Sterile cockpits are distraction-free cockpits. And I'm not talking about a sparkling yoke and throttle with "sanitized for your protection" ribbons around the front seats. And, no, a sterile cockpit does not mean the crew is prohibited from using bad words or conversing about unwholesome topics at all times on the flight deck. A sterile cockpit is a cockpit without non-operational chatter, usually during taxi, takeoff and climb, and approach and landing. In more general terms, sterile cockpit is utilized in the vicinity of an airport and during high workload and high risk phases of flight. It's also used during in-flight emergencies.
I'll provide a little more detail for those pilots who are not familiar with the sterile cockpit concept. In simple plain language, sterile cockpit requires the pilot(s) and passengers (if not separated by a door or isolating intercom system) to refrain from engaging in non-essential discussion that is not directly related to the operation of the aircraft or safety of flight. For instance, talking about high fuel prices on short final would be a violation of sterile cockpit, but a co-pilot or first officer alerting the captain to wildlife on the runway would not be a violation. The cockpit is considered "sterilized" when the only conversation between crew and, if applicable, passengers is restricted only to the task at hand and nothing else. The idea here is to eliminate distractions in the cockpit during critical phases of flight.
Many aviation regulations and airline policies were "written in blood," meaning the new rules were born in response to a serious incident or crash. Sterile cockpit regulations are no exception. Airlines started using sterile cockpit procedures after a series of aircraft accidents occurred where the crew could be heard discussing non-essential (sometimes utterly unrelated) items on the cockpit voice recorder shortly before the crash. The distraction created by these off-topic conversations was determined to be the leading cause or at least significant link in the accident chain of these crashes. The FAA and airlines decided that crews must be required to focus solely on the operation of the aircraft during key phases of flight to prevent future distraction-related accidents. Airline crews now typically must maintain sterile cockpit from pushback through taxi, takeoff, and initial climb. The crew may elect to suspend sterile cockpit after passing 10,000 feet MSL. The reverse applies on descent and arrival. Sterile cockpit must be resumed below 10,000 feet and remain in effect until shutdown. The sterile cockpit rule seems to have helped reduce distraction-related accidents, although there have still been a few over the years, usually where crews were violating sterile cockpit and forgot to carry out certain checklist items, etcetera. The recent crash of Colgan 3407 is a prime example of a blatant and intentional violation of sterile cockpit procedures resulting in distraction causing the crew to forget an important checklist item. Some will contend that this wasn't the primary reason for the crash, and I agree, but it was certainly an important link in the chain of events that led to the loss of control.
Pilots of non-transport airplanes typically do not use sterile cockpit procedures because their use is not currently required by regulation. That is unfortunate, and I believe all pilots should use and enforce these anti-distraction procedures. Because light airplanes lack the explicit guidance that the airlines receive about where and when to use sterile cockpit, pilots of these airplanes should create their own policies and brief their passengers on them before every flight. My sterile cockpit begins at engine start and remains in effect through taxi, run-up, takeoff, and initial climb. It may be suspended after ten miles from the departure airport unless the aircraft is penetrating complex airspace or there is some other special circumstance that requires additional quiet time. Many light airplanes cruise below 10,000 feet MSL and climb more slowly than airline jets, so using the airlines' protocol of maintaining sterile cockpit at all times below 10,000 feet doesn't work. It's better to think in terms of lateral distance for us since we don't fly as high. On descent and arrival I'll resume sterile cockpit within ten miles of the arrival airport and maintain it during approach, landing, and taxi in until the engine is shutdown. I always include a sterile cockpit portion in my pre-flight briefing to my passengers informing them that all chit-chat must be put on hold during sterile times, and if they see something that they think directly relates to safety of flight to tell me. I let them know that I'll tell them when sterile cockpit periods begin and end. Remember, you're the pilot in command and it's your responsibility to brief your passengers on these things. This is important information, and these procedures are designed to keep you and your passengers alive.
Sterile cockpit procedures should be used routinely every flight, even at your home field where you know every crack in the taxiway. Familiarity often leads to complacency, and complacency very often leads to accidents. And just because you're familiar with the airport doesn't mean the pilots in the airplane that just landed are, and they could make a wrong turn onto your runway during your takeoff run. The FAA has deemed runway incursions as a safety hot spot in recent years, and most runway incursions are caused by GA airplanes. Maybe part of the reason for this is because most GA guys don't use sterile cockpit procedures. Most runway incursions are caused by crew distraction. Engaging in unrelated banter as you cross an active runway is a bad idea, and even if you think you're a good multi-tasker you're still a human, and the human brain works best when all of its resources are devoted to only the task at hand. Once off the ground, sterile cockpit is just as important for purposes of collision avoidance as well as checklist tasks and initial navigation and air traffic control communication.
Sterile cockpit procedures are another great idea gleaned from the airlines for GA pilots. The idea behind these procedures is that a human brain does a better job of keeping the flight safe when all its resources are as undivided as possible. Distractions don't belong in cockpits. A sterile cockpit yields a sterile mind, and sterile minds are less likely to crash airplanes.
Saturday, June 13, 2009
Friday, June 12, 2009
Stabilized Approach
Last summer I flew in the back of an MD-80 on my way to Florida by way of Dallas/Fort Worth International Airport. I was seated over the wing and I watched as the ailerons and roll spoilers flapped about rhythmically all the way down final until touchdown on DFW's Runway 17 Center. Like many other airline flights I've been on, I also noticed large pitch and power excursions which intensified as we progressed toward the runway. As I'm sure many of my readers have done, I've also watched many YouTube videos of airliner landings, recorded both from the passenger cabin and from the flight deck, and I've seen this happening in the majority of these videos. I enjoy the flight deck videos because I'm often able to observe the pilot flying pushing, pulling, turning, and tussling with the yoke all the way down final. Of course, many general aviation pilots fly approaches this way, too. But, there's a better way.
I feel that the approach and landing phase reveals a great deal about a pilot's ability to be master of his or her machine. It is the phase of flight which requires proper technique to be executed correctly with efficiency and grace, and any imperfections in flying technique are often revealed here. This is because while approaching a runway the pilot has a target: the aiming point on the runway. And during landing the pilot must contact a very fixed and very unforgiving runway gently and at the correct spot and speed. This kind of precision usually is not required during any other phase of flight. Landing is one of the most difficult things we pilots do, and the accident statistics concur. Approach and landing accidents represent a large chunk of total accidents; luckily, many are not fatal. Accident data also indicates that many approach and landing accidents are the result of unstabilized approaches.
A stabilized approach is defined as the airplane being established on the proper glide (airspeed, power setting[s], and descent angle) and track, and minimal, if any, control inputs from the pilot are necessary. That means the airplane is at the appropriate approach speed (or landing reference speed when closer in), at a constant power setting which produces the proper glide angle, on a constant heading that will keep the airplane aligned with the runway, and in the proper aircraft configuration. Wind correction should also be included depending on the airplane or pilot technique (crab or wing-low method). Once you're established and the airplane is on power and in trim, sit back and ride the invisible glide rails to the aiming point where the flare should begin. Very minimal control input should be needed until it's time to change things for the flare maneuver. If you find yourself wrestling with the yoke, rudder pedals, and throttle(s) just remember that somewhere nestled inside all that frantic movement is the proper control position. Usually, only one fixed magic spot on the yoke exists until the flare. The same is true for the throttle(s) and rudder pedals. When you slop the flight controls around in incessant movement all the way down final you're engaging in a series of over-correcting oscillations. This will still get you to the runway, but with much wasted energy, sloppy flying technique, a greater chance of a bad or dangerous landing, and uncomfortable passengers. You'll also waste fuel if you're constantly changing power settings because when you do this you're continuously slowing down then speeding back up. Hidden right in the middle of those oscillations is the proper value, and all you need to do is set the power there and leave it alone. If it were possible to mathematically average, for instance, pitch oscillations that occurred during a sloppy approach, we'd find the single proper pitch attitude that would've sent the airplane to exactly the same place in space but without all the ups and downs. Tiny power changes might be required every now and then to keep the airplane on the proper glide path, but they should be small and few and far between. Try watching an approach video recorded from the flight deck on YouTube in time lapse by dragging the video progress ball forward manually. When the video is sped up the pitch and roll excursions become easier to see, and it appears as though the airplane is "homing" on the runway like a missile gyrating toward its target. Things get a whole lot easier and more efficient if you just take the direct route to the runway instead of constantly making minute changes to heading, pitch attitude, airspeed, and power setting(s).
For a given set of circumstances (aircraft weight, air density, wind, required glide angle, aircraft configuration) there is always a singular exact proper position for the ailerons, elevator (or stabilator), rudder, and power setting(s). This is the essence of the stabilized approach. Dipping, swooping, banking, and deviating from proper glide path and airspeed is nothing other than sloppy flying, and it's unnecessary. If you need more convincing, I've got an experiment for you to try. If your airplane is equipped with an approach capable autopilot, take it out and let it fly an ILS approach to two hundred feet. You'll still have to set the power manually (unless you fly an auto-throttle equipped jet!), so set it at the appropriate value and do not change it for the rest of the approach. Observe as your autopilot flies the approach, perfectly stabilized with extremely little control movement. If your autopilot can do it, so can you.
The only exception to all of this, of course, is when gusty winds are about. During those conditions the wind direction and velocity may be constantly shifting, therefore renewed control application will be required on a second-by-second basis. There is nothing improper about that, and your autopilot would do it the same way. In smooth (or mostly smooth) air, though, there's no excuse for imposing a hand and feet spasm on the flight controls. The only time an approach calls for constantly changing control inputs is when the wind is also constantly changing. If the wind is calm, your hands and feet should be, too.
Most airlines have policies regarding stabilized approaches. For instance, a policy might require that the airplane be "in the slot" (stabilized on speed, on glide path, and properly configured) by five hundred feet above the surface. If the approach is not stabilized by five hundred feet the crew must execute a mandatory go-around. These policies are great and are aimed at reducing landing accidents. Pilots of general aviation airplanes should use these guidelines, too. Our go-around altitudes can be lower, perhaps two hundred feet, since we're not required to reverse as much inertia as jets, but the rest of the requirements should remain the same. If the airplane isn't in the slot at the minimum altitude, go-around and do a better job on the next approach.
Next time you find yourself harassing the flight controls take a moment to intentionally stop all yoke movement. You'll probably find that the approach continues in about the same way as it was with all the man-handling, so really all you were accomplishing was releasing some of your nervous energy, which, ironically, was probably being produced by your insecurity about landing an airplane. Good airmanship involves a gentle touch. A pilot should never "wrestle" his airplane, only the wind and weather. The airplane is on your side, so keep the communication lines open and listen to what it is telling you. Your approaches will become less stressful and more stabilized.
I feel that the approach and landing phase reveals a great deal about a pilot's ability to be master of his or her machine. It is the phase of flight which requires proper technique to be executed correctly with efficiency and grace, and any imperfections in flying technique are often revealed here. This is because while approaching a runway the pilot has a target: the aiming point on the runway. And during landing the pilot must contact a very fixed and very unforgiving runway gently and at the correct spot and speed. This kind of precision usually is not required during any other phase of flight. Landing is one of the most difficult things we pilots do, and the accident statistics concur. Approach and landing accidents represent a large chunk of total accidents; luckily, many are not fatal. Accident data also indicates that many approach and landing accidents are the result of unstabilized approaches.
A stabilized approach is defined as the airplane being established on the proper glide (airspeed, power setting[s], and descent angle) and track, and minimal, if any, control inputs from the pilot are necessary. That means the airplane is at the appropriate approach speed (or landing reference speed when closer in), at a constant power setting which produces the proper glide angle, on a constant heading that will keep the airplane aligned with the runway, and in the proper aircraft configuration. Wind correction should also be included depending on the airplane or pilot technique (crab or wing-low method). Once you're established and the airplane is on power and in trim, sit back and ride the invisible glide rails to the aiming point where the flare should begin. Very minimal control input should be needed until it's time to change things for the flare maneuver. If you find yourself wrestling with the yoke, rudder pedals, and throttle(s) just remember that somewhere nestled inside all that frantic movement is the proper control position. Usually, only one fixed magic spot on the yoke exists until the flare. The same is true for the throttle(s) and rudder pedals. When you slop the flight controls around in incessant movement all the way down final you're engaging in a series of over-correcting oscillations. This will still get you to the runway, but with much wasted energy, sloppy flying technique, a greater chance of a bad or dangerous landing, and uncomfortable passengers. You'll also waste fuel if you're constantly changing power settings because when you do this you're continuously slowing down then speeding back up. Hidden right in the middle of those oscillations is the proper value, and all you need to do is set the power there and leave it alone. If it were possible to mathematically average, for instance, pitch oscillations that occurred during a sloppy approach, we'd find the single proper pitch attitude that would've sent the airplane to exactly the same place in space but without all the ups and downs. Tiny power changes might be required every now and then to keep the airplane on the proper glide path, but they should be small and few and far between. Try watching an approach video recorded from the flight deck on YouTube in time lapse by dragging the video progress ball forward manually. When the video is sped up the pitch and roll excursions become easier to see, and it appears as though the airplane is "homing" on the runway like a missile gyrating toward its target. Things get a whole lot easier and more efficient if you just take the direct route to the runway instead of constantly making minute changes to heading, pitch attitude, airspeed, and power setting(s).
For a given set of circumstances (aircraft weight, air density, wind, required glide angle, aircraft configuration) there is always a singular exact proper position for the ailerons, elevator (or stabilator), rudder, and power setting(s). This is the essence of the stabilized approach. Dipping, swooping, banking, and deviating from proper glide path and airspeed is nothing other than sloppy flying, and it's unnecessary. If you need more convincing, I've got an experiment for you to try. If your airplane is equipped with an approach capable autopilot, take it out and let it fly an ILS approach to two hundred feet. You'll still have to set the power manually (unless you fly an auto-throttle equipped jet!), so set it at the appropriate value and do not change it for the rest of the approach. Observe as your autopilot flies the approach, perfectly stabilized with extremely little control movement. If your autopilot can do it, so can you.
The only exception to all of this, of course, is when gusty winds are about. During those conditions the wind direction and velocity may be constantly shifting, therefore renewed control application will be required on a second-by-second basis. There is nothing improper about that, and your autopilot would do it the same way. In smooth (or mostly smooth) air, though, there's no excuse for imposing a hand and feet spasm on the flight controls. The only time an approach calls for constantly changing control inputs is when the wind is also constantly changing. If the wind is calm, your hands and feet should be, too.
Most airlines have policies regarding stabilized approaches. For instance, a policy might require that the airplane be "in the slot" (stabilized on speed, on glide path, and properly configured) by five hundred feet above the surface. If the approach is not stabilized by five hundred feet the crew must execute a mandatory go-around. These policies are great and are aimed at reducing landing accidents. Pilots of general aviation airplanes should use these guidelines, too. Our go-around altitudes can be lower, perhaps two hundred feet, since we're not required to reverse as much inertia as jets, but the rest of the requirements should remain the same. If the airplane isn't in the slot at the minimum altitude, go-around and do a better job on the next approach.
Next time you find yourself harassing the flight controls take a moment to intentionally stop all yoke movement. You'll probably find that the approach continues in about the same way as it was with all the man-handling, so really all you were accomplishing was releasing some of your nervous energy, which, ironically, was probably being produced by your insecurity about landing an airplane. Good airmanship involves a gentle touch. A pilot should never "wrestle" his airplane, only the wind and weather. The airplane is on your side, so keep the communication lines open and listen to what it is telling you. Your approaches will become less stressful and more stabilized.
Saturday, June 6, 2009
Follow the Leader
On July 9, 1982 a Boeing 727 crashed shortly after takeoff from New Orleans International Airport. All aboard were killed plus eight people on the ground, and six houses were destroyed. There was a thunderstorm in progress at the airport as the flight rolled down runway 10. Almost immediately after the airplane lifted off a microburst violently slammed it right back down. Similar-type airplanes had successfully taken off ahead of the 727, and the crew's decision to takeoff in questionable weather conditions seems to have been influenced by this. They must've thought, "If they made it, so can we." They were wrong. One hundred and forty-six people died as a result of their mistake. This is not the only accident of this nature.
Humans are pack animals. Deep down inside of us is thousands of years of conditioning that leads us to believe if other people are doing it, it must be okay for us to do too. This primitive "follow the leader" instinct can lead pilots into dangerous situations if it goes unchecked. In New Orleans that day there were other pilots who decided to takeoff despite the risky weather conditions. When I read this accident report I could almost see the thought bubbles above the crew thinking, "Well, everyone else is doing it." Think of this as subconscious peer pressure. These pilots took comfort in the fact that other aircraft had successfully taken off right before them, and they became falsely reassured that they could do the same. Their pack instincts clouded their decision making and these pilots failed to accurately and objectively assess the risk level associated with the current weather conditions affecting their takeoff. The result was disastrous.
Weather is extremely dynamic. It changes quickly and sometimes unexpectedly. It is not bound by rules and regulations, and no matter how badly we want it to behave a certain way it will never oblige. Don't expect it to. The weather is in charge of us, not the other way around. Just because ten airplanes on approach ahead of you successfully negotiated a windy and turbulent final during a thunderstorm does not in any way suggest that you will be able to do the same. Just imagine you're the only aircraft in flight at that moment and think about what you would do. This will help you manage the hazardous "follow the leader" mentality and make a wise and healthy decision. Objectivity is key. Don't think about the King Air ahead of you that just landed successfully. You're not him, you're you, and the weather Mother Nature has prepared for you may be completely different than the weather the King Air encountered. Thunderstorms especially are a rapidly changing weather phenomenon and can produce extremely dangerous conditions that weren't present a mere sixty seconds earlier. Microbursts, one of the most lethal byproducts of heavy precipitation, can form quickly and unexpectedly, and many airliners have been lost to microbursts over the years because pilots forged their way into dangerous weather because, after all, everyone else was doing it. Sometimes nature is picky and will only choose one aircraft out of a large stack of inbounds to have its way with. The guy before you could've made it, and the guy after you could make it. That means nothing about your circumstances, so eject this piece of information from your decision making process when it comes to questionable weather situations.
I once watched a video recreation of an incident which occurred at the Daytona Beach International Airport involving a formation flight of several general aviation airplanes. The tower cleared the flight to land then watched as the formation leader inadvertently landed on a taxiway parallel to the assigned runway. Each of the other airplanes then followed the leader landing one after another on the same taxiway. The tower tried several times to interrupt the sequence but none of the pilots listened. Clearly these pilots were under the influence of "pack blindness," thinking not for themselves as they should've been but as one big defective group of pilots. This is the same mental phenomenon that leads pilots into dangerous weather instead of objectively and honestly evaluating the current weather affecting their airplane.
Our pack animal instincts must be managed while flying. As aviation hero Richard L. Collins says, "Weather is what you get, not what you expect to get." The more realistic our expectations are, the better prepared we will be to handle the actuality of the circumstances affecting our flight instead of resisting them with futility. And remember, following the leader may lead you directly into the lion's den.
Humans are pack animals. Deep down inside of us is thousands of years of conditioning that leads us to believe if other people are doing it, it must be okay for us to do too. This primitive "follow the leader" instinct can lead pilots into dangerous situations if it goes unchecked. In New Orleans that day there were other pilots who decided to takeoff despite the risky weather conditions. When I read this accident report I could almost see the thought bubbles above the crew thinking, "Well, everyone else is doing it." Think of this as subconscious peer pressure. These pilots took comfort in the fact that other aircraft had successfully taken off right before them, and they became falsely reassured that they could do the same. Their pack instincts clouded their decision making and these pilots failed to accurately and objectively assess the risk level associated with the current weather conditions affecting their takeoff. The result was disastrous.
Weather is extremely dynamic. It changes quickly and sometimes unexpectedly. It is not bound by rules and regulations, and no matter how badly we want it to behave a certain way it will never oblige. Don't expect it to. The weather is in charge of us, not the other way around. Just because ten airplanes on approach ahead of you successfully negotiated a windy and turbulent final during a thunderstorm does not in any way suggest that you will be able to do the same. Just imagine you're the only aircraft in flight at that moment and think about what you would do. This will help you manage the hazardous "follow the leader" mentality and make a wise and healthy decision. Objectivity is key. Don't think about the King Air ahead of you that just landed successfully. You're not him, you're you, and the weather Mother Nature has prepared for you may be completely different than the weather the King Air encountered. Thunderstorms especially are a rapidly changing weather phenomenon and can produce extremely dangerous conditions that weren't present a mere sixty seconds earlier. Microbursts, one of the most lethal byproducts of heavy precipitation, can form quickly and unexpectedly, and many airliners have been lost to microbursts over the years because pilots forged their way into dangerous weather because, after all, everyone else was doing it. Sometimes nature is picky and will only choose one aircraft out of a large stack of inbounds to have its way with. The guy before you could've made it, and the guy after you could make it. That means nothing about your circumstances, so eject this piece of information from your decision making process when it comes to questionable weather situations.
I once watched a video recreation of an incident which occurred at the Daytona Beach International Airport involving a formation flight of several general aviation airplanes. The tower cleared the flight to land then watched as the formation leader inadvertently landed on a taxiway parallel to the assigned runway. Each of the other airplanes then followed the leader landing one after another on the same taxiway. The tower tried several times to interrupt the sequence but none of the pilots listened. Clearly these pilots were under the influence of "pack blindness," thinking not for themselves as they should've been but as one big defective group of pilots. This is the same mental phenomenon that leads pilots into dangerous weather instead of objectively and honestly evaluating the current weather affecting their airplane.
Our pack animal instincts must be managed while flying. As aviation hero Richard L. Collins says, "Weather is what you get, not what you expect to get." The more realistic our expectations are, the better prepared we will be to handle the actuality of the circumstances affecting our flight instead of resisting them with futility. And remember, following the leader may lead you directly into the lion's den.
Glide Range
[A post for curious non-pilots...]
"What happens if the engine quits?" Most pilots have been asked this question at some point during their flying career. It seems that society has been the victim of substantial conditioning on this subject. I wonder if survey statistics have ever been compiled to indicate the leading fear of the average airline passenger. This has got to be the winner. Many people believe certain doom is the only possible result after an airplane loses power in its engine(s). And why wouldn't they? Consider how many movies depict horrifying scenes of airplane crashes caused by engine trouble. Passengers are under the impression that if the engine (or engines) quits, the airplane will fall from the sky like a rock. What a dreadful misapprehension these nervous flyers must live with. Luckily, they're wrong.
Remember making paper airplanes as a kid? Did you ever attach an engine to one of them? Your airplane was nothing more than a folded up piece of paper, yet when you threw it, it didn't fall from your hand like a rock, right? That's because your airplane was aerodynamic. Perhaps its lift-to-drag ratio wasn't quite up to par with the modern airline jet, but it was still aerodynamic and that's what allowed it to travel through the air differently than a rock, pencil, pillow or anything else you could throw across the room. Essentially, you created a glider. Human-flown gliders like the Schweizer 1-26 are flown by pilots everyday without engines. This is because it is not the engine that makes an airplane fly, it's the wings.
As a wing, or airfoil, moves forward through the air it creates lift. This lift makes an airplane fly. The engine (or engines, in the case of large airplanes) is only there to propel the wing forward through the air so that it can produce the lift needed to fly. Once you're off the ground, though, gravity may be substituted to keep the airplane moving forward if the airplane loses engine power. The airplane will come down, yes, but it will do so in a shallow controlled glide in just the same way as it would if the engine was still running but at idle power. Most jets descend with their engines at idle power. The jet is gliding under the influence of gravity. With the help of gravity the momentum of the airplane carries it forward which keeps the wings producing lift. In this way, gravity is acting as a friend. The only possible way for an airplane to drop vertically like a rock is if the wings fall off. In fact, many airplanes are incapable of descending downward at ninety degrees toward the earth with the wings still attached. An airplane is capable of maintaining that angle only for a short time before its airspeed increases to such an extent that the excess lift being produced by the wings either forces the nose back up and/or rips the wings off. Airplanes are designed to fly so well that you can't make one (excluding military jets and aerobatic airplanes) come down steeply without destroying it before impact, engines running or not. When an airplane's engines fail it simply reverts to being a glider.
"Sure, but doesn't one of those big, heavy jets still come down fast because they're so heavy?" No. In fact, the heavier, the better. The heavier the airplane, the greater its momentum and the better the glide performance. Competition glider pilots know this. These pilots load water ballast onto their gliders before takeoff because it allows them to glide farther due to the increased momentum the weight provides. Now, here's something that will blow your mind. The average airline jet can out-glide a hang-glider. In fact, these jets enjoy similar glide performance as some gliders and even birds. This is because jets are so heavy (added momentum) and so slippery (pilot talk meaning aerodynamically "clean" or efficient). A typical wide body airline jet can glide somewhere in the neighborhood of one hundred miles across the surface from a typical cruising altitude. That means if a jet's engines all fail at once (which is incredibly remote) during cruise the airplane can glide one hundred miles before contacting the earth, sometimes farther depending on wind. That leaves lots of room for options. The airplane might be within reach of a suitable runway for a power-off (known as a dead-stick) landing. One hundred miles of glide range is a mere fantasy to a light airplane pilot. Most light airplane pilots use a rule-of-thumb for calculating glide range during an emergency: one mile across the ground for every thousand feet of altitude above the surface. Light airplanes often cruise at altitudes only four or five thousand feet above the surface. That means we typically only count on four or five miles of glide range following an engine failure. Most light airplanes will glide a bit farther than this, but good pilots use this conservative calculation to prevent turning in an unsafe direction to attempt to make a landing site which may end up being out of reach. Light airplanes tend to be inefficient gliders because they're lightweight (less momentum) and dirty (pilot talk meaning aerodynamically inefficient).
Passenger jets are far superior gliders. However, passenger jets in Hollywood movies are notoriously bad gliders. The physics of the cinematic world differ greatly from those of the real world. They're far more unforgiving, havoc-creating, and revenue-generating. Luckily, the real world of flying isn't as exciting. So before you get nervous about an airplane's engines failing, just think about a Boeing 747 gliding from Philadelphia all the way to Washington D.C. with all four engines shut down. I've never seen a rock do that.
"What happens if the engine quits?" Most pilots have been asked this question at some point during their flying career. It seems that society has been the victim of substantial conditioning on this subject. I wonder if survey statistics have ever been compiled to indicate the leading fear of the average airline passenger. This has got to be the winner. Many people believe certain doom is the only possible result after an airplane loses power in its engine(s). And why wouldn't they? Consider how many movies depict horrifying scenes of airplane crashes caused by engine trouble. Passengers are under the impression that if the engine (or engines) quits, the airplane will fall from the sky like a rock. What a dreadful misapprehension these nervous flyers must live with. Luckily, they're wrong.
Remember making paper airplanes as a kid? Did you ever attach an engine to one of them? Your airplane was nothing more than a folded up piece of paper, yet when you threw it, it didn't fall from your hand like a rock, right? That's because your airplane was aerodynamic. Perhaps its lift-to-drag ratio wasn't quite up to par with the modern airline jet, but it was still aerodynamic and that's what allowed it to travel through the air differently than a rock, pencil, pillow or anything else you could throw across the room. Essentially, you created a glider. Human-flown gliders like the Schweizer 1-26 are flown by pilots everyday without engines. This is because it is not the engine that makes an airplane fly, it's the wings.
As a wing, or airfoil, moves forward through the air it creates lift. This lift makes an airplane fly. The engine (or engines, in the case of large airplanes) is only there to propel the wing forward through the air so that it can produce the lift needed to fly. Once you're off the ground, though, gravity may be substituted to keep the airplane moving forward if the airplane loses engine power. The airplane will come down, yes, but it will do so in a shallow controlled glide in just the same way as it would if the engine was still running but at idle power. Most jets descend with their engines at idle power. The jet is gliding under the influence of gravity. With the help of gravity the momentum of the airplane carries it forward which keeps the wings producing lift. In this way, gravity is acting as a friend. The only possible way for an airplane to drop vertically like a rock is if the wings fall off. In fact, many airplanes are incapable of descending downward at ninety degrees toward the earth with the wings still attached. An airplane is capable of maintaining that angle only for a short time before its airspeed increases to such an extent that the excess lift being produced by the wings either forces the nose back up and/or rips the wings off. Airplanes are designed to fly so well that you can't make one (excluding military jets and aerobatic airplanes) come down steeply without destroying it before impact, engines running or not. When an airplane's engines fail it simply reverts to being a glider.
"Sure, but doesn't one of those big, heavy jets still come down fast because they're so heavy?" No. In fact, the heavier, the better. The heavier the airplane, the greater its momentum and the better the glide performance. Competition glider pilots know this. These pilots load water ballast onto their gliders before takeoff because it allows them to glide farther due to the increased momentum the weight provides. Now, here's something that will blow your mind. The average airline jet can out-glide a hang-glider. In fact, these jets enjoy similar glide performance as some gliders and even birds. This is because jets are so heavy (added momentum) and so slippery (pilot talk meaning aerodynamically "clean" or efficient). A typical wide body airline jet can glide somewhere in the neighborhood of one hundred miles across the surface from a typical cruising altitude. That means if a jet's engines all fail at once (which is incredibly remote) during cruise the airplane can glide one hundred miles before contacting the earth, sometimes farther depending on wind. That leaves lots of room for options. The airplane might be within reach of a suitable runway for a power-off (known as a dead-stick) landing. One hundred miles of glide range is a mere fantasy to a light airplane pilot. Most light airplane pilots use a rule-of-thumb for calculating glide range during an emergency: one mile across the ground for every thousand feet of altitude above the surface. Light airplanes often cruise at altitudes only four or five thousand feet above the surface. That means we typically only count on four or five miles of glide range following an engine failure. Most light airplanes will glide a bit farther than this, but good pilots use this conservative calculation to prevent turning in an unsafe direction to attempt to make a landing site which may end up being out of reach. Light airplanes tend to be inefficient gliders because they're lightweight (less momentum) and dirty (pilot talk meaning aerodynamically inefficient).
Passenger jets are far superior gliders. However, passenger jets in Hollywood movies are notoriously bad gliders. The physics of the cinematic world differ greatly from those of the real world. They're far more unforgiving, havoc-creating, and revenue-generating. Luckily, the real world of flying isn't as exciting. So before you get nervous about an airplane's engines failing, just think about a Boeing 747 gliding from Philadelphia all the way to Washington D.C. with all four engines shut down. I've never seen a rock do that.
Monday, June 1, 2009
AF 447
An A330 has been lost with 228 souls on board. The airplane was over the Atlantic Ocean when it encountered convective activity. The cause of the crash is unknown at this time.
My heart is with those lost and their families. What a tragedy.
My heart is with those lost and their families. What a tragedy.
Consequences
If you've read my first series of posts and are now reading this, it means you believe in responsible and disciplined behavior in the cockpit. I suspect there are a great many pilots who've read a few of my posts and opted not to return to read another. Perhaps I have offended some pilots with my blunt observations and harsh conclusions. While I do not intend for my writing to be reacted to in this way, I am not bothered that some readers turn away with disagreement or assaulted egos. I believe in honest reflection and self-assessment, directed both toward myself and other pilots. It is my belief that a good pilot is an honest pilot, and while readers might disagree with some of my comments the pure ones will not resent them because they come only from the bottom of my safety-conscious heart. Those readers who do become offended by my posts should go elsewhere because I suspect most of them aren't the type of pilot I want to interact with anyway. But what gives me the right to make other pilots' business my business? Well, quite a few things.
Some readers may've noticed I've repeatedly mentioned "the innocent folks on the ground" in my first handful of posts. This is a theme you'll continue to see in future posts because it is always at the forefront of my mind. And if you fly airplanes it should always be at the forefront of your mind too. I'm a firm believer in the phrase, "To each his own." It excites me that we live in an individualistic society where each person is free to express himself in any way he chooses, so long as his expression does not intrude on another's expression. That is a tremendously positive way of community living and allows each of us to pursue passions or hobbies as we wish, as long our passions or hobbies don't negatively impact another individual's activities. If you want to dress up, turn the music up and party all night, power to you -- just as long as you're at a nightclub or not disturbing the neighbors who are in the middle of a meditation session. When we climb into an airplane then remove that airplane from the earth's surface we are free to enjoy ourselves in any way that we want, as long as we comply with all regulations and operate the airplane in a safe and efficient manner. But what happens when a pilot makes a boo-boo? Not only does that pilot put himself at risk (which is his prerogative), he puts innocent people on the ground at risk (as well as other pilots), too. This changes everything and makes flying a unique hobby. Now the pilot's self-expression has the potential to involuntarily become another person's uninvited ultimate disturbance.
When airplanes are in flight they always have the potential to come down suddenly and violently, and what happens to be below an airplane when and if that should happen could quite possibly be a home, an office building, a busy thoroughfare, or a little league softball game. It is for this reason that people who engage in this activity must be held to extremely high standards and maintain a safety-conscious mindset while conducting and enjoying their hobby. Flying demands a high degree of responsibility and maturity. Those who do not possess these traits should absolutely not be allowed to command an aircraft (at least without an instructor on board) because they do not have the right to put you, me, your children, the mayor, and anyone else on the ground at risk in their process of self-expression. They'd be better suited to swimming the English Channel or climbing Mount Everest. These activities don't involve putting others at risk. I don't believe people should have to be concerned with an aircraft crashing through the roof of their home during their Thanksgiving dinner. Certainly they didn't ask for that and they don't deserve it. Flying is high stakes, period. It takes a professional and evolved mentality to participate in it properly, and those who aren't capable of that mentality have no business behind the controls of an airplane. I wish them a life full of happiness in other hobbies which involve no collateral risk. There are other consequences for irresponsible flying too.
When a bonehead violates the Washington D.C. Special Flight Rules Area (SFRA) he makes a mess not only for himself but for all general aviation pilots. This mess comes in the form of new rulemaking and increased regulation. It slowly chips away at our collective freedom as pilots and reduces our ability to express ourselves through flying in an unrestricted way. Aircraft accidents work in just the same way. Accidents caused by irresponsible pilots often spur governmental concern (as they should) and new regulations are born. Sometimes the new rules are quite restrictive and unnecessarily apply to responsible pilots because it is currently impossible for the government to discern between a smart pilot and an inept pilot in terms of pilot certification and privileges. When a rule gets made for the silly pilots it's imposed on the whole lot of us, smart pilots and all. That's not fair to the responsible pilots because they didn't ask for the new restrictions nor do they need them. But our current system is limited to the "one for all" approach, so each one of us needs to do our part to fly safely and properly so as to preserve the wonderfully free flying system we enjoy today. Those who aren't capable or willing to do this need to change hobbies.
Flying is a challenging and uniquely high stakes hobby. Those who engage in flying must understand the consequences of mistreating it. If you don't want the pressure of those consequences constantly lurking in the background of every flight, stay away from the cockpit. Find something else that you enjoy pouring your heart into that doesn't involve the potential for loss of innocent life. And to my readers who are still with me after reading this, I give you my thanks. I'm glad to have you.
Some readers may've noticed I've repeatedly mentioned "the innocent folks on the ground" in my first handful of posts. This is a theme you'll continue to see in future posts because it is always at the forefront of my mind. And if you fly airplanes it should always be at the forefront of your mind too. I'm a firm believer in the phrase, "To each his own." It excites me that we live in an individualistic society where each person is free to express himself in any way he chooses, so long as his expression does not intrude on another's expression. That is a tremendously positive way of community living and allows each of us to pursue passions or hobbies as we wish, as long our passions or hobbies don't negatively impact another individual's activities. If you want to dress up, turn the music up and party all night, power to you -- just as long as you're at a nightclub or not disturbing the neighbors who are in the middle of a meditation session. When we climb into an airplane then remove that airplane from the earth's surface we are free to enjoy ourselves in any way that we want, as long as we comply with all regulations and operate the airplane in a safe and efficient manner. But what happens when a pilot makes a boo-boo? Not only does that pilot put himself at risk (which is his prerogative), he puts innocent people on the ground at risk (as well as other pilots), too. This changes everything and makes flying a unique hobby. Now the pilot's self-expression has the potential to involuntarily become another person's uninvited ultimate disturbance.
When airplanes are in flight they always have the potential to come down suddenly and violently, and what happens to be below an airplane when and if that should happen could quite possibly be a home, an office building, a busy thoroughfare, or a little league softball game. It is for this reason that people who engage in this activity must be held to extremely high standards and maintain a safety-conscious mindset while conducting and enjoying their hobby. Flying demands a high degree of responsibility and maturity. Those who do not possess these traits should absolutely not be allowed to command an aircraft (at least without an instructor on board) because they do not have the right to put you, me, your children, the mayor, and anyone else on the ground at risk in their process of self-expression. They'd be better suited to swimming the English Channel or climbing Mount Everest. These activities don't involve putting others at risk. I don't believe people should have to be concerned with an aircraft crashing through the roof of their home during their Thanksgiving dinner. Certainly they didn't ask for that and they don't deserve it. Flying is high stakes, period. It takes a professional and evolved mentality to participate in it properly, and those who aren't capable of that mentality have no business behind the controls of an airplane. I wish them a life full of happiness in other hobbies which involve no collateral risk. There are other consequences for irresponsible flying too.
When a bonehead violates the Washington D.C. Special Flight Rules Area (SFRA) he makes a mess not only for himself but for all general aviation pilots. This mess comes in the form of new rulemaking and increased regulation. It slowly chips away at our collective freedom as pilots and reduces our ability to express ourselves through flying in an unrestricted way. Aircraft accidents work in just the same way. Accidents caused by irresponsible pilots often spur governmental concern (as they should) and new regulations are born. Sometimes the new rules are quite restrictive and unnecessarily apply to responsible pilots because it is currently impossible for the government to discern between a smart pilot and an inept pilot in terms of pilot certification and privileges. When a rule gets made for the silly pilots it's imposed on the whole lot of us, smart pilots and all. That's not fair to the responsible pilots because they didn't ask for the new restrictions nor do they need them. But our current system is limited to the "one for all" approach, so each one of us needs to do our part to fly safely and properly so as to preserve the wonderfully free flying system we enjoy today. Those who aren't capable or willing to do this need to change hobbies.
Flying is a challenging and uniquely high stakes hobby. Those who engage in flying must understand the consequences of mistreating it. If you don't want the pressure of those consequences constantly lurking in the background of every flight, stay away from the cockpit. Find something else that you enjoy pouring your heart into that doesn't involve the potential for loss of innocent life. And to my readers who are still with me after reading this, I give you my thanks. I'm glad to have you.
CTAF Abuse
The traffic pattern was busy as I maneuvered for a downwind entry. It was a beautiful Saturday afternoon with light winds and excellent visibility. There were lots of weekend flyers buzzing around Miami County Airport (K81), a small but accommodating uncontrolled airport in northeast Kansas. The Common Traffic Advisory Frequency (CTAF) was congested. Transmissions were being blocked and garbles and squeals were coming through my headset frequently as I searched for traffic outside. As with most CTAF or unicom frequencies, Miami County shares their advisory frequency with several other nearby uncontrolled airports. It was difficult to get a word in to broadcast my position and intentions as I turned base then final. Interjected between the routine traffic calls on the frequency was a conversation between two gentlemen discussing their plans for the weekend. Anytime these individuals heard free air time they'd key up and resume their conversation, and evidently they had a lot to say. After a couple minutes of being briefed on Bob's plans for Sunday I butted in and requested they discontinue their conversation as aircraft were already struggling for air time.
The behavior of these gentlemen was rude, inconsiderate, irresponsible, and improper. I was amazed by their complete disregard for the needs of other pilots on the frequency who were attempting to use the CTAF properly to reduce the chance of a mid-air collision or runway incursion. The CTAF is not a chat line. It is a frequency to be used for official business only to allow pilots operating in the vicinity of one another to communicate and keep themselves separated. It is never okay to use a CTAF for any other purpose. Pilots who engage in personal conversation over a CTAF are displaying a fundamental inability to separate business from personal recreation in their mind, even when the frequency is dead because aircraft operating in the vicinity of an airport should be utilizing sterile cockpit procedures and any chit-chat must be suspended until the aircraft is parked and shutdown. Save the banter for the ground. It is irresponsible and foolish to steal valuable air time away from safety-conscious pilots who are trying to maintain safety during some of the riskiest phases of flight (takeoff and landing).
The next time you're flying in the vicinity of an uncontrolled airport and utilizing a CTAF be sure to ask those chatty knuckleheads to zip it (perhaps in nicer words) so that you can conduct business. Other pilots listening will appreciate your effort to sterilize the frequency. If they won't quiet down, do your best to obtain their N-number and report them to the FAA after you land. I perceive this as an urgent matter. This type of unprofessionalism is completely unacceptable, and CTAFs lack the oversight that air traffic control frequencies have so it's up to us, the users of the system, to maintain its integrity. Daytime visual meteorological conditions (VMC) in the vicinity of an airport has long been the area where most mid-air collisions occur. The proper use of a CTAF in the areas where these accidents are concentrated greatly reduces the risk of bumping into another aircraft, but if the frequency is tied up with useless chatter about Ted's new Harley the system fails. Those of us with a head on top of our shoulders are then subjected to increased risk, and that's not acceptable.
I once watched an Internet video of a Bonanza landing at Telluride Airport (TEX) in the San Juan Mountains of Colorado. Telluride is a busy airport with a fair mix of transient GA traffic and regional airline traffic. It has only one runway which can typically only be used one-way, land east, takeoff west due to high terrain immediately east of the field. The pattern typically has a concentration of traffic south through west of the runway which contributes to the congestion when the airport gets busy. I watched as the Bonanza entered the pattern and maneuvered for landing while communicating with other aircraft in the area including a jet the Bonanza was to follow. Suddenly someone from the FBO interrupted the communications and began interrogating the Bonanza pilot about how long he would be on the ramp, how much fuel he needed, and other non-essential information. Unfortunately, the Bonanza pilot answered the questions instead of politely informing the FBO person that he'd discuss that after he got on the ground. The FBO person then further tied up the frequency by asking other aircraft in the pattern the same line of questions. The frequency became over-congested and the efficiency of the CTAF system was significantly compromised. I was surprised and disappointed that not a single pilot on the frequency asked this non-pilot salesman to pipe down and save his business for the ramp. His questions had nothing to do with safety of flight or collision avoidance. They were non-essential conversation about a business-related subject which had no business interrupting aircraft-to-aircraft collision avoidance transmissions. The CTAF is not intended to be used this way, and requesting a pilot to divert his attention away from maneuvering in complex terrain during a high risk and high workload phase of flight in order to discuss how long he'll be on the ramp (if he makes it there) is completely irresponsible and inappropriate.
As pilots our duty is to maintain safety of flight at all times. This includes using CTAFs properly and requesting those who are not using them properly to discontinue their actions. Is this strict? Yes, it certainly is. Flying demands strict discipline. If that's not up your alley, change your hobby. Conducting yourself appropriately on a CTAF is just one way of demonstrating your professionalism and discipline as well as your regard for other pilots and the innocent folks below.
The behavior of these gentlemen was rude, inconsiderate, irresponsible, and improper. I was amazed by their complete disregard for the needs of other pilots on the frequency who were attempting to use the CTAF properly to reduce the chance of a mid-air collision or runway incursion. The CTAF is not a chat line. It is a frequency to be used for official business only to allow pilots operating in the vicinity of one another to communicate and keep themselves separated. It is never okay to use a CTAF for any other purpose. Pilots who engage in personal conversation over a CTAF are displaying a fundamental inability to separate business from personal recreation in their mind, even when the frequency is dead because aircraft operating in the vicinity of an airport should be utilizing sterile cockpit procedures and any chit-chat must be suspended until the aircraft is parked and shutdown. Save the banter for the ground. It is irresponsible and foolish to steal valuable air time away from safety-conscious pilots who are trying to maintain safety during some of the riskiest phases of flight (takeoff and landing).
The next time you're flying in the vicinity of an uncontrolled airport and utilizing a CTAF be sure to ask those chatty knuckleheads to zip it (perhaps in nicer words) so that you can conduct business. Other pilots listening will appreciate your effort to sterilize the frequency. If they won't quiet down, do your best to obtain their N-number and report them to the FAA after you land. I perceive this as an urgent matter. This type of unprofessionalism is completely unacceptable, and CTAFs lack the oversight that air traffic control frequencies have so it's up to us, the users of the system, to maintain its integrity. Daytime visual meteorological conditions (VMC) in the vicinity of an airport has long been the area where most mid-air collisions occur. The proper use of a CTAF in the areas where these accidents are concentrated greatly reduces the risk of bumping into another aircraft, but if the frequency is tied up with useless chatter about Ted's new Harley the system fails. Those of us with a head on top of our shoulders are then subjected to increased risk, and that's not acceptable.
I once watched an Internet video of a Bonanza landing at Telluride Airport (TEX) in the San Juan Mountains of Colorado. Telluride is a busy airport with a fair mix of transient GA traffic and regional airline traffic. It has only one runway which can typically only be used one-way, land east, takeoff west due to high terrain immediately east of the field. The pattern typically has a concentration of traffic south through west of the runway which contributes to the congestion when the airport gets busy. I watched as the Bonanza entered the pattern and maneuvered for landing while communicating with other aircraft in the area including a jet the Bonanza was to follow. Suddenly someone from the FBO interrupted the communications and began interrogating the Bonanza pilot about how long he would be on the ramp, how much fuel he needed, and other non-essential information. Unfortunately, the Bonanza pilot answered the questions instead of politely informing the FBO person that he'd discuss that after he got on the ground. The FBO person then further tied up the frequency by asking other aircraft in the pattern the same line of questions. The frequency became over-congested and the efficiency of the CTAF system was significantly compromised. I was surprised and disappointed that not a single pilot on the frequency asked this non-pilot salesman to pipe down and save his business for the ramp. His questions had nothing to do with safety of flight or collision avoidance. They were non-essential conversation about a business-related subject which had no business interrupting aircraft-to-aircraft collision avoidance transmissions. The CTAF is not intended to be used this way, and requesting a pilot to divert his attention away from maneuvering in complex terrain during a high risk and high workload phase of flight in order to discuss how long he'll be on the ramp (if he makes it there) is completely irresponsible and inappropriate.
As pilots our duty is to maintain safety of flight at all times. This includes using CTAFs properly and requesting those who are not using them properly to discontinue their actions. Is this strict? Yes, it certainly is. Flying demands strict discipline. If that's not up your alley, change your hobby. Conducting yourself appropriately on a CTAF is just one way of demonstrating your professionalism and discipline as well as your regard for other pilots and the innocent folks below.
Subscribe to:
Posts (Atom)