[UPLIFTING MUSIC PLAYING]

CARL AZUZ: One chamber of the US Congress

has voted to overturn a presidential emergency

declaration.

I'm Carl Azuz with your down-the-middle explanation

of what that means.

When he was on the campaign trail in 2016,

future US president Donald Trump promised

to build a wall along America's southern border with Mexico.

He recently asked Congress for $5.7 billion to pay for it.

Congress did not approve that.

It set aside a little less than $1.4 billion

for border security.

So earlier this month, the president

declared a national emergency.

That would allow him to access the money to build a wall

or barrier without the approval of Congress,

even though Congress has the constitutional control over how

the government spends public money.

Presidents have been allowed to declare

national emergencies under a law that was passed in 1976.

And they've done that dozens of times.

But under that law, Congress also

has the authority to stop the emergency declaration.

And while it hasn't done that before, one chamber of it,

the House of Representatives, voted

yesterday to overturn President Trump's emergency declaration.

So what happens next?

Well, it's now up to the Senate to vote in the weeks ahead.

And we don't know how that'll turn out.

The house is controlled by Democrats who

mostly disapprove of the wall.

In the Senate, Republicans, who mostly support the wall,

have a small majority.

But some may still vote against the Republican president's

Emergency declaration because they're concerned

that a future Democratic president

can use the same power to do something they don't want.

Even if the Senate joins the house in overturning

the emergency declaration, President Trump

would veto that, and it would probably stand.

But there are other challenges.

16 states have filed a lawsuit to block the declaration

from going through.

President Trump said he expected that and that the Supreme

Court would ultimately side with his administration.

How and when all this plays out is in the hands

of Congress and the courts.

Another priority for President Trump

is getting the communist nation of North Korea

to completely give up its nuclear program.

He's in the Southeast Asian country of Vietnam

right now for a second historic summit

with North Korea's leader.

Kim Jong-un is hoping that the US

will end its sanctions, its economic penalties,

on his country.

The question of which nation should make the first move

has been a sticking point since the two leaders first summit

last summer.

Ahead of their second meeting, the White House

said just the fact that these rival leaders were getting

together was a victory and that a third summit down the road

might be necessary for them to reach a final agreement.

But several international analysts

are saying that this summit is when action needs to be taken.

WILL RIPLEY: US President Donald Trump

and North Korean leader Kim Jong-un

are meeting for a second time.

First, it was Singapore-- now, Hanoi, Vietnam.

Whatever you want to call it, Trump-Kim,

Round Two, Trump-Kim, The Sequel, Trump-Kim 2.0,

it's surreal.

These guys went from trading threats--

DONALD TRUMP: They will be met with fire and fury.

WILL RIPLEY: --to exchanging letters.

DONALD TRUMP: And then we fell in love, OK?

No, really.

He wrote me beautiful letters.

WILL RIPLEY: But let's be real.

Analysts say it'll take much more

than letters for the Hanoi summit

to deliver what Singapore did not--

actual progress on denuclearization.

The first summit was heavy on symbolism, light on specifics.

Trump and Kim signed a vaguely worded agreement.

It allowed them to walk away with very different ideas

of what should happen next.

Now, you can argue both sides have

taken steps to reduce tensions.

Before the summit, Kim suspended missile

launches and nuclear tests.

The North Koreans even took us to their nuclear test sites

so we could watch them blow parts of it up.

After the summit, North Korea handed over a few dozen

sets of Korean War remains.

Trump suspended joint military exercises with South Korea.

He sent his top diplomat, Mike Pompeo, to Pyongyang

four times.

MIKE POMPEO: We had productive, good-faith negotiations.

WILL RIPLEY: But talks fell apart.

The US wanted North Korea to be transparent about its nuclear

program and to start taking irreversible steps

to get rid of nuclear weapons.

DONALD TRUMP: Complete denuclearization.

WILL RIPLEY: Did that happen?

No.

North Korea wanted the US to ease up

on sanctions pressure, work on building trust,

normalizing relations.

Did that happen?

No.

That's what makes the second summit in Hanoi so important.

Analysts say both sides need to come

to the table with realistic expectations, a willingness

to compromise, and they need to walk away with a specific plan.

Singapore delivered plenty of made-for-TV moments.

Hanoi needs to deliver results.

CARL AZUZ: 10-second trivia, which

of these airports sees more passengers than any other--

Hartsfield-Jackson Atlanta, Beijing Capital, London

Heathrow, or Chicago O'Hare?

With more than 100 million passengers annually,

Atlanta's Hartsfield-Jackson International is considered

the world's busiest airport.

And it's near that airport that a major US airline

has just opened a massive facility

where jet engines are tested.

Let's say a plane with two engines is in the air,

and one of them gives out.

The plane can still stay aloft.

But the thrust in the working engine

needs to be increased quickly to produce an extraordinary amount

of power.

And facilities like this one are built

to make sure the engines, with their tens of thousands

of parts, can handle that pressure

long before they're mounted on a plane and put in the air.

The future of testing some of the most powerful jet engines

in the world is right here at Delta's

brand-new facility in Atlanta.

MIKE MOORE: This is exciting because this is the largest

test cell in the world.

And we're going to be able to run engines 30, 40,

50 years into the future because of the way

we've built this facility.

CARL AZUZ: The engines that keep travelers

up in the air during tens of thousands of flights a day

have to be checked regularly to make sure they're safe to fly.

That's what this place is for.

DON MITACEK: Well, airline engines

are getting bigger and bigger because we're

building bigger and bigger, more efficient wide-body aircraft.

MIKE MOORE: This test cell can handle

up to 150,000 pounds of thrust.

And when you think of thrust, just think

of as you stand on a scale.

Instead of standing on the scale,

you would hold the scale horizontally

and push it in space.

That's thrust.

CARL AZUZ: Everything in here is gigantic,

designed to keep the engines' massive power inside the cell

and away from bystanders.

The walls are made of concrete 3-feet thick,

and the doors weigh more than 300,000 pounds.

A huge lift is built into the floor

so workers can reach the engines, which

can weigh more than 8 tons.

MIKE MOORE: A typical engine when

it goes through the rebuild process is in a shop

anywhere from 60 to 90 days.

The engines are completely disassembled.

All the piece parts are inspected.

Everything's reassembled, and then it has to come

to this facility to be tested.

The testing allows us to make sure that oil, temperatures,

oil pressures, rotor speeds, exhaust gas temperatures,

thrust, everything meets the parameters that we know

that when we put it out on the aircraft

that it's going to last as long as it's supposed to.

DON MITACEK: We expect this facility

to support not only Delta Airlines but 150

other customers we have.

And that should equate to about 1,000,

1,200 engines in the next three to five years.

The real story about this facility

is not that it's the largest test cell in the world,

but it's what it represents.

It's a legacy our senior technicians

are going to leave behind.

CARL AZUZ: It's all aimed at making Delta more

competitive as more and more airliners and passengers

take to the skies.

[GUITAR ROCK PLAYING]

Winning 10 out of 10 today, what could be the world's

most extreme model plane.

A Chinese farmer always dreamed of owning a passenger jet,

but they're expensive.

So he built his own.

This is a model of an Airbus A320.

It is life-sized.

It reportedly took more than 60 tons of steel to build,

and its materials cost the farmer almost $400,000.

Along with a team of a few other farmers turned mechanics,

they put this together in a little over two years.

(RAPPING) It's a dream of a model and a model of a dream.

Maybe it'll never catch an in-flight airstream.

But it's taken off in interest if not taken off the ground.

It's a soaring success even though it's earthbound.

It's a one-to-one scale reproduction fantasy.

Was it worth it?

Well, that's plain to see.

I'm Carl Azuz.

"CNN 10" is back tomorrow.

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