Browsing Posts in Accidents/Incidents

It’s Not Actually News When a Plane’s Landing Gear Doesn’t Go DownConde Nast Daily Traveler
A United Express flight had its nose gear fail to extend earlier this week. This shouldn’t be news.

In the Trenches: Defining RolesIntuit Small Business Blog
Trying to define roles in a small business is tougher than it might seem.

Many cities lose out in Southwest-AirTran mergerUSA Today
I was interviewed about the loss of service from Southwest in smaller cities.

Even though I’m on break, I did have two articles that went live and one guest post as well.

An incredibly safe year for air travelCNN Out of the Office
I take a look at the year in review for accidents. As the title says, it was a very good year.

When Is a Nonstop Flight Not Really a Nonstop Flight?Conde Nast Daily Traveler
It’s winter and that means a lot more fuel stops are happening. Here’s why that happens.

Guest Post: What is a Travel Concierge?Bangalore Aviation
The guys at Bangalore Aviation asked me to follow up my top 10 list guest post with one about what we do at Cranky Concierge. I was, of course, happy to oblige.

This is more of a non-traditional Ask Cranky in that it’s been asked several times over the years, particularly in light of the Air France accident over the Atlantic when the thought was that the black boxes would never be found. The question? Why don’t airlines stream black box data so that they don’t have to actually find the box itself? It’s a great question, and there Ask Crankyare ways to do it. I spoke with Mark McWhirter, Business Development Coordinator at FLYHT about a product they have that does just that.

But first, let’s back up a little. What is a black box? There are actually two separate devices and neither of them are black. (It’d be a lot harder to find that way.) The Cockpit Voice Recorder (CVR) is used to record conversation in the cockpit. It doesn’t record for very long and so there isn’t a ton of history on there; it just keeps recording over itself so the most recent data is available. Then there’s the Flight Data Recorder (FDR) which takes a bunch of different data points about what the airplane is doing and stores them. Newer versions collect more data points with better info, but these also don’t record for very long.

The idea is that if something goes wrong, you won’t need to know what happened a week ago. You’ll really need to know what happened in the final moments. The most important thing about these devices is that they need to be crash-hardened so that they can survive a massive wreck, and that they do. When they pulled the black boxes off the ocean floor from that Air France wreck long after the airplane went down, and they could actually recover the data, it was a testament to how good these things are. But, doesn’t that seem strange in this day and age that the data isn’t just sent down to the ground? It’s not as easy as it might seem.

With internet access becoming more and more available, you would think that would create more opportunity for streaming the data, but reliable inflight internet is still only in a small geographic subset of the world. In many places where you’d really want to have this capability the most (over oceans, mountains, etc.), it’s not cheap to get data off the airplane using more traditional methods. At upwards of $3 to $5 a minute or so, that can get expensive quickly. That probably doesn’t make any sense, but there are better ways.

FLYHT has a product called Automated Flight Information Reporting System (AFIRS) which is actually quite smart. What is does is basically set up a recording device the plugs in and takes the feed between the aircraft and the data recorder. It stores anywhere from a week up to a month of data depending upon the aircraft, and the data can be removed at any time. This is useful for airlines that have FOQA programs and really work to analyze the data to improve safety.

The system uses the Iridium satellites to then communicate that data from anywhere in the world. On the legacy system, there would be a variety of triggers that would automatically send an alert back to base if something went wrong. These were the catastrophic types of events but normal issues that would want to be analyzed later. After Air France 447, however, there was a renewed interest in doing something more. And that’s exactly what’s happening.

Now, if an emergency happens, there are three ways that the mechanism can be triggered. One is automated depending upon the parameters set, the other is by the pilots in the cockpit, and the third is from the airline on the ground. If one of those is triggered, then the system will not just send an alert but will immediately begin streaming all the black box data down to the ground. Within 30 seconds, that data can be viewed in a simulation with only a slight transmission delay. Looks like this:

FLYHTStream graphic

Kind of awesome, right? At $3 to $5 a minute, it’s only a concern if all data was being streamed throughout the flight. If it’s just during an emergency, that price is peanuts and worth a lot more than that.

Great idea, huh? And who is using this? Well, it’s not widely out there yet, at least not the streaming stuff. It’s being tested on two customer aircraft right now. One is a US-based 767, but they wouldn’t tell me anything more than that. They do hope, however, that there will be more to talk about it down the line. Having this kind of information streaming makes a ton of sense, and as data coverage gets better and cheaper it will soon become a no-brainer to have a system like this if it isn’t already.

There was plenty of backlash when I wrote about the causes of the 2009 crash of Air France flight 447 into the Atlantic Ocean back in May. Many of you wanted to wait until the final report came out, but I was confident that the story had become quite clear. With the latest interim report (which I can only find in French – summary in English is here), it looks like I was right on track.

Un Airbus A330 d'Air France

Here’s what I said at the end of my last post:

Remember, the pilots were already working to pick their way through the worst of the storms. Add to that the loss of the autopilot, dozens of failure messages, and inconsistent speed readings and it seems like the answer might be simple. The pilots may have been so distracted that they forgot to do the one thing they needed to do to survive: fly the airplane. Once the final report is issued, look for training changes to come out of this and possibly even some changes in the way Airbus puts its airplane logic together.

Sure enough, the focus of the latest report is on training and puts a lot of the blame on Air France, but there is some discussion about aircraft logic as well. This has been enough for the investigators to push out safety recommendations, though not without controversy.

Throughout this 3rd interim report, a picture of normalcy is painted throughout the beginning of the flight. It was noted that when the Captain left to take his rest, he didn’t leave “clear operational instructions” and there was “no explicit task-sharing” between the two remaining pilots, but the crew composition was fine and the aircraft weight and balance was within the proper limits.

As mentioned in the last report, the crew was well aware of the weather ahead and had made course corrections to avoid the worst of it. That’s when things got ugly.

According to the report, the aircraft was flying at the “upper limit of a slightly turbulent cloud layer” when the autopilot disconnected. It’s believed that this happened because the pitot tubes froze over and that gave the aircraft incorrect speed information. When the system can’t make sense of the information it’s being fed, it shuts off autopilot and the pilots have to fly the airplane. Turbulence, however, was not a problem. The plane was perfectly flyable, but poor decision-making fed by weak training brought the airplane down.

Proper procedures were not followed for dealing with unreliable airspeed indication. To make things worse, neither of the two copilots had been trained to properly handle manual flying at high altitude. Despite the stall warning, the pilots continued to apply nose-up pressure, the opposite of what they should have done. In less than a minute, the plane went from being correctable to operating outside the design limits because of the improper recovery efforts by the pilots.

About 1 minute and 30 seconds after the autopilot disconnected, the Captain came back into the cockpit. At this point, stall warnings were going on and off and the airplane was still at 35,000 feet. Unfortunately, it was also losing 10,000 feet per minute as forward speed just disappeared. At times, the aircraft rolled from side to side as the pilots struggled to get the airplane under control. Those in the back must have felt sheer terror. The pilots never made an announcement to the passengers, and soon after, they all plunged into the Atlantic. I get goose bumps just thinking about how awful that must have been.

So after all that, what have we learned? We know the aircraft functioned properly. Were it not for the pitot tubes freezing over, this would have been a routine flight. Even when the pitot tubes failed, had the pilots been able to properly fly the aircraft manually, the passengers probably wouldn’t have even known there was an issue. Out of this, the French accident investigators have released safety recommendations that will need to be implemented by regulators in order to go into effect.

The main recommendation is around training. The idea is to make sure that all pilots have the proper training for manual flight at high altitudes, a skill which is rarely used in commercial aviation today. There is also additional training suggested around stall avoidance and recovery. Additionally, it’s suggested that the role of relief captain should be better-defined when the Captain is on rest. This way, there will be less confusion and more defined task-sharing if something goes wrong.

But the blame wasn’t solely on the training and pilots. One recommendation for aircraft manufacturers is to look at including an angle of attack indicator that pilots can see on the flight deck. There is an indicator showing the angle of the aircraft to the ground, but there isn’t one that shows the angle of the wing as compared to the direction of the air (angle of attack). That could have helped the pilots in their recovery efforts.

One recommendation not made was to revisit the way stall warnings are handled on the A330 aircraft. In fact, the pilots union at Air France is so angry about this being left out that it has decided to stop cooperating with the investigation. The on-and-off nature of the stall warning may have simply added to the confusion, and made it more difficult for the pilots to make the right moves. The investigators say that there wasn’t enough evidence to include this just yet, but it will be discussed in some form in the final report.

Regardless of what comes out in the final report, the picture is already very clear. It seems that current pilot training standards were not enough to help these pilots get out of an entirely recoverable situation. Were the Brazilians running this investigation, they probably would have already filed criminal charges against anyone they could, but the French handle this properly. Find the problem, fix the holes, and make sure that something like this never happens again.

[Photo of Sister Ship to Crashed Airplane via Flickr user Tab59|CC 2.0]

When the French found the black boxes from Air France flight 447 nearly two years after the A330 airplane crashed in the Atlantic off Brazil, it was an incredible feat. But now, the French probably are wishing those black boxes remained on the floor of the ocean, because its national airline is about to face some tough questions regarding the actions of its pilots on that flight. No airplane accident happens because of just one problem, and this is no exception, but so far pilot error is really sticking out as the single largest contributor here.

Un Airbus A330 d'Air France
Photo of Sister Ship to Crashed Airplane via Flickr user Tab59|CC 2.0

The French accident investigation group, the BEA, has put out an update on its investigation around what caused Air France 447 to crash (pdf) in the Atlantic back in 2009. Flightglobal has a good minute-by-minute breakdown of what all of the technical verbiage means, but let’s focus here on a few key points.

Pilots Were Not Inexperienced
One thing that has been picked up on elsewhere is that the Captain was not in the cockpit when this all started happening. That’s true, and it’s not a surprise. That’s why there are three pilots on longer flights like these. They rotate taking rest and this was the Captain’s turn. Does that mean that there were two inexperienced fools manning the controls? No. The co-pilots were highly trained and should have been able to handle this situation without needing the Captain. As Flight notes, one of the co-pilots had more time on the A330 than the Captain himself (just not in command). Experience shouldn’t have been the issue.

Turbulence Was Not a Factor
The aircraft went down in an area near strong equatorial storms, so many people assumed that the storms and the likely associated turbulence played a role. That no longer appears to be the case. The pilots were actively working their way around the storms, and while there was turbulence around, it doesn’t appear to have been anything severe. The storm likely did play a role in that it caused the pitot tubes to freeze over. Let’s talk about that . . .

Frozen Pitot Tubes Are the Likely Trigger
I don’t believe this has been officially confirmed, but the belief remains that the pitot tubes froze and that kicked off the problems on the airplane. Pitot tubes are little pokey-looking things that stick off the side of the airplane and measure airspeed. If the pitot tubes froze as expected, then speed readings would have been erratic and incorrect. That would have caused the airplane to shut off the autopilot as happened here. While it is a serious issue, it shouldn’t have cause and accident on its own.

Ultimately, the Pilots Screwed Up
Regardless of what happened with the pitot tubes, what happened next seems just unbelievable and certainly casts a great deal of blame on the pilots even though we won’t have the final report until next year. About 10 minutes before the autopilot shut off, the pilots noted that they couldn’t climb any higher than the 35,000 feet they were at because of their weight and the relatively warm air outside. In other words, if they climbed higher, they wouldn’t be able to generate enough lift. That makes what happens next even more strange.

When the autopilot shut off, the pilots should have worked to keep the plane flying as it was. After all, there wasn’t an actual speed problem but just a speed measurement issue. The engines worked just fine, so it should have been quite possible to keep the airplane on its path. That’s not what happened. Over the next four minutes, the pilots pulled the airplane into a climb and right into a stall and that led to the crash into the ocean. This goes against one of the most basic rules of flight.

If Your Airplane Stalls

When an airplane stalls, that means its angle of attack (the angle of the wing as compared to the direction of the air) is too great. Fixing it is pretty straightforward and it’s something that gets trained at very basic levels. As the FAA says in its Airplane Flying Handbook:

Reducing the angle of attack is the only way of recovering from a stall regardless of the amount of power used.

That means pushing the airplane’s nose down until the air once again runs smoothly over the wings. If you’re at 35,000 feet, don’t worry about losing altitude. Just get the airplane back into normal flight. How do you know if you’re in a stall? This is where the Boeing vs Airbus people will start their “mine is better than yours” fight.

On Boeing airplanes, the control column actually shakes to warn the pilot. (It’s known, unsurprisingly, as a stick shaker.) But most Airbus types, including the A330 that crashed here, operate with little joysticks on the side and these don’t have stick shakers. Instead, there is a very loud verbal warning repeated multiple times. Either way, it shouldn’t be missed. But don’t Airbus airplanes have greater automation to prevent these things anyway? Not in this case.

Airbus normally has automation protection that prevents pilots from doing something stupid like going into a steep climb in a situation like this, but those protections weren’t in effect because of the inaccurate airspeed readings. That pushed the airplane into Alternate Law which shuts down many of the protections that are in place during Normal Law.

When the Captain got back into the cockpit, the airplane had an angle of attack at an incredibly high 40 degrees and it was losing 10,000 feet per minute in altitude. Despite his best efforts to recover, it was a failed effort. The airplane hit the water with its nose up 16 degrees but still losing more than 10,000 feet per minute in altitude. I can’t imagine how awful those few minutes were for the passengers.

But the Pilots Aren’t To Be Blamed Completely
The final report hasn’t been issued and won’t be until next year, but it’s easy to see from this that the pilots and the pitot tubes were the two biggest contributors. Why did the pilots continue to apply nose-up pressure when that was the exact opposite of what would have happened? We’ll never know what was running through their heads, but it’s easy to see that they could have been distracted.

Remember, the pilots were already working to pick their way through the worst of the storms. Add to that the loss of the autopilot, dozens of failure messages, and inconsistent speed readings and it seems like the answer might be simple. The pilots may have been so distracted that they forgot to do the one thing they needed to do to survive: fly the airplane. Once the final report is issued, look for training changes to come out of this and possibly even some changes in the way Airbus puts its airplane logic together.


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