NBC'S TOM COSTELLO COVERS AVIATION FOR US.

AVIATION FOR US. >> Reporter: AMERICAN AND

>> Reporter: AMERICAN AND SOUTHWEST FLY THE MAX 8.

SOUTHWEST FLY THE MAX 8. UNITED FLIES THE MAX 9.

UNITED FLIES THE MAX 9. SEVERAL KANDCANADIAN AIRLINES FL

SEVERAL KANDCANADIAN AIRLINES FL THE PLANE.

THE PLANE. ALL OF THEM STANDING BY THE

ALL OF THEM STANDING BY THE PLANE.

PLANE. THE FAA IS UNDER SERIOUS

THE FAA IS UNDER SERIOUS PRESSURE TO GROUND THIS PLANE IF

PRESSURE TO GROUND THIS PLANE IF THERE'S THE SLIGHTEST HINT OF A

THERE'S THE SLIGHTEST HINT OF A FATAL FLAW.

FATAL FLAW. THIS MORNING BOEING IS ON

THIS MORNING BOEING IS ON NOTICE.

NOTICE. THE FAA SAYS IT EXPECTS TO ORDER

THE FAA SAYS IT EXPECTS TO ORDER MANDATORY DESIGN CHANGES TO THE

MANDATORY DESIGN CHANGES TO THE 737 MAX 8 BY THE END OF APRIL.

737 MAX 8 BY THE END OF APRIL. OVERNIGHT, AUSTRALIA BECAME THE

OVERNIGHT, AUSTRALIA BECAME THE LATEST COUNTRY TO GROUND THE MAX

LATEST COUNTRY TO GROUND THE MAX 8 UNTIL INVESTIGATORS GET A

8 UNTIL INVESTIGATORS GET A READOUT FROM THE ETHIOPIAN

READOUT FROM THE ETHIOPIAN AIRLINES BLACK BOXES.

AIRLINES BLACK BOXES. CHINA AND INDONESIA HAD ALREADY

CHINA AND INDONESIA HAD ALREADY MADE THE DECISION TO GROUND

MADE THE DECISION TO GROUND ALONG WITH ABOUT TWO DOZEN

ALONG WITH ABOUT TWO DOZEN AIRLINES.

AIRLINES. THE CRITICAL QUESTION IS THERE

THE CRITICAL QUESTION IS THERE ANY CONNECTION BETWEEN THE MAX 8

ANY CONNECTION BETWEEN THE MAX 8 CRASH IN ETHIOPIA AND THE LION

CRASH IN ETHIOPIA AND THE LION AIR MAX 8 CRASH IN INDONESIA

AIR MAX 8 CRASH IN INDONESIA LAST OCTOBER?

LAST OCTOBER? IN A LETTER TO BOEING EMPLOYEES,

IN A LETTER TO BOEING EMPLOYEES, THE CEO WRITES WE ARE CONFIDENT

THE CEO WRITES WE ARE CONFIDENT IN THE SAFETY OF THE 737 MAX AND

IN THE SAFETY OF THE 737 MAX AND IN THE WORK OF THE MEN AND WOMEN

IN THE WORK OF THE MEN AND WOMEN WHO DESIGN AND BUILD IT.

WHO DESIGN AND BUILD IT. BUT A FORMER NTSB CHAIRMAN SAYS

BUT A FORMER NTSB CHAIRMAN SAYS THE WORLDWIDE FLEET SHOULD BE

THE WORLDWIDE FLEET SHOULD BE GROUNDED, INCLUDING THOSE FLOWN

GROUNDED, INCLUDING THOSE FLOWN IN THE U.S.

IN THE U.S. >> AN AIRCRAFT OUGHT TO

>> AN AIRCRAFT OUGHT TO VOLUNTARILY ITSELF GROUND THESE

VOLUNTARILY ITSELF GROUND THESE AIRCRAFT.

AIRCRAFT. >> THE FAA SAYS ITS

>> THE FAA SAYS ITS INVESTIGATORS ARE AT THE CRASH

INVESTIGATORS ARE AT THE CRASH SCENE WITH THE NTSB, AND IF WE

SCENE WITH THE NTSB, AND IF WE IDENTIFY AN ISSUE THAT AFFECTS

IDENTIFY AN ISSUE THAT AFFECTS SAFETY, THE FAA WILL TAKE

SAFETY, THE FAA WILL TAKE IMMEDIATE AND APPROPRIATE APGS.

IMMEDIATE AND APPROPRIATE APGS. ONE OF THE WORLD'S BIGGEST

ONE OF THE WORLD'S BIGGEST FLIGHT ATTENDANT UNION WANTS

FLIGHT ATTENDANT UNION WANTS CONCRETE ACTION TO KEEP THE

CONCRETE ACTION TO KEEP THE PUBLIC SAFE.

PUBLIC SAFE. >> WE'RE CALLING FOR

>> WE'RE CALLING FOR TRANSPARENCY SO THE CREWS AND

TRANSPARENCY SO THE CREWS AND THE PUBLIC CAN HAVE FULL

THE PUBLIC CAN HAVE FULL CONFIDENCE.

CONFIDENCE. >> AMONG THE 167 PEOPLE WHO

>> AMONG THE 167 PEOPLE WHO DIED, 19 UNITED NATIONS WORKERS

DIED, 19 UNITED NATIONS WORKERS AND PASSENGERS FROM NEARLY 30

AND PASSENGERS FROM NEARLY 30 DIFFERENT COUNTRIES, 32 KENYANS,

DIFFERENT COUNTRIES, 32 KENYANS, 18 CANADIANS, NINE ETHIOPIANS

18 CANADIANS, NINE ETHIOPIANS AND EIGHT AMERICANS TWO OF THE

AND EIGHT AMERICANS TWO OF THE AMERICANS IDENTIFIED AS MELVIN

AMERICANS IDENTIFIED AS MELVIN AND BENNETT RIFFLE, THE BROTHERS

AND BENNETT RIFFLE, THE BROTHERS WERE RETURNING FROM A TRIP TO

WERE RETURNING FROM A TRIP TO AUSTRALIA

AUSTRALIA AUSTRALIA.

AUSTRALIA. MELVIN AND HIS WIFE WERE

MELVIN AND HIS WIFE WERE EXPECTING THEIR FIRST CHILD.

EXPECTING THEIR FIRST CHILD. >> THEY'RE GOING TO BE MISSED

>> THEY'RE GOING TO BE MISSED DEEPLY BY THIS COMMUNITY.

DEEPLY BY THIS COMMUNITY. >> A THIRD AMERICAN IDENTIFIED

>> A THIRD AMERICAN IDENTIFIED OVERNIGHT, ANTWAN LEWIS, A

OVERNIGHT, ANTWAN LEWIS, A MEMBER OF THE U.S. MILITARY,

MEMBER OF THE U.S. MILITARY, ALSO AMONG THE VICTIMS, DR.

ALSO AMONG THE VICTIMS, DR. DR. MANISHA A DOCTOR AT EAST

DR. MANISHA A DOCTOR AT EAST TENNESSEE STATE UNIVERSITY WHO

TENNESSEE STATE UNIVERSITY WHO WAS FLYING TO KENYA TO SEE HER

WAS FLYING TO KENYA TO SEE HER SISTER WHO HAD JUST GIVEN BIRTH

SISTER WHO HAD JUST GIVEN BIRTH TO TRIPLETS.

TO TRIPLETS. NBC'S SARAH HARMAN IS IN NAIROBI

NBC'S SARAH HARMAN IS IN NAIROBI NAIROBI, KENYA, THE PLANE'S

NAIROBI, KENYA, THE PLANE'S INTENDED DESTINATION.

INTENDED DESTINATION. >> THIS IS A TERMINAL WHERE

>> THIS IS A TERMINAL WHERE PASSENGERS SHOULD HAVE ARRIVED

PASSENGERS SHOULD HAVE ARRIVED ON SUNDAY.

ON SUNDAY. INSTEAD, THEIR GRIEF STRICKEN

INSTEAD, THEIR GRIEF STRICKEN FAMILIES ARE RECEIVING

FAMILIES ARE RECEIVING COUNSELING AT A HOTEL NEARBY.

COUNSELING AT A HOTEL NEARBY. >> Reporter: THIS MORNING THE

>> Reporter: THIS MORNING THE PRESSURE IS ON INVESTIGATORS TO

PRESSURE IS ON INVESTIGATORS TO FIND OUT WHY TWO BRAND NEW

FIND OUT WHY TWO BRAND NEW PLANES SUDDENLY FELL OUT OF THE

PLANES SUDDENLY FELL OUT OF THE SKY, AND WHETHER BOTH CREWS

SKY, AND WHETHER BOTH CREWS STRUGGLED TO KEEP THE PLANE IN A

STRUGGLED TO KEEP THE PLANE IN A TRIM OR LEVEL FLYING CONDITION.

TRIM OR LEVEL FLYING CONDITION. >> IF IT'S A TRIM PROBLEM, IT'S

>> IF IT'S A TRIM PROBLEM, IT'S GOING TO BE A MAJOR ISSUE THAT

GOING TO BE A MAJOR ISSUE THAT THEY'RE GOING TO HAVE TO SOLVE

THEY'RE GOING TO HAVE TO SOLVE IN A HURRY, BUT THAT COULD