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.
The mid air collision is probably the most
scary thing that could happen to you.
NTSB investigators talked to the surviving
pilot. Look, he was just there. I couldn't
avoid him. When they examined the Onard
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.
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
co 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 gonna have the best
view in Alaska. You 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.
Sponder on and broadcasting. Okay, guys,
put your headsets on.
Mountain Air was a small operator doing
primarily sightseeing. TR reps. 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 light's check. Just after
12 noon, the mountain Air float plane 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.
Missy traffic, this is Beaver Five two
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 C and B SC 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 Rudyard 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
grade 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. The Hapland 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. 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 Rudyard, climbing through 1900
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 haywell 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 called this place the
Misty Fjord for a reason. Whetherather
like this is pretty rare.
Beaver 8 Golf Mike is 2700ft in the climb
exiting the bay. We've got the mountain
air Beaver ahead. We will fall inrail
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. 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 SE&AV void
because it will alert you of aircraft that
you may have missed because of visibility
issues. For 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.
Twenty 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 fel
3,000ft from the sky.
A retired fisherman on George Inlet is
shocked by what he sees.
Meday. Meday. This is Hotel SE calling
Coast Guard radio.
Go ahead, state the nature of your
emergency.
The second plane involved is a larger 10
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
an otter float planane crash into the
water with a huge splash. And they got
closer and all I saw was a whole bunch of
people floating in an area 50,
60 yards. But there was one person
ever made it out of the airplane.
The 10 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 midair?
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
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 3,000ft. 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.
And 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 80ft of water.
The floor 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.
Tag the beaver wreckage, and when the
otter comes, we're goingna 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 s 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, let 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 patterns 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 Rudyard Bay here and
headed to the cruise ship in Ketchikin.
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
collision, 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 cab 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. 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 an area
like the Misty fjords where there is so
much to see. It is a lot for a pilot to do
all 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 my 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 the 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 ADSB traffic warning
system.
ADSB, 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? Yep, 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 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.
Where does s 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, 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 Rudyard climbing through 1900
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 outter pilot would know.
Seems like so many of these investigations
when you have midairr are just not
survivable. And so it. 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 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.
Hey, got one. Three miles out,
three o'clock. Opposite direction.
No conflicts.
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 looseke. Ok, hey folks,
in a few seconds we're going to arrive at
the beautiful F. 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 midair
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 otterilot.
The question is why? Hang on everyone.
Let's have a look at the otters traffic Al
learning system investigators use
the ground station data to recreate what
the otopilot 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 auttter
didn't provide traffic alerts because
that's a really important defense against
midair 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'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 transceer 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
the 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 Beavers system also
fail to alert the pilot?
Investigators used 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
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 ADSB 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 GSL71.
The GSL71 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 examined the
role of each component of The Otter's
traffic systems to consider the
consequences of having the GSL71 turned
off.
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 GSL71 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 GSL71 was off, other aircraft
had no idea what altitude the Otter was
currently operating at.
Was that airplane above him? Below him?
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 29.
The last inspection and maintenance was
April 30, the day after its last
broadcast. The team considers whether the
GSL71 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 autopilot 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 plane preceding the
accident with the accident pilot who
apparently didn't catch that the GSL71 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
GSL71 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 autopilot to understand
why a crucial part of the alerting system
wasn't turned on.
Radio sets, altimeter sets,
fuel checked. It's not
on my pre flight checklist.
Okay, thank you.
Investigators determine the autopilot
wouldn't have checked the status of the
GSL71 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 autopilot? 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.
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 about 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, etc. 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 autopilot
could see at the time of the crash.
So let's assume that he was looking to his
right, say about 2:00. 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.
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.
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.
Beaver came out of nowhere. I didn't see
it until impact. The Otter's ADSB 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 gonna
pass our famous mah.
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. This
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 ab. 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 autopilot's view. The
beaver is 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. I'll check on it.
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.
Now 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.
Zoom in. But can it answer the question
of whether the otterilot could see the
beaver? I can see into the outer cockpit.
It's the break the investigators needed.
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 Taquane Air
Otter collided.
Okay folks, in a few seconds we're gonna
pass our famous.
Neither pilot could see nor be alerted to
how close their aircraft were to each
other. Hang on everyone.
RA for impact.
You just can't afford not have a traffic
system when it's so busy. Is 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 seea and avoid and the
technology that exists today should be in
these aircraft to help reduce these number
of collisions that take place.