Air Disasters (2022) Season 17 Episode 4: Double Trouble
A cargo flight from Luxembourg to Nigeria turns into a nightmare over the French Alps for its five-person crew. A large explosion has blown both engines off the right wing, the weather is worsening, and the cockpit has lost contact with air traffic control. It will take every bit of muscle and piloting expertise to steer the disabled Boeing 707 over the mountains and reach Marseille for an emergency landing. Witness the harrowing flight of Trans-Air Cargo Flight 671, then discover the microscopic but deadly flaw that almost doomed the plane.
#documentary #historical
A cargo flight from Luxembourg to Nigeria turns into a nightmare over the French Alps for its five-person crew. A large explosion has blown both engines off the right wing, the weather is worsening, and the cockpit has lost contact with air traffic control. It will take every bit of muscle and piloting expertise to steer the disabled Boeing 707 over the mountains and reach Marseille for an emergency landing. Witness the harrowing flight of Trans-Air Cargo Flight 671, then discover the microscopic but deadly flaw that almost doomed the plane.
#documentary #historical
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TVTranscript
00:00An emergency above the French Alps strikes Transair Cargo Flight 671.
00:12There was an enormous bang and the aircraft almost inverted.
00:17Mayday, mayday, mayday.
00:20The crew needs to land, but are flying blind.
00:23Cargo 671, we have no radar contact.
00:27They stood a very real chance of hitting a mountain.
00:31Then they discover something even more horrifying.
00:37I saw nothing.
00:39In a number four engine position, the wing was clean.
00:42Assuming the worst, the first officer leaves a clue for investigators.
00:48I took the photograph because I wasn't sure what would happen next.
00:53Somebody might find the camera.
00:55They'd see the truth.
00:56Mayday, mayday, mayday.
00:57Oh, God.
00:58Transair Flight 671 is preparing for takeoff at Luxembourg Airport.
01:29Walker says we'll get some weather in an hour.
01:34As we cross over the Alps.
01:37Typical.
01:38Captain Ingemar Berglund is a highly experienced Swedish pilot who has been flying Boeing 707
01:46aircraft for over a decade.
01:49The captain had been a military pilot and he'd been on air transport flying for most
01:54of his working life.
01:56His experience was pretty vast in Africa and in Europe.
01:59He knew the routes.
02:00He was a very good pilot.
02:01Cargo 671, you are cleared for takeoff.
02:02Runway 24.
02:03671, cleared for takeoff.
02:04Roger.
02:05First officer Martin Emery is an accomplished British pilot who has worked as an instructor
02:18and an air traffic controller.
02:22Ready to go.
02:28The first officer had about 10,000 hours, about half of which was on the Boeing 707,
02:33so he was very experienced, too.
02:38V1, 170, rotate.
02:47The Boeing 707 is a long-range aircraft powered by four Pratt & Whitney engines.
02:54It was a very basic airplane, very strong, very reliable, and could carry 40 or 50 tons
03:01of freight.
03:05Assisting the pilots is flight engineer Terry Boone.
03:12Boeing 707 didn't have much in the way of automated systems, but this meant that there
03:18was a whole panel sideways in the flight deck in which the flight engineer had to operate
03:24every system manually.
03:27He was probably one of the most experienced Boeing 707 flight engineers in the world.
03:35His flight is a seven-hour journey from Luxembourg to Kano, Nigeria.
03:45Feels a little heavy today.
03:46Well, do you see what's loaded back there?
03:49So oil, weather equipment?
03:51Yeah, not the light kind.
03:55Flight 671 is operated by the newly formed Nigerian company Transair Limited.
04:02Their client, Cabo Air Cargo.
04:06Transair had only been formed a few weeks before this incident.
04:11It was purely for the oil industry to transport a lot of equipment down to Nigeria for the
04:16oil works.
04:18This was an extra special flight in that it was carrying equipment that would have helped
04:22Nigeria in their modernizing.
04:27Cabo 671 levels off at 29,000 feet.
04:36The flight plan indicated with the weight of the aircraft, we should stay at a slightly
04:40lower than normal flight level for the first part of the flight until we burned off fuel,
04:46and then we could gain a higher flight level.
04:48How are the guys in the back?
04:51Good.
04:52They made us coffee.
04:54Also on board are a cargo supervisor and a maintenance engineer.
04:59Like them more every day.
05:02So the five of them were knowledgeable about the 707.
05:05They were knowledgeable about this sort of ad hoc air cargo work.
05:11Although they hadn't met until a fortnight previously, I think they worked well together
05:15as a team.
05:18Over the Alps, the weather deteriorates.
05:25Pretty much ground level up to about 33,000 feet was in cloud, and the cloud was rough
05:31and turbulent.
05:32We're going to buckle up until we're above it.
05:40Right here.
05:42We engaged our five-point seat harness rather than just the four-point harnesses that we
05:47normally keep on to a top of climb, and then moved our seats forward to be really guarding
05:52the controls in this turbulent air.
05:54It was getting quite rough.
05:55Ask if we can go to 3-3.
05:56Cabo 6-7-1.
05:57Request flight level 3-3-0.
05:586-7-1.
05:59Roger.
06:00Climb to flight level 3-3-0.
06:01Climb 3-3-0.
06:026-7-1.
06:03The requested climb was to go up another 4,000.
06:29One hour into the flight, just as the plane reaches 33,000 feet.
06:41There was an enormous bang, followed almost immediately by another one, and the aircraft
06:49absolutely rolled to the right.
07:01The captain uses all his strength to level the plane.
07:07Had the captain not reacted as quickly as he did, the aircraft could have rolled over,
07:12in fact, inverted.
07:15Engine fire.
07:18Engines three and four show signs of fire.
07:23While the flight engineer deals with the engine alarms, the first officer checks on the engines.
07:34I saw nothing in the number four engine position.
07:39Number four engine has left the wing.
07:42Mayday, mayday, mayday.
07:46Mayday, mayday, mayday, Cabo 6-7-1.
07:50With reduced engine power and an unbalanced configuration, the flight drops out of the
07:55sky in an uncontrolled descent.
07:58The descent rate was horrific.
08:00I think I saw 8,000 or 9,000 feet per minute.
08:06It's diving quickly towards the French Alps through heavy clouds.
08:12They need to get out of the mountains, and they can't see outside because of the thick
08:17cloud.
08:19They need the air traffic controller to give them a direction in which to head for a safe
08:25haven, for a safe airport.
08:27Mayday, mayday, mayday, request descent for radar landing.
08:34The ground service can follow your track over the ground, your heading, height and speed.
08:39I'm a transponder, and I can point you to the nearest available runway.
08:46But air traffic control has bad news.
08:49Cabo 6-7-1, we have no radar contact.
08:57Say your position, please, sir.
08:59They can no longer see flight 6-7-1 on the radar.
09:04With nobody able to give them a direction to steer, they stood a very real chance of
09:10hitting a mountain.
09:13The plane's radar transponder has failed.
09:23I was considering which direction we could go to avoid the mountains.
09:28It was very scary.
09:38The situation is dire enough that the first officer records the damage to the wing.
09:45I wasn't sure what would happen next.
09:49I believed that if anything ended, like the flight before we were ready, somebody might
09:55find the camera and they'd see the truth.
10:06Flight 6-7-1 is in an uncontrolled descent over the French Alps.
10:11With thick clouds and no transponder for the controller to guide them, the crew is flying
10:17blind.
10:18Mayday, mayday, mayday, request descent for radar landing.
10:19The flight engineer attempts to get the transponder
10:28working again.
10:29He suspects there is a power issue.
10:33The reason the air traffic control lost the radar initially was probably because the electrics
10:38powering the radar failed when engine number four fell off.
10:46The flight engineer redirects the power to engine one.
10:51He selected the essential power selector to engine number one, which had an operative
10:56electrical generator.
11:01It works.
11:02Request descent, radar landing.
11:05Roger.
11:06Turn left heading south to Marseille.
11:09The controller directs flight 6-7-1 to Marseille airport, 75 miles away.
11:16You turn left 1-8-0.
11:17Okay.
11:18There was immense relief as they descended out of the cloud and finally could see the
11:29mountains around them.
11:32But relief is short-lived after the first officer gives the right wing a further inspection.
11:42We've lost both engines on the right wing.
11:44What?
11:46With a five-point harness, you are slightly restricted, but I did manage to look right
11:52over my right shoulder and both the engines were off the wing.
11:55The wing was clean, which was a really big shock.
12:00We've lost both engines.
12:01Both engines?
12:04Just about the worst thing that can happen in an airliner is to have an engine depart
12:09from the aircraft.
12:11The only thing worse than that would be to have two engines depart from your aircraft.
12:17With only the two left engines functioning, control of the plane is compromised.
12:24When you've lost both engines from the right wing and still have a lot of thrust from the
12:29engines on the left wing, it upsets that balance and causes the airplane to turn and to roll
12:36very powerfully to the right.
12:40Getting the airplane to turn left is a huge ask under these circumstances.
12:44You turn 180?
12:47Yeah.
12:48I'm trying.
12:54Flying the disabled plane is testing the captain's strength.
13:02The Boeing 707 has all manual flying controls.
13:05It's very heavy to fly when everything's working well.
13:09When you've lost two engines on one side, it's virtually at the limit of physical capability
13:15for the captain.
13:16We want to dump fuel?
13:22Yes, dump fuel.
13:25To keep Flight 671 in the air, the crew decides to reduce its load.
13:31This aircraft was carrying a very heavy fuel load, and it was imperative to reduce that
13:36fuel load.
13:38But it requires a precise calculation.
13:41They need to leave themselves enough fuel to reach Marseille and land safely.
13:46112 tons is the maximum safe weight at which they can land.
13:51If they're any heavier than that and hit the ground hard, they would be sliding along the
13:55wrong way on their belly, shedding fuel and burning.
13:59This is not a position you want to be in.
14:01The process is time-consuming.
14:13As Flight 671 completes its left turn toward Marseille, Captain Berglund reduces power
14:19in the two left engines.
14:21They had to reduce the power on the left engines to give themselves a chance of staying upright
14:27and going in the direction they wanted to go in.
14:32Reducing airspeed means an increase in the angle of descent.
14:37Unfortunately, this of course meant they then descended more rapidly.
14:43They have to land soon, and they have to land somewhere very nearby.
14:48Airspeed isn't the crew's only concern.
14:50Request the weather.
14:53Give me the weather for Marseille, 671.
14:57I really needed the weather at Marseille to make a plan for an approach to land either
15:01direct or a circuit or whatever we could do.
15:05But air traffic control isn't responding.
15:09Request weather.
15:10Mayday, mayday, mayday, 671, request weather.
15:20It was quite a tough call to actually get the instant weather at that moment at Marseille
15:25airport that we needed right now.
15:31Making matters worse, the fuel dump is not going as expected.
15:37Fuel tank number one isn't discharging.
15:44It became evident to the flight engineer that the number one fuel tank wasn't emptying.
15:49This would cause a lateral imbalance across the airplane, which is not a good thing.
15:54I've got limited maneuvering.
16:00You dumping?
16:02Yeah.
16:08The flight engineer discovers that a circuit breaker has popped.
16:16By pushing the circuit breaker back in, he was able to reactivate the number one fuel
16:22pump and get the fuel jettisoning from all four tanks simultaneously.
16:31Flight 671 is 30 miles from the runway in Marseille.
16:36Mayday, mayday, mayday, 671, request weather.
16:43It's raining on the airfield.
16:47Two octas Stratocumulus, 500 feet.
16:49Three octas Cumulus Limbus, 1,600 feet.
16:52Three octas Cumulus, 2,000 feet.
16:55No, no, no.
16:58Thunder clouds and the risk of turbulence will make a difficult landing harder.
17:03We were pushed to even get there with the height available and with thunderstorm activity,
17:07it was really a no-go.
17:10Cabo 671, what is our distance to the runway?
17:1522 miles for landing, sir.
17:19We had no plan B. At that point, that was a nasty moment.
17:24What we wanted was a runway and we wanted it quickly.
17:37Hey, you see the airfield?
17:41I don't see it.
17:43Flight 671 is in a rapid descent with limited maneuverability.
17:48Less than 9,000 feet above southern France when the crew finally gets a break.
17:55I looked through just cloud underneath us and I glimpsed some ribbon black tarmac.
18:02It was a runway.
18:07Cabo 671, we have an airfield ahead. What is that airfield?
18:12It's a military airfield at your 12 o'clock for six miles.
18:18Can we land there?
18:19No, it's too short, too short.
18:22How long is the runway on this military airfield?
18:2513,000 feet.
18:27Oh, yeah.
18:28Okay.
18:30The runway at Istra is long. It is France's flight test center
18:35and it was also a space shuttle alternate learning ground.
18:38It's probably the biggest airport in Europe.
18:42Military airfield, Mayday, traffic 671.
18:44The first officer makes contact with air traffic control at Istra airport.
18:50671, this is Istra. You are cleared for arrival. Runway 33.
18:57We're just overhead. What's the wind?
19:00Wind is 330, 10 knots, gusting one to four knots.
19:07We'll make a left-hand pattern from the west.
19:09Yeah.
19:11The French military air traffic controller was one of my gang. I thought he was great.
19:17We turn left to land.
19:18Yes.
19:20As they start their turn, the crew lowers the plane's flaps in preparation for landing.
19:27The wheels were down and locked and the flaps were coming down
19:30so Captain Bergland could have more roll control.
19:33But when the flaps are extended, disaster strikes.
19:39There was another big explosion, which tried to roll us right again.
19:48Turn left. Turn left to land.
19:54Turn left.
19:55I'm trying.
19:57Turn left to land. Left turn.
19:58Yeah.
20:04We missed the runway.
20:09They're unable to line up for landing.
20:20671, we have fire on board. I confirm, fire on board.
20:26I could hear the fire, but I didn't say anything.
20:30We need another runway.
20:32Take runway 15, wind is...
20:35320, 10 knots, cleared direct.
20:40After failing to make a hard left for a landing on runway 33,
20:45the crew attempts to circle back and land on the runway's opposite end, known as 15.
20:52The captain doesn't have the strength to make the turn on his own,
20:56but the first officer has an idea.
20:58I said, I'll take the power.
21:00And Captain Bergland said to me, be careful.
21:03I said, I will, I promise.
21:06The first officer adjusts the throttles to help steer the plane to the runway.
21:11And bringing back number one and advancing number two,
21:13it actually turned the airplane left and he could fly it going towards the runway,
21:17which was a miracle.
21:19Truly was.
21:21It's a race against time to get the plane on the ground before the wing is incinerated.
21:29Good descent, you are on axis.
21:33Flight 671 is flying 50 knots faster than normal landing speed.
21:44Captain did a perfect landing, kept it just left of the center line,
21:48and we were safely on the ground at a great speed, but we were on the ground.
21:53If they don't break soon, the plane will be destroyed.
21:56If they don't break soon, they will overshoot the runway.
22:01Without hydraulics, they have only the plane's emergency brake to reduce speed.
22:06There was no anti-skid protection.
22:08That would have meant that the tires would start scuffing and bursting,
22:11which would then reduce their ability to slow down.
22:18Stopping was the only thing that mattered.
22:20You want both thrust reverses?
22:22The flight engineer wanted to use reverse thrust on the two left engines
22:26because that was the only way he could see of slowing down.
22:29No, cut the engines.
22:31The first officer didn't want him to do that
22:33because that would pull the airplane off to the left of the runway.
22:36I'll do reverse engine two.
22:42As a compromise, they used reverse thrust on the inboard left engine,
22:46the number two engine, which did help reduce their galloping speed,
22:50but pulled the airplane off the runway to the left.
22:58The aircraft did come to a halt in the mud.
23:06We're on fire. Evacuate! Evacuate!
23:08I realized that we were on fire,
23:10and it was burning and belching smoke and flame.
23:13We needed to get down, get out and get away.
23:21With two missing engines, a wing on fire, and no brakes,
23:26Flight 671 has landed in Istres, France, with its cargo and crew safe.
23:33To actually have two of the four engines fall off the wing,
23:37virtually unheard of in the history of aviation.
23:41The heroic escape from death makes headlines around the world.
23:45As French investigators arrive,
23:47they're faced with an important question.
23:49What caused two engines to fall off a plane?
23:54Losing two engines is a huge thing.
23:56So the investigators had quite a big task
24:00to establish what had happened and, more importantly,
24:03why and how to prevent it happening again.
24:07The damaged 707 is moved to a hangar to be examined by the BEA,
24:12France's Air Investigation Authority.
24:15The level of damage on this aircraft was very close
24:19to looking like a total structural failure.
24:24I've got something.
24:26Investigators make an early discovery about the fire onboard the plane.
24:31These wires from the cable loom short-circuited.
24:34That, plus a fuel leak from near the engine three area,
24:37causes a fire to erupt.
24:39The engine three area is the main fuel leak.
24:43The fire is caused by the high pressure from the engine three.
24:46The fire is caused by the high pressure from the engine three.
24:49The fire is caused by the high pressure from the engine three.
24:51A fuel leak from near the engine three area caused the fire.
24:54Good work.
24:56When the engines came away from the wing,
25:01they tore, with them, electrical wiring.
25:05Some of that wiring still had power available.
25:10When the flaps were extended,
25:12leaking fuel made contact with live wires and ignited them.
25:18Let's get this cleaned up.
25:20Get a better look at what tore the engine loose from the wing.
25:27Investigators are counting on the plane's flight data recorder
25:30to provide more information.
25:34Okay.
25:35Let's see what it can tell us.
25:47Looks like engines three and four were producing thrust right up until here.
25:559, 10, 50 a.m., one hour into the flight.
25:59The FDR data reveals that both engines stopped working almost concurrently.
26:05The flight data recorder basically showed the engines operating as normal
26:12when they left the aircraft.
26:18To understand why two perfectly functioning engines detached from the 707's wings,
26:24investigators need to find the missing engines.
26:27Here's the flight path.
26:34This is where they probably fell off.
26:41I'll send a search and recovery team out there.
26:4824 hours into the investigation,
26:52the engines of Flight 671 are located on a mountainside near Ceteron, France,
26:5855 miles northeast of where the plane landed.
27:04Investigators found the engines about 800 meters apart.
27:09That's very close.
27:12Their locations also suggest the engines detached at almost the same time.
27:18While the team waits for the engines to be recovered,
27:21they turn to the crew for further insight.
27:25We're climbing to 43,000 feet to avoid some pretty bad turbulence.
27:30Suddenly, there were loud sounds.
27:43I saw engine four was missing.
27:48You reported the engines missing at two different times.
27:52Is it possible you were mistaken?
27:54It's possible.
27:56The harness I was wearing kept me from getting a good look out the window at first.
28:00You said you were climbing to avoid turbulence. How bad was it?
28:03It was severe. I wouldn't want to go through that again.
28:07They'd flown through extremely heavy turbulence of a level not normally encountered.
28:17So there were two cumulonimbus clouds here and here,
28:22and they went up past 33,000 feet.
28:27Investigators examined the weather conditions at the time of the incident.
28:32Looks like there was also a 90-knot jet stream over here.
28:37They discovered that Flight 671 flew through two weather conditions when they reached 33,000 feet.
28:46Those two conditions would have generated severe turbulence.
28:50But you'd think it could withstand the turbulence.
28:53Did two colliding weather conditions tear the engines off the 707?
28:58Let's see what the engines can tell us.
29:01Hey, boss.
29:05Close examination of the engines gives investigators an important new clue.
29:12You see this dent on engine four?
29:14It's shaped like a jet stream.
29:16It's not a jet stream.
29:18It's not a jet stream.
29:20It's not a jet stream.
29:22It's not a jet stream.
29:24It's not a jet stream.
29:26It's not a jet stream.
29:28It's not a jet stream.
29:30The shape and diameter match a dent on engine three.
29:33So does this white paint.
29:37You could tell from the shape of the damage
29:40and from transfer of white paint from one engine to the other engine
29:46that the number three had struck the number four engine
29:51and separated it.
29:53Investigators now need to find out what caused engine three to detach.
30:00Looks like a clean break of all four fittings.
30:06Each engine is attached to a pylon.
30:09The pylon is then bolted to the wing using four large fittings.
30:14During flight 671, all four fittings broke on engine three.
30:23Three of the four fittings broke like this one.
30:25You can see from the surface they broke from stress.
30:30This mid-spar fitting is different.
30:36There's some distortion here.
30:38It likely broke from a fatigue fracture.
30:43You could see some characteristics surface-wise, coloration-wise
30:49that were consistent with the fatigue cracking.
30:53Over time, the inboard mid-spar fitting on engine three
30:57was weakened because of a crack caused by metal fatigue.
31:02When it snapped off in severe turbulence, the other fittings broke too.
31:08As a metallurgist, I want to take a closer look at these things.
31:22Okay, let's see what we got.
31:25To establish a detailed history of flight 671's broken mid-spar fitting,
31:31investigators use an electron microscope to examine it.
31:35I can see multiple arrest lines.
31:38With each takeoff and landing, the crack grows a little bit.
31:43And it leaves a mark.
31:45And each little stress cycle makes the crack a little bigger.
31:51These are likely from the flights the plane flew
31:53since Transair put it back in service a few weeks ago.
31:57What about before that?
32:00As the team continues examining the cracked mid-spar fitting,
32:04they make an unusual finding.
32:07It looks like corrosion.
32:10The plane had to have been exposed to moisture over a long period of time.
32:14Well, looks like the previous owner had the plane in storage
32:20for 13 months prior to the incident.
32:24Where was it stored?
32:30In a field in England.
32:34Steel will corrode if it's in a salty atmosphere
32:39or a very moist atmosphere.
32:41This particular aircraft was stored at airfields which weren't far from the sea.
32:47That explains corrosion.
32:53What about those? Those little marks?
32:57Near the bottom of the fitting, they discover several telltale marks.
33:03Those are corrosion pit marks.
33:06Corrosion pits are tiny holes in the ground.
33:09Corrosion pits are tiny holes that appear in metal
33:13after water has gained access to that metal
33:17and caused corrosion to take place.
33:20And the pit can be the start of a long crack.
33:24And in this case, there were corrosion pits
33:27that grew into one crack and eventually fractured the mid-spar fitting.
33:33So when did these pit marks start to develop?
33:35Well, it's hard to pinpoint exactly.
33:37Given their distance from the arrest lines,
33:39it suggests that the pitting started even before the plane went into storage.
33:43The crack doesn't occur in storage.
33:47The oxidation does.
33:49So that tells us the cracking occurred before storage.
33:55Probably years before storage.
34:01He's sitting for a time bomb waiting to blow.
34:03So how did the maintenance team miss it?
34:11This just arrived from Transair. Maintenance records.
34:14Oh, let's have a look.
34:16Investigators want to know if poor maintenance on Flight 671
34:21contributed to the crash.
34:24You start to look at the age of the parts that failed
34:28and what was the maintenance requirements for those parts.
34:31And did they play a role in the accident?
34:36In the 1990s, Nigerian airlines like Transair
34:41gained a reputation for poor maintenance.
34:45For a while, Nigerian airways were in fact banned from United Kingdom airspace.
34:53According to this, Transair didn't do a mid-spar maintenance check.
34:56Transair had only owned that airplane for a very small amount of time.
35:01So it's unlikely that they've performed any maintenance on it.
35:05So maybe Transair inherited the problem before it was owned by them.
35:13Looks like the previous owner did two maintenance checks.
35:16One on October 10th, 1991, when the plane was in storage.
35:21And the other in May 1991.
35:23The first time the plane was in storage.
35:25And the other in May 1990, before it went into storage.
35:30The team learns that the plane passed two maintenance checks
35:34in a two-year period prior to the incident.
35:38If the metal fatigue started before the storage,
35:41the maintenance checks should have caught the problem.
35:44There were certain cracks that should have been picked up, which weren't.
35:49Then, one month into the investigation,
35:51another 707 loses an engine.
35:55The incident is similar to what happened to Flight 671.
36:00During takeoff from Miami International Airport,
36:03the number three engine is torn off the wing and then hits engine four.
36:09With the Miami accident, the pilots managed to land the aircraft safely,
36:14with no one being hurt.
36:15The NTSB investigates and discovers that a broken mid-spar fitting
36:20also caused the engine to fall off the wing.
36:24This was perhaps history repeating itself.
36:31Is that from the NTSB?
36:33Yep.
36:35French investigators review the NTSB's preliminary report,
36:39curious about the Miami plane's maintenance history.
36:41Maintenance on the 707 in Miami was performed 328 flights before the accident.
36:46Which is well within the 600-flight recommendation by the FAA.
36:51They discover that the plane had also passed maintenance checks
36:55and reported no fatigue cracking or corrosion.
36:59In both the Miami accident and the French accident,
37:04the mid-spar fitting had failed in both cases.
37:08The mid-spar fitting had failed with a very similar way
37:13and had also been maintained as specified by the FAA and Boeing Aircraft Company.
37:21Perhaps they weren't maintaining properly.
37:25At the time, the mid-spar fittings were required to be inspected
37:32in a close visual examination.
37:34Basically, you gain access to the fitting,
37:39you wipe it off the best you can,
37:42and what you can see is what you examine.
37:47Was there a problem with the inspection process?
37:51Investigators interview a maintenance supervisor
37:54about how engine fittings are approved for flight.
37:58So, how do you inspect the fitting?
38:00You're supposed to carry out a close visual inspection
38:03for cracks on the exposed surfaces of the fitting.
38:06And?
38:08Well, cracks can start on the inside of the fitting.
38:11So why is that a problem?
38:13Well, it's a problem because you can't see inside
38:16unless you remove the engine and the pylon from the wing.
38:19It's a troubling discovery.
38:22The mid-spar fitting is normally inspected by removing a panel on the pylon,
38:26but the entire fitting cannot be seen from the access panel.
38:31The engine and pylon need to be removed
38:34to check for cracks on the inside of the fitting.
38:39Boeing did not require disassembly of the mid-spar fitting.
38:46Their risk assessment basically said
38:49it's not worth it on this old airframe.
38:52So there could be 707s out there with cracks in this fitting that no one could see?
38:56Yeah.
39:00As an investigator, you always have to wonder
39:03how many more engines are going to fall off of 707s.
39:18Listen to this.
39:20Listen to this.
39:22Investigators of Flight 671
39:25do a deep dive into the history of the Boeing 707's mid-spar fitting.
39:30There have been reports of more than 35 cracked mid-spar fittings on the 707.
39:35These planes are at the end of their life cycle.
39:38The 707 in Miami had flown over 50,000 hours.
39:42The Transair 707 had flown more than 60,000 hours.
39:46This was an old fitting on an old airplane
39:49that had been designed a very long time ago.
39:52When they didn't know how these materials would age,
39:56the consequence of this and perhaps not the best maintenance or inspection
40:00meant that eventually this fitting just gave up.
40:03By 1992, most 707s were considered too old to fly passengers
40:09and were converted to freight transport.
40:12We need to make sure this doesn't happen again.
40:16Investigators conclude that a hidden fracture in the mid-spar fitting
40:20almost took the lives of the five men on Transair Flight 671.
40:32The fate of the plane is sealed when a maintenance inspection
40:36fails to catch the fatigue crack.
40:38Ask if we can go to 33.
40:43The 707 is pushed to its breaking point when two weather events collide.
40:50The in-flight turbulence was the last little bit
40:56that was necessary to cause fracture.
40:59Basically, it was the last straw that held this pylon together.
41:04The weakened mid-spar fitting finally breaks
41:08and both engines are lost.
41:15If not for the heroics of the crew, the plane would have crashed.
41:21The 707 is not an easy airplane to fly when everything's going well.
41:25It's a very difficult airplane to fly when things are going wrong.
41:29I've got limited time.
41:31You're dropping?
41:33Yeah.
41:35Captain Berglund's skill and stamina prove remarkable
41:39as he physically keeps the plane stable until landing.
41:44From the beginning of the incident
41:47to when they finally landed on the runway, 24 minutes,
41:50are 24 minutes that most pilots wouldn't have had
41:55all those things happen to them in an entire career.
41:57He was just one fantastic pilot.
42:04Cargo 671, we have no radar contact.
42:07Say your position, please, sir.
42:09Throughout the harrowing flight,
42:12flight engineer Boone troubleshoots and fixes key systems.
42:17The flight engineer looked at his panel
42:20and came up with the solution as to why the radar wasn't working.
42:23You turn left 180.
42:25OK.
42:32Hey, you see the airfield?
42:35And First Officer Emery's quick thinking and intuition proved vital.
42:39Cabo 671, we have an airfield ahead. What is that airfield?
42:43It was an absolute genius decision to land at a military base
42:47with a long-run plane.
42:50It shows an awful lot about the spirit of pilots and survival,
42:55that they somehow coalesce together
42:58and they all use their own individual skills.
43:05The BEA recommends that inspections of the current mid-spar fittings
43:09be modified to ensure the safety of the aircraft.
43:13And that's what we're doing.
43:15The BEA recommends that inspections of the current mid-spar fittings
43:19be modified to enable the detection of hidden cracks
43:22or be replaced by reinforced fittings.
43:29The FAA decided to mandate replacement of the mid-spar fittings
43:34with a new and improved mid-spar fitting,
43:38which did not require inspections
43:41that were ineffective in the first place.
43:45In 1992, the crew of Transair Cargo 671
43:49received the Hugh Gordon Burge Award for Outstanding Airmanship.
43:54This flight was a heroic achievement,
43:57where the crew have recovered from a virtually impossible situation
44:02and they deserve the awards they got.
44:05So, a lot of luck and a bit of teamwork
44:08and a bit of shouting and a bit of action,
44:11but a happy landing.
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