The Bureau d’Enquêtes et d’Analyses today released an Update on Investigation regarding flight Air France 447. AF 447 was an Airbus A330-203 on a scheduled flight from Rio de Janeiro Galeão to Paris Charles de Gaulle on the 1st of June 2009. Contact with the flight was lost in the early hours of the morning. A week later, a few pieces of the aircraft were found.

The crash made international headlines because the aircraft appeared to simply disappear: there was no mayday call nor radar information and initial attempts to find the crash site and wreckage has failed.

Last month, an expedition ship, the Alucia, discovered the wreckage at the bottom of the South Atlantic Ocean and was able to recover the black boxes. This Update on Investigation is a result of the data recovered. It is not a final report.

The BEA have released an English translation of the document which I am using for this post. However, it includes a foreword to state that the original text in French should be considered the work of reference.

You can read the full document online: Update on Investigation in PDF format. The French original is also available: accident survenu a l’Airbus A330-203. The report is also available in German and Portuguese translations.

I’ve written this to help people keep to the facts in mind when reading news coverage, which traditionally gets somewhat confused and over-excited when reporting on this incident.

Here are the highlights of the document, hopefully in an easy-to-follow format.

The report confirms that there were no initial issues with the crew nor the weight and balance of the flight.

22:29 The flight took off.

Initially, the Captain was Pilot Not Flying and one of the co-pilots was Pilot Flying which was in accordance with standard procedure. During the flight, the Captain took a rest break and the other co-pilot took his place as Pilot Not Flying.

This is important to understand as I’ve already seen media headlines screaming that the Captain was not in the cockpit when the problems began. This is a non-issue. There were three flight-crew members on board, all fully trained, in order to ensure that the pilots can have rest breaks.

SKYbrary – Pilot Flying and Pilot Not Flying

When two pilots fly a fixed-wing aeroplane which requires a two-person flight crew, the aircraft commander, who must be appropriately qualified and hold the rank of Captain, occupies the left hand seat and the First Officer or Co-Pilot occupies the right hand seat.

Before the commencement of each flight sector, the aircraft commander decides which pilot will take direct responsibility for flying the aircraft for the complete flight or for particular parts of it such as the Descent/Approach and Landing and they become ‘Pilot Flying’ (PF) for that sector or the specified part of it. The other pilot is then designated for that sector or relevant parts of it as ‘Pilot Monitoring’ (PM) or alternatively as ‘Pilot Not Flying’ (PNF) and in that role must monitor the flight management and aircraft control actions of the PF and carry out support duties such as communications and check-list reading. The Operations Manual will specify fully the roles for the PF and PM/PNF, but one of the most important aspects of the duties of any PM/PNF is the cross-check of the actions of PF. Indeed, this part of the role represents one of the most important single reasons why a two-pilot flight crew is specified.

01:35 The crew were in contact with air traffic control. Everything seemed normal.

01:55 The Captain woke the second co-pilot to take his place as Pilot Not Flying.

Between 1 h 59 min 32 and 2 h 01 min 46, the Captain attended the briefing between the two co-pilots, during which the PF said, in particular “the little bit of turbulence that you just saw […] we should find the same ahead […] we’re in the cloud layer unfortunately we can’t climb much for the moment because the temperature is falling more slowly than forecast” and that “the logon with Dakar failed”. The Captain left the cockpit.

At this stage, everything was normal. Ten minutes later, the incident begins.

02:06 The Pilot Flying warns the cabin crew about upcoming turbulence.

02:08 The crew make a slight turn to the left. The turbulence increased and they reduce the speed to about Mach 0.8.

At this point, it’s worth watching the timeline including the seconds.

02:10:16 The autopilot and then the auto-thrust disengages. The Pilot Flying says, “I have the controls.” The plane begins to roll to the right. The Pilot Flying rolls left and raises the nose. The stall warning sounds. The plane appears slows right down.

The recorded parameters show a sharp fall from about 275 kt to 60 kt in the speed displayed on the left primary flight display (PFD), then a few moments later in the speed displayed on the integrated standby instrument system (ISIS).

The autopilot and auto-thrust remained disengaged for the rest of the flight.

Now in my opinion, the notes in the Update on Investigation are very interesting:

Note 1: The angle of attack is the angle between the airflow and longitudinal axis of the airplane. This information is not presented to pilots.

Note 2 : In alternate or direct law, the angle-of-attack protections are no longer available but a stall warning is triggered when the greatest of the valid angle-of-attack values exceeds a certain threshold.

Alternate Law means that there is a disruption to the aircraft flight control system(s). As the data input could not be trusted (the speed displays in this case), some of the monitoring protective functions of the control system are not available.

It’s interesting that this is pointed out: the angle-of-attack was critical to the incident and that the Airbus A330 does not display this information as flight information for the flight crew.

At any rate, the angle of attack increased and the plane began to climb.

The recordings show that the Pilot Flying made nose down control inputs. The Pilot Not Flying attempts to call the Captain back to the cockpit.

The vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied between 12 degrees right and 10 degrees left. The speed displayed on the left side increased sharply to 215 kt (Mach 0.68). The airplane was then at an altitude of about 37,500 ft and the recorded angle of attack was around 4 degrees.

If I understand this correctly, the speed displayed on the left side increased but the integrated standby instrument system had not updated yet, so would have shown 60 knots. I’m not quite clear on this though.

02:10:51 The stall warner triggers again.

The thrust levers are moved to the Take Off/Go Around position. The Pilot Flying maintains nose-up inputs on the controls. The recorded angle of attack continues to increase.

Around fifteen seconds later, the speed displayed on the ISIS increased sharply towards 185 kt; it was then consistent with the other recorded speed. The PF continued to make nose-up inputs. The airplane’s altitude reached its maximum of about 38,000 ft, its pitch attitude and angle of attack being 16 degrees.

Note: The inconsistency between the speeds displayed on the left side and on the ISIS lasted a little less than one minute.

02:11:40 The Captain re-enters the cockpit. The report says that the recorded speeds “became invalid” which means that the measured speeds were shown as below 30 knots. The stall warning stopped.

The altitude was then about 35,000 ft, the angle of attack exceeded 40 degrees and the vertical speed was about -10,000 ft/min.

This means the plane was falling out of the sky. The Pilot Flying holds the sidestick to full left and nose-up position for around 30 seconds.

There is a lot of speculation that this is what caused the crash. Based on the information given here, it would seem that the plane was in a stall and the nose needed to come down. Pitching the nose-up to the full extent would be a bad response in a stall situation.

However this is a preliminary report and no such conclusion is drawn in the report. It is not stated in the report that the crash was caused by this action, simply that the action occurred.

02:12:02 The Pilot Flying says, “I don’t have any more indications” and the Pilot Not Flying responds with, “we have no valid indications”.

By now, the thrust levers are in the idle position and the engine power is at 55%.

The Pilot Flying pitches the nose down, decreases the angle of attack and the speeds become valid again. The stall warning sounds again.

02:13:32 The pilot says “we’re going to arrive at level one hundred”. Fifteen seconds later, both pilots manipulate the sidesticks and the Pilot Flying passes control to the Pilot Not Flying.

02:14:28 The recordings stop.

The document includes a list of new findings. The penultimate point is chilling:

After the autopilot disengagement:

• the airplane climbed to 38,000 ft,
• the stall warning was triggered and the airplane stalled,
• the inputs made by the PF were mainly nose-up,
• the descent lasted 3 min 30, during which the airplane remained stalled. The angle of attack increased and remained above 35 degrees,
• the engines were operating and always responded to crew commands.

The information in this report would seem to imply that the pilot became overwhelmed and incorrectly interpreted the situation. I recommend reading the full Update on Investigation. The initial problem remains the pitot and the bad speed data. The pilot was handed control of a plane (when the autopilot and auto-thrust failed) that was incorrectly configured. There are many aspects to any incident and AF 447 is no exception. It is possible that the BEA will conclude that pilot error was a primary cause but, as yet, we do not have a full report.

So remember: be wary of news reports that state any cause as fact until the BEA release their conclusions!

This post is nothing to do with aviation. I was as far away from flying as I could possibly get, being underground and all. But pilots are adventurers and this was an adventure and so I hope that you will find this as interesting as I did.

I have been researching the original rivers of London, specifically the Fleet, which is a part of the famous Victorian sewer system designed by Bazalgette in the 1860s and 70s. I found photographs on various websites: dark brick curved walls with a trickle of grey water pooling at the centre, all edges fuzzy in the low light. I wondered if there was a way to see them for myself and, on a whim, I sent a message to Thames Water asking if that might be possible.

You could have knocked me over with a feather when they said yes.

They were kind enough to allow me to join them for an afternoon out at the Abbey Mills Pumping Station in West Ham, an industry event that included a descent into the sewers at the Wick Lane Depot. “Wear comfortable clothes,” they told me. “We’ll provide protective clothing including a harness and oxygen masks.”

It was raining as the bus pulled up to the pumping station and I dashed in, not paying much attention to the outside of Station A which was covered with scaffolding. The Grade II listed building has apparently been in need of a tidy-up for a while but now with the London Olympics bringing crowds walking directly past, the Victorian brickwork is receiving some attention. I know very little about architecture and I was not particularly interested in structural details.

Those of us who had no connection to the industry huddled together, discussing what had brought us on this tour and what we were most looking forward to. Many others, I discovered, were there specifically for the tour of the pumping station and one woman had already decided she was most definitely not going down into the sewer at all. I began to pay more attention to my surroundings.

Jokes were made about how long the speaker, Ben Nithsdale, would bore us about the history of London’s sewers. I squirmed in my seat. I shouldn’t have sat in the front row where the speaker would see if I dozed.

He began by telling us about the sewers at Wick Lane, of serious interest to us because we would soon be traipsing along them. They are 3 metres in diameter, he told us, and the water flow limited for our visit, so that we would only have about a foot of water to wade through. That didn’t sound like very much.

The water would normally go up to his chin, he told us, and if it rained, the tunnels would fill. This is what causes the pollution in the Thames. And with that, he took us back to the old rivers of London and the evolution of the water supply. We started in the 13th century and by 1730 and the creation of the New River, I was scribbling frantically, wishing there was some way I could take a copy of his speech with me.

I wrote three pages of notes before he even touched on the Bazalgette sewers and the work which began at Wick. But all too soon, it was over and we were led on a tour of the pumping station, affectionately referred to as the “Cathedral of Sewage.”

Thames Water staff speak about the architecture (Neogothic Italianate, apparently) and brick work (simply gorgeous) with clear admiration and affection. A heated argument was in progress as to whether the carved plants on the far side of the building were strawberries (the leaves, we were told by one adamant gentleman, were all wrong) or some other plant and he admitted that they had only just positively identified the peonies carved near the main entrance. The detail in the building is amazing, especially when you consider that it was built as a pumping station in the middle of the marshes. Even the drain pipes were beautiful.

“When you go down into the sewer, look at where the two tunnels meet. They didn’t just cut away the bricks to make the join, they formed them for the junction. It’s the finest quality brickwork down there. Breathtaking.”

Our tour guide was that perfect combination of informative and amusing, interspersing architectural details with anecdotes about the works and brief asides about office politics. He told us that the sun rises in the south because the wind vane was reattached to the roof by a man dangling by his ankles, who was not too fussed about making sure the directional markers were set correctly.

With a smile, he pointed out where the Luftwaffe had bombed the coal storage of station during World War 2. “If we were still using the coal, it would have been a disaster. However, the station was completely electrified by then. So thank you, Mr Goering, for our car park.”

He led us into the main pumping station and my mouth fell open. It was brilliant, a perfect Steampunk Fantasy. Disney could not have done it better. Robotic looking devices, gleaming brass, moulded stone around the pillars and twisted iron rails along catwalks, all towered over by ornamental arches.

This is a working station which kicks in when it rains. I felt like I had walked onto a movie set. I missed half the descriptions. I was wandering between the machines in a daze, reading oversized dials and trying to make sense of the pure glamour of this place which was built to pump sewage, for gods sake.

And they let us touch things.

I think I must have three dozen photographs of the the electrical motors, affectionately known as Daleks. And the high ceiling, the roof lantern surrounded by arched windows, well… I don’t know enough about architecture to explain it but this should be on your life list of things to see.

When I signed up, I thought I would “put up with” the tours of the buildings in anticipation of going down to the sewers. I was wrong. They had to drag me out with promises of the archive.

And oh, the archive! I’ve never been so close to such ancient books. Detailed maps of London were spread on broad tables. The modern maps were explicit: streets were marked with the pipelines detailed underneath with their diameter and depth. As we stepped back in time, we saw the maps with the pipelines marked but without an overlaying roadmap and with no information as to how deep the pipes were laid. The version before that looked like something from a teenager’s science project: brightly coloured lines and very little hard information. The bookshelves were stuffed with large leather-bound books. A further display of photographs showed the sewer workers – we were told they are called flushers – over the past century. I could have spent a day in that tiny little room alone. I tried to dawdle.

“The bus is going to leave without you. You’ll miss the sewer tour.”

Oh yes, the sewer tour. The whole reason that I came here today! I ran.

We were taken to the Wick Lane depot where the Wastewater Operatives – the flushers – were waiting. They confirmed that the sewer had been prepared for us. “We reduced the water flow for you,” said one man with a smile. “But don’t worry. We left all the good stuff in there.”

Oh, thanks.

First, we had to don our protective gear: thick woollen socks, disposable latex gloves and a white jumpsuit which fit easily over my clothes. Our escort looked at my long hair with dismay. “Do you have a hair band? Anything to tie it up with? Well, put your hood up, that will have to do.”

Have to do? I was only expecting to get my feet wet, not dive in!

We were then fitted with a harness and handed thigh-high waders. The man looked at my feet. “Size 5? Hah! This is a Size 7 Fits All.” I pulled them on and tried to get them up to my hips, as directed by the three Thames Water workers who, to their credit, never burst out laughing once, even when I tugged too hard and tipped myself over. The boots were too long for me (I’m only 153cm / 5-foot tall!) and I could not get the bunched up rubber to come up to the top of my thighs. I gave up and waddled to pick up my gloves: huge red Mickey Mouse gloves which I still don’t understand the purpose of. Finally, a bright blue helmet was gently placed over my hooded head.

Then they took a photograph of the group of us in all our glory. You can stop laughing now.

“You need to pull those boots up.”

“I know.” I tried not to whine. “I tried to.” I tugged ineffectually at them again.

The third person to inform me of this gave up and knelt in front of me to help. “I’m really sorry about this,” he said as he grasped the boots at my mid-thighs, “but it has to be better than getting sewage in your boots.” He tugged, hard, just about lifting me off the ground.

“Best time I’ve had all week,” I countered, genuinely grateful that he was helping me out. He grinned and called over a chaperone.

We were given a set of instructions including basics such as don’t splash and don’t panic. “And when you are ready to climb out? Don’t look up. Remember the person above you is dripping wet having just vacated the sewer.” We laughed nervously. I discovered one of the flushers, Daniel, writes The Sewerman’s Log which was a primary resource for me when I first started writing fictional scenes taking place under the city.

Finally, it was time. We queued up to be attached to the shiny metal hook, a winch to catch us if we slipped off the thin metal ladder as we climbed down 10 metres into the barrel below.

I worried about how thin and slippery the rungs were as I stepped on. I was petrified that my feet – encased in huge rubber boots – would slip out from under me. I stepped down carefully and then looked up. My gut clenched. Don’t look up! I panicked, trying to remember why. One by one, I brought my hands down and then carefully inched the next foot down a rung.

At the bottom, a soothing voice told me to step down one more time. “There’s a rung under the water level, just step down onto that, then step back off the ladder and turn to your left.”

I nodded but my fingers clenched the ladder even tighter. Step down then turn left, I thought, but I had no idea which way was left. I realised I was panicking over nothing and took a deep breath.

I lowered my foot into the liquid until I felt the last rung. I twisted to the left. The man put a hand on my shoulder. “Stop! Step off the ladder first and then turn left.”

I stepped back into the liquid, the quick current snatching at my rubber heels. I was thigh high in green-grey water streaming past me at a fast rate. I’d done it! I stared at the darkness around me spotlit by the helmet lights of the flushers. I was in a real Bazalgette tunnel, wading through real sewage. The rubber of the thigh-high wading boots felt chilly against my calves and I realised that although it was warm in the tunnels, the water was cold. I felt like I had entered some other world, an underground labryninth. An evil dungeon full of hate and bile.

“Turn left, love,” said the man. I apologised and released my grip on the rungs.

He handed me a bright orange sack holding 10 minutes of oxygen and an oxygen mask. The grit crunched beneath my feet as I shuffled up to the others. The next person quickly descended the ladder.

We edged along the middle of the barrel in single file, feet sliding against the rough ground of silt and gravel below. The water came up over my knees. I stared at the water as if I could see the ground beneath, fighting off the fear that I was about to get tipped off my feet and dragged along the tunnel, my helmet swirling in an eddy behind me. I expected to step through sludge, not wade through fast-moving sewage. I felt off-balance and out of sorts.

We shuffled forward, the flushers alongside us making sure we were steady.

I wasn’t. I’m of a shape that naturally bobs to the surface and I was wearing rubber waders that were two sizes too big for me. The current dragged at my legs. Every step I took, I worried that I was going to slip backwards and over. The flushers were vigilant and I regularly felt a hand at my elbow. Piles of grit crunched beneath my feet. I peered at the muck unhappily.

A bright smile appeared at my side. “Everything OK?”

“Just fine.” My tone was defensive. Certainly I could walk a few feet along a sewer without making a fool of myself. Bazalgette’s sewers! The excitement filled me. I was finally here!

Knowing I couldn’t handle a notebook in the sewers, I planned to rely on memorisation tricks. I would focus on the different senses and recite keywords to help me to remember the scents and sounds of the tunnels, the feel of the underground breezes, the spotlit views. I wanted to be able to write about London below convincingly.

I took a deep breath and focused on the warm air around me. Musty, dank, sweet, cloying… too many words to try to remember the sharp scent of the air. Even as I sniffed, it shifted to something different. My foot slid against a slick brick. My arm flailed towards the brickwork, one small part of my mind remembering that it was exquisite and I needed to take a better look. A strong arm came around me before I was even aware that I was slipping. I gasped, the sewer bouquet forgotten.

“You’re all right,” the flusher said, holding me steady. Then he smiled reassuringly. “Are you all right?”

“Yes.” And then, aware that I had been precariously close to slipping into a fast moving sewage stream, I smiled back. “Thank you.”

I slithered my feet forward, feeling for the gravel and slippery rocks through the rubber boots and woolen socks. The flusher, also known as the kindest person in the entire universe, took my hand and the hand of the woman behind me, making soothing noises as he walked alongside us. I tried not to clutch, my eyes firmly on the running water coming well past my knees now.

The tunnel (sorry, barrel) widened out and I could see streams of grey daylight reflecting against the green-grey water ahead. My best friend led me to another flusher, passing my hand over as if it were a Scottish country dance. “Look after her,” he told him.

My new best friend looked at me. “You need to pull those boots up,” he said.

“I’ve tried!” I must have sounded almost tearful. He bent over, face precariously close to the running water, and tugged.

“Well, that will have to do,” he said with a sigh. “Wade very carefully across and grab the rope.”

I slithered forward again, trying desperately not to splash. The water lapped at the top of my waders but didn’t quite make it over the edge. Then another flusher splashed through, water streaming behind him. I held my breath and stood on my tiptoes, trying not to think about woolly socks infused with raw sewage.

We lined up along the rope, weak beams of light streaming through gaps in the ceiling. I could see a modern metal catwalk above us and wondered if that was for rescuing people who fainted into the muck. Then our cameras were passed out so that we could take photographs.

The water only came up to my knees here and the current was less swift. However, the additional light and security of the rope were cancelled out by my fear of dropping my camera. I gulped and began taking photographs. It was difficult to get clear images in the low light without blasting the area with flash. I have a number of murky green/grey photographs with soft edges, exactly the type of image I complained about seeing on the web.

The Chief Flusher offered to answer any questions we might have but I couldn’t think of a single one.

He told us about the mounds of fat that gather in tunnels. “A tree passed through the sewers without causing any blockage but the fat gathers. You can see it at the edges here. We end up with mountains of fat blocking the sewers and they trap all the other detritus passing through.” He scowled. “Fat and baby wipes. They’re the worst.”

He spoke with some regret about overflowing untreated sewage into the river a few winters ago. “It was that or flood people’s houses with raw sewage,” he said with a sigh. “These sewers just aren’t quite up to the job.”

Bazalgette, he tells us, was a visionary. The size of the tunnels and the usage of Portland cement have meant the his sewers have taken care of London’s sewage for over 150 years despite rising populations. But it is a combined system, mixing rain water and natural run off with the foul water from our drains and toilets, so after heavy rain fall when the flow rises even more, the system becomes overloaded and there is nowhere for the sewage to go.

The Thames Tunnel will be the solution to this problem: a thirty-two kilometre storage tunnel which will run underneath the Thames.

Daniel of the The Sewerman’s Log offered to take a photograph of me and I happily handed over my camera, knowing it was more secure in his hands than mine. It turns out that a mix of fear and excitement cause me to grin like a loon.

And then, sadly, it was time to leave. We were led out through a parallel barrel which was slightly higher. The flusher spread themselves along the way. As I reached the first one, he held my elbows loosely and told me to reach forward with my foot until I felt the step up. I found the slick edge of a brick that would have had me sprawling if I’d encountered it without warning. Each flusher took us past the next few steps where the sewage level was lower but the footing much more treacherous. I was encouraged again to ask questions but I was already reeling with information. I had to get it written down for processing before I could think of anything new! I made it to the ladder where they connected me to the winch and bade me be careful climbing up, especially now that my boots were slick with … well, it might be slippery.

I made it to the top without incident, the dreary rainclouds seeming vibrantly bright after the dark of the tunnel. I stomped around in the tray of disinfectant they’d put out for us and then walked across to the changing rooms, where I promptly tripped over my oversized boots and stumbled to the ground. Thank god for that, I said, so relieved that it hadn’t happened down below.

That was the end of the most marvelous day out I could possibly imagine. I know this was an extra-ordinarily long post but it was an extraordinary day. Thames Water were unbelievably awesome for letting me go on this tour and everyone I met was so friendly and informative and so visibly proud of the Victorian enterprise that they worked in. Never was there a sense of resenting the old technology or wishing to avoid the issues of working in listed buildings (in fact, there were some snide comments about how ugly the newer buildings at the station were compared to their Victorian counterparts). Everyone was enthusiastic about the pumping stations and the sewers and pleased to be able to share some of that history. I cannot speak highly enough of the Thames Water representatives I met on my tour.

I have a Certificate of Completion from Thames Water Utilities which certifies that I have entered a J.W. Bazalgette sewer. I never thought I’d be so proud of being in deep shit.

It’s been 15 years since the famous ValuJet crashed into the Everglades, a tragic accident that did much to focus our views on cost-savings and in-flight safety. There’s been a lot of discussion of the flight, including a National Geographic Seconds From Disaster episode.

On the 11th of May in 1996, ValuJet Flight 592 disappeared. The domestic passenger flight had taken off from Miami International Airport, en route to Atlanta, with 110 people on board. The departure at 14:04:09 seemed normal but a few minutes later, there was an unexpected sound.

Valujet 592′s Last Flight – New York Times

14:10:02 (Sound of click.)

14:10:03 (Sound of chirp heard on cockpit area microphone channel with simultaneous beep on public address channel.)

14:10:07 Pilot: What was that?

14:10:08 Co-pilot: I don’t know.

14:10:15 Pilot: We got some electrical problems.

14:10:17 Co-pilot: Yeah. That battery charger’s kickin’ in. Ooh, we gotta — .

14:10:20 Pilot: We’re losing everything.

14:10:21 Tower: Critter five-nine-two, contact Miami center on one-thirty-two-forty-five, so long.

14:10:22 Pilot: We need, we need to go back to Miami.

14:10:23 (Sounds of shouting from passenger cabin.)

14:10:25 Female voices in cabin: Fire, fire, fire, fire.

The pilots contacted Miami Departure and declared that they needed to return to Miami immediately. Miami Departure gave vectors but within a minute, the pilots realised they were not going to make it. At 14:11 the first officer asked for the closest airport available but the radio was breaking up and Miami Departure did not understand the request. It was too late. By 14:12, there was no response from the flight crew and the intra-cockpit recording consists of the sounds of rushing air. The controller continued to try to guide the plane, based on the descent path he could see on the radar.

Transcript of Actual Air Traffic Control Audio Tape in ValuJet Crash

Flight 592: One-four-zero. (That was the last transmission from ValuJet Flight 592).

Miami Departure: Critter 592, keep the turn around heading one-two-zero.

Miami Departure: Critter 592, contact Miami approach on corrections. No, you just keep my frequency.

Miami Departure: Critter 592, you can turn left heading one-zero-zero and join runway one-two localizer at Miami.

Miami Departure: Critter 592 descend and maintain 3,000.

Miami Departure: Critter 592, Opa Locka Airport’s about 12 o’clock at 15 miles.

American Eagle Flight 809: OK, 35-17. How did critter make out?

American Eagle Flight 809 never received a response.

Flight 592 disappeared from radar at 14:13:42, less than four minutes after the unexpected soft click that alerted the pilots.

A fisherman saw the plane come down.

The Lessons of ValuJet 592 – Magazine – The Atlantic

On a muggy May afternoon in 1996 an emergency dispatcher in southern Florida got a call from a man on a cellular phone. 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.”

At the time of the accident, it was clear that the aircraft had suffered an in-flight fire of unexpected ferocity and very little warning. How could this happen? The fire started in the cargo hold classified as D, which means it was not required to include fire suppression units nor smoke detectors. This didn’t seem much of a risk: these cargo holds are not created for the transportation of hazardous materials. Besides, the hold was airtight. Fire would have a limited amount of oxygen and as result it would cease to burn very quickly, without needing crew intervention. Effectively, the built-in fire suppression is oxygen starvation.

Except that in this case, the hold was full of oxygen.

The class D cargo hold had been loaded with five boxes of unexpended oxygen generators which were improperly packed and which the airline was not authorised to transport.

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 agreed that all the oxygen generators should be replaced and directed SabreTech to do so.

There were some 144 oxygen generators removed from the jets. Of these, six were reported as expended. The rest held oxygen and should have had their pin disabled with legally required safety caps.

These generators worked using a chemical reaction which had a side-effect of getting hot. Very hot.

NTSB Accident Report AAR9706

When heated to its decomposition temperature by the action of the percussion cap, a chemical reaction begins in the core whereby the NaClO3 is reduced to sodium chloride (NaCl) and the oxygen is liberated as a gas. The oxygen flows through the granular insulation between the chemical core and the outlet shell of the generator toward the outlet end of the generator. At the outlet end, the oxygen flows through a series of filters, through the outlet manifold, and into the plastic tubes connected to the reservoir bags on the mask assembly.

The chemical reaction is exothermic, which means that it liberates heat as a by-product of the reaction. This causes the exterior surface of the oxygen generator to become very hot; the maximum temperature of the exterior surface of the oxygen generator during operation is limited by McDonnell Douglas specification to 547 °F when the generator is operated at an ambient temperature of 70 to 80 °F. Manufacturing test data indicate that when operated during tests, maximum shell temperatures typically reach 450 to 500 °F.

However, the safety caps required were not available and the generators were stored without them. The boxes were not clearly labelled. The generators themselves were tagged with green “repairable” labels which had the reason for removal written near the bottom: “out of date” or “expired”. One mechanic stated that they were under pressure to complete the work and had been working 12-hour shifts and 7-day weeks. The mechanics were aware that the canisters still required safety caps. The oxygen generators were temporarily collected into five cardboard boxes without packaging material.

On the 4th of May, the work cards associated with the MD-80s were signed off. The focus was on the MD-80s and the new generators, rather than the transport of the old generators for repair. The mechanics who signed work cards did not look in the boxes and did not check the canisters for safety caps. One stated that he was reassured that the problem would be taken care of “in stores”.

The boxes were left at the hold in the ValuJet section of SabreTech’s shipping and receiving area. No one at the hold was informed that the boxes contained hazardous materials.

The boxes were in the way. On the 8th of May, a stock clerk quickly re-packed the oxygen generators with bubble pack and labelled the boxes as containing “aircraft parts”. He noted the green labels: as far as he knew, oxygen canisters which were marked with a green label were empty and in need of refilling.

He spoke to a receiving clerk to have the five boxes and 9 tires shipped to ValuJet in Atlanta. He stated that the contents of the boxes were “Oxygen Canisters – Empty.”

NTSB Accident Report AAR9706

According to the stock clerk, he identified the generators as “empty canisters” because none of the mechanics had talked with him about what they were or what state they were in, and that he had just found the boxes sitting on the floor of the hold area one morning. He said he did not know what the items were, and when he saw that they had green tags on them, he assumed that meant they were empty. The stock clerk stated in postaccident interviews that he believed green tags indicated that an item was “unserviceable,” and that red tags indicated an item was “beyond economical repair” or “scrap.” When asked if he had read the entries in the “Reason for Removal” block on these tags, he said that he had not.

The stock clerk asked a SabreTech driver to take the boxes to the ValuJet ramp area. The boxes were unloaded onto a baggage cart and signed off by a ValuJet employee.

On the 11th of May, the oxygen generators – five boxes of hazardous material without safety caps – were loaded on top of the rubber tires in the class D cargo hold of Flight 592. ValuJet’s policy was not to transport hazardous materials such as the chemical oxygen generators under any circumstances. Even if the generators had been properly packaged with safety caps, they should not have been transported by Flight 592. But the crew believed that the cargo consisted of a few old tires and boxes of empty canisters.

According to the ramp agent inside the cargo compartment when the boxes were being loaded, “I was stacking—stacking the boxes on the top of the tires.” The ramp agent testified at the Safety Board’s public hearing that he remembered hearing a “clink” sound when he loaded one of the boxes and that he could feel objects moving inside the box. He told Safety Board investigators that when the loading was completed, one of the large tires was lying flat on the compartment floor, with the small tire laying on its side, centered on top of the large tire. He further indicated that the COMAT boxes were also loaded atop the large tire, positioned around the small tire, and that the boxes were not wedged tightly.

When the NTSB recreated the hold scenario in a test, they reached temperatures of about 2,000°F (1,100°C) at 10 minutes after ignition. The fourth test peaked at 3,000°F (1,650°C). A main gear tire, inflated to 50psi, ruptured 16 minutes after the first oxygen generator was activated.

Based on this timing, the NTSB report believes that one of the oxygen generators was actuated during the loading of the plane or possibly as late as the take-off roll. The abundance of oxygen and the liner of the cargo hold meant there was no early indication of smoke or fire. The unexpected sound in the cockpit was a result of the rupturing of the main gear tire in the hold, long after the temperatures in the hold had reached 2,000°F (1,100°C). The crew still did not know the extent of the problem until the fire breached the cargo compartment ceiling and the smoke reached the passenger cabin.

Because of the lack of evidence from the CVR, FDR, and the wreckage, the Safety Board was unable to determine with certainty the reason for the loss of control that occurred at that time. However, examination of the wreckage showed that before the impact the left side floor beams melted and collapsed, which would likely have affected the control cables on the captain’s side. It is possible that the first officer might have taken over flying from the captain, but the remaining control cables also were possibly affected by distorting floor beams. Based on the continuing degradation of flight controls and the damage to cabin floorboards in the area of the flight controls, the Safety Board concludes that the loss of control was most likely the result of flight control failure from the extreme heat and structural collapse; however, the Safety Board cannot rule out the possibility that the flight crew was incapacitated by smoke or heat in the cockpit during the last 7 seconds of the flight.

The accident report, 142 pages not including the appendixes, concluded that probably causes were:

1. the failure of SabreTech to properly prepare, package, and identify unexpended chemical oxygen generators before presenting them to ValuJet for carriage
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
3. the failure of the Federal Aviation Administration to require smoke detection and fire suppression systems in class D cargo compartments.

ValuJet Crash Remembered 15 Years Later | NBC Miami

The ValuJet story played out for months. A heartbreaking story of family losses juxtaposed with a web of a lack of oversight, error compounding error. A story of tumbling dominoes led to the crash.

Fifteen years later the stark memorial stands on the side of the Tamiami Trail, a series of descending columns that, in the shape of an arrow, point northeasterly towards the crash site 8 miles away.

The legacy of the ValuJet crash is indeed vast. Lawyer Mike Eidson, who represented two families that lost loved ones is quick to note, “ We have not had an accident like this fire in cargo holds since this happened.”

That’s because in the wake of the crash, the FAA has tightened oversight of maintenance companies and slapped strict regulations on what could be shipped in airline cargo holds. In addition the FAA quadrupled the inspectors who check out cargo shipments on passenger jets.

• Air France 447 Update on Investigation
• Human Factors: Crossair Flight 850
• Alaska Airlines Flight 1866
• PULL UP PULL UP: Garuda Indonesia flight GA200 in Yogyakarta

This week, I’ve had a terrible cold and have spent an inordinate amount of time clicking random webpages. As a result, I spent more time reading (and listening) than writing about aviation. In an attempt to redeem myself, I am sharing with you the best of the pieces I found online. Enjoy!

On-board a Cessna 172 on April 25, we had an engine failure over the highway 10 in Quebec, Canada.
We had to make an emergency landing on the highway.

What Happened to Air France Flight 447? – NYTimes.com

The search had already taken two years and cost more than $25 million. Another $12 million was committed to the Alucia this year, but French investigators had quietly decided that this year would be the last. If the Alucia did not find the plane, no one ever would.

John Roderick crashed a quarter-mile west of Water Oak Road in Flagler County around 3 p.m. Wednesday in his experimental biplane, the report said. He was able to walk away from the crash unharmed.

The plane landed in the tree tops of an area surrounded by young pine trees, the report said.

BBC – BBC Radio 4 Programmes – Face the Facts, 04/05/2011

John Waite investigates the Belfast commuter flight that crashed in February killing six people. He hears how the crew were inexperienced and breached air safety regulations. The company running the route, Manx 2, has since denied responsibility for the accident, claiming it is only a ticket seller and that the actual operator was a small company from Spain. The British Airline Pilots Association tells the programme that such arrangements are likely to become more common in the industry and that the government and regulator needs to act to ensure transparency for passengers.

English Russia » Russian Jet Cabrio Flight

Those photos are real and were made during the filming of the Russian movie involving jet fighter stunts. In one episode they had to film the jet without a canopy, so rather to film it on the ground they decided to hire a high-class pilot to make a real flight without that glass thing. He had to take off a few times on such plane in order to film enough material to be included in the final footage.

Photos: Lockheed HC-130H Hercules (L-382) Aircraft Pictures | Airliners.net

USA – Coast Guard: There’s no better location to view the Golden Gate Bridge than from a Coast Guard C-130…Note the trail of dust left behind from our engines.

Stranded at Sea | Military Aviation | Air & Space Magazine

With their airplane nearly out of fuel, they had to ditch in the ocean, beginning a month-long ordeal recounted in this excerpt from Fly Navy: Discovering the Extraordinary People and the Enduring Spirit of Naval Aviation, by Alvin Townley, Thomas Dunne Books, 2011.

Boeing: Boeing Phantom Ray Completes 1st Flight

The Boeing [NYSE: BA] Phantom Ray unmanned airborne system (UAS) successfully completed its first flight April 27 at NASA’s Dryden Flight Research Center at Edwards Air Force Base, Calif.

The 17-minute flight took place following a series of high-speed taxi tests in March that validated ground guidance, navigation and control and verified mission planning, pilot interface and operational procedures. Phantom Ray flew to 7,500 feet and reached a speed of 178 knots.

Have you seen (or even posted) interesting aviation articles or photographs that you think others would like? Add them in the comments!