- vor 22 Stunden
On 13 May 2019, a floatplane operated by Mountain Air Service collides with another floatplane operated by Taquan Air over George Inlet in Alaska, United States. All five people on board the Beaver and one passenger on board the Otter are killed in the accident.
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00:00Above the remote Alaskan wilderness, two planes collide.
00:11Mayday, mayday.
00:13A witness races to help.
00:16All I saw was a whole bunch of people floating.
00:20Six people are dead.
00:22The mid-air collision is probably the most scary thing that could happen to you.
00:26NTSB investigators talk to the surviving pilot.
00:30Look, he was just there. I couldn't avoid him.
00:33When they examine the onboard alerting system...
00:36Why didn't he turn away?
00:38...the mystery deepens.
00:40We're missing something.
00:42But then investigators get an unexpected glimpse...
00:45Whoa.
00:46...into a key moment in time.
00:48It was eerie and disturbing to see the photos because they were taken in a person's last moments.
00:56It's a busy day at Alaska's Misty Fjords floatplane base.
01:24Four cruise ship passengers have booked a sightseeing flight over Alaska's spectacular southeast coast.
01:31Okay, folks. Get comfortable and fasten your seat belts.
01:3646-year-old Randy Sullivan is the owner of Mountain Air Services and its only pilot.
01:44Hey. Looks like you're gonna have the best view in Alaska.
01:48I can hardly wait.
01:50This will be Sullivan's second flight of the day.
01:55Just got a few things to do before we get started.
01:58Randy Sullivan has spent most of his career flying over Misty Fjords.
02:03And Sponder on and broadcasting.
02:09Okay, guys. Put your headsets on.
02:14Mountain Air was a small operator doing primarily sightseeing trips.
02:20Can you guys hear me okay?
02:22Okay. Here we go.
02:24This would have been his entire life running this company, and he would have loved what he was doing.
02:31All right. Flight controls free and correct.
02:37Master fuel check. Landing lights check.
02:42Just after 12 noon, the Mountain Air float plane is ready for takeoff.
02:52Okay. That's five minutes since last departure.
02:55Pilots space out their takeoff since there's no air traffic control in this area.
03:03Misty traffic. This is Beaver 52 Delta Bravo. Ready for a straight out. Any conflicting? Misty traffic.
03:09Sullivan radios other pilots in the area.
03:15In airspace like the Misty Fjords, the pilots all control themselves.
03:19And it's primarily a C and B scene situation.
03:25Without any air traffic control to keep you separated, you have to maintain that separation yourself.
03:39It's a textbook takeoff in light winds.
03:43Today's 40-mile flight will take passengers from Rudyard Bay to Ketchikan.
03:50They'll cross high mountains and dramatic terrain.
03:54Misty Fjords is an absolutely beautiful area.
03:56It's towering mountains, glaciers, lakes, fjords, wildlife.
04:00And 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.
04:12Every year, more than 100,000 cruise ship passengers visit Alaska's Misty Fjords.
04:18The flight tours have become an essential experience for those who can afford the luxury price tag.
04:27If you look out to your left, you'll see cliffs that were carved smooth by the last great ice age.
04:33Randy Sullivan points out the highlights throughout the flight.
04:37Being 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.
04:50At the same time, you're also multitasking as a pilot, where you're trying to maintain your situational awareness of all the other aircraft,
04:57as 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.
05:04Mountain Air Services operates a de Havilland Beaver, a single engine prop plane.
05:14The Beaver was originally built for the United States Air Force in 1951, but many are now operated by northern bush pilots.
05:24The Havilland Beaver was a uniquely designed airplane, and the takeoff and landing is absolutely incredible.
05:30That's what makes it so versatile in the bush is that you can get it in and out of pretty much any little lake.
05:36If you're on wheels or skis, you can get it off short strips or short frozen lakes.
05:40Misty traffic, Beaver 2 Delta Bravo, exiting Rudyard, climbing through 1900 westbound.
05:50Check that. 45 Mike Mike is just off the water now and well behind you.
05:55It's May, and this part of Alaska is enjoying exceptionally good weather.
06:04On the Alaska coast, the weather can change extremely rapidly.
06:09It can go from a beautiful clear day to just horrible weather within a very short period of time.
06:16When the days are good, all the aircraft are flying, everybody is out making hay while the sun shines.
06:23Have a good cruise so far? It's been great.
06:25The forecast for tomorrow is low clouds and rain.
06:31So today, Sullivan plans to operate a full day of flights.
06:36We all are pretty lucky. They call this place the Misty Fjord for a reason.
06:40Weather like this is pretty rare.
06:42Beaver 8 Golf Mike is 2,700 feet in the climb, exiting the bay.
06:51We've got the Mountaineer Beaver ahead. We will fall in trail behind.
06:56Hey Dave, I've got you on display, but I don't have your visual.
07:00As long as you can see me, we're good.
07:02I got you above and ahead of me, Randy. Enjoy the ride.
07:05Oh, even if we can't see each other, the display lets us know where the other planes are.
07:13Cool.
07:15The traffic systems will enhance your ability for the sea and avoid because it will alert you of aircraft that you may have missed because of visibility issues before you get too close.
07:27Coming up in about two minutes on your right, you're going to see one of the highlights of the trip, the majestic Mahoney Falls.
07:35Twenty minutes into the flight, the beaver approaches the waterfall.
07:44Passengers are treated to a spectacular view.
07:56The beaver and another aircraft collide.
07:59The beaver basically came apart.
08:01It free fell 3,000 feet from the sky.
08:07A retired fisherman on George Inlet is shocked by what he sees.
08:14Mayday, mayday. This is Hotel C calling Coast Guard Radio.
08:21Go ahead. State the nature of your emergency.
08:23The second plane involved is a larger 10-passenger de Havilland Otter.
08:32Two float planes down George Inlet.
08:34The Otter was still largely intact.
08:43There was damage.
08:45The pilot obviously kept his cool and managed to control the aircraft.
08:50I saw an Otter float plane crash into the water with a huge splash.
08:59And I got closer and all I saw was a whole bunch of people floating in an area 50, 60 yards.
09:08But there was one person never made it out of the airplane.
09:15The ten survivors, including the pilot, are rushed to hospital.
09:20There are no survivors from the plane piloted by Randy Sullivan.
09:24How could two planes in one of the most popular tourist destinations on Earth collide in mid-air?
09:42Within hours, the National Transportation Safety Board, or NTSB, dispatches a team of investigators to search for wreckage.
09:50We 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.
10:01But we have some great experts at the NTSB who are well-versed in that.
10:06Aaron Sauer is named lead investigator.
10:10The wreckage area of the beaver was scattered for about 3,000 feet.
10:15A portion of the main fuselage was located upside down in the saltwater.
10:20There was a lot of debris that was mixed into the terrain in that mountainous area.
10:25Vegetation was high.
10:27It was very difficult to navigate to try and recover as much of the debris from the beaver that we could.
10:34The other aircraft, the Otter, is owned by the largest tour operator in the area, Takwan Air.
10:41It sank in 80 feet of water.
10:45The floats of the Otter were separated.
10:47They ended up washing ashore.
10:50But 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.
10:58Tag the beaver wreckage, and when the Otter comes, we're going to put it there.
11:12The small sightseeing planes were not required to carry black boxes.
11:17Keep an eye out for avionics, cameras, phones, anything with photos or data that will help us piece this together.
11:25Without recorders, the investigation becomes much more difficult.
11:29So without the cockpit voice recorder and flight data recorder, we had to look for other sources of data.
11:35Hey, let me move this.
11:41As the team surveys the beaver wreckage, they find evidence that can help them piece together the violent collision.
11:49These are sawtooth marks from a propeller striking the right wing.
11:55We wanted to understand what angle did we have.
12:00That was very important for us to understand in order to recreate the collision and aid us in the investigation.
12:10The pattern's in the inboard direction.
12:13So the Otter came from behind and to the right.
12:18The discovery begins to unveil what happened in the skies over Misty Fjord.
12:23The collision angle was important for us because what it told us is both airplanes weren't necessarily on a head-on collision course.
12:34They were more or less headed to the same location.
12:37With a shallow degree of angle, the collision was more of a sideswipe.
12:43Both planes took off from Rudyard Bay here and headed to the cruise ship in Ketchikan.
12:51The beaver left first, and a few minutes later the Otter departed.
12:59With a basic understanding of how the two planes collided, investigators try to pinpoint where the accident occurred.
13:07We had one witness who was located here.
13:19We 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.
13:33Based on his account, the collision happened somewhere in here.
13:40Investigators now know exactly where the accident occurred, but they still don't know why.
13:47Maybe they were converging on this point.
13:54The planes collided very near the scenic Mahoney Falls.
13:57It is certainly possible.
14:01It has happened before.
14:04A similar mid-air collision happened over Arizona in 1986.
14:10A twin otter and a helicopter collided over the Grand Canyon, killing 25 people.
14:16Both aircraft were also approaching a popular scenic attraction.
14:22Air tour flights have a higher rate of mid-air collisions, statistically speaking, because they operate in areas with dense traffic around various scenic landmarks.
14:31And in addition, they operate without air traffic control separation.
14:40What was the weather like that day?
14:43I'll check it out.
14:46Did Alaska's rapidly changing weather play a role in the accident?
14:51So weather conditions in any accident are important to understand the environment that these pilots are operating in.
14:58Are the weather conditions cloudy? Does that limit their ability to see?
15:03Does it limit their ability to react to certain situations?
15:09These are from a weather cabin, eight miles from the accident.
15:13Investigators review weather reports for nearby George Inlet at the time of the accident.
15:19A few scattered clouds, but much higher than they were flying.
15:24Mm-hmm.
15:27The weather conditions in Ketchikan on the day of the accident were beautiful.
15:31So at that point we knew that the conditions were not going to be a factor in this accident.
15:36Something else prevented these guys from seeing each other.
15:38What if the pilots didn't have enough time to look out the window for other traffic?
15:56Well, maybe the pilots were trying to give their customers the best view.
16:07What prevented the pilots from seeing each other as they converged on the scenic waterfall?
16:13Flying an aircraft full of tourists can be a very challenging task.
16:18You have a number of people that all want to ask questions, they all want to see different things,
16:24especially in an area like the Misty Fjords where there is so much to see.
16:28It is a lot for a pilot to do all at the same time.
16:31Well, the local pilots certainly were concerned. Enough to create this.
16:38Investigators discover a set of guidelines agreed upon by tour operators to enhance safety over Misty Fjords.
16:47The 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.
17:02The companies were aware of this hazard of mid-air collisions and that they were attempting to implement some procedural mitigations against this hazard.
17:11It looks like most aircraft flying tours also had on board an ADS-B traffic warning system.
17:22ADS-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.
17:35If two airplanes get too close to each other, an alert is issued in both cockpits.
17:42When your traffic system tells you you've got a conflict, it's going to have your attention immediately.
17:46It will only tell you that there's a problem when there is.
17:49It looks like the Otter had an alerting system installed on board.
17:54What about the Beaver?
17:56Yeah, it had a system installed on it as well.
17:59It was important for us to understand which aircraft had which equipment as far as alerting capability traffic displays.
18:10OK, here's the Otter system.
18:13Investigators first examined the Otter, the aircraft that collided with the smaller plane to its left.
18:19The Otter uses GPS and a radio transponder to broadcast its altitude and position.
18:28A color screen inside the cockpit plots other nearby aircraft on a moving map.
18:34Where's the Beaver have?
18:36Well, the Beaver pilot had a different system.
18:39It had a tablet to display traffic info.
18:43So we knew that both aircraft were equipped with some level of traffic display.
18:47So the question was, were they able to function as designed?
19:02Let's see what we got.
19:04Investigators review whether ground stations received any GPS transmissions from the aircraft, detailing their locations.
19:13There's the Beaver.
19:14Misty traffic, Beaver 2 Delta Bravo, exiting Rudyard, climbing through 1900 westbound.
19:23And there's the Otter.
19:28Alright folks, if you look outside your windows down at the hills below, you might just see some wildlife.
19:33Both airplanes were broadcasting their position, but they still hit each other.
19:42Doesn't make sense.
19:46Maybe the system didn't issue an alert.
19:48The Otter pilot would know.
19:50The Otter pilot would know.
19:54Seems like so many of these investigations, when you have it midair, are just not survivable.
20:00And so it was, it was very fortunate to be able to talk to the pilot.
20:05Tell me about the flight.
20:11Investigators interview the Otter pilot, Lou Beck, who has just been released from hospital.
20:18Passengers were happy.
20:21Air was smooth.
20:24Was it busy out there?
20:28Visually, I never saw anyone else.
20:31What about the traffic alerting system?
20:34It was on.
20:35I saw targets on the screen, but they were well south of me.
20:42Okay.
20:44Got one three miles out.
20:46Three o'clock.
20:48Opposite direction.
20:50No conflict.
20:54I flew a longer route than the other planes.
20:57Took me away from most of the regular traffic.
21:00But you still ended up at the waterfall.
21:02I did.
21:03That's when all hell broke loose.
21:06Okay, folks.
21:07In a few seconds, we're going to arrive at the beautiful-
21:10Look, he was just there. I couldn't avoid him.
21:15Hang on, everyone!
21:20Was there any alert from the traffic system?
21:23Nothing.
21:24After the impact, I just went into survival mode.
21:28Brace your impact!
21:30Brace, brace, brace!
21:33The pilot seemed very attentive to mid-air collisions as a hazard.
21:46He was aware of the cockpit display of traffic information in the cockpit,
21:50and he recalled looking at it to scan for traffic before the collision.
21:54Look, I just want to reiterate that the alert system did not sound an alert.
22:03This was very helpful.
22:07Investigators are now confident the collision happened without a warning to alert the autopilot.
22:12The question is, why?
22:13Hang on, everyone!
22:24Let's have a look at the otter's traffic alerting system.
22:27Investigators 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.
22:36It's painting targets.
22:41There's the beaver approaching.
22:43The alert should happen any second now.
22:46As the beaver gets within two and a half miles, an alert should sound.
22:51It's not doing anything. There's no alert.
22:53It was very surprising to us that the cockpit display of traffic in the otter didn't provide traffic alerts,
23:08because that's a really important defense against mid-air collisions.
23:12There is something not right with the alerting function.
23:14Okay, folks, in a few seconds, we're going to arrive at the beautiful...
23:26The NTSB must now figure out why a critical piece of safety equipment failed.
23:31Traffic alerting system was installed in 1999.
23:46One of the first in the country.
23:49They take a closer look at the de Havilland otter's traffic alerting system.
23:54Looks like the FAA paid for it as part of an experimental program.
23:59The capstone project that the FAA sponsored was a program to reduce mid-air collision accidents in Alaska.
24:08In 2015, the otter got an upgrade from the FAA.
24:15What kind of upgrade?
24:20Take a look.
24:24They swapped out a Garmin transceiver for a Ranger 978.
24:27Right.
24:28Yes.
24:30And take a look at what wasn't included in the upgrade.
24:32When the traffic system was upgraded on the otter, its alerting function was removed.
24:38The FAA considered the traffic alerting audio capability to be classified as immature,
24:47and no longer part of the upgraded system.
24:50That was a head-scratcher for our team.
24:51But even if the otter pilot didn't receive an alert, the beaver pilot should have received one on his system.
25:00In this part of the world, alerting systems are neither mandated nor regulated.
25:06Planes can have different systems, or none at all.
25:08The beaver pilot had been utilizing an iPad that was using an application for navigating and understanding where traffic would be in his surrounding area.
25:18The pilot paid for his own system, and so he would have had a fully functional system, including alerting capabilities.
25:29According to this, yes.
25:31I think it's clear the beaver pilot was concerned about safety.
25:37He had gone at his own expense and installed ADS-B equipment in his airplane that was not required per regulation.
25:44Did the beaver's system also fail to alert the pilot?
25:50Investigators used the ground station data to recreate what the beaver pilot would have seen and heard in the cockpit leading up to the crash.
26:00The center is the beaver. The otter is at three miles out now.
26:07There is no alert, warning of the approaching otter.
26:15We're missing something.
26:20Determining 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.
26:33Is that everything?
26:45With the beaver's ADS-B system destroyed in the crash, the NTS-B turns to the only evidence that remains.
26:53Salvaged parts of the otter's traffic alerting system.
26:57Hey, check this out.
26:59It's turned off.
27:04A key component was not operating at the time of the crash.
27:09That is odd.
27:11There was a critical piece of equipment on board the otter called the GSL-71.
27:19The GSL-71 is a control panel for the alerting system.
27:23It broadcasts the plane's altitude to aircraft and ground stations.
27:28Let's see exactly how these components work.
27:34Investigators examined the role of each component of the otter's traffic systems to consider the consequences of having the GSL-71 turned off.
27:44Hold on, this is not a simple setup.
27:52So a surprising thing about the system on the otter was that it was a mixture of new and old parts.
27:57Look at this.
27:58If the GSL-71 is off, altitude information will not be broadcast to other aircraft.
28:14If the otter wasn't broadcasting, then the beaver would not have gotten an alert.
28:22Investigators get their biggest lead yet.
28:26Because the GSL-71 was off, other aircraft had no idea what altitude the otter was currently operating at.
28:34Was that airplane above them, below them, same altitude? Unsure.
28:47When was the last time the otter transmitted altitude data?
28:51Investigators review when the Takwan Air otter last broadcast its altitude to ground stations.
28:58The last inspection and maintenance was, uh, April 30th.
29:17The day after its last broadcast.
29:20The team considers whether the GSL-71 was turned off for maintenance two weeks before the crash,
29:27and never turned on again.
29:30We spoke to maintenance personnel, but during the course of interviews,
29:35we never really were able to completely understand why the unit was in the off position.
29:42Since the otter wasn't broadcasting its altitude, the beaver never received an alert.
29:49Why didn't the otter pilot check if he was broadcasting his altitude on the day of the crash?
29:55I have some additional questions for you.
30:01Were you aware that the control panel was off?
30:07No.
30:09Why not?
30:10I saw other aircraft on the display screen, so that told me the system was working.
30:20Investigators discover that the pilot didn't fully understand how all the components of the traffic surveillance system worked.
30:27No conflict.
30:30We learned that there had been other pilots in the airplane preceding the accident with the accident pilot,
30:37who apparently didn't catch that the GSL-71 was in the off position either.
30:42I think on one of those flights, he actually had the chief pilot of the company with him,
30:47and the GSL-71 was still in the off position.
30:50And we know that because the data wasn't streamed, the pressure altitude wasn't streamed.
30:55Did you check to see if the GSL unit was on during your pre-flight checklist?
31:01No, it wasn't a piece of equipment that I ever touched or concerned myself with.
31:09They review the company's pre-flight checklist with the otter pilot,
31:14to understand why a crucial part of the alerting system wasn't turned on.
31:18And a radio set.
31:23Altimeter set.
31:26Fuel checked.
31:29It's not on my pre-flight checklist.
31:38Okay.
31:43Investigators determine the otter pilot wouldn't have checked the status of the GSL-71.
31:50In an airline environment, something as critical as that would definitely be on a checklist.
31:55And so the fact that it wasn't might lead him to think that it wasn't super critical,
32:01or it would just not have risen to the level of something that he would pay attention to each and every time.
32:07What did you learn from the otter pilot?
32:10He didn't know the unit was turned off.
32:15It wasn't on his pre-flight checklist.
32:19You have to be so diligent at all times when you're flying the aircraft, especially in a busy, busy area like that.
32:26As good as the traffic systems can be, they can sometimes fail.
32:29The team now knows why neither traffic system alerted the pilots.
32:35It still doesn't explain why the pilots didn't see each other on a perfectly clear day.
32:41See and avoid is the system by which pilots are taught to avoid one another when air traffic control is not providing positive separation.
32:50It 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.
33:03Okay, let's check out the pilots' field of view.
33:09NTSB investigators consider exactly what the pilots could see from the cockpits of their airplanes.
33:16So the beaver pilot would have been doing his scans, looking left, no problem, looking right.
33:32There was a passenger in the front seat restricting his view.
33:37And the otter was to the right, coming from behind.
33:47The passenger sitting in your seat might have been able to see it, but not the pilot.
33:54What about looking back through the cabin?
33:57I don't think so.
34:01The windows are too small and passengers are in the way.
34:04There's no way he could have seen the otter approaching from behind and to the right.
34:12The beaver has issues with visibility because of the structural design of the airplane.
34:18You have door posts and window posts and overhead structure, et cetera, that does obscure your view.
34:24And, 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.
34:31The otter pilot might have had a perfect view to the left and straight ahead.
34:38Let's figure that out.
34:41So the otter pilot said he was lining up the waterfall to his right.
34:52So this was the pilot's field of view.
34:57Investigators consider what the otter pilot could see at the time of the crash.
35:02So let's assume that he was looking to his right, say about 2 o'clock.
35:10But the pilot was adamant that he was still doing his full visual scans, left and right, up and down.
35:17So what would he see if he looked to his left towards the beaver?
35:23Using 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.
35:35This is just minutes before the collision.
35:39This is just minutes before the collision.
35:42The beaver is still 3 miles away, roughly in this area of the windscreen.
35:49The beaver is little more than a speck on the horizon.
35:52It's hard to pick up the beaver against the dark mountains in the distance.
35:58When two objects are converging, there is little relative motion in a pilot's visual field to attract a pilot's attention.
36:06Okay.
36:08Got one 3 miles out.
36:103 o'clock.
36:12Opposite direction.
36:14No conflict.
36:18The beaver's an eighth mile away.
36:20Still don't see it.
36:23The window post, called an A-pillar, obstructs the view of the beaver.
36:28Okay, we're coming up on the moment of impact.
36:33The beaver came out of nowhere.
36:35I didn't see it until impact.
36:38The otter's ADS-B system doesn't have the alerting capability to warn of the other plane.
36:45And the pilot's view of it is obstructed.
36:47Okay, folks.
36:50In a few seconds, we're gonna pass our famous ma-
36:53Oh!
36:54The 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.
37:09And it wasn't until the last half second or so that it sort of blossomed from behind the post and became a red flash.
37:17But they can't be completely certain.
37:21It's hard to know for sure.
37:25His perspective is gonna change depending on where his seat is set and where his head is.
37:33Investigators need more information.
37:35We 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.
37:53The 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.
38:07The beaver's mostly hidden.
38:10Except for here.
38:13It's hard to be 100% certain without knowing the pilot's exact seat position.
38:22What about the cameras that we recovered from the wreckage?
38:26Maybe there's something on them.
38:28I'll check on that.
38:29Based on it being an air tour operation, being in 2019, fortunately we were able to locate quite a bit of still imagery and video.
38:42Okay, let's see what we've got.
38:46After several weeks of painstaking work, investigators review images taken by the otter passengers.
38:53No, there's nothing here.
39:01There are no pictures taken near the time of the collision.
39:05Let's check out the photos taken from the beaver.
39:11Whoa.
39:13They find a photo of the otter taken by a passenger in the beaver.
39:18It was eerie and disturbing to see the photos taken by the passengers.
39:23Let's take a closer look.
39:29The photo of the approaching otter was taken seconds before impact.
39:40It was a moving experience.
39:42You knew it was going to be the last moments for some of those people.
39:48Zoom in.
39:49But can it answer the question of whether the otter pilot could see the beaver?
39:55I can see into the otter cockpit.
39:59It's the break the investigators needed.
40:02Uh, try to zoom in a little bit more.
40:05The photo captures the otter's exact position.
40:08The A-pillar is blocking the pilot's head.
40:12If we can't see the otter pilot's head from this perspective, he wouldn't have seen the beaver.
40:17Investigators 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.
40:26It'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.
40:38Investigators now understand why the mountain air beaver and the taquan air otter collided.
40:48Okay, folks. In a few seconds, we're gonna pass our famous...
40:54Neither pilot could see nor be alerted to how close their aircraft were to each other.
41:00Hang on, everyone!
41:05Brace for impact!
41:09You just can't afford not to have a traffic system.
41:12When 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.
41:19The NTSB's final report highlights the limitation of see and avoid for pilots
41:25and recommends new rules for preventing the downgrading or disabling of traffic alerting systems.
41:33This 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.
41:42The NTSB recommends regulations requiring mandatory air traffic alerting for air tour operators in high traffic areas.
41:50I have worked a number of mid-air collisions during my career here at the NTSB.
41:56And this accident was very preventable.
42:00There are limitations, as all of us all well know, with the concept of see and avoid.
42:06And the technology that exists today should be in these aircraft to help reduce these number of collisions that take place.
42:13There are a number of laws that take place.
42:17.