This week, the FBI announced a $10,000 reward for information leading to the arrest of a man who once worked as a mechanic at SabreTech, the airline maintenance company at the centre of the tragic loss of ValuJet flight 592, which crashed into the Florida Everglades on the 11th of May 1996.

It’s not often that an old aviation incident makes the news over twenty years later so I was immediately intrigued. To understand what the news is about, though, we need to know the details of the disorganisation and mismanagement which led to the violent fire and crash of the flight ten minutes after take off.

On that day, ValuJet flight 592 was a Douglas DC-9-32 which had arrived from Atlanta late after unplanned maintenance. The flight was due to depart Miami to fly back to Atlanta at 13:00.

There were five crew and 104 passengers listed on the manifest. Actually, there was an additional passenger, a four-year old boy travelling with his family who was also not included on the weight and baggage calculation. When the aircraft departed, however, there was a total of 110 souls on board.

The cargo for the flight was a combination of baggage, mail and company-owned material. According to the shipping ticket, the company-owned material consisted of

two main gear tyres and wheels

a nose gear tyre and wheel

five boxes listed as Oxy Cannisters – ‘Empty’

The lead ramp agent showed the first officer the shipping ticket and asked for approval to load the company-owned material into the forward cargo compartment, which he got.

The DC-9 departed Miami just over an hour late at 14:04. A few minutes after departure, with the aircraft at 10,000 feet and travelling 260 knots, the cockpit voice recorder recorded an unidentified sound and the voice of the captain asking, “What was that?” The timestamp was 1410:03

He said, “We got some electrical problem” followed by “We’re losing everything.” As he told the first officer that they needed to go back to Miami, the CVR recorded voices shouting fire in the background. The first officer contacted ATC but as they started their turn and descent, the cockpit was already full of smoke and a cabin crew members voice could be heard shouting that they were “completely on fire.”

The first officer transmitted that they needed the closest available airport. There was an unintelligible transmission while the controller tried to offer details of a closer airport. That was the last thing heard from the DC-9. ValuJet 592 crashed at 1413:42, less than four minutes after the strange sound.

Two men out fishing saw the low-flying aircraft in a steep bank. The nose was dropping and by the time the it struck the ground, the plane was almost vertical. Then it crashed with a great explosion, followed by a huge cloud of water and smoke. The Atlantic gives the following account of their phone call to emergency.

The Lessons of ValuJet 592.

The caller said, “Yes. I am fishing at Everglades Holiday Park, and a large jet aircraft has just crashed out here. Large. Like airliner-size.” The dispatcher said, “Wait a minute. Everglades Park?” “Everglades Holiday Park, along canal L-sixty-seven. You need to get your choppers in the air. I’m a pilot. I have a GPS. I’ll give you coordinates.” “Okay, sir. What kind of plane did you say? Is it a large plane?” “A large aircraft similar to a seven-twenty-seven or a umm … I can’t think of it.” “Yes, sir. Okay. You said it looked like a seven-twenty-seven that went down?” “Uh, it’s that type aircraft. It has twin engines in the rear. It is larger than an executive jet, like a Learjet.” “Yes, sir.” “It’s much bigger than that. I won’t tell you it’s a seven-twenty-seven, but it’s that type aircraft. No engines on the wing, two engines in the rear. I do not see any smoke, but I saw a tremendous cloud of mud and dirt go into the sky when it hit.” “Okay, sir.” “It was white with blue trim.” “White with blue trim, sir?” “It will not be in one piece.”

It was immediately clear that there had been an intense in-flight fire and from the wreckage it was clear that it started in the forward cargo hold. This hold was a “Class D compartment” which meant that at the time, it wasn’t required to include fire suppression units nor smoke detectors as the hold was airtight – so theoretically, any fire that started there would burn itself out quickly. Effectively, Class D compartments used oxygen starvation as a built-in fire suppressor.

However, the hold had been loaded with the five boxes of oxygen generators. Although the shipment was labeled ’empty’ (in quotes), they weren’t actually empty.

It turned out that a few months earlier, ValuJet had purchased three MD-80 jets a few months earlier and the maintenance contact was given to SabreTech Corporation. The maintenance included the inspection of the oxygen generators on the planes, of which many were past their expiration date. ValuJet decided that all of the oxygen generators should be replaced and directed SabreTech to do so.

SabreTech removed 144 oxygen generators from the MD-80s, of which six were expended. The rest of the cannisters were still active*. The oxygen generators use a chemical reaction to flow the oxygen to the reservoir bags of the mask. As a side effect of this exothermic reaction, the generators get very hot. When operated at normal room temperature, the outside of the oxygen generators can reach up to 547°F (286°C).

Edit: I’ve rephrased this because, Tammy Cravit points out in the comments, they do not hold oxygen. The generators contain an oxidizing chemical, such as sodium chlorate. Burning the oxidizer produces oxygen, along with a great deal of heat.

Normally, if an oxygen generator is transported, it is fitted with a safety cap which disables the pin and stops the oxygen generator from, well, generating oxygen. However, SabreTech didn’t supply the safety caps that day so, as far as the mechanics were concerned, the caps weren’t available. The oxygen generators were tagged with green “repairable” labels, although there was no intent to use them again. It’s not clear whether the maintenance staff understood this but one thing is certain, they knew that the oxygen generators were not empty and thus that they needed safety caps. But, as one SabreTech employee said, they’d been working 12-hour shifts and 7-day weeks and were under pressure to get the job done. The mechanics added reason for removal written near the bottom of the green tags: out of date or expired and collected them into five cardboard boxes so they could be moved out of the way. One of them remembers noticing that the job hadn’t been finished, but he was reassured that the problem would be taken care of “in stores”.

Two Sabretech mechanics signed off the work cards for the MD-80 maintenance once the new generators were installed, confirming that the safety caps had been fitted onto the old ones, even though they haven’t. As far as they were concerned, the oxygen generators were ready for disposal and, more importantly, they had finished the job before the deadline.

The boxes were moved to SabreTech’s shipping and receiving area and left in the ValuJet section. They appear to have been abandoned; there was no record of what was in the box or that the contents were hazardous material.

A few days later, a stock clerk was told to tidy up and the boxes sitting on the floor were obviously in the way. They belonged to ValuJet so it made sense to send them to the company’s headquarters in Atlanta. This was something he’d done before and did not need to get approval for. He quickly repacked the oxygen generators with bubble pack, labelling the boxes as ‘aircraft parts’.

He saw the green labels, which he knew meant unservicable, while red meant ‘beyond economical repair’ or ‘scrap’. So he presumed that the oxygen generators were were empty and needed refilling. He never read the ‘reason for removal’ text on the tags.

He listed the contents as Oxygen Cannisters — ‘Empty’ and handed the boxes and nine tyres to a SabreTech driver to deliver them to the ValuJet ramp area.

There, a ValuJet employee signed for the items and stored them in a baggage cart, with no idea that he’d accepted five boxes of hazardous material.

On the day of the crash, a ValuJet ramp agent loaded the rubber tyres into the class D cargo hold and then stacked boxes of oxygen generators — loosely packed with no safety caps — on top. He heard a clink sound as he moved one of the boxes and he could feel objects moving inside the box. He placed the boxes on top of a large tyre circling a smaller one. They weren’t wedged in but he had no idea that it mattered. He didn’t see any reason to believe there was dangerous cargo in the box.

The first officer had been trained to watch for hazardous materials and knew that they should not transport hazardous materials such as working chemical oxygen generators on a passenger flight, even if they had been capped. But again, there was no reason to open the boxes; as far as he knew, they had a few old tyres and some empty canisters. The flight was already almost an hour late departing and they needed to get moving. He probably never gave it a second thought.

From here, it was only a matter of time until one of the improperly packed oxygen generators ignited.

We’ll never know exactly what happened but it seems likely that an oxygen generator was activated while the boxes were being loaded (maybe even at the moment of the clinking sound) or, at the latest, during the vibrations of the take-off roll.

The NTSB recreated the set up with a test hold. About ten minutes after they ignited an oxygen container, the hold reached 2,000°F (1,100°C). Another test reached 3,000°F (1,650°C). A main gear tyre ruptured sixteen minutes after the first ignition.

The sound of the gear tyre rupturing is probably what the captain heard in the cockpit, the first sign that anyone had that things were not right. By now, the temperatures in the hold were already fantastically high; there was no way that the fire could be contained. It was only seconds before the fire breached the cargo compartment ceiling, filling the passenger cabin with smoke.

The left-side floor beams melted and collapsed, probably taking out the control cables on the captain’s side. As the fire continued, the flight controls possibly failed completely or the flight crew may have been incapacitated by the smoke and heat in the cockpit in the last seconds. Whatever the cause, ten minutes after take off, the aircraft was no longer under anyone’s control and smashed into the ground.

The NTSB investigation pointed the finger serious failings of ValuJet airline and the airline’s maintenance company, Sabretech, both of whom failed to follow regulations regarding the transport of hazardous materials by air. The FAA also came under fire for not adequately monitoring airlines.

From the conclusion of the final report:

The Board determined that the accident was caused by: (1) the failure of SabreTech (a contract maintenance operation in Miami) to properly prepare, package, and identify inexpended chemical oxygen generators before presenting them to ValuJet for transportation; (2) the failure of ValuJet to properly oversee its contract maintenance program to ensure compliance with maintenance, maintenance training, and hazardous materials requirements and practices; and (3) the failure of the Federal Aviation Administration to require smoke detection and fire suppression systems in Class D cargo compartments. Contributing to the accident, the Board found, was the failure of the FAA to adequately monitor ValuJet’s heavy maintenance program and responsibilities, including ValuJet’s oversight of its contractors, and SabreTech’s repair station certificate; the failure of the FAA to adequately respond to earlier chemical oxygen generator fires with programs to address the potential hazards they posed (the Board cited 6 cases in the 10 years before the ValuJet accident involving fires caused by oxygen generators); and the failure of ValuJet to ensure that both ValuJet and contract maintenance employees were aware of the airline’s “no-carry” hazardous materials policy and had received appropriate hazardous materials training.

The US Attorney’s Office filed 24 indictments against Sabretech and three of its employees for various violations of federal regulations regarding the transportation of hazardous materials. This was the first criminal prosecution over a U.S. airline crash. The charges included conspiracy to make false statements to the FAA and false statements in aviation maintenance records. The three SabreTech employees were the company’s Director of Maintenance and the two mechanics who had signed off the work order for the removal of the oxygen generators.

Both of the mechanics were specifically charged with falsifying work cards because the cards they had signed indicated that safety caps had been installed on the oxygen generators.

But before the trial took place, one of the mechanics, Mauro Ociel Valenzuela-Reyes, at the time more commonly known as Mauro Valenzuela, disappeared.

He may have fled the country back to Chile, where he was from, or he may have remained in the US under a false identity to be close to his family and children. All that is known for sure is he was never seen again.

The trial lasted several weeks. The SabreTech defence argued that, although the mechanic hadn’t ensured that the safety caps were used before signing off, he couldn’t possibly have known that someone would load those oxygen generators into an aircraft. As far as he (and all the other mechanics) were concerned, the generators were to be thrown away, not transported. The defence also argued that there were other factors contributing to the fire, including faulty wiring issues. The two employees (the Director of Maintenance and the remaining mechanic) were acquitted of all charges.

SabreTech was aquitted of most of the counts, including conspiracy, but found guilty on nine charges relating to the reckless transportation of hazardous materials and failing to properly train its employees. The case was later appealed and eight of the charges were dismissed; the US circuit court only upheld the the charge of improper training.

This means that if Valenzuela had stayed and gone to trial, he would have been acquitted. However, by then he was already on the American Environmental Protection Agency’s (EPA) most wanted list as a fugitive.

In 2011, the New York Times questioned whether this was sensible.

Indicted in 1996 ValuJet Crash, Airline Mechanic Still on EPA’s Most-Wanted List

Considering the outcome of the case, there is some question as to what the government would do if they are able to one day capture Valenzuela and bring him back to the United States. Alicia Valle, a spokeswoman and special counsel to the U.S. Attorney in the Southern District of Florida, declined to comment about what might happen in that scenario. “Valenzuela already is charged … in one case with the SabreTech matter, in the other case with bond-jump [and] contempt of court,” Valle said. “We really cannot speculate about which charges we would go forward on if the fugitive were arrested.”

Now, 22 years after the tragic crash, the FBI has offered a $10,000 reward for information leading to the arrest of the mechanic and released a new WANTED poster, showing what the man might look like now.

ALERT FBI offers $10,000 reward for arrest in ValuJet 592 crash case

“We’ve tried over the years to find him,” said [FBI Miami Special Agent] Fruge, who has been a special agent for 29 years and hopes to close this case while it’s under her watch. “It bothers me. I’ve lived and breathed it for many, many years.”

There’s no question that the crash of ValuJet flight 592 was a terrible tragedy. The investigation highlighted serious issues at the airline, the maintenance company and the overseeing authority, the FAA. The day after the crash, the FAA administrator announced to the media that ValuJet was a safe airline, assuring the public that he would fly the airline. He asked for trust in the FAA to do their job and it was only a detailed and unflinching investigation by the NTSB that showed that the airline was not safe and that inspectors at the FAA had been worried about ValuJet for quite some time for cutting corners and repeated issues.

Thirty-three safety recommendations were made and many regulations were put into effect which increase the safety of airline passengers and crew to this day. More importantly, it forced the US and the world to focus on safety in the aviation industry the importance of proper government oversight.

However, this latest update does nothing whatsoever to improve aviation safety. The families of the victims of that awful crash are said to want closure, but they already know that the identical case against the other mechanic was dismissed, as was the case against the Director of Maintenance, as were 23 of the 24 charges against SabreJet. Whether they believe that the result was correct or unfair, chasing down this last mechanic is not going to change that outcome. He’s already lost everything for something that he likely never even understood.

I was initially intrigued to see a current investigation relating to ValuJet 592 in the press so many years after the crash but, when I realised what it was about, I just felt sad and tired.

The full report is available on the NTSB website as a PDF. You can also read the 33 recommendations that were made as a result. I also recommend this article from The Atlantic which I quoted above: The Lessons of ValuJet 592.