How 1 In A Billion Chance Brought Down a Whole Airplane

When the chips are down, how do you respond? All of us like to think that we can rise to emergency challenges, but hope to never have a moment where the extreme end of our ability is tested. Unfortunately, during what should have been a routine flight, the crew of United Airlines Flight 232 was suddenly faced with unimaginable disaster, a scenario considered so improbable there was no formal procedure for addressing it. This is the tragic, yet miraculous tale of the crash of UA Flight 232 and how the flight crew rose to the challenge and attempted to do their very best under the circumstances.

On Wednesday, July 19, 1989, UA Flight 232 took off at 2:09 pm central time (CDT) from Stapleton International Airport in Denver, Colorado. The McDonnell Douglas DC-10 jet airliner was bound for O'Hare International Airport in Chicago with continuing service to Philadelphia International Airport. The liftoff was picture perfect, the sky a bright, cloudless blue; soon the plane was cruising at an altitude of 37,000 feet (11,277 m) with the autopilot engaged. In the cockpit was veteran pilot Capt.ain Al Haynes with two experienced co-pilots; First Officer William Records and Second Officer Dudley Dvorak. It was a full flight with 296 souls aboard. In addition to the 3 pilots, there were 8 flight attendants and 285 passengers.

Due to a Children's Day promotion where children could fly for $.01 with purchase of a regular adult ticket, there was an unusually high number of children on the flight, 52 to be exact. Four of these children were ‘lap children’ or children under 2 years old and per American flight regulations could be held in the parent’s arms with no seats of their own for the duration of the flight. The first half of the 2-hour flight was uneventful. Then at 3:16 pm while the plane was making a right turn over Iowa, there was a loud bang in the rear. An explosion jolted the plane, causing it to shudder violently. Immediately several freaked out passengers wondered if a bomb had gone off. On the flight deck, the pilots were bombarded with warning alarms and flashing lights. The autopilot disengaged and Officer Records took control of his steering column. The flight instruments indicated that engine 2 on the tail had malfunctioned, so Capt.. Haynes and Officer Dorvak rapidly shut it down which stopped the plane’s shaking.

Luckily DC-10 are equipped with 3 engines, engine 1 is mounted in front of the left wing, engine 2 is in tail and engine3 is mounted in front of the right wing. The plane could still fly with only 2 engines working. Capt.. Haynes hastily made a reassuring announcement over the PA that engine 2 had some problems and as a result they might be a few minutes late to O’Hare. However, as this was happening, the plane suddenly swerved hard to the right, began to roll over, the nose diving. Officer Records turned his steering column, trying to straighten out the plane, but it wouldn’t respond to his commands.

Capt. Haynes also tried turning his steering column, but the plane still wouldn’t respond. Officer Dvorak quickly realized that the gauges registering fluids for all 3 hydraulic systems were displaying zeros. The plane had lost all hydraulic fluid, therefore losing all conventional flight controls. The hydraulic systems on the plane control vital functions such as steering, and manipulation of the flaps, ailerons, rudder and braking systems. The DC-10’s 3 hydraulic systems are fully independent of each other and are designed to be redundant in case of emergency, meaning that the plane could fly with just 1 of the hydraulic systems working. For all 3 hydraulic systems to fail on a DC-10, it’s a billion to one chance. In just seconds after the explosion the plane was more or less simply sailing through the sky on an unmanageable trajectory much like a thrown paper airplane.

A single question dominated Capt. Haynes’ thoughts--how do we keep this plane in the sky? Thankfully, the1 and3 engines on each wing appeared to be working properly. To level out the tilted plane, Capt. Haynes decided to use the throttles to manipulate the remaining engines. He throttles back the power of the left engine to idle and increases power to the maximum on the right engine. This causes the plane to yaw left and air to flow slightly faster over the right wing, generating more lift and forcing the wing down which levels out the plane. In the cabin, passengers were panicking. Chief flight attendant Jan Brown and the rest of the flight staff have been attempting to keep things as calm as possible. Capt. Haynes calls Brown to the deck and informs her of the situation. Back in the cabin, she thought calling a meeting with the flight attendants would scare passengers, so she surreptitiously alerted them one by one as she passed by them in the aisle.

As it just so happened, seated in first class was Denny Fitch, a United Airlines pilot instructor. Despite crew reassurances, he knew there was something very wrong. He let the flight attendants know his job and stated that he’d be happy to help the flight crew. At 3:29 pm, about 15 minutes after the explosion and the loss of the controls, Capt. Fitch joins the flight crew in the cockpit. They explain the issue and have him go look out a cabin window to check if the ailerons are moving when they attempt to steer them. They are not. Capt. Haynes has Capt. Fitch take over control of the throttle for the 2 working engines. He maintains a white knuckled grip on the throttle for the rest of the flight while Capt. Haynes and officer Records continue to manipulate the steering columns in the hopes, they can control the plane. Meanwhile, Officer Dvorak has been communicating with air traffic control, the UA maintenance base in San Francisco, McDonnell Douglas the maker of the plane, basically anyone they could get ahold of. It’s considered virtually impossible that all 3 hydraulic systems would fail on a DC-10 and there’s no emergency procedure to deal with the crisis. Furthermore, no one has any real suggestions on what to do.

The pilots of UA flight 232 are on their own. Capt. Haynes realizes the best course of action is to make an emergency landing as soon as possible. They decide on the small regional airport of Sioux City some 65 miles away. Capt. Haynes informs senior flight attendant Brown and makes an announcement over the PA, telling passengers to prepare for a crash landing. In addition to the plane constantly skewing right and trying to roll over, the plane’s doing what’s called in aviation a phugoid cycle. Basically it’s acting like a ship going over heavy waves; it pitches up and climbs, and then pitches down and descends, while speeding up and slowing down as it goes "downhill" and "uphill". With each iteration of the cycle, the aircraft loses approximately 1,500 feet (460 m) of altitude. In the cabin Brown and the other flight attendants go row by row, checking seat belts, making sure that all passengers know what to do. Per United Airline rules, the parents of the lap children are told to place the babies on the floor and when bending in the brace for impact position, hold them in place. In the cockpit, the four pilots worriedly discuss whether to try to use the landing gear or land the plane on its belly. Landing gear is controlled by hydraulics.

However, on a DC-10 when the landing gear doors are opened, gravity will make the landing gear fall out and lock into place. Also, there is also a lever for activating the landing gear which also unlocks the outboard ailerons. They hope that when the landing gear is in place, some residual hydraulic fluid will flow back into the proper system and they’d be able to steer the plane. On the other hand, the pilots have been managing to keep the plane in the air through throttle usage. Trying to utilize the landing gear could cause a whole new set of problems. At around 3:49, some 30 minutes after the initial explosion, the pilots use the lever to open the landing gear doors. Luckily the landing gear drops, locks into place and doesn’t cause other issues.

The landing gear actually somewhat increases the stability of the flight, although it doesn’t push any trapped hydraulic fluid to the controls. Meanwhile in Sioux City, the airport’s been preparing for a crash landing with ambulances, firetrucks and volunteers. Fortuitously, two Sioux City hospitals, one of them a regional burn center are in the midst of a shift change. This means more people are available to treat survivors. For the last 20 minutes or so flight 232 has been flying towards Sioux City airport in wide, awkward loops, trying to dump as much fuel as they can to make the plane which weighed some 360,000 lbs. (163,293 kg) including passengers and luggage, lighter before attempting to land. The plan is to land on runway31 which at 9,000 feet (2743 m) long, is the longest runway at the airport. But Flight 232 comes out of a turn lined up with closed runway22 which unfortunately is where all the emergency services vehicles have been parked. Worried about keeping the plane in the air, they decided not to make another approach and warned air traffic control that they would land on the shorter 6,600-foot (2011 m) runway22. Just minutes before the plane touches down, emergency services scrambled to move their vehicles.

Flight 232 would be landing at a high rate of speed. With the loss of hydraulics, the flaps couldn’t be extended, which meant flight crew would be unable to control both the airspeed and sink rate. Another huge problem is that hydraulics also controls the braking system for the plane. At the edge of runway22 was a cornfield. They hoped that as the plane touched down, it could roll into the cornfield and that would help slow it. On the final descent Flight 232 is going 220 knots (253 mph) and falling out of the sky at 1,850 feet (563m) per minute (approximately 407 km/h forward and 34 km/h downward speed). This is over twice the speed of a normal safe landing. In the cockpit alarms sound for the ground proximity warning system. The cabin is utterly silent as the flight attendants shout for passengers to brace for landing. At 4:00 pm the right wing of the wobbling plane struck the ground, spilling 10,000 pounds of kerosene and bursting into flame on impact.

The clang of steel hitting the runway reverberated through the cabin as the plane bounced and skidded forward. The plane broke into three main pieces as it careened down the runaway and skidded into the cornfield. The cockpit went one way, the tail another. The main center of aircraft slid sideways, rolled over onto its back, and came to a stop upside-down in the corn field. Passengers are tossed about, some still strapped in their seats. Due to a ruptured fuel tank, a huge orange fireball rolls through the cabin. Survivors help each other out of the burning plane as first responders rush to the chaotic scene. It took rescuers almost 30 minutes to identify the debris that was the remains of the cockpit. It had burrowed into the ground due to force. It took a forklift and cutting equipment to free the 4 alive, but injured pilots. Capt. Haynes was knocked out upon impact, he had a severe concussion and received 90 stitches. The wreck of flight 232 burned for 2 hours. 34 ambulances and 9 helicopters transported the injured.

Of the 296 people onboard, 111 died, while 185 or 62.5% of the passengers survived. 125 passengers suffered only minor injuries and 13 actually walked away unharmed. 11 children, including one lap child, died. 35 passengers survived the crash only to pass away of smoke inhalation while trying to escape from the wreckage. Only a single crew member died, flight attendant Rene Lebeau. The tragedy was the fifth-deadliest crash involving the DC-10. A long and complex investigation by the National Transportation Safety Board [NTSB] eventually revealed the cause of the tragedy. An infinitesimal flaw was created when the titanium fan disk for the plane tail engine was manufactured, due to impurities contaminating the metal melting process. Over 18 years of plane usage, stress on the flaw in the fan disk caused it to form a crack. Slowly the crack grew larger and larger and on Flight 232, at 3:16 pm the fan disk fractured causing engine 2# to explosively disintegrate.

In a stroke of pure bad luck, shrapnel perforated the lines to all 3 hydraulic systems which ran through the horizontal stabilizer in the tail, causing them to leak all the hydraulic fluid. Though the plane had undergone regular maintenance, the crack in the fan disk wasn’t noticed, although it had eventually grown big enough to be seen with the naked eye. Despite the loss of life, flight 232 is held up as a model of CRM or crew resource management and studied in flight school. The number of deaths could have been far greater. Both the cockpit and flight attendant crews communicated well with one another and tried to keep cool under pressure. Though Capt. Haynes was in charge, he actively listened to his co-pilots. In addition to expertise, cooperation and teamwork played a vital role in troubleshooting the unfolding problem and landing the plane. Once recuperated and cleared of any blame, the four pilots returned to work for United Airlines. In May of 2012, Capt. Denny Fitch lost his battle with brain cancer. Capt. Haynes flew for United Airlines for 35 years until his retirement in 1991. He also became a public speaker on aviation safety. Capt. Al Haynes passed away in August of 2019 at the age of 87. Haunted by guilt over the death of Evan Tsao, the lap child killed during the crash, senior flight attendant Jan Brown began lobbying Congress and the FAA to introduce child safety seats on board planes across the USA. Even after retiring in 1998, Jan Brown has continued her campaign.

Unfortunately, despite some industry support, to this day, airlines in the United States are still not required to provide infants under the age of two travelling as ‘lap children’ with any forms of restraint. As a result of the crash, the manufacturing process for making titanium fan disks for planes was improved. Also, new aircraft designs have incorporated hydraulic fuses to isolate a punctured section to prevent total loss of hydraulic fluid. Though many people called Capt. Haynes a hero, he didn’t consider himself to be one. He praised his coworkers, saying that he felt like they all just simply tried to do the best they could.