July 22, 2013
The recent crash of an Asiana Boeing 777 at San Francisco International Airport is a perplexing case. How does a jetliner as sophisticated as a 777 crash on a routine visual approach, in good weather, with no mechanical problems?
Like most pilots, I am very hesitant to speculate on accidents like this until the facts are in. So many factors can contribute to an accident, but in this case it’s hard not to think those dreaded two words: pilot error. How do experienced pilots let a plane get so low and slow on a visual approach? Was something distracting them? The cockpit voice recorder might shed some light on this, and I’m anxiously awaiting the findings of the NTSB, though experience says that wait could be a year or more.
If you’ve read much about this accident, you know that the pilot in the left seat was new to the 777, although he was a Captain with Asiana who had logged around 10,000 hours in various aircraft. The right seat pilot was an instructor pilot who was technically the pilot in command, overseeing the new Captain in the left seat. Some people outside the industry were aghast that a pilot with so few hours in the plane could be flying it. But every pilot has to get his first hours in a new type, and those hours are accumulated during revenue flights (i.e. carrying passengers). When a pilot transitions to a new type, or when he upgrades from First Officer to Captain, he goes through a training program that includes ground school (systems knowledge), simulator training (normal procedures as well as abnormal and emergency situations) and, finally, IOE (Initial Operating Experience), which consists of revenue flights with an instructor pilot/check airman riding along in the other seat. IOE will generally be about 20 hours of flight experience for domestic pilots and somewhat more for international pilots. So…we don’t really have a “beginner” in the left seat, as some news reports have implied.
For this approach, the ILS (Instrument Landing System) for the runway was out of service, and some early news reports implied that this might have been a contributing factor. It’s true that having an electronic glideslope is helpful, but any experienced pilot can make an approach with nothing more than visual cues, using the simple 3-to-1 rule as a good crosscheck (for every mile from the runway, we should be about 300 feet above the ground, so we should be at 1,500 feet when on a five-mile final). In fact, there are many runways at major airports that don’t even have an electronic glideslope. Runway 19 at Washington National and Runway 31 at New York’s La Guardia airport are two that come to mind.
Also, in this case there was a visual aid for flying a proper glideslope. Runway 28L at SFO has a PAPI, Precision Approach Path Indicator, to the left of the runway. The PAPI is a set of four lights, each split between a lower red light and an upper white light. Depending on the plane’s descent angle, the light will appear red when low or white when high. Each of the four lights has a slightly different angle for where the transition between red and white occurs. If you are on the proper glidepath, you’ll see two white and two red lights (a 2.85° glidepath for this runway). If you see four red lights, you’re much too low; four white lights and you’re much too high.
The focus now seems to be on the crew’s over-reliance on automation, perhaps coupled with some misunderstanding of the various modes of the automation. This is somewhat reminiscent of the Air France crash over the Atlantic in June 2009; in both cases airmanship has come into question. Automation (autopilot, autothrottles and a computer loaded with speed and altitude restrictions) can be a great tool on a plane, but in some cases, particularly when lots of quick changes are required in a short time (as on final approach with Air Traffic Control throwing altitude and speed restrictions at you), it can be preferable to turn off the autopilot and just hand-fly the plane.
For me, the most amazing thing about this accident is how a crew could get that slow on an approach. I wasn’t there, so I don’t know what distractions there might have been. But I can’t remember the last time I’ve seen a fellow pilot get as much as 10 knots slow on an approach, never mind the 30+ knots under speed for Asiana 214. If the flying pilot gets even five knots slow, the other pilot will call out “airspeed” and expect a reply of “correcting,” along with necessary power and/or pitch inputs to regain the speed. Airspeed is life, and every pilot knows it.
May 2, 2013
Unless you’re in the aviation business, you’re probably unfamiliar with the acronym FOQA. In fact, many pilots couldn’t tell you what it means.
Pronounced foe-kwah, it stands for Flight Operational Quality Assurance. It’s an automatic recording and reporting system installed in some commercial aircraft. I don’t know all the details of how it works or what it tracks, but it continuously records a wide range of data about aircraft systems and flight performance. The goal is to improve flight efficiency and safety.
But FOQA can also be a snitch. If, for example, we overspeed the flaps (i.e., either put flaps down while going too fast or retract them too slowly while accelerating), FOQA will record the event, and it will get flagged once the data is downloaded. This shouldn’t be an issue, because the pilots are supposed to make a logbook entry for the overspeed event. But if they missed it, or elected to ignore it because it was only “a little fast,” they can probably expect a phone call from the chief pilot. A much more serious example would be if the pilots took off without selecting takeoff flaps (a very rare event, but it’s happened). This is definitely going to trigger some action.
Does this make pilots a little more attentive on a FOQA-equipped plane? You might think so, but the truth is that we don’t even pay attention to it. If you asked me halfway through a flight if the plane I was on had FOQA, I would have to check. The reason is simple: we don’t push the edge of the envelope, so we don’t worry about the snitch. It’s kind of like the security cameras in a bank: Honest people don’t worry about them.
April 22, 2013
A common question that laypeople ask airline pilots is “What route do you fly?” The perception seems to be that we go to work and fly to the same place every time. It can be true for certain individuals, usually pilots who have enough seniority to get their pick of schedules. I knew a Washington-based American Airlines pilot who used to bid for day trips (no overnight) from Dulles to Dallas-Fort Worth and return. Another pilot (at Delta) flew JFK to Nice, France almost exclusively. He told me he made 48 crossings of the Atlantic in one year, and 44 of them were to Nice.
But for most of us, we bid for our monthly schedule and get whatever can be cobbled together from the leftover trips not selected by the more senior pilots. And if there aren’t enough trips to go around, or if the trips available are undesirable, a pilot can bid or be assigned to be on Reserve for the month. I’ve found myself in that situation for the past few months.
It’s all driven by the pilot’s seniority within his category, i.e. base/equipment/seat. For example, a pilot might be quite senior flying as a co-pilot in the MD-88 based in New York, but if he chooses to upgrade to Captain or just switch to a larger aircraft, his relative seniority within that new category will probably be lower and his ability to control his schedule (and quality of life) will be reduced.
My current situation was not caused by any change that I opted for. I’m just a casualty of reduced flying for my category and a lower relative seniority as other, more senior pilots bid into this plane and home base. The erosion in my bidding power has been apparent for some time now. A few years ago I was flying only international trips, which were all easily commutable from my home in D.C. to my base in New York. Many of these destinations have been switched over to other equipment (Airbus 330 and Boeing 747), leaving my category with fewer trips overall and a larger concentration of domestic trips.
So what’s it like being an “on-call” pilot? A Reserve pilot actually gets a schedule, listing the days that he is on call. The other days are off, just like a regular pilot who holds a line. The responsibility of the Reserve pilot is company-specific, and is spelled out in whatever working agreement the pilot group has with the company. In my case, I have two different situations: “Long Call” and “Short Call.”
Long Call is the default status, and means that I have 12 hours to report for duty if the company calls me. That’s a pretty long time, and it means I can sit at home in D.C., knowing I can make it to New York within 12 hours (driving if I have to). Occasionally, the company will call and assign me Short Call. In that case, I have about two hours to report for duty if Crew Scheduling calls. I can’t do that sitting at home in D.C., so I head to New York to be there in case I’m needed.
How often a Reserve pilot gets called is really a function of the staffing for the airplane type. Keeping the right ratio of pilots to planes is a challenge. Marketing people decide which airplanes serve which cities and how many flights they make, while other planners in the company have to try to get the staffing right for the airplane. Changing the number of pilots on a particular type of plane can’t be done overnight, so for some months we have an abundance of pilots, while at other times we operate with barely adequate staffing. (Note: a company like Southwest, with one type of airplane, doesn’t have this issue.) If you’re sitting Reserve on a category that is thinly staffed, you can expect lots of calls to head to the airport to replace a pilot who has called in sick or is otherwise unavailable.
I’ve been in the other situation lately (i.e. well staffed) and I’ve flown very little in the last few months. Don’t worry, I still get paid (ok, I knew you weren’t worried). We get paid a minimum number of hours whether they use us or not. That number is a little less than if we could bid an actual schedule, but in my case I haven’t flown anywhere near that number, so I guess you could say it’s a good deal. Except that I’d rather fly.
Being a Reserve pilot means never knowing where you might be from one day to the next. Since being on Reserve over the past several months, I’ve been to Stockholm, Mexico City, Cancun, San Francisco, Los Angeles, Minneapolis, Atlanta, Phoenix, Kansas City and Miami. So when someone asks me “What route do you fly?”, I just say “I never know until the phone rings.”
March 18, 2013
I still clearly remember when the jig was up with my fingernail clippers.
I had been flying with the clippers in my shaving kit for several weeks after 9/11, but I couldn’t slip them by one very alert security screener in Jackson, Mississippi. At first I thought he was kidding me, but he was in deadly earnest. He explained that the small pointed file would have to be broken off the clippers before they would be allowed to pass through. I resisted the urge to point out that — as the pilot of the airplane — I already have a very sharp crash axe within easy reach when I sit in the cockpit (I had already heard of some pilots getting in hot water for making such observations).
The screener held out the clippers as if to hand them to me, and I asked what he was doing. He said, “You need to break off the file.” My response: “I’m not touching that thing. You’ve just identified it as a serious potential weapon and I don’t want to risk an injury.” This was my subtle way of highlighting the absurdity of the situation (best I could do on short notice). The screener broke off the file and I continued my day.
Over the past decade, I’ve become inured to the theater-of-the-absurd that is our screening process, and I’ve come to accept the dangers inherent in shoes and liquids (but only for amounts over 3.5 fluid ounces). But now, apparently, knives of a certain size are safe for flight. This strikes me as odd. Couldn’t any small knife be wielded with just as much menace as the box cutters from the hijackings of 9/11?
It seems like an odd place to ease up the scrutiny, and it appears to me that the TSA is focusing on those things which could potentially bring down the plane, i.e. explosives. Pilots are trained to never open the cockpit door in a threat situation, so small knives don’t pose a threat to the plane, just to the flight attendants and passengers.
But pilots and flight attendants are concerned with this new rule. The safety of the people on our flight is our main concern, and the new policy does not enhance that safety. The stated reason for the change is to speed up the screening process, but I can’t imagine the small time savings is worth the added risk.
March 6, 2013
I recently had my first medical diversion ever.
It was the first flight of a three-day trip, JFK to LAX, and the weather was good all the way across the country. About 300 miles east of Denver, we got a call from the lead flight attendant. A passenger had opened an overhead bin to retrieve her bag and another bag fell out onto the top of a 56 year-old gentleman’s head. The flight attendant told us that the man said he was fine, but she thought we should know. I thought that would be the end of it.
Twenty minutes later, the flight attendant called again. The man now complained of pains radiating from his head down through his neck and shoulders. The Captain asked her to get all the pertinent information to us (we have a form for that) then to see if there’s a doctor on board (there frequently is). We then initiated a call over the radio to our on-call medical resource, called STAT-MD, which lets us talk to a doctor for advice on handling the situation.
While we were doing that, the flight attendants did find a doctor on board, who discovered that the “patient” was taking a medication called coumadin, a blood thinner. This increased the doctor’s concern with the symptoms, and when we relayed that bit of information to the doctor at STAT-MD, he advised us to get this passenger on the ground immediately for further diagnosis. At this point, we were about 100 miles east of Denver so we started down from Flight Level 380 (38,000 feet).
The passenger didn’t want to divert, but it wasn’t his call. I suppose we can all imagine the kind of liability issues that could arise if we elected to skip the diversion and the man’s condition became critical during the last 90 minutes of flight to L.A.
We were pretty busy during the descent, getting out the approach charts for Denver, briefing the approach, calling Denver Operations to get a gate assignment, and running checklists for the descent and approach. Normally one of us would make a PA to the passengers, but we were so busy that we had to delegate that to the lead flight attendant. Declaring a medical emergency really gets you some expeditious handling by Air Traffic Control, and we got cleared straight in to the airport and got taxi clearance right to the gate, with other planes holding for us.
The passenger/patient was met by medical personnel, who escorted him off the plane. Then we got some fuel and a new dispatch release to continue our flight. We were on the ground for 40 minutes. As we continued on our way to Los Angeles, I wondered just how much of an inconvenience this would end up being for that passenger. There was a good chance he wouldn’t make it to L.A. until the next day, but we’d never know the rest of the story.
February 6, 2013
Saturday was a perfect day, with the winds forecast to be five knots or less all day. We arrived at the airport, and after checking out the airplane (a Cessna 172), it was time for Tyler and me to start our experiment. First he set up some cameras in the plane. He had two iPhones, which he set up on top of the forward panel, one directed at each of us. A digital camera was mounted on top of the center of the panel facing forward. Another camera was on a tripod placed behind the seats, with one leg in each of the seat back pockets. Lastly, he had a digital audio recorder that he plugged in to one of the audio phone outlets in the back seat.
We got in the plane and strapped in, Tyler in the left seat and me in the right. (Since this was a trainer, we had identical dual yoke and controls.) Before starting the engine, I went over the panel so that he understood where all the controls are. To anyone who might say that this “instruction” is beyond the scope of the experiment, I would point out that the plane and the sim aren’t identical in layout. In fact, if we looked at each of the C-172s on the ramp we’d see differences among the various models. For example, in some of them the flap handle has labeled detents for each flap setting (and that’s what Tyler was expecting). But in this plane, the flap handle was a three position toggle switch. To put flaps down, hold the toggle down and watch the flap indicator to see how much flaps you have. Flip the toggle up and the flaps retract without the need to hold the switch. I wanted to be sure he understood the operation, as it’s easy to accidentally retract flaps by moving the switch inadvertently past the center detent.
Besides the flap handle, the only other things that Tyler would need to touch during the flight were the yoke, the throttle and the trim wheel. I showed him the operation of the trim wheel and explained its use. It’s a convenience, used to alleviate elevator control pressure, but not a requirement. You can muscle through those control forces, but it makes things a lot easier if you have the plane trimmed for fingertip control.
Next, I pointed out the Directional Gyro (DG) and explained that we would set it to runway heading just prior to takeoff. Tyler was hoping for runway 12L, which he had flown on his simulator. He was used to the headings needed for the pattern from this runway.
After turning all the cameras on, I started the engine and contacted Ground Control for taxi clearance, requesting a closed pattern (i.e., we would be returning to land), and we proceeded to the runway. On a straightaway portion of the taxiway, I let Tyler put his feet on the rudders just to get the feel of taxiing the plane. We got to the run up area and ran the Before Takeoff checklist, ensuring that everything was ready to go. I then called the tower and advised the controller that we were ready for takeoff.
The tower controller threw us a curve, clearing us for takeoff on Runway 7 with instructions to land on Runway 12L. This is a significant change, since it wouldn’t be a standard rectangular pattern, and I felt that it was unfair to not briefly discuss what he had to do. You only get one chance to make a first attempt and I didn’t want to see it ruined for Tyler because he was having trouble with situational awareness. So I told the controller that I had a student pilot on board and we needed a minute. I took out the airport diagram and showed Tyler the relation of the runways and how he could takeoff and simply turn to enter the downwind for 12L. He was satisfied, and I advised the Tower that we were ready. My biggest regret about the experiment is that I didn’t simply ask the controller for a takeoff on 12L, which I am sure would have been approved.
Here’s where I made a serious omission: I neglected to verify and set runway heading on the DG once we lined up on the runway. I got us on the centerline and told Sparks “Your airplane.” He advanced the throttle, a little timidly at first, and we started rolling. As I expected, he began drifting left of centerline. The plane wants to go left due to several factors, and right rudder is required to keep it tracking straight ahead.
He had drifted halfway from the centerline to the left edge of the runway, and I was mentally allowing him about five more feet before I would take over. But at this point, he finally applied sufficient rudder to stop the drift. (By the way, if I had taken over, my plan was to initiate the climb and then turn the plane back over to him to see if he could make the landing.) His takeoff was very good and I was pleasantly surprised to see that he didn’t over-rotate, another very common error for first-timers. If you rotate too fast or too much, the airspeed can bleed off dangerously, running the risk of a stall very low to the ground.
Climbout was pretty good. We drifted a little more left, but now that we were airborne there was no major concern with that. At about 500′ above the ground (2700′ msl) Tyler started a left turn to bring the plane around to downwind for 12L. He was looking for a heading of 300° and at this time he noticed that the heading on the gyro was way off from what it should have been. I quickly reset the gyro to our magnetic heading (indicated by a magnetic compass attached to the center of the windshield). Ugh, I felt horrible for missing that before takeoff!
Tyler leveled off at pattern altitude of 3000′ msl and began accelerating much more than he should have for staying in the landing pattern. We got up to almost 120 knots before he realized that he needed to reduce power. As we continued on downwind, I finally made a small gesture, pointing left, to indicate that we needed to turn base soon. I wouldn’t have done this if we had been at an uncontrolled field, but I didn’t want the Tower to have to call us to ask about our extended downwind.
At this point, I watched as Sparks slowed the plane and extended flaps. He settled on 20° of flaps, which was his plan ahead of time and is fine for landing. As we turned final, we were really coming to the critical part of the experiment. As long as we were in the air, there was really little he could do to put us in immediate danger. But close to the ground I had to be ready to take the plane. Of course, that’s true for any student pilot making a first landing. The main difference is that I would normally be giving constant verbal feedback during this phase. But the rules were that I couldn’t say anything.
His glide path control was pretty good. We got a little low at one point, but he recognized it and shallowed the descent until we were back on path. As we got closer, the VASI (Visual Approach Slope Indicator) became discernible and I pointed it out. Again, there might be some who find fault with that, and perhaps I shouldn’t have said anything. Maybe it’s the flight instructor in me, but I didn’t see any problem with pointing it out. I didn’t discuss how to interpret it or make any suggestions about his control of the plane.
Coming up on the runway threshold, I was waiting to see if he would make some of the classic first-time mistakes. It’s very easy to misjudge the round-out of the descent and the flare for landing. A common mistake is to pull back too much, causing the plane to balloon upward as the airspeed drops off toward stall. If this happened, I’d have to take over. Another mistake is simply to fly the plane into the ground without breaking the glide at all. This will cause a nose wheel strike, which can damage the plane (though it will usually be a survivable landing). I couldn’t risk damage to the plane, and I’d have to take over if I saw this coming too.
But Tyler did a beautiful job, bleeding off the power as he shallowed the descent. We drifted a little right, but not as much as he drifted left during takeoff. I was watching airspeed and descent rate closely, with my attention constantly shifting from outside to the instruments. We touched down at a very acceptable speed and began rolling down the runway with power at idle. At this point, I was satisfied that he had done it, and said “I’ve got the airplane.”
Tower had cleared us for “the option,” which meant that we could have done either of four things: (1) make a low pass and go around, (2) make a touch and go (i.e. land, than apply power and take off), (3) make a stop and go (land, come to a full stop, then apply power and takeoff), or (4) make a full stop landing and taxi clear of the runway. I told Tyler I had the plane and I retracted the flaps and applied power for takeoff. It was my turn.
Once on downwind, I asked Tyler if he wanted to go do some more flying and I could actually give him instruction, but he was happy to call it a day, so we just returned for a full-stop landing. As we taxied in, I congratulated him and told him that he had just made a mockery of my entire life. When we tied down the airplane, we had logged .5 hours on the plane.
Afterward, we headed off for lunch and relived the experience. I think we both agreed that the perfect weather, especially dead calm winds, made it possible, but that doesn’t take away from the accomplishment. Tyler acknowledged that the real airplane is a whole lot different than flying the simulation software, but it obviously gave him the basics. I think he also said that some of the online discussion beforehand about what to expect actually helped him.
Even though the experiment was a success, I can’t say how common Tyler’s experience would be. So if you’ve spent a few hours flying Microsoft Flight Simulator, and now think you’re ready to solo, I’d still say: Don’t.
After he got home, Tyler posted this YouTube video of the flight. Unfortunately, the backseat camera video, which was supposed to show the instrument panel, was not usable.
January 25, 2013
If you’ve fooled around with flight simulation software for your desktop computer, you know that it can be pretty realistic. You can “fly” just about any type of airplane, from almost any airport in the world. If you go the extra mile and add rudder pedals, a control wheel and a throttle to your setup, you’ve got everything except the full motion of a multimillion dollar simulator like the ones used to train airline pilots.
Is it possible for a person to get proficient enough on this home software to be able to takeoff and land a real airplane — with no other instruction or experience? Recently, I came across a discussion on the internet by a 46-year-old electrical engineer in California who proposed that he could do just that. He said he had “tons of hours” on his flight simulation software and felt confident that he could fly an airplane around the pattern and land it safely.
I read his posting and the discussion it generated with great interest, and I even chimed in with my opinion. Flying a real airplane with only simulator experience isn’t impossible (the “Barefoot Bandit” apparently did it), but I have to think it’s extremely rare, and was firmly of the belief that this guy wouldn’t be successful. My reasoning was that the simulation software just doesn’t give the feel of the controls and the aerodynamic load on the control surfaces, which will change depending on the airspeed. Also, the software provides an artificially stable experience, whereas flight in a real airplane will provide completely different sensations.
The guy proposing this experiment, Tyler Sparks, already had an instructor lined up to fly with him, but as the online discussion continued, it seemed as if the flight would never take place. Finally, he posted that the instructor had backed out. At this point I was so interested in the experiment that I volunteered to be the instructor/safety pilot. There was no doubt in my mind that I’d have to take over the plane, but I wanted to see just how well he could do on his first time in a plane.
The basic rules for the experiment were laid out by Tyler in the first post of his online discussion:
The rules are that he [the instructor/safety pilot] will do all the preflight checks and the plane will be ready to go. He will communicate with the tower for clearance and such, and will taxi us out to the runway and line me up for take off. Weather will have to be clear and calm. After that, he can’t say or do anything to assist me, from the moment I push in the throttle. If we encounter any other air traffic, which is unlikely at this location, he will take over and, steer us clear, then I’m back on the controls. Once I (hopefully) land, he would take over and taxi us back to the parking area.
I talked to Tyler the week before heading out, just to cover some basics about the flight. The most important thing to me was his clear understanding that my main concern was safety and preventing any damage to the airplane. It was agreed that if I said “I have the airplane” at any time during the flight, he would relinquish controls without hesitation or discussion.
I flew out to meet him the day after Thanksgiving, and admit that I had some misgivings. There was really not much upside to this trip for me, other than satisfying my curiosity, and lots of downside if anything went wrong. Our rendezvous at the airport went as planned, and I was relieved to find that my initial impression from our phone conversations was confirmed. Tyler wasn’t some crazy kid. He was intelligent and very personable, and right away I felt better about my decision to participate.
We discussed the flight, reconfirming the “rules of engagement,” and it was agreed he would pick me up at 8:30 the next morning. I’ll post the rest of the story next week…
November 14, 2012
The movie trailer intrigued me. A plane in distress is put down in an open field by a great pilot who uses a very unusual maneuver to save the day: He rolls the plane inverted to arrest an uncontrolled dive, saving 96 of the 102 “souls on board.” Denzel Washington plays the Captain, “Whip” Whitaker, in Flight and that’s enough reason for me to see the movie (big Denzel fan). So I headed off for a Saturday matinee, fully expecting that this movie, like almost every aviation movie I’ve ever seen, would take some liberties with the technical aspects of the flying scenes. I wasn’t disappointed.
The plane is a JR-88, a type that exists only in the mind of a screenwriter. It looks suspiciously like an MD-88, but I suppose when you’re making a movie about an aviation disaster you don’t want the liability of naming an actual type of plane. It’s a rainy morning in Orlando, and Captain Whitaker is completing his pre-flight walkaround inspection of the plane. That’s when the movie loses all credibility for me. Very few captains perform any walkaround, and virtually no captain will do one in the rain.
The cockpit is authentic, and it’s definitely an MD-80 variant. The Air Traffic Control (ATC) chatter is pretty realistic, if not perfect, and the crew coordination on takeoff and climb is also not bad. But then they encounter some rough weather, and things start to go Hollywood. Whip decides to penetrate this weather in a very unconventional way. For some reason he decides to stay low and push the speed up until the plane is hitting the max allowable speed, indicated on the airspeed indicator by a “barber pole.” The First Officer (FO) brings the excessive speed to his attention, but Whip isn’t deterred, and applies even more power.
In the real world, the pilots would have been thinking much farther ahead, trying to avoid the weather displayed on their weather radar. After encountering rough air, one of the first things we do is reduce speed to soften the bumps. (Much like riding on a bumpy road in your car, the effect of the bumps is amplified if you go faster.) At this low altitude, we would use a speed of 290 knots to get a better ride. Flying that close to the “barber pole” in that kind of turbulence not only makes for a very uncomfortable ride, but also exposes the plane to potential structural damage.
After successfully penetrating the weather and finding smooth air, Whip’s plane is cruising at 30,000 feet when the plane begins an uncontrollable dive. You can hear the audio warning “SINK RATE, SINK RATE,” which is a warning that would only occur if the plane is down low and descending too fast. Up at altitude we can, and do, descend at rates that would be unacceptable when in the approach phase of flight. We sometimes descend at rates in excess of 4,000 feet per minute if necessary for ATC, or to make a crossing restriction. We don’t want to get meaningless warnings about this, so the system is programmed to inhibit these alerts when we’re more than 2,500 feet above the ground.
A number of things happen at this point in the movie that a good technical adviser could have caught. For one, Whip directs the FO to dump fuel. I think I heard him say that they needed to reduce the weight of the plane, but this wouldn’t really be a consideration in this situation. I guess one conceivable reason you might want to dump fuel is to minimize the amount on board to feed a post-crash fire, but the MD-88 doesn’t even have fuel dump capability (though perhaps the JR-88 does).
Whip then tells ATC that they’ve lost hydraulics to the elevator. Maybe in the make-believe JR-88, but the MD-88 doesn’t have hydraulically powered flight controls. It’s all cables and pushrods moving control tabs on the elevator, rudder, and ailerons. Next, he directs the FO to put the flaps down. I’m not sure what this would accomplish, other than to cause structural damage to the flaps and maybe even rip them off the plane. The flaps have maximum speeds associated with each setting and we’re very careful not to exceed these limitations.
As if things weren’t bad enough, they now have a fire in the left engine—a pretty random occurrence that doesn’t seem related in any way to the mechanical difficulty they’re having with the plane’s elevator. They’re just having a really bad day. Whip directs the FO to “put out the fire,” and he dutifully pulls the fire handle for the left engine. This action shoots halon into the burning engine to put out the fire, but that’s not all it does. It also isolates the engine, closing the fuel valve, hydraulic valve, and pneumatic valve associated with that engine. In other words, it shuts down the engine. (All airliners work this way, and this function of the fire handle is part of the certification requirements for transport category airplanes.) But in the movie, the engine keeps running.
Minutes later they have a fire in the right engine! Wow, this is a really, really bad day. The chances of two independent engine fires right on the heels of a catastrophic flight control failure are just astronomical. So rare, in fact, that we don’t ever train for these kind of compound failures. Whip directs the FO to put out this fire, and he pulls the fire handle for the right engine. If you did this in the real world, things would get very quiet as you would now become a glider, with no engines running. If this really happened, we’d let that second engine burn because we’d need the power from it to continue flying.
And now we get to the fantastic display of airmanship by Whip. He rolls the plane inverted while directing the FO to retract the flaps and directing one of the flight attendants to pull a mysterious handle on the center console “on the count of three.” I’m not sure what that handle did. If he explained it, I missed it. But I’m very familiar with the MD-88 cockpit, and I don’t remember any such handle. He also directs her to push the throttles forward during this maneuver. After flying inverted for a a brief time, he rolls back to normal flight attitude just in time to crash land in an open field.
Could this maneuver actually work? It’s an imaginative premise. They were in a situation where the elevator was locked in a position forcing a nose-down pitch attitude, which caused a rapid dive. By going inverted, the nose will be pointed skyward, but there would still be no control of the pitch. With enough power, the plane would now climb skyward under negative G’s, but the pitch attitude would still be uncontrollable. In such a desperate situation I guess it would be worth a try. As I watched the movie, I found myself willing to suspend disbelief and just go along with Whip’s fantastic flying ability. But even superb flying can’t overcome unresponsive controls.
In the aftermath of the accident, the NTSB determines the cause of the dive to be a mechanical defect in a jackscrew that moves the elevator trim. This is taken from a real-life accident which occurred in January 2000, when Alaska Air Flight 261, an MD-83, suffered just such a failure of the jackscrew, causing a loss of pitch control. At one point, that crew actually attempted to arrest the dive by going inverted, but the plane continued to descend at a rate in excess of 13,000 feet per minute and crashed into the Pacific Ocean.
Watch the movie trailer, below:
August 10, 2012
The autopilot has to be one of the greatest inventions to come down the pike for pilots. The first plane I owned (actually I owned half of it), was a 1969 Cherokee 180D, N7728N, and it had a very rudimentary autopilot. It could hold a heading that I set with a moveable “bug” on the directional gyro. It wouldn’t hold altitude, and it sure wouldn’t fly an instrument landing. But just the ability to hold heading was a great thing to have, especially when flying alone in the clouds. It allowed me to consult my maps without worrying about drifting off heading or entering a gradual spiral.
The autopilots in modern jet aircraft can fly the plane from shortly after takeoff all the way to landing. But contrary to the image that many people have, it’s not just a matter of pressing a button, then forgetting about it (despite the old pilot’s joke when engaging the autopilot, “Let George fly it.”) In truth, the pilot tells the autopilot what to do throughout the flight by setting inputs for both the lateral and vertical modes.
The minimum altitude at which the autopilot may be engaged varies among airlines. My company’s minimum is 200 feet, but I don’t think I’ve ever seen a pilot engage it that low. Occasionally I’ll see someone engage it by 1,000 feet, but most pilots hand-fly the plane until much higher, often above 18,000 feet.
Once engaged in LNAV (lateral navigation), the autopilot will follow the entire flight plan that’s been loaded into the plane’s computer. The third dimension, altitude (vertical navigation, or VNAV), will also be flown according to the flight plan, but no altitude change occurs until the pilot sets the desired altitude on the mode control panel (the “dashboard”).
The autopilot does an excellent job of delivering a very smooth flight, and its use frees up the pilots to manage and monitor the flight. For the majority of the flight, the pilots’ involvement in flying the plane is initiating altitude changes, occasionally deviating from the planned flight path (e.g. due to weather) by flying in heading mode (as opposed to LNAV mode), and making changes to the stored flight plan in response to clearances from ATC (e.g. “You are cleared direct to Albany” or “After Brickyard, proceed direct Wilkes-Barre VOR”).
Most pilots will turn off the autopilot and hand fly the approach and landing. I’ve occasionally clicked it off as high as 20,000 feet, but usually I’m somewhere below 5,000 feet. Many modern planes have autoland capability, the ability to fly an ILS right down to landing. Using this feature is not just a matter of watching it happen. The pilots must configure the plane with flaps and landing gear, as well as ensuring that it slows to the proper speeds.
You might think we’d use this capability a lot, but most pilots like landing the plane themselves, and I’ve only used autoland one time in a real-world situation of very low visibility (fog at LAX; we could barely see the taxiway lights after landing as we made our crawl to the gate). Sometimes our flight plan will contain a remark from the dispatcher asking us to perform an autoland in order to keep the plane certified for this capability, and in this case we will grudgingly comply if the winds and runway in use allow it. We always remain ready to take over in case it doesn’t perform satisfactorily.
Lately, there’s been some concern that reliance on automation is eroding the basic skills of pilots. There is some truth there. My first airline job was flying the Jetstream 32, a 19-seat turboprop. I remember being amazed that it had no autopilot whatsoever, not even something as simple as a bug tracker like the one I had in my Cherokee 180. I hand flew that plane for five years, and I can honestly say that my flying skills and instrument scan probably peaked during that time. Hand flying five to eight legs a day, down low in the weather in the northeast corridor, will hone one’s flying skills.
Contrast this with my situation a couple of years ago, when I was on a steady diet of international flights. I would fly four trips a month, for a total of eight ocean crossings. With a three-man crew, I would be lucky to be the flying pilot on three of those flights, and often I would only get two takeoffs and landings in a month. In my turboprop days, I would sometimes get twice that number in a single day.
But the thing is, if you reach a certain experience level you’re not going to forget the basics, just like riding a bike. The problem today is that pilots new to the industry are starting right out in very sophisticated jets with glass cockpits, and, of course, a fully capable autopilot. The training focuses on using the automation, and less emphasis is placed on hand flying and the use of raw data. For a generation raised on computers and video games, mastery of this equipment comes quickly. But I sometimes wonder if the stick and rudder skills are there.
July 27, 2012
There’s an old saying that every student pilot has heard at some point in their training: “The three most useless things to a pilot are the runway behind them, the altitude above them, and the fuel they left behind.”
Pilots love to have lots of fuel, but it’s expensive to carry excessive amounts (called “tankering” in the biz), and the company doesn’t like to spend money unnecessarily. Federal Aviation Regulations (FARs) dictate the minimum fuel loads required for a flight. For domestic operations, we must carry enough fuel to reach the destination airport, then fly to the most distant alternate airport (a suitable field selected based on weather forecasts), and then fly at normal cruise speed for another 45 minutes. (If you want to read the actual regulation for airlines, see FAR 121.639; for general aviation flights, see FAR 91.151 and FAR 91.167) In many cases, the company will pad this amount with “Contingency fuel” which is just what it sounds like, i.e., just a little extra for more options.
Fuel became an issue on one of my recent flights. We were flying from LAX to JFK, and it looked like we’d be about 20 minutes early. We were within an hour of landing and the weather looked good in New York, so it came as a surprise when New York Center gave us holding instructions. This was particularly unexpected since we were still at our cruise altitude of 39,000 feet. Most airborne holding occurs down lower, when we’re closer to the destination airport. The reason for the holding was weather on the arrival route.
The holding instructions were: “Hold northwest of the HOXIE intersection on J70, right hand turns, 20 mile legs. EFC 1850Z. Reduce speed at your discretion.” [HOXIE is one of thousands of aviation fixes in the country, simply defined as a Lat/Lon; they all have five character names. J70 is a defined route for high altitude traffic, a "highway in the sky."] We brought the power back a little to save fuel, slowing to about 240 knots indicated airspeed — still a safe speed for our clean (no flaps) configuration. Our true airspeed (TAS) was still around 445 knots. We programmed the FMC (Flight Management Computer) for the hold, then got to work developing a plan in case we couldn’t get in to JFK. These can be some of the busiest situations in airline flying, as we have to continuously monitor the weather situation and our fuel state.
The EFC is the “Expect Further Clearance” time. This is an important part of the clearance. If we were to lose communications, we would hold until that time and then proceed according to our flight plan, knowing that ATC would clear the path for us. It also gives us an idea of how long ATC expects us to hold, but that can vary significantly either way. I’ve been released from holding before completing one turn, and other times I’ve reached the EFC time only to be given a revised, much later, EFC.
As we made the first turn at HOXIE, I made the required call to ATC to let them know we were entering the hold. Then I got on the PA to let the passengers know what was going on. I’m sure there were a lot of groans in the cabin at that point, as everyone with connections started wondering just how bad the rest of their day was going to be. We looked at several possible divert airports, and Buffalo looked like the best option based on weather reports and proximity. It was within 100 miles of the hold, which is very close when you’re at 39,000′, so things would get busy if we decided to go there. We decided on a “bingo” fuel figure, i.e. the least amount of fuel we felt comfortable with before diverting. Then we got out the charts for Buffalo.
After about three turns in the holding pattern, the controller called to revise our EFC, making it 1920Z. We could now plainly see that we would reach our minimum fuel before the EFC. This might seem to dictate making the diversion now rather than waiting — why burn fuel for no good reason? — but again, it’s not unusual to be released from the hold prior to the EFC. Just to keep ATC in the loop, we let the controller know that we would have to divert before reaching the EFC and that Buffalo was our planned diversion airport. At this point, I was pretty sure we’d be shuffling off to Buffalo to refuel and wait out the weather.
Then, as often happens, New York Approach started accepting arrivals and we were given clearance to continue on our flight plan route. We advised our dispatcher via ACARS (Aircraft Communications Addressing and Reporting System, a sort of on-board email system) that we were continuing towards JFK. This gets to be the tricky part, because we aren’t really assured of making it into JFK but now we’re getting farther from the alternate and burning more fuel. Our dispatcher calculated that we should have at least 11,000 lbs of fuel on board to divert from JFK to Buffalo with comfortable margins, and we concurred. If that did become necessary, we’d refuel at Buffalo and wait out the weather.
It was apparent as we continued to JFK that we would be going below that 11,000 pound number before landing. If it had been night with no other obvious options, we very likely would have just headed to Buffalo rather than get ourselves into a situation where our options disappeared. But in this case, it was mid-afternoon with good visibility for us and we could plainly see all of the scattered build-ups of cumulonimbus clouds. There were other suitable airports much closer to JFK (e.g. Bradley and Providence), and we could see that the weather was better to the north.
Approach control vectored us for the ILS to Runway 22L, and when it was all over, we shut down with just over 9,000 pounds of fuel — well above what would even be considered a “minimum fuel” state. (In the 757, we would declare “minimum fuel” when getting down to 4,500 lbs; we would declare “emergency fuel” at 3,500 lbs.] We were about an hour late, and it’s likely that some passengers missed their connections, but there was very little grumbling as they deplaned. Most reasonable people understand that there are factors out of our control.
As I walked off the plane, heading to the crew room, I heard one woman asking the gate agent how to get to terminal three. I volunteered to be her guide since I was heading that way. She had a connection for Moscow, scheduled for 4:10 pm. It was already after 4:00 but maybe the Moscow flight was late due to the weather. It was a long walk, but I got her to the gate and the flight was late. So I know of at least one passenger who got to where she wanted to be that night.
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