(CNN) After sifting through the wreckage of the crash that killed Kobe Bryant and eight others , investigators revealed the helicopter lacked a safety feature recommended 14 years ago.

The aircraft did not have a terrain awareness and warning system (TAWS), the National Transportation Safety Board said. It also lacked a cockpit voice recorder and a flight data recorder, an NTSB member said.

TAWS is a safety feature that alerts pilots when they might hit land. The recorders can help authorities investigate a wreck.

A California congressman i ntroduced a bill Thursday directing the Federal Aviation Administration to require all helicopters to have TAWS. The Kobe Bryant and Gianna Bryant Helicopter Safety Act "will also establish a commission on helicopter safety and require a report to Congress on best practices for helicopters in cases of low visibility," US Rep. Brad Sherman said in a statement.

It's not clear whether TAWS would have helped prevent the helicopter carrying Bryant, his daughter and the others from crashing into a California hillside . Investigators are trying to determine the cause of the crash and whether the pilot should have been granted special permission to fly in the foggy conditions.

In 2006, the NTSB recommended all helicopters with six or more passenger seats be equipped with TAWS

"A terrain warning system would have given the pilots enough time to arrest their descent and save the lives of all aboard," NTSB Acting Chairman Mark Rosenker said in 2006.

But the NTSB doesn't have the authority to set new rules based on recommendations. That's up to the FAA, which never turned the recommendation into a new rule, NTSB member Jennifer Homendy said.

An FAA spokesman did not respond directly Wednesday to CNN's request for an explanation for why the agency did not make TAWS mandatory for all helicopters with six or more passenger seats.

Instead, the FAA provided a written statement explaining why it made TAWS mandatory for air ambulances, though not for all helicopters, including the one used by Bryant.

"Many helicopter air ambulance operations are conducted at night and from unimproved and unfamiliar landing areas," the statement said. "By contrast, on-demand operations tend to occur in populated areas, relying on a robust network of routes and landing facilities."

The FAA must consider cost-benefit analyses before making new rules, said Peter Goelz, a former managing director of the NTSB.

The FAA has estimated that TAWS would cost "$35,000 per helicopter for equipment and installation, plus $7,000 for revenue loss for equipment downtime," according to a government document from 2014

Goelz said he and other aviation experts believe "when it comes to safety, the cost-benefit analysis should never be the final call."

Some helicopter pilots might consider TAWS to be a nuisance, especially in good conditions when the terrain is visible but the system still triggers alerts, he said.

"If you have a device in a helicopter, which is often flying at low altitudes, often (TAWS) will go off and you will get alerts and that will cause the pilot to ignore it," Goelz said.

But that concern, he said, is "overstated."

"You can calibrate these things very carefully," Goelz said. "The workload argument doesn't hold up when you weigh it against the safety benefits."

What the helicopter maker and owner are saying

The Sikorsky S-76B helicopter carrying Bryant , his daughter and seven others was built in 1991. That was 15 years before the NTSB recommended all new and existing helicopters that can carry six passengers be equipped with TAWS.

Photos: The world mourns NBA legend Kobe Bryant Photos: The world mourns NBA legend Kobe Bryant Los Angeles Lakers' LeBron James, center, and Quinn Cook react to a video tribute for Kobe Bryant, before their game against the Portland Trail Blazers on January 31. Hide Caption 1 of 39 Photos: The world mourns NBA legend Kobe Bryant The jerseys of Kobe Bryant, right, and his daughter Gianna are draped on the seats the two last sat on at Staples Center, prior to the Lakers' game against the Portland Trail Blazers in Los Angeles, Friday, January 31. The last game the two attended was on December 29, 2019, when the Lakers faced the Dallas Mavericks. Hide Caption 2 of 39 Photos: The world mourns NBA legend Kobe Bryant A message honoring Kobe Bryant and his daughter Gianna is seen on the marquee of the Hollywood Paladium on Sunset Boulevard. Hide Caption 3 of 39 Photos: The world mourns NBA legend Kobe Bryant A makeshift memorial outside Staples Center in Los Angeles on January 31. Hide Caption 4 of 39 Photos: The world mourns NBA legend Kobe Bryant A mural of Kobe Bryant and his daughter Gianna adorns a basketball court on Monday, January 28, in Taguig, Metro Manila, Philippines. Hide Caption 5 of 39 Photos: The world mourns NBA legend Kobe Bryant The Empire State Building is illuminated gold and purple to honor Kobe Bryant on January 28. Hide Caption 6 of 39 Photos: The world mourns NBA legend Kobe Bryant Serbia's Novak Djokovic gets emotional as he talks about Kobe Bryant after winning a men's singles quarter-final match against Canada's Milos Raonic on day nine of the Australian Open tennis tournament in Melbourne on January 28. Hide Caption 7 of 39 Photos: The world mourns NBA legend Kobe Bryant Notes are seen on a wall with painted portraits of Kobe Bryant and his daughter Gianna outside the "House of Kobe" basketball court on January 28 in Valenzuela, Metro Manila, Philippines. Hide Caption 8 of 39 Photos: The world mourns NBA legend Kobe Bryant Store manager Satoshi Kanazawa, right, and Kazuhiro Taguchi hang a poster showing an image of former NBA basketball player Kobe Bryant at Selection in Tokyo on Monday, January 27. Hide Caption 9 of 39 Photos: The world mourns NBA legend Kobe Bryant The Detroit Pistons honor Kobe Bryant by wearing numbers 8 and 24 on their jerseys prior to a game against the Cleveland Cavaliers on January 27 at Little Caesars Arena in Detroit, Michigan. Hide Caption 10 of 39 Photos: The world mourns NBA legend Kobe Bryant Coco Gauff pays tribute to Kobe Bryant and his daughter, Gianna, with their names hand-written on her tennis tennis shoes during her Australian Open doubles tennis match on January 27. Hide Caption 11 of 39 Photos: The world mourns NBA legend Kobe Bryant Fans place flowers at a makeshift memorial outside of the Staples Center in Los Angeles on January 27. Hide Caption 12 of 39 Photos: The world mourns NBA legend Kobe Bryant Nicole Mascarenhas wipes her eyes in front of the Staples Center on January 27. Hide Caption 13 of 39 Photos: The world mourns NBA legend Kobe Bryant Children play with paper balls and a trash can in front of a makeshift memorial on January 27. A group of fans gathered at the LA Live Plaza and took turns shooting paper balls into the trash can while yelling "Kobe," a gesture practiced in classrooms and offices across America. Hide Caption 14 of 39 Photos: The world mourns NBA legend Kobe Bryant A sign at the 42nd St-Bryant Park subway station in New York City is covered with tape to read "Kobe Byrant Park" on January 27. Hide Caption 15 of 39 Photos: The world mourns NBA legend Kobe Bryant Gregg Donovan holds flowers at a memorial for Kobe Bryant near the Staples Center on January 27. Hide Caption 16 of 39 Photos: The world mourns NBA legend Kobe Bryant A spectator at the Australian open wears a Kobe Bryant jersey on January 27. Hide Caption 17 of 39 Photos: The world mourns NBA legend Kobe Bryant Flowers, jerseys and other memorabilia is left at the entrance of the Bryant Gymnasium at Lower Merion High School in Wynnewood, Pennsylvania, on January 27. Hide Caption 18 of 39 Photos: The world mourns NBA legend Kobe Bryant People mourn for former NBA star Kobe Bryant near the Staples Center on January 26. Hide Caption 19 of 39 Photos: The world mourns NBA legend Kobe Bryant People gather near a small memorial outside of a basketball court in Calabasas, California, on January 26. Hide Caption 20 of 39 Photos: The world mourns NBA legend Kobe Bryant The Pacific Park Ferris wheel at the Santa Monica Pier is lit up purple and gold with Kobe Bryant's number 24 in Los Angeles on January 26. Hide Caption 21 of 39 Photos: The world mourns NBA legend Kobe Bryant From left, Houston Rockets players Tyson Chandler, Austin Rivers and P.J. Tucker react during a tribute to Kobe Bryant before their game against the Denver Nuggets on Sunday, January 26. Hide Caption 22 of 39 Photos: The world mourns NBA legend Kobe Bryant Host Alicia Keys speaks about Bryant during the 2020 Grammy Awards on Sunday at the Staples Center in Los Angeles. Bryant spent his 20-year NBA career with the Lakers, who play in the Staples Center. Hide Caption 23 of 39 Photos: The world mourns NBA legend Kobe Bryant From left, Alex Fultz, Eddy Rivas and Rene Alfaro react to Bryant's death on Sunday outside of the Staples Center. Hide Caption 24 of 39 Photos: The world mourns NBA legend Kobe Bryant AFC defensive end Calais Campbell kneels as he and his teammates react to the announcement of Bryant's death Sunday in the second quarter of the 2020 Pro Bowl on Sunday in Orlando. Hide Caption 25 of 39 Photos: The world mourns NBA legend Kobe Bryant Dharma Brown, 8, writes a note to the late Bryant outside of the Staples Center in Los Angeles on Sunday. Hide Caption 26 of 39 Photos: The world mourns NBA legend Kobe Bryant LA Clippers assistant coaches Sam Cassell and Tyronn Lue react on the bench after honoring Kobe Bryant during a game against the Orlando Magic at Amway Center in Orlando on Sunday. Hide Caption 27 of 39 Photos: The world mourns NBA legend Kobe Bryant The ceiling of Madison Square Garden is lit in the colors of the Los Angeles Lakers as Bryant's picture is displayed during a moment of silence Sunday. Hide Caption 28 of 39 Photos: The world mourns NBA legend Kobe Bryant People gather at a memorial for Kobe Bryant near the Staples Center in Los Angeles on Sunday. Hide Caption 29 of 39 Photos: The world mourns NBA legend Kobe Bryant A fan shows off a Bryant jersey during a game between the Orlando Magic and the LA Clippers on Sunday. Hide Caption 30 of 39 Photos: The world mourns NBA legend Kobe Bryant Players and fans in Memphis observe a moment of silence for Bryant before the Phoenix Suns game against the Memphis Grizzlies on Sunday. Hide Caption 31 of 39 Photos: The world mourns NBA legend Kobe Bryant Inside the Staples Center, a man takes a photo of a mural featuring Bryant on Sunday. Hide Caption 32 of 39 Photos: The world mourns NBA legend Kobe Bryant Fans mourn in front of Bryant's image across from Staples Center on Sunday. Hide Caption 33 of 39 Photos: The world mourns NBA legend Kobe Bryant A memorial for Bryant is seen Sunday near the Staples Center. Hide Caption 34 of 39 Photos: The world mourns NBA legend Kobe Bryant A moment of silence is taken before the game between the San Antonio Spurs and the Toronto Raptors on Sunday at the AT&T Center in San Antonio, Texas. 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While that recommendation never became a federal mandate, Sikorsky started making TAWS standard on all its new S-76 helicopters starting in 2005, company spokeswoman Callie Ferrari told CNN.

TAWS for helicopters was also available as an optional equipment kit prior to 2005, Ferrari said.

Island Express Holding Corp., the owner of Bryant's helicopter that crashed, declined to comment to CNN about why the aircraft was not retrofitted with TAWS.

"Because this is an ongoing investigation, Island Express defers comment on this matter to the NTSB," according to a company statement.

The helicopter also lacked 2 recommended recorders

TAWS isn't the only feature recommended by the NTSB that wasn't on the helicopter. The aircraft also lacked a cockpit voice recorder and a flight data recorder, Homendy said.

"Having a CVR and an FDR would have helped us significantly in this investigation," the NTSB member said.

NTSB investigator Carol Hogan examines wreckage at the crash site.

Just like TAWS, cockpit voice recorders and flight data recorders are not required by the FAA for all helicopters.

"The FAA promotes voluntary equipage of flight recorders in aircraft for which regulations do not require these devices," the FAA said in a statement.

Island Express, the owner of Bryant's helicopter, declined to say why the aircraft didn't have the recorders, citing the ongoing investigation.

Some operators in the past have said flight data recorders are "too big and too heavy," Goelz said.

But "they have now miniaturized them. They are 5 pounds, at the most," he said.

"The idea that these kinds of devices aren't mandatory is really unacceptable."