All language subtitles for Air.Crash.Investigation.S24E04.Without.Warning.1080p.HDTV.x264.STER.en

Above the remote Alaskan wilderness…

two planes collide.

Mayday. Mayday.

A witness races to help.

All I saw was a whole
bunch of people floating.

Six people are dead.

A mid-air collision is probably the most
scary thing that could happen to you.

NTSB investigators talk
to the surviving pilot.

Look, he was just there.
I couldn't avoid him.

When they examine
the on-board alerting system…

Why didn't he turn away?

the mystery deepens.

We're missing something.

But then investigators
get an unexpected glimpse,

-Whoa.
-into a key moment in time.

It was eerie and
disturbing to see the photos

because they were taken
in a person's last moments.

Mayday! Mayday!

[warnings blaring]

PULL UP!

[indistinct radio chatter]

It's a busy day at Alaska's
Misty Fjords floatplane base.

Four cruise ship passengers
have booked a sightseeing

flight over Alaska's
spectacular southeast coast.

Okay, folks, get comfortable
and fasten your seat belts.

46-year-old Randy Sullivan is the owner of
Mountain Air Services and its only pilot.

Hey, looks like you're going
to have the best view in Alaska.

I can hardly wait.

This will be Sullivan's
second flight of the day.

Just got a few things to
do before we get started.

Randy Sullivan has spent most of
his career flying over Misty Fjords.

Transponder on and broadcasting.
Okay, guys, put your headsets on.

Mountain Air was a small operator
doing primarily sightseeing trips.

Can you guys hear me okay?

Okay, here we go.

This would have been his
entire life running this company,

and he would have loved what he was doing.

All right.
Flight controls free and correct.

Master fuel, check.
Landing lights, check.

Just after 12 noon, the Mountain
Air floatplane is ready for takeoff.

Okay, that's five minutes
since last departure.

Pilots space out their takeoffs since
there's no air traffic control in this area.

Misty traffic, this is
Beaver 52 Delta Bravo.

Ready for a straight out.
Any conflicting? Misty traffic.

Sullivan radios other pilots in the area.

In airspace like the Misty Fjords,

the pilots all control themselves,

and it's primarily a see
and be seen situation.

Without any air traffic
control to keep you separated,

you have to maintain
that separation yourself.

It's a textbook takeoff in light winds.

Today's 40-mile flight will take
passengers from Rudyerd Bay to Ketchikan.

They'll cross high mountains
and dramatic terrain.

Misty Fjords is an
absolutely beautiful area.

It's towering mountains,
glaciers, lakes, fjords, wildlife.

And the best way to see a place
like that of course is from an airplane,

where you can get the full impact of the
scenery and the immenseness of the area.

Every year, more than 100,000 cruise ship
passengers visit Alaska's Misty Fjords.

The flight tours have become
an essential experience

for those who can
afford the luxury price tag.

If you look out to your left,

you'll see cliffs that were carved
smooth by the last great ice age.

Randy Sullivan points out the
highlights throughout the flight.

Being a single pilot operation
while you're doing the tours,

you're multitasking with
your customers all the time,

trying to give them the best
tour that you can give them.

At the same time, you're
also multitasking as a pilot,

where you're trying to maintain your

situational awareness
of all the other aircraft,

as well as you're a lot of times flying
at very low level through the terrain,

which adds one more bit of
complexity to the entire operation.

Mountain Air Services
operates a de Havilland Beaver,

a single-engine prop plane.

The Beaver was originally built for
the United States Air Force in 1951,

but many are now operated
by northern bush pilots.

De Havilland Beaver was a
uniquely designed airplane,

and the takeoff and landing
is absolutely incredible.

That's what makes it
so versatile in the bush,

is that you can get it in and
out of pretty much any little lake. Uh.

If you're on wheels or skis, you can get
it off short strips or short frozen lakes.

Misty traffic, Beaver 2
Delta Bravo exiting Rudyerd,

climbing through 1,900 westbound.

Check that. 45 Mike Mike is just
off the water now and well behind you.

It's May, and this part of Alaska is
enjoying exceptionally good weather.

On the Alaska coast, the weather
can change extremely rapidly.

It can go from a
beautiful clear day to just

horrible weather within a
very short period of time.

When the days are good,
all the aircraft are flying,

everybody is out making
hay while the sun shines.

-Have a good cruise so far?
-It's been great.

The forecast for tomorrow
is low clouds and rain.

So today, Sullivan plans to
operate a full day of flights.

You all are pretty lucky. They call
this place the Misty Fjord for a reason.

Weather like this is pretty rare.

Beaver 8 Golf Mike is 2,700
feet in the climb, exiting the bay.

We've got the Mountain Air Beaver ahead.

We will fall in trail behind.

Hey Dave, I've got you on
display, but I don't have you visual.

As long as you can see me, we're good.

I got you above and ahead
of me, Randy. Enjoy the ride.

Oh, uh huh, uh

even if we can't see each other the display
lets us know where the other planes are.

Cool.

The traffic systems will enhance
your ability for the see-and-avoid,

because it will alert
you of aircraft that you

may have missed because of visibility
issues, before you get too close.

Coming up in about
two minutes on your right,

you're going to see one of the highlights
of the trip, the majestic Mahoney Falls.

20 minutes into the flight,
the Beaver approaches the waterfall.

Passengers are treated
to a spectacular view.

The Beaver and another aircraft collide.

The Beaver basically came apart.
It free-fell 3,000 feet from the sky.

A retired fisherman on George
Inlet is shocked by what he sees.

Mayday. Mayday. This is Hotel
Sea calling Coast Guard radio.

Go ahead, state the
nature of your emergency.

The second plane involved is a
larger ten passenger de Havilland Otter.

Two float planes down, George Inlet.

The Otter was still largely
intact. There was damage.

The pilot obviously kept his cool
and managed to control the aircraft.

I saw a, an Otter floatplane crash
into the water with a huge splash and,

I got closer and all I saw
was a whole bunch of people

floating in the, in an area 50, 60 yards.

But there was one person um,
that never made it out of the airplane.

The ten survivors, including
the pilot, are rushed to hospital.

There are no survivors from the
plane piloted by Randy Sullivan.

How could two planes in one of the most
popular tourist destinations on Earth,

collide in mid-air?

Within hours, the National
Transportation Safety Board, or NTSB,

dispatches a team of
investigators to search for wreckage.

We still have to recover the planes,
and then we have to look at those,

and it, it takes some significant work to

really understand how
the two came together,

but we have some great experts at
the NTSB who are well versed in that.

Aaron Sauer is named lead investigator.

The wreckage area of the Beaver
was scattered for about 3,000 feet.

Uh, a portion of the main fuselage was
located upside down in the saltwater.

There was a lot of debris that was mixed
into the terrain in that mountainous area.

Vegetation was high. It was very
difficult to navigate to try and recover

as much of the debris from
the Beaver that we could.

The other aircraft, the Otter, is owned
by the largest tour operator in the area,

Taquan Air.
It sank in 80 feet of water.

The floats of the Otter were separated.

They ended up washing ashore.

But ultimately, they
were able to get divers

down, locate the wreckage
almost immediately,

and they were able to successfully
get that aircraft up on that barge.

Um, tag the Beaver wreckage, and when the
Otter comes, we're going to put it there.

The small sightseeing planes were
not required to carry black boxes.

Keep an eye out for avionics, cameras,
phones, anything with photos or,

data that will help
us piece this together.

Without recorders, the investigation
becomes much more difficult.

So without the cockpit voice
recorder and flight data recorder,

we had to look for other sources of data.

Hey, help me move this.

As the team surveys the Beaver wreckage,

they find evidence that can help
them piece together the violent collision.

These are sawtooth marks, from
a propeller striking the right wing.

We wanted to understand
what angle did we have.

That was very important
for us to understand

in order to recreate the collision
and aid us in the investigation.

The pattern's in the inboard direction.

So the Otter came from
behind and to the right.

The discovery begins to unveil what
happened in the skies over Misty Fjord.

The collision angle was important for us
because what it told us is both airplanes

weren't necessarily on a
head-on collision course.

They were more or less headed to the same
location with a shallow degree of angle.

The collision was more of a sideswipe.

Both planes took off from Rudyerd Bay here

and headed to their
cruise ship in Ketchikan.

The Beaver left first,

and a few minutes later,
the Otter departed.

With a basic understanding
of how the two planes collided,

investigators try to pinpoint
where the accident occurred.

We had one witness…

who was located, here.

We had a witness that
was hunting in the area

that didn't see the
collision but heard the

collision, which then
in turn gave us an idea

of where exactly did this
happen up in a point in sky.

Based on his account the collision
happened, somewhere in here.

Investigators now know exactly
where the accident occurred,

but they still don't know why.

Maybe, they were converging on this point.

The planes collided very
near the scenic Mahoney Falls.

It is certainly possible.

It has happened before.

A similar mid-air collision
happened over Arizona in 1986.

A Twin Otter and a helicopter
collided over the Grand Canyon,

killing 25 people.

Both aircraft were also approaching
a popular scenic attraction.

Air tour flights have a higher rate of
mid-air collisions, statistically speaking,

because they operate in areas with dense
traffic around various scenic landmarks.

And in addition, they operate
without air traffic control separation.

What was the weather like that day?

I'll check it out.

Did Alaska's rapidly changing
weather play a role in the accident?

So weather conditions in
any accident are important

to understand the environment
that these pilots are operating in.

Are the weather conditions cloudy?

Does that limit their ability to see?

Does it limit their ability to
react to certain situations?

These are from a weather camera,
eight miles from the accident.

Investigators review
weather reports for nearby

George Inlet at the time of the accident.

A few scattered clouds,

-but much higher than they were flying.
-Mmhm

The weather conditions in Ketchikan
on the day of the accident were beautiful.

So at that point, we
knew that the conditions

were not going to be
a factor in this accident.

Something else prevented
these guys from seeing each other.

What if…

the pilots didn't have enough time
to look out the window for other traffic?

Or maybe the pilots were trying
to give their customers the best view.

What prevented the pilots from seeing each

other as they converged
on the scenic waterfall?

Flying an aircraft full of tourists
can be a very challenging task.

You have a number of people
that all want to ask questions.

They all want to see different
things, especially in a

area like the Misty Fjords,
where there is so much to see.

It is a lot for a pilot to
do all at the same time.

Well the local pilots
certainly were concerned.

Enough to create this.

Investigators discover a set of guidelines

agreed upon by tour operators to
enhance safety over Misty Fjords.

The letter of agreement
between the operators

was intended to help them
coordinate their routes of flight,

and their call-outs, so that
they could become better aware

of where they would each be
operating and avoid each other.

The companies were aware of
this hazard of mid-air collisions,

and that they were attempting to implement

some procedural mitigations
against this hazard.

It looks like most aircraft flying tours

also had on board an
ADS-B traffic warning system.

ADS-B, or Automatic Dependent
Surveillance-Broadcast,

is a traffic alerting system
that transmits a plane's GPS

location and altitude to ground
stations and other aircraft.

If two airplanes get
too close to each other,

an alert is issued in both cockpits.

When your traffic system
tells you you've got a conflict,

it's going to have your
attention immediately.

It will only tell you that there's
a problem when there is.

It looks like the Otter had an
alerting system installed on board.

What about the Beaver?

Yeah, it had a system
installed on it as well.

It was important for us to understand
which aircraft had which equipment

as far as alerting
capability traffic displays.

Okay, here's the Otter's system.

Investigators first examine the Otter,

the aircraft that collided with
the smaller plane to its left.

The Otter uses GPS and a radio transponder
to broadcast its altitude and position.

A color screen inside the cockpit plots
other nearby aircraft on a moving map.

What does the Beaver have?

Well, the Beaver pilot
had a different system.

It had a tablet to display traffic info.

So we knew that both aircraft were equipped
with some level of traffic display.

So the question was, were
they able to function as designed?

Let's see what we got.

Investigators review
whether ground stations

received any GPS
transmissions from the aircraft,

detailing their locations.

There's the Beaver.

Misty traffic.
Beaver 2 Delta Bravo exiting Rudyerd.

Climbing through 1,900 westbound.

And there's the Otter.

All right, folks, if you look outside
your windows down at the hills below,

you might just see some wildlife.

Both airplanes were broadcasting their
position, but they still hit each other.

Doesn't make sense.

Maybe the system didn't issue an alert.

The Otter pilot would know.

Seems like so many of these investigations

when you have a mid-air
are just not survivable.

And so it was, it was very
fortunate to be able to talk to the pilot.

Tell me about the flight.

Investigators interview
the Otter pilot, Lou Beck,

who has just been released from hospital.

Passengers were happy.

Air was smooth.

Was it busy out there?

Visually I, I never saw anyone else.

What about the traffic alerting system?

It was on.

I saw targets on the screen but,
they were well south of me.

Okay.

Got one three miles out.

Three o'clock.

Opposite direction.

No conflict.

I flew a longer route,
than the other planes.

Took me away from
most of the regular traffic.

But you still ended up at the waterfall.

I did.

That's when all hell broke loose.

Okay, folks.

In a few seconds,

we're going to arrive at the beautiful-

Look, he was just there.
I couldn't avoid him.

Hang on, everyone.

Was there any alert from
the traffic system?

Nothing.

After the impact, I just
went into survival mode.

Brace for impact!

Brace, brace, brace!

The pilot seemed very attentive
to mid-air collisions as a hazard.

He was aware of the cockpit display
of traffic information in the cockpit,

and he recalled looking at it
to scan for traffic before the collision.

Look I just want to reiterate that
the, alert system did not sound an alert.

Thank you.

This was very helpful.

Investigators are now confident the
collision happened without a warning

to alert the Otter pilot.

The question is, why?

Hang on, everyone!

Let's have a look at the
Otter's traffic alerting system.

Investigators use the ground station
data to recreate what the Otter pilot

would have seen on
his traffic alerting system

moments before crashing into the Beaver.

It's painting targets.

There's the Beaver approaching.

The alert should happen any second now.

As the Beaver gets within two and
a half miles, an alert should sound.

It's not doing anything. There's no alert.

It was very surprising to us that the
cockpit display of traffic in the Otter

didn't provide traffic alerts,

because that's a really important
defense against mid-air collisions.

There is something not
right with the alerting function.

Okay, folks. In a few seconds,
we're going to arrive at the beautiful-

The NTSB must now figure out why a
critical piece of safety equipment failed.

Traffic alerting system, was installed…

in 1999.

One of the first in the country.

They take a closer look at the de
Havilland Otter's traffic alerting system.

Looks like the FAA paid for it as
part of an experimental program.

The capstone project
that the FAA sponsored

was a program to reduce mid-air
collision accidents in Alaska.

In 2015,

the Otter got an upgrade from the FAA.

What kind of upgrade?

Take a look.

They swapped out a Garmin
transceiver for a Ranger 978.

Yes, and take a look at what
wasn't included in the upgrade.

When the traffic system
was upgraded on the Otter,

its alerting function was removed.

The FAA considered the traffic alerting

audio capability to be
classified as immature

and no longer part of the upgraded system.

That was a head-scratcher for our team.

But even if the Otter
pilot didn't receive an alert,

the Beaver pilot should have
received one on his system.

In this part of the world, alerting
systems are neither mandated nor regulated.

Planes can have different
systems or none at all.

The Beaver pilot had been utilizing an
iPad that was using an application

for navigating and understanding where
traffic would be in his surrounding area.

The pilot, paid for his own system.

And so he would have had a fully functional
system including alerting capabilities.

According to this,

yes.

I think it's clear the Beaver
pilot was concerned about safety.

He had gone at his own expense
and installed ADS-B equipment

in his airplane that was
not required per regulation.

Did the Beaver's system
also fail to alert the pilot?

Investigators use the ground station
data to recreate what the Beaver pilot

would have seen and heard in
the cockpit leading up to the crash.

The center is the Beaver.

The Otter is at three miles out now.

There is no alert,
warning of the approaching Otter.

We're missing something.

Determining why neither of the traffic
alerting systems in, in the airplanes

warned the pilots about
the impending collision was,

something that we had
to sort out in order to figure out,

why the collision happened.

Is that everything? Thank you.

With the Beaver's ADS-B
system destroyed in the crash,

the NTSB turns to the
only evidence that remains,

salvaged parts of the
Otter's traffic alerting system.

Hey, check this out.

It's turned off.

A key component was not
operating at the time of the crash.

That is odd.

There was a critical piece of equipment
on board the Otter called the GSL 71.

The GSL 71 is a control
panel for the alerting system.

It broadcasts the plane's altitude
to aircraft and ground stations.

Let's see exactly how
these components work.

Investigators examine the role of each
component of the Otter's traffic systems

to consider the consequences
of having the GSL 71 turned off.

Well this is not a simple setup.

So a surprising thing about,

the system on the Otter was that
it was a mixture of new and old parts.

Look at this.

If the GSL 71 is off,

altitude information, will not,
be broadcast to other aircraft.

If the Otter wasn't broadcasting, then
the Beaver would not have gotten an alert.

Investigators get their biggest lead yet.

Because the GSL 71 was off,

other aircraft had no idea what altitude
the Otter was currently operating at.

Was that airplane above them?
Below them? Same altitude? Unsure.

When was the last time the Otter,
transmitted altitude data?

Investigators review
when the Taquan Air Otter

last broadcast its
altitude to ground stations.

April 29th.

The last inspection and
maintenance was on, April 30th.

The day after its last broadcast.

The team considers whether
the GSL 71 was turned off for maintenance

two weeks before the crash,
and never turned on again.

We spoke to maintenance personnel,

but, during the course of interviews,
we never really were able to

completely understand why
the unit was in the "OFF" position.

Since the Otter wasn't
broadcasting its altitude,

the Beaver never received an alert.

Why didn't the Otter pilot check if he was

broadcasting his altitude
on the day of the crash?

I have some additional questions for you.

Were you aware that
the control panel was off?

No.

Why not?

I saw other aircraft on the display screen,
so that told me the system was working.

Investigators discover that the
pilot didn't fully understand how

all the components of the traffic
surveillance system worked.

No conflict.

We learned that there had
been other pilots in the airplane

preceding the accident with
the accident pilot who apparently

didn't catch that the GSL 71
was in the "OFF" position either.

I think on one of those
flights he actually had the

chief pilot of the company
with him and the GSL 71

was still in the "OFF" position and we
know that because the data wasn't

streamed, the pressure
altitude wasn't streamed.

Did you check to see if the GSL unit
was on during your pre-flight checklist?

No. It, wasn't a piece of equipment that
I ever touched or concerned myself with.

They review the company's
pre-flight checklist with the Otter pilot,

to understand why a crucial part
of the alerting system wasn't turned on.

Radio set.

Altimeter set.

Fuel checked.

It's not on my pre-flight checklist.

Okay.

Thank you.

Investigators determine the Otter pilot

wouldn't have checked
the status of the GSL 71.

In an airline environment,

something as critical as that
would definitely be on a checklist.

And so, the fact that it wasn't might,

lead him to think that
it wasn't super critical or,

it would just not have risen to
the level of something that he would

pay attention to each and every time.

What did you learn from the Otter pilot?

He didn't know the unit was turned off.

It wasn't on his pre-flight checklist.

You have to be so diligent at all
times when you're flying the aircraft,

especially in a busy, busy area like that.

As good as the traffic systems
can be, they can sometimes fail.

The team now knows why neither
traffic system alerted the pilots.

It still doesn't explain why
the pilots didn't see each other

on a perfectly clear day.

See-and-avoid is, the system by which
pilots are taught to avoid one another

when air traffic control is not
providing positive separation.

It is considered a last line
of defense, and it involves

systematically scanning different parts
of the sky visible through the windscreen

to ensure that there aren't any
other aircraft on a collision course.

Okay, let's check out
the pilot's field of view.

NTSB investigators consider
exactly what the pilots could see

from the cockpits of their airplanes.

So the Beaver pilot would
have been doing his scans.

Looking left.

No problem.

Looking right.

Hmm, there was a passenger in
the front seat restricting his view.

And the Otter was to the
right coming from behind.

The passenger sitting in your seat
might have been able to see it but,

not the pilot.

What about looking back through the cabin?

I don't think so.

The windows are too small,
and passengers are in the way.

There's no way he could have seen,

the Otter approaching
from behind and to the right.

The Beaver has issues
with visibility because

of the structural design of the airplane.

You have door posts and window posts
and overhead structure, et cetera,

that does obscure your view.

And of course, in the old days,
that wasn't really a huge concern,

because of course, there
was a lot less airplanes in the sky.

The Otter pilot, might have had a perfect
view to the left and straight ahead.

Let's figure that out.

So, the Otter pilot said he was
lining up the waterfall to his right.

So, this, was the pilot's field of view.

Investigators consider what the Otter
pilot could see at the time of the crash.

So let's assume, that he was looking
to his right, say about two o'clock.

Eh, but the pilot was adamant that he
was still doing his full visual scans,

left and right, up and down.

So what would he see if he
looked to his left towards the Beaver?

Using a 3D scan of an Otter cockpit,
the team recreates the pilot's view out of

the left windshield in
the moments before the collision.

This is just minutes before the collision.

The Beaver is still three miles away,

roughly in this area of the windscreen.

The Beaver is little more
than a speck on the horizon.

It's hard to pick out the Beaver against
the dark mountains in the distance.

When two objects are converging,

there is little relative
motion in a pilot's

visual field to attract
a pilot's attention.

Okay.

We've got one three
miles out, three o'clock.

Opposite direction.

No conflict.

The Beaver's an eighth mile away.

Still don't see it.

The window post, called an A pillar,
obstructs the view of the beaver.

Okay, we're coming up
on the moment of impact.

The Beaver came out of nowhere.

I didn't see it until impact.

The Otter's ADS-B system doesn't have the

alerting capability to
warn of the other plane.

And the pilot's view of it is obstructed.

Okay, folks, in a few seconds,
we're going to pass our famous Mahon-

The animation was fascinating because,

it showed how almost perfectly
the Beaver was obscured by the window post

in the cockpit of
the Otter from the pilot's perspective.

And, it wasn't until the last half
second or so that it sort of

blossomed from behind the
post and, became a red flash.

But they can't be completely certain.

It's hard to know for sure.

His perspective is going to change

depending on where his seat is set

and where his head is.

Investigators need more information.

We can, change sight lines
we can, adjust angles,

we can adjust views,

but we do not have the ability
to say that that was in fact

the pilot's position at any
point in time during that flight.

The team performs a study
using 27 different eye positions

to evaluate how the A pillar
would have blocked the Beaver

from the Otter pilot's view.

The Beaver's mostly hidden.

Except for here.

It's hard to be 100% certain without,
knowing the pilot's exact seat position.

What about the cameras that,
we recovered from the wreckage?

Maybe there's something on them.

We'll check on that.

Based on it being an air
tour operation, being in 2019,

fortunately we were able to locate
quite a bit of still imagery and video.

Okay let's see what we've got.

After several weeks of painstaking work,

investigators review images
taken by the Otter passengers.

No, there's nothing here.

There are no pictures taken
near the time of the collision.

Let's check out the photos
taken from the Beaver.

Whoa.

They find a photo of the Otter
taken by a passenger in the Beaver.

It was eerie and disturbing to see
the photos taken by the passengers.

Let's take a closer look.

The photo of the approaching Otter
was taken seconds before impact.

It was a moving experience.

You knew it was going to be the
last moments for some of those people.

Um, zoom in.

But can it answer the question of whether
the Otter pilot could see the Beaver?

I can see into the Otter cockpit.

It's the break the investigators needed.

Uh, try to zoom in a little bit more.

The photo captures
the Otter's exact position.

The A pillar is blocking the pilot's head.

If we can't see the Otter pilot's
head from this perspective,

he wouldn't have seen the Beaver.

Investigators are now certain that for
almost three minutes before the collision,

the Otter's windshield structure blocked

the pilot's view of the
approaching Beaver.

It's crucial for us to
understand that at that point,

the Otter pilot had very limited chance
of avoiding that collision due to his

sight being obscured
by that aircraft structure.

Investigators now understand
why the Mountain Air Beaver

and the Taquan Air Otter collided.

Okay, folks, in a few seconds,
we're going to pass our famous Mahon-

Neither pilot could see nor be alerted to

how close their aircraft
were to each other.

Hang on, everyone!

Brace for impact!

You just can't afford not
to have a traffic system.

When it's so busy as that in terrain
like that, when the pilot is so darn busy,

he needs all the help he can get.

The NTSB's final report highlights the
limitation of see-and-avoid for pilots,

and recommends new rules for
preventing the downgrading

or disabling of traffic alerting systems.

This accident in a nutshell to me is about
the rolling back of safety protections

without anybody taking a critical
look at what they were doing.

The NTSB recommends regulations
requiring mandatory air traffic alerting

for air tour operators
in high traffic areas.

I have worked a number of
mid-air collisions during my career

here at the NTSB, and
this accident was very preventable.

There are limitations as all
of us all well know with the

concept of see-and-avoid and the
technology that exists today should be

in these aircraft to help reduce these
number of collisions that take place.

UNOFFICIAL SUBS BY STER