Lion Air: Why did a brand new Boeing jet crash 13 minutes after takeoff?

"Exactly at the same time as the altitude, which meant that there was quite some loss of control."

The plane, which has been operating since August 15, was carrying 181 passengers and two pilots, bound for Pangkal Pinang on the Indonesian Island of Bangka.

Former US National Transportation Safety Board air crash investigator and CNN aviation analyst Peter Goelz told CNN the data clearly showed issues with both the speed and altitude of the plane.

"There is something obviously wrong in both the air speed and the altitude that would point to the flight control systems," he said. "These are fly-by-wire systems – highly automated – and pilots may not be able to troubleshoot failures in a timely manner."

'Airplanes do not just fall out of the sky'

Butterworth-Hayes said that it was only a few months ago, the reason behind the crash was "very unlikely" to be a mechanical fault.

"Airplanes do not just fall out of the sky," he said. "I can not think of any mechanical issue apart from a sudden, unexplained loss of engine power (or) complete electrical failure. It's far more likely to be an external event. "

He suggests that an environmental issue is to blame – such as a microburst, or the plane hitting something like a flock of birds.

"Microbursts are very difficult to detect – they're a sudden down-rush of wind, like a vortex and you can not really see it – you hit it start doing all sorts of recovery motions and then it's too late. "

The new Boeing 737 MAX 8 made a request to air traffic control to return to the airport 19 kilometers (12 miles) after takeoff, but did not indicate there was any emergency.

Sait, Yohanes Sirait, spokesman for AirNav Indonesia, told CNN.

Butterworth-Hayes said that the pilots had a minor incident where they were dealt with.

"Their call suggests it was a minor incident that they were in control of and they did not require assistance," he said. "But that quickly escalated."

"There was an altitude loss (and then just after that was fine," Butterworth-Hayes said while looking at the FlightRadar24 data.

"Whatever happens to that is a correction but that was not very long and that's when the plane started falling."

Speaking earlier with CNN, David Soucie – a safety inspector with the US Federal Aviation Administration – said the fact that an emergency was not a cause for concern.

"What's more, they're just saying that they're just saying, 'We're going back,'" said Soucie, to CNN safety analyst.

"But when I look at the track of the aircraft after that, the aircraft made it very rough, which is not typical of what they would have done," he added. "They would have maintained altitude and made that turn back to the airport."

Soucie added that something had to happen to the aircraft to lose control.

He did not look forward to seeing Jakarta. "That says that something abrupt and very fast happened to the aircraft."

Are pitot tubes to blame?

Haryo Satmiko told reporters, including Reuters, during a conference on Monday, "unreliable airspeed," the deputy chief of Indonesia's National Transport Safety Committee.

Engineers had checked and repaired the issue, Lion Air Chief Executive Edward Sirait told local media, and that they gave the plane to fly.

When asked about the "unreliable airspeed" problem that was reported, Butterworth-Hayes said the pilots would have been reporting an issue with the pitot tubes that determined air speed. Infamously, Pitot tubes were blamed for the Air France Flight 447 crash in 2009 when it plunged into the Atlantic Ocean. Ice crystals blocked the plane's pitot tubes, the autopilot disconnected and the pilots did not know how to react to what was happening.

"It reminds me of the fact that it has come to the fore in the Atlantic where you had accelerating speed and a loss of altitude – which there was a sudden loss of control of the aircraft," he said.

"But if you look at the speed (from the data from FlightRadar24), it's pretty constant."

He says, however, "Pitot tubes are only one part of the issue – if there is a difference in aircraft performance indications."

Boeing 737 MAX 8 'best of the line, best you can buy'

The aircraft was one of 11 Boeing planes in Lion Air's fleet. In a statement, Boeing said the company was "deeply saddened" by the loss and offered "heartfelt sympathies" to passengers and crew on board, and their families.

Soucie said 800 hours was plenty of time to get this tried and true.

He added the MAX 8 was "the top of the line, it's one of the best you can buy …"

Goelz agreed that the loss of such a new aircraft was "highly unusual."

But because Air Lion's pilot and co-pilot were experienced – 6,000 and 5,000 flight hours, respectively – and the weather did not seem to be a factor, investigators would be focusing on the aircraft, he said.

Indonesian aviation authorities will inspect all Boeing 737 Max 8 planes belonging to the country's commercial airlines, Transportation Ministry official Capt. Avirianto told CNN.

Avirianto said Garuda's plane was inspected on Monday night. The ministry waited for inspection at least one of Lion's remaining aircraft Tuesday night and the other eight soon. "We will checklist one by one, with its system and technical things," he said.

Until the aircraft's flight recorders are found and investigated, it's unlikely we'll be able to find out more about the cause of the Monday's crash, Aviation consultant and former pilot Alastair Rosenschein told CNN's Becky Anderson.

Rosenschein said it was particularly important to find the black boxes because it was a new aircraft.

"What happened here could possibly affect the same model of aircraft flying in other parts of the world," he said.

Until those boxes are found, it's unlikely that they will be able to figure out what brought down the plane.

Goelz said the Lion Air crash is still another one.

"I also think it will take a few days to find the date recorders," he said, adding it's hard to find things in the ocean.

"(It) again highlights the need for more sophisticated tracking and recovery devices."