- vor 22 Stunden
On 26 August 2003, Colgan Air Flight 9446 crashes into water shortly after takeoff from Barnstable Municipal Airport, killing both pilots. The causes of the crash were an improper replacement of the forward elevator trim cable and the pilots not following checklist procedures.
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00:00Pilots of Colgan Air Flight 9446 fight for their lives as their plane dives towards the ground.
00:10You pull for all your work. Just keep pulling for all your work.
00:14Picture trying to do your day job while deadlifting 250 pounds.
00:18Oh no!
00:23Both pilots are killed.
00:25The wreckage reveals very little.
00:31That is a rat's nest.
00:33The cockpit voice recording provides a key insight.
00:37Listen to how exhausted they are trying to keep the nose up.
00:40But analysis of flight data turns the case on its head.
00:44This doesn't look right.
00:45Well, that was a huge aha moment for me.
00:48How is that possible?
00:49Everybody missed what was just such a simple mistake.
00:55They've been brought to me.
00:56They'll plant them apart.
00:57They're done, they're done, they're done, they're done, they're done.
01:00They're done, they're done.
01:01They're done.
01:03A Colgan Air crew prepares for the last flight of the day
01:24in a recently serviced aircraft.
01:28Weather looks good. Should be an easy ride.
01:32Captain Scott Knabe has been with Colgan Air for more than two years.
01:37Six months ago, he was promoted to captain.
01:41Scott Knabe was among the most careful and meticulous pilots.
01:47He was a very successful and very good accountant,
01:51but he had the aviation bug.
01:56How's the paperwork?
01:57Weight and balance is checked and filed.
01:59First officer Stephen Dean has been with the airline for less than a year.
02:05Did you put in for that upgrade?
02:07Actually, no, I didn't. I put in my notice.
02:10I can't afford to do this anymore.
02:13Understood.
02:14Being a young pilot moving his way up the ladder in the regionals,
02:19the first officer quickly discovered that his pay could not support his wife and daughter.
02:25So a week before this flight, he gave notice.
02:30Don't mind these reposition flights.
02:32Colgan Air has a small fleet of Beach 1900s.
02:45The aircraft operate as part of U.S. Air's regional arm.
02:49The Beechcraft is a smaller plane, popular for commuter flights.
02:53They fly short distances.
02:58They fly into places that the big name carriers wouldn't be able to fill up or make a lot of money.
03:08Maintenance log checked and aircraft is released.
03:11After four days of routine maintenance in Hyannis, the plane is being returned to service.
03:20Colgan 9446 will fly empty to upstate New York.
03:24Sometimes we have to resort to these non-revenue flights to reposition the plane from one location to another.
03:32Occasionally that could also happen when you have to bring the plane to a specified maintenance facility.
03:36Today's flight from Hyannis, Massachusetts, west, to Albany, New York, should take 50 minutes.
03:45Circuit breakers, check.
03:47Checked.
03:48The pilots perform their final checks.
03:55All right, I'm not getting any radios here.
03:57Have you got anything in your headset?
03:58Check, check, check.
04:01What a cluster.
04:02When an airplane is returned back to service, pilots will expect that all subsistence are working.
04:09So you will show up to the airplane and expect that everything has been serviced accordingly and it's safe to return back to flying.
04:17After a short delay because of a minor radio problem, flight 9446 taxis for takeoff.
04:26Takeoff terms are set.
04:27Cabin PA not required.
04:29Tower Colgan 9446.
04:32We're good to go.
04:3224.
04:36Colgan 9446.
04:38Runway 24.
04:39Cleared for takeoff.
04:41Cleared for takeoff.
04:4324.
04:43Colgan 9446.
04:49Set the power.
04:53Power set.
04:54The Beech 1900 being such a stable aircraft, as soon as it accelerates on the takeoff roll, it will reach flyable speed in a distance as short as 4,000 feet.
05:0680 knots.
05:07And it will basically fly itself off the runway with very minimal pilot input.
05:16At 3.38 p.m., flight 9446 lifts off the runway, but it's barely gaining altitude.
05:25We have a hot elevator trim.
05:28The captain suspects there's an issue with the trim system, which is preventing the plane from climbing normally.
05:37Trim tabs on the elevator adjust the plane's pitch during takeoff.
05:42They're powered by a switch on the control column.
05:49But the captain's trim switch isn't working.
05:51If you have a trim issue on takeoff, it is very difficult to overcome.
05:59You have seconds, not minutes, because you don't have any altitude.
06:03Just 50 feet off the ground, the plane's nose is dropping.
06:11Roll back, roll back, roll it back.
06:13I got it.
06:16Knabe instructs the first officer to adjust the trim manually.
06:22A manual trim is a wheel located on the left side of the throttle quadrant that allows you to trim it into a nose-up attitude.
06:29But that doesn't help.
06:34Pull back.
06:37An airplane that is nose-heavy will continuously require back pressure on the control yoke.
06:44It's heavy, buddy.
06:46Using brute force, the pilots manage to raise the plane's nose and climb away from the runway,
06:52despite the plane's determination to pitch down.
06:55Do the electric trim disconnect.
07:01The captain wants to cut the power to the trim altogether.
07:07But before the co-pilot can even find the right circuit breaker...
07:12Back, Steve.
07:13No, stay on the controls with me.
07:15The nose drops again.
07:23Put up our gear.
07:23Selecting the gear up in an airplane will reduce the amount of drag being exposed to the airstream,
07:32improving your climb performance.
07:35This would make the pilots gain altitude at a faster rate.
07:4045 seconds into the flight, the pilots still can't get the plane to climb normally.
07:4594-46 is requesting emergency back, sir.
07:52Got a runaway trip.
07:54The captain wants to return to Hyannis Airport.
07:57Colgan, 9446.
07:59Roger.
07:59Right and left downwind, your choice.
08:01Report midfield.
08:04Okay, Roger, will do.
08:04Using all of their physical strength, the pilots manage to level off at 1,200 feet
08:11and start the turn back to Hyannis.
08:17All right.
08:21We have a beached 1900 aircraft that just took off reporting control problems.
08:26We need fire and rescue to runway 33.
08:28With brief respite from the struggle...
08:33Could I pull the breaker?
08:34Yeah.
08:35Pull the breaker, Steve. Pull the breaker. I have the yoke.
08:38The pilots return to troubleshooting the trim issue.
08:41Where is it?
08:42Find it.
08:43In the confusion, the first officer can't locate the breaker for the automatic trim.
08:49Look left of the silver thing, Steve. Left of the silver thing.
08:51Left of the silver thing?
08:52Left of the silver thing.
08:52Oh, the stick. Steve, stay with me.
08:57The second attempt to disconnect the trim system also fails.
09:04Less than two minutes after taking off, Colgan, 9446, is losing altitude.
09:12You pull for all you're worth. Just keep pulling for all you're worth.
09:16Really, what he was saying is pull for your life.
09:19Because that was the only hope they had at that time.
09:22Five miles from the airport, the pilots struggle to return to Hyannis.
09:319446 is requesting 33, sir.
09:369446, roger. Runway 33 cleared the land.
09:40We're gonna need both of us on this, Steve.
09:45The pilots use all their strength to keep their plane airborne.
09:48Ah, Steve, keep, I'm pulling!
09:51But it's still not enough.
09:53All right, Steve!
09:57Ah!
09:58Ah!
09:59Oh, no!
10:00Ah!
10:00Ah!
10:00Ah!
10:00Ah!
10:01Ah!
10:01Ah!
10:02Ah!
10:02Ah!
10:03Ah!
10:04Ah!
10:04Ah!
10:05Ah!
10:06Ah!
10:07Ah!
10:08Ah!
10:09Ah!
10:10Ah!
10:11Ah!
10:12Ah!
10:13Ah!
10:14Ah!
10:15Ah!
10:16Ah!
10:17Ah!
10:18Ah!
10:19Two minutes after takeoff, Colgan 9446 crashes, three and a half miles from the airport in Hyannis,
10:26Massachusetts.
10:30The Coast Guard was there almost immediately, but they were not able to save the pilot and
10:36the co-pilot.
10:38Hitting the water at a very high rate of speed is like hitting cement.
10:43The pilot's bodies are recovered from the wreckage within four hours.
10:55A team from the National Transportation Safety Board, the NTSB, arrives in Cape Cod to
11:01begin the investigation.
11:02It can be posted on the recovery process.
11:07This is the second Beach 1900 to crash in six months.
11:11There was the Air Midwest accident down in Charlotte.
11:15The big question was, you know, is there anything related?
11:17Was there a fleet-wide problem?
11:19NTSB investigators consider why Colgan Air Flight 9446 crashed so soon after takeoff, killing
11:31both pilots.
11:33It's similar to an Air Midwest crash in Charlotte, North Carolina, which took the lives of 21
11:39people.
11:40Witnesses reported that the aircraft climbed for a few seconds, and then the nose pitched
11:48up high in the air.
11:50It edged over and then literally tumbled towards the ground into a building.
12:00With hundreds of American-built Beach 1900s in service, investigators need to find out if
12:06there's a design fault with the aircraft that could put even more lives at risk.
12:12Steve.
12:13Hey.
12:14Great.
12:15You can set up over there.
12:17Thanks, boss.
12:19The NTSB calls in Steve Carbone, an investigator who has been working for months on the Beach
12:251900 accident in Charlotte.
12:27What do we know so far about the cause of that other Beach 1900 crash, the one in Charlotte?
12:34We think the plane was loaded wrong, and the pilots lost control of it.
12:37A witness reported that Colgan Air 1900 seemed to struggle to hold altitude before descending
12:43into the water south of the airport.
12:45Pilots understand that altitude is their best friend, and taking off from the airport and
12:50then pretty much flying right into the ocean is a sure sign that something was wrong.
12:57There could be control problems after takeoff in both accidents.
13:05The similarities between Colgan and Air Midwest wasn't just the fact that both were Beach
13:101900.
13:12In both instances, the attitude of the aircraft was uncontrollable.
13:16Charlotte, they lost control of the pitch.
13:22Was it outside its center of gravity?
13:26The balancing point of an airplane is called its center of gravity.
13:31Passengers and luggage must be carefully distributed from front to back to keep the plane stable
13:36in flight.
13:38In Charlotte, investigators believe the Beach 1900 may have been tail heavy, which caused
13:45it to pitch up after takeoff.
13:50The Colgan flight was empty, so without any passengers, maybe the center of gravity was
13:54too far forward.
13:56You could have an empty airplane and still be out of your center of gravity.
14:02The crew weight, 454 pounds.
14:07They calculate flight 9446's center of gravity based on the distribution of the weight on board.
14:14And then the fuel weight was 3,271 pounds.
14:21That should do it.
14:27Look how far forward that is.
14:31Yeah, but it's within limits.
14:34The team is now certain that whatever brought down Colgan 9446, it was not related to its center
14:40of gravity.
14:44With Colgan, center of gravity didn't turn out to be an issue, even though it did have to
14:49be eliminated as a possibility.
15:00Thank you for meeting with me.
15:02Investigators turned to the air traffic controller for insight into why the pilots of Colgan 9446
15:08lost control after takeoff.
15:12Tell me about the flight.
15:14Normal takeoff about a minute after they wanted to return to the airport.
15:229446 is requesting emergency back, sir.
15:26We have a runaway trim.
15:29He told you a runaway trim?
15:31Yeah.
15:33Pilot reported a runaway trim to air traffic control, which is a control issue.
15:37And so that information was very helpful.
15:39It helped us work smarter, not harder.
15:43Runaway trim occurs when the motorized trim tabs on the elevator malfunction,
15:48causing the plane to pitch nose up or nose down.
15:52A runaway trim close to the ground will be specifically challenging because pilots will have very limited
15:58time to perform the required actions to safely control that aircraft.
16:03Now, he came off a runway 24 and reported his emergency about here.
16:11Turned back toward the airport and the plane never got above 1,200 feet on my radar.
16:17And he hit the water here.
16:21If the pilot feels that he's having a trim runaway, there's something in the pitch system
16:28that is clearly a problem.
16:30This is very helpful.
16:33And we're certainly going to investigate that.
16:35Will the wreckage confirm what the pilots reported
16:39and help explain what brought down a widely used commuter aircraft in just over two minutes?
16:53Good.
16:54You've got them.
16:55The flight data recorder and cockpit voice recorder of Colgan Air Flight 9446 are recovered
17:02from the sea floor.
17:03They are in good shape.
17:08Ship them to the lab.
17:10Maybe we'll get some answers from these.
17:13We were lucky in some areas where we had the flight data recorder and we had the cockpit
17:17force recorder.
17:19If we didn't have flight recorders on this one, boy, I don't know.
17:23That is a rat's nest.
17:25Investigators turn their attention to what remains of the control systems.
17:31So there's a lot of cables that go to the tail.
17:36Cables that control the elevator, the trim, and the rudder as well.
17:41I see some of the trim cable in there.
17:43Let's find as many pieces of it as we can.
17:47The trim cables are smaller and head fractured, and so it's a big puzzle to be able to track
17:55the cables from one end to the other.
17:58Could take a while.
18:02While one team looks for the cables connecting the trim system, another focuses on the maintenance
18:08of Colgan 9446.
18:27Could a faulty repair be connected to the pilot's report of runaway trim?
18:33Check out which inspection they were in.
18:37Colgan Air monthly routine inspections are divided into phases, focusing on different
18:42areas of the plane.
18:44They were working on the tail.
18:47Exactly.
18:48Which means they might have done work on the trim system.
18:51They flew in with no problems.
18:53And then on the first flight out, they couldn't control it.
18:57Something happened that was detrimental to safety of the aircraft.
19:02They spent at least four separate days on the inspection.
19:06What took them so long?
19:12It doesn't say.
19:14A phase check, in this case what they call a detail check, you can do it within an eight-hour
19:20period, especially on a 1900, because it's a very simple aircraft.
19:24But the fact that it took four days led us to understand that there was something else that occurred.
19:30Mind if I record this?
19:32Yeah, sure.
19:34I was wondering, why did it take you so long to do your phase checks?
19:43Well, we definitely found a lot of stuff that we needed to replace.
19:47I got the flashlight.
19:58Just bring the light a little to my left.
20:03Yeah, the trim actuators worn out.
20:07Cables from the cockpit connect to the trim actuators.
20:12Mechanical rods in the tail that move the trim tabs up or down.
20:17What did you do when you found the problem with the actuators?
20:21We removed the old ones, ordered new ones, and installed them.
20:26And the new ones went in easily and it worked fine?
20:30Uh, well, not exactly.
20:38Okay, Bob, run the trim system, please.
20:44Did the actuators move?
20:46No.
20:47Neither did the trim cable.
20:49The test revealed problems with the actuator replacement.
20:53When we replaced the actuator, we bent and kinked the cable that connects it to the cockpit
20:59controls, it was just a dumb mistake.
21:03If he's an experienced, competent mechanic, why would he do that?
21:08And the answer was, he was not.
21:10He was a new hire, had never done this job before,
21:13and their training program allowed him to do this without any supervision.
21:19I ordered a new cable and installed it.
21:22That's why it took four days.
21:25And you tested it?
21:27Yeah, yeah.
21:28After the new cable was installed, maintenance workers performed a visual check.
21:35Okay, let's give it a try.
21:38When examining the paperwork after the accident, everything looked in order.
21:43That's it.
21:44It's working.
21:45Thanks, man.
21:46Yet we still had an issue because it didn't explain what actually happened.
21:52With no credible leads to explain why the pilots thought they had a trim issue, investigators
21:57must rely on what they learned from the CVR, the cockpit voice recorder.
22:01Okay.
22:02Let's hear it.
22:03The recording runs about 17 minutes from the moment the pilots powered up on the ground.
22:18Could the pilot's communications reveal why Colgan Air Flight 9446 failed to maintain altitude?
22:26Yeah, they might call you and turn you back because they did find a problem.
22:39I don't know for sure.
22:43Why would maintenance want to turn them around?
22:45Maybe there was something wrong with the plane.
22:48Somebody had doubts about the work they did.
22:52I, as a mechanic, could not ever release an aircraft that there was a question of its airworthiness.
23:00You cannot say, well, you know, the wings are pretty, pretty strong on there.
23:05We're 90% positive they're not going to fall off.
23:08You can't do that.
23:09I prefer not to fly something if it's broken.
23:12I'd rather you do it.
23:14Because you are the pilot in command.
23:16All right.
23:17A broken airplane?
23:19I wouldn't want to screw it up.
23:21Okay, it'll be a standard Colgan takeoff.
23:27If things get spooky on the runway, we'll abort it.
23:31Did you just say spooky?
23:34As investigators continue to review the CVR...
23:38Flight Chris should not be that nervous.
23:40...they're surprised by the pilot's concern about the condition of their aircraft.
23:46Sadly, the aircraft manuals went down with the aircraft.
23:51So exactly what the maintenance personnel put in those log books for the pilots to review, we will never know.
24:00When did they first realize there was a serious issue with their aircraft?
24:05It looks like merely seconds after takeoff.
24:12V-1, rotate.
24:15We have a hot elevator trim.
24:18They identified a trim issue seconds after takeoff, long before contacting the controller.
24:24So what did they do about it?
24:27Kill the trim, kill the trim.
24:31The captain tries to disconnect the trim system on his yoke.
24:37But his attempts fail.
24:40Roll back, roll back, roll it back.
24:42I got it.
24:44They're commanding nose-up trim inputs, but it doesn't seem to help.
24:5494-46 is requesting emergency back, sir.
24:58Got a runaway trim.
25:01Okay, there it is.
25:02Runaway trim.
25:04Just like the controller said.
25:09Did they try pulling the breaker?
25:11It looks like it.
25:15Pull the breaker, Steve.
25:16Pull the breaker.
25:17I had the yoke.
25:19Listen to how exhausted they are trying to keep the nose up.
25:21Where is it?
25:23Find it.
25:24The pilot was calling for the co-pilot to pull the circuit breaker so they can stop these
25:30electrical signals that are commanding the runaway trim.
25:33But you have to have time to pull the circuit breakers.
25:37Look left of the silver thing, Steve.
25:39Left of the silver thing.
25:40Left of the silver thing?
25:41Left of the silver thing.
25:42Oh, the stick.
25:43Steve, stay with me.
25:45The co-pilot had to abandon pulling the breaker in order to help the captain.
25:51Steve, keep pulling!
25:55Oh, no!
26:04Two minutes.
26:06I'm going to take off the impact.
26:09Those guys fought the trim right until they hit the water.
26:14We need to find out what's going on with that trim system.
26:19Was there a mechanical issue with the trim that the pilots could not overcome?
26:27Okay, let's have a look.
26:30We were lucky.
26:31We had a solid-state flight data recorder.
26:33Some of the old, old flight recorders might only have 16 parameters.
26:36This one had a lot more.
26:39Investigators examined the FDR, the flight data recorder, to determine why the pilots reported a runaway trim.
26:49This doesn't look right.
26:50What do you mean?
26:52This trim data is way out of calibration.
26:56It either wasn't maintained properly, or it was damaged in the accident.
27:01And so on this one, we didn't have exact trim position.
27:07If the FDR wasn't calibrated, those readings are worthless.
27:11It's a major setback.
27:13Without the FDR data, the investigators may not be able to confirm the pilot's report of a runaway trim.
27:20We have all those other parameters.
27:22Pitch, elevator.
27:24Let's ask the lab to try and calculate what the trim position would be.
27:28Performance case study.
27:30It's a great idea.
27:32A case study like this would help us to define whether the elevator trim tape cables had anything to do with the accident.
27:41It was one other thing that we could check into to verify the results we were finding.
27:46Will the team be able to get accurate trim data?
27:49Steve, keep...
27:50I'm pulling!
27:51And explain why two experienced pilots were unable to keep their plane in the air?
27:56Oh, no!
27:57Oh, no!
28:12So, the lab took the control column positions and extrapolated for trim.
28:17I see. Excellent.
28:20A performance study using the FDR data gives the NTSB a new look at the trim inputs on Flight 9446.
28:30So, they adjust the trim to take off right here.
28:34Yep.
28:35It's part of the before taxi checklist.
28:40Before taxi checklist.
28:42Before taxi weather radar.
28:45On standby?
28:47Yeah.
28:48Trim set?
28:490.5.
28:50Takeoff trim set.
28:54The takeoff trim was set to 0.5 nose down instead of 0.5 nose up.
29:00That's odd.
29:02When's the next input?
29:04Right after takeoff.
29:06That's right after he said...
29:09We've got a hot elevator trim.
29:12The plane is pitching down instead of up.
29:15How's that possible?
29:17Investigators discover the plane wasn't responding to the pilot's nose up trim inputs.
29:24And it happens again here, one last time, a few seconds later.
29:29Roll back, roll back, roll it back.
29:31I got it.
29:32The more the first officer tries to manually trim the nose up, the more the nose drops.
29:42It's like the trim is reversed.
29:45A good analogy is learning to drive.
29:48Imagine how weird it would be if you turned your steering wheel right and the car went left.
29:52Talk about confusing.
29:55And exhausting.
29:58You pull for all your worth. Just keep pulling for all your worth.
30:01They were dealing with the backwards trim, which I don't know how anyone would have ever fathomed that.
30:09Investigators calculate that within a minute of takeoff, the pilots would have required 250 pounds of force to hold the nose up.
30:18Steve, keep pulling!
30:21Hold on, Steve!
30:23How on earth could they have wired a trim system backwards?
30:38The team retrieved this from the wreckage.
30:40Oh, great.
30:41In an effort to prove the trim cables on Flight 9446 were reversed, investigators study a key piece of the trim system found in the wreckage.
30:56The trim cable is threaded and wrapped around this drum and then runs in a loop from the cockpit to the tail.
31:04Maybe they fed the cable incorrectly around the drum.
31:13Let's check the installation manual.
31:16Looks like maintenance threaded the drum correctly.
31:31Yeah.
31:35But how did they install it?
31:38The cable drum is one piece of the story that was telling us that it might have been incorrectly rigged.
31:44But we needed to dig deeper.
31:47Okay.
31:48Let's give this a try.
31:49The NTSB considers how the maintenance crew installed the drum.
31:56It's good.
32:00I don't know.
32:02Yeah, that's it.
32:11Well, that doesn't fit.
32:14No.
32:19Yeah, the only way to install this thing.
32:28Like this.
32:30Investigators discover that in order for the drum to fit the pin, it had to be flipped, thereby crossing the wires.
32:38Well, that was a huge aha moment for me.
32:40The manual, the way it was depicted at that time, it could mislead somebody.
32:47In this case, it did.
32:51We have a hot elevator trim.
32:53Because the wires were crossed, the trim tab operated in reverse.
32:57Kill the trim, kill the trim.
33:05Pull back.
33:07They knew they had a malfunction.
33:09They just couldn't figure out what it was.
33:12There's only one explanation.
33:15Maintenance manual must be wrong.
33:18I'll check with the manufacturer.
33:20But even if the manual is wrong, why didn't anyone notice the trim cables were crossed?
33:28I'll check to see if the maintenance team got an inspector to sign off on the work.
33:32They are a second set of eyes.
33:35They have to be the one who is making sure that the job is done right.
33:38That is what an inspector does.
33:39After you installed the drum, did an inspector sign off on the work?
33:45Yes, he did.
33:47In fact, he assisted with it.
33:50He assisted?
33:52Yep.
33:54The inspector cannot get in there with wrenches.
33:56He cannot get in there and tell you, okay, you got to put this bolt here, or anything like that.
34:01Thanks for your help tonight.
34:03The thing is, with an inspector being part of the job,
34:06he's making the same mistakes that the people that he's supposed to be overlooking are making.
34:12So he becomes part of the problem.
34:15The inspector, who helped with the installation, didn't notice the crossed wires and signed off on the work.
34:23The last time we spoke, you said you tested it?
34:27That's right.
34:30After the new cable was installed...
34:33Okay, let's give it a try.
34:34Maintenance workers performed a visual check.
34:37Yeah, that's it.
34:38It's working.
34:39Yeah, thanks, man.
34:45Yeah.
34:47It's coming in now.
34:49Thanks.
34:54Hey.
34:56Hey.
34:57What'd you find out?
34:58The inspector helped with the installation, so not exactly an objective inspection.
35:03What about you?
35:05Well, it's just like we thought.
35:07The drawing in the manual was wrong.
35:10This is how the drum should have been oriented when they threaded the cable.
35:15The manual shows the slots on the drum are facing out.
35:18But the correct way to thread the cable is with the flat side facing out.
35:26Here's what I don't get.
35:27They tested the trim system when the installation was complete and said it was working fine.
35:31How's that possible?
35:34Long night?
35:48Yeah.
35:50Found a recording of the trim check test.
35:51You're kidding.
35:52It's on the CVR, recorded well before their flight.
35:56In order for the mechanics to do an operational check correctly, they had to power the airplane up.
36:02Okay, Bob, run the trim system, please.
36:05So the power was on, the CVR was on, it worked to our advantage.
36:08I think I know how the trim tabs passed the visual ground test even though they were running in reverse.
36:17Are you good in the cockpit?
36:20Yeah.
36:22Okay, let's give it a try.
36:25Trim nose up.
36:27Trimming nose up.
36:29Yeah, moving up.
36:32Looks good.
36:34Yeah, trim nose down.
36:36Trimming down.
36:39Okay.
36:41Yeah, that's it.
36:42That's working.
36:43Thanks, man.
36:47Sounds like a normal test.
36:49No.
36:50They got it backwards.
36:52We hear the cockpit call trim up, and the maintenance worker says he sees the trim tab move up.
36:58That is reversed.
37:00If you trim nose up, the trailing edge moves down in the opposite direction.
37:05The same is true for trimming the nose down.
37:11It is counterintuitive, but you're right.
37:14It is an easy mistake to make.
37:17Checking a trim system can be a little confusing.
37:19You have to make sure you're on the same page with the other person.
37:22Are you talking tab up or nose up?
37:25Because tab up is nose down.
37:28The ground guys missed it okay.
37:30Why didn't the pilots catch it?
37:31The trim test is definitely a pre-take-off checklist item, but then they run it.
37:44According to the transcript, they ran the checklist.
37:46All right.
37:50Before start checks.
37:52Parking break.
37:54It's set.
37:55Pre-flight complete.
37:57Before taxi checklists.
37:59Before taxi, weather radar.
38:03They skipped the trim check.
38:04I'm biased because I have a pilot background.
38:08I feel like that first flight of the day checklist is crucial.
38:11That's where you can catch it.
38:13Even if they had checked it, would they have known whether the trim system was reversed just by looking at the direction the trim wheel was spinning?
38:23Good point.
38:24Pilots test the trim by pressing the trim switch and monitoring the direction in which the manual trim wheel spins.
38:34To trim nose up, the wheel would turn backwards.
38:41Investigators recreate the reverse trim system on the same model of Beach 1900 that crashed,
38:47to determine whether the pilots could have detected that the trim was reversed.
38:52Let's give this a try.
38:55Investigators trim the plane nose up.
39:01The wheel is moving backwards.
39:04The way the pilots expected it to turn.
39:07Even though the trim cable was reversed, the wheel still moves backwards as it should.
39:13What is in error is the fact that the drum is upside down.
39:18It is now running the cables in the wrong direction.
39:21So everything in the cockpit is correct.
39:24The test reveals the pilots of Colgan Air Flight 9446 wouldn't have realized the cables were reversed even if they had checked them prior to takeoff.
39:35We have a hot elevator trim.
39:39In their final report, the NTSB concludes the cause of the accident was the improper installation of the trim cable system, and Beechcraft's erroneous depiction of the elevator trim drum in their maintenance manual.
39:56The stick!
39:57Steve!
39:58The stick!
39:59Steve!
40:00Stay with me!
40:02These factors ended up sealing the pilots' fate.
40:05The pilots' grueling efforts kept the plane in the air for more than two minutes.
40:10Pulling up!
40:11But in the end, the extreme stick pressures were too much for the pilots to overcome.
40:15Picture trying to do your day job while deadlifting 250 pounds.
40:16It's just too much.
40:17Hold on, Steve!
40:18Ah!
40:20Hold on, Steve!
40:21Ah!
40:22Oh no!
40:23Ah!
40:24Ah!
40:25No!
40:27No!
40:28No!
40:29It's too much as possible.
40:30Mm unhealthy grub won't let them know when they wreck it as a airplane!
40:32其實 contradictor of a Moscou physical carrier, but in any strange, some red rely.
40:37It's just too much.
40:41Hold on, Steve!
40:45Oh, no!
40:46Ah!
40:57This accident was 100% preventable.
41:00First and foremost is your plane has to be flyable,
41:05and it's only flyable if the manuals and maintenance
41:08and pilot instructions make sense.
41:11The Colgan Air 9446 report echoed similar findings
41:16to the other Beach 1900 crash months earlier
41:19in Charlotte, North Carolina.
41:22Improperly installed control cables were also a factor
41:25in the Air Midwest accident that killed 21 people.
41:29If you looked up the term maintenance accident in dictionary,
41:32those two accidents would be there.
41:34Colgan and Air Midwest were poster childs
41:37for maintenance accidents.
41:40If Colgan properly followed the maintenance program
41:45as dictated by the regulations,
41:48this accident never would have happened.
41:51After the accident,
41:52Beechcraft's maintenance manuals were amended,
41:55and airlines adopted stricter procedures
41:58for airplane checks after undergoing routine maintenance.
42:01The person in the cockpit missed it,
42:05the people on the elevators missed it,
42:06the inspector missed it.
42:08Everybody missed what was just such a simple mistake.
42:12Mistake.
42:13Mistake.
42:13Mistake.
42:13Mistake.
42:13Mistake.
42:13Mistake.
42:14Mistake.
42:14Mistake.
42:14Mistake.
42:14Mistake.
42:15Mistake.
42:15Mistake.
42:16Mistake.
42:17Mistake.
42:18Mistake.
42:18Mistake.
42:19Mistake.
42:19Mistake.
42:19Mistake.
42:20Mistake.
42:20Mistake.
42:21Mistake.
42:21Mistake.
42:22Mistake.
42:23Mistake.
42:23Mistake.
42:24Mistake.
42:25Mistake.
42:26Mistake.
42:27Mistake.
42:28Mistake.
42:29Mistake.
42:30Mistake.
42:31Mistake.
42:32Mistake.
42:33Mistake.
42:34Mistake.
42:35Mistake.
42:36Mistake.
42:37Mistake.
42:38Mistake.
42:39Mistake.