect mental problems in pilots?
ac pkg ripley germanwings copilot hometown_00004517.jpg
ac pkg ripley germanwings copilot hometown_00004517.jpg
Now playing
02:53
Germanwings copilot's hometown copes with crash
Caption:FRANKFURT, GERMANY - MARCH 14:(EXCLUSIVE COVERAGE)(EDITOR
Caption:FRANKFURT, GERMANY - MARCH 14:(EXCLUSIVE COVERAGE)(EDITOR'S NOTE: This photo is available exclusively through Getty Images except in Germany) In this photo released today, co-pilot of Germanwings flight 4U9525 Andreas Lubitz participates in the Frankfurt City Half-Marathon on March 14, 2010 in Frankfurt, Germany. Lubitz is suspected of having deliberately piloted Germanwings flight 4U 9525 into a mountain in southern France on March 24, 2015 and killing all 150 people on board, including himself, in the worst air disaster in Europe in recent history. (Photo by Getty Images)
PHOTO: Getty Images
Now playing
04:01
Someone with severe depression 'should not be flying'
nr lklv pleitgen germanwings plane crash lubitz_00004210.jpg
nr lklv pleitgen germanwings plane crash lubitz_00004210.jpg
PHOTO: Getty Images
Now playing
03:10
Should co-pilot's past have disqualified him for work?
A search and rescue worker at the crash site of the Germanwings Airbus A320 that crashed in the French Alps, above the town of Seyne-les-Alpes, southeastern France, 25 March 2015. Search crews resumed helicopter flights around dawn on 25 March to the remote mountainside where Germanwings Flight 4U 9525 from Barcelona to Duesseldorf crashed after a rapid descent, likely killing all 150 people aboard on 24 March.
A search and rescue worker at the crash site of the Germanwings Airbus A320 that crashed in the French Alps, above the town of Seyne-les-Alpes, southeastern France, 25 March 2015. Search crews resumed helicopter flights around dawn on 25 March to the remote mountainside where Germanwings Flight 4U 9525 from Barcelona to Duesseldorf crashed after a rapid descent, likely killing all 150 people aboard on 24 March.
PHOTO: GUILLAUME HORCAJUELO/EPA/Landov
Now playing
02:33
Report: Pilot heard screaming 'open the door!'
A man stands on March 29 2015 in front of a commemorative headstone in Seyne-les-Alpes, the closest accessible site to where a Germanwings Airbus A320 crashed on March 24 in the French Alps, killing all 150 people on board.
A man stands on March 29 2015 in front of a commemorative headstone in Seyne-les-Alpes, the closest accessible site to where a Germanwings Airbus A320 crashed on March 24 in the French Alps, killing all 150 people on board.
PHOTO: JEAN-PIERRE CLATOT/AFP/Getty Images
Now playing
05:37
Should doctor have told pilot's employer of problems?
nr lklv pleitgen germanwings plane crash lubitz_00004210.jpg
nr lklv pleitgen germanwings plane crash lubitz_00004210.jpg
PHOTO: Getty Images
Now playing
01:27
Report: Ex-girlfriend recalls co-pilot's dark side
A stele and flowers laid in memory of the victims are placed in the area where the Germanwings jetliner crashed in the French Alps, in  Le Vernet, France, Friday, March 27, 2015. The crash of Germanwings Flight 9525 into an Alpine mountain, which killed all 150 people aboard, has raised questions about the mental state of the co-pilot. Authorities believe the 27-year-old German deliberately sought to destroy the Airbus A320 as it flew Tuesday from Barcelona to Duesseldorf. (AP Photo/Christophe Ena)
A stele and flowers laid in memory of the victims are placed in the area where the Germanwings jetliner crashed in the French Alps, in Le Vernet, France, Friday, March 27, 2015. The crash of Germanwings Flight 9525 into an Alpine mountain, which killed all 150 people aboard, has raised questions about the mental state of the co-pilot. Authorities believe the 27-year-old German deliberately sought to destroy the Airbus A320 as it flew Tuesday from Barcelona to Duesseldorf. (AP Photo/Christophe Ena)
PHOTO: Christophe Ena/AP
Now playing
01:38
Germanwings pilot identified

Story highlights

Police search co-pilot Andreas Lubitz's apartment for clues

A pilot who knew Lubitz calls him a "very normal young person"

Investigators say they believe he deliberately crashed Germanwings Flight 9525

(CNN) —  

Co-pilot Andreas Lubitz’s voice isn’t heard in a recording of the final moments of Germanwings Flight 9525.

But investigators say he was the one at the controls inside the cockpit, deliberately locking out the plane’s captain and setting the plane on a crash course for the French Alps.

Andreas Lubitz had medical note for day of crash, hid illness, officials say

The only sound the recorder picked up from Lubitz as the Airbus A320 went down, Marseille prosecutor Brice Robin said, was the co-pilot’s steady breathing.

Authorities didn’t mince words Thursday as they blamed Lubitz for the crash, but questions are still swirling over the 27-year-old’s past.

Officials say Lubitz passed a psychological test when he was hired, had no known ties to terrorism and showed no sign of medical distress during the flight.

It seems, Robin said, that Lubitz “wanted to destroy the aircraft.”

But why?

Lufthansa CEO ‘speechless’

Police search apartment

That’s the question police were hoping to answer as they searched Lubitz’s apartment.

Police spokesman Markus Niesczery said a team of five investigators went “through the apartment looking for clues as to what the co-pilot’s motivation might have been, if he did indeed bring the plane down.”

Meanwhile, about 85 miles (136 kilometers) away in the town of Montabaur, the house where Lubitz’s parents live was shuttered and guarded by police.

A group of men, perhaps investigators, were the only ones granted access on Thursday. On Friday, there was no activity at all.

’This is just inconceivable’

Montabaur, in western Germany, is where Lubitz pursued his love of flying from a young age.

At a club on the outskirts of town, pilots who knew Lubitz said they were shocked to hear what investigators said.

They said the man they know never would have deliberately crashed a plane.

Between age 14 and age 20, Lubitz was a regular fixture at the gliding club.

“(He was) a very normal young person, full of energy,” Klaus Radke said. “What can I say? He had a bright future. He made his hobby into his job. What more can you hope to achieve?”

The authorities’ explanation doesn’t ring true for Peter Ruecker, another pilot who knew him from the flight club.

“Knowing Andreas, this is just inconceivable for me,” Ruecker told the Reuters news agency.

“He was a lot of fun, even though he was perhaps sometimes a bit quiet,” Ruecker said. “He was just another boy, like so many others here.”

An acquaintance said Lubitz was health conscious. He was a recreational athlete and didn’t smoke.

“I can’t imagine that he was mentally ill, depressed and sad. He doesn’t seem like that,” Johannes Rossbach told CNN. “So I was shocked when I heard that.”

An 8-minute descent to death

’Interrupted’ training

Lubitz had been with Germanwings, a budget airline owned by Lufthansa, since September 2013 and had completed 630 hours of flight time, the airline’s media office said.

Lufthansa CEO Carsten Spohr told reporters that Lubitz “interrupted” his training, which he began in 2008. That break lasted several months, he said, but added that such an interruption isn’t uncommon.

Spohr said he couldn’t give any information about why the co-pilot had stopped and then restarted his training.

If it was for medical reasons, he said, then that information would have been private before the crash, but it will be part of information gathered during the investigation.

Most of Lubitz’s training took place at the Lufthansa flight training center in Germany.

He also trained in the United States, spending six months at facility in Arizona as part of a required program to get his license, a Lufthansa spokesperson said.

Spohr said Lufthansa pilots get medical testing but do not undergo regular or routine psychological testing once they are flying. However, the airline does consider an applicant’s psychological state, along with other factors, when hiring pilots, he said.

Lubitz and the captain passed a psychological test when they were hired, he said.

“We don’t only look at competence but we also give a lot of room to psychological capabilities,” Spohr said.

“He was 100% set to fly without restrictions,” he added. “His flight performance was perfect. There was nothing to worry about.”

Students, singers among the victims

5 cases of pilots intentionally crashing

Diana Magnay reported from Montabaur. Catherine E. Shoichet and Ashley Fantz reported from Atlanta. CNN’s Fred Pleitgen contributed to this report from Cologne, Germany. CNN’s Mark Thompson, Eliott C. McLaughlin Laura Smith-Spark, Bharati Naik and Sara Sidner also contributed to this report.