Mac McClellan of Flying magazine nailed it this month. Mac wrote about autothrottle systems and the tactical advantages they provide. He also exposed that Southwest Airlines, whose flying practices have stirred my gut before, does not use the autothrottle systems installed in their fleet of Boeing 737 jets. Southwest says the reason for their disuse of autothrottles is because it helps to "keep the pilots in the loop." That's simply foolish. That's what the N1 and airspeed indications are for.
Mac had a great comeback for this. He suggested Southwest discontinue use of their entire autopilot system, including lateral and vertical navigation modes, in order to really keep the pilots in the loop. More like in a spin.
Humans fail constantly. A staggering majority of aircraft accidents (airline included) are caused by pilot error. Cockpit automation rarely fails. It is highly reliable and precise, and offers tremendous enhancement to flight safety by backing up the human pilot. That's the idea behind autothrottle systems. Airspeed control is higher priority than lateral, or even vertical navigation. Autothrottles provide overspeed and, more importantly, underspeed protection during all phases of flight. This is especially critical during approach and landing when airspeed is low and pilot workload is high. Just look at the crash of Colgan 3407. The Dash 8 wasn't equipped with autothrottles and the captain failed to add power after the airplane leveled off at an intermediate altitude on the approach. A stall and horribly botched recovery resulted in a spin and loss of life. An autothrottle system would have prevented this accident.
Southwest just doesn't get it. I think it will take a stall/spin accident of one of their 737s before Southwest recognizes and embraces the importance of using autothrottles, especially on heavy, high performance jets. I'm not sure if this is still true today, but I once read that Southwest didn't use their autobrake systems either. It's that "cowboy" attitude that concerns me. Boeing installed these systems in their airplanes for a reason. They should be used.
Thursday, July 30, 2009
Friday, July 24, 2009
Reg Review #2
Let's look at a simple, yet important regulation that is often forgotten or misunderstood.
Regulation
§ 91.209 Aircraft lights.
No person may:
(a) During the period from sunset to sunrise (or, in Alaska, during the period a prominent unlighted object cannot be seen from a distance of 3 statute miles or the sun is more than 6 degrees below the horizon)—
(1) Operate an aircraft unless it has lighted position lights.
Interpretation
Position lights must be illuminated between sunset and sunrise (except in Alaska). Let's define position lights. Position lights are often referred to by pilots and aircraft manufacturers as navigation lights or "nav" lights. They are the red (left wingtip) and green (right wingtip) lights with white aft sections and sometimes an all white light on the aft empennage.
Explanation
The purpose of position lights is to make aircraft visible to other pilots at night or in reduced visibility and to assist pilots in determining the orientation of nearby traffic. For instance, if we see three dim white lights, that indicates the traffic is most likely moving directly away from us (if they're bright white lights, the opposite might be true because we might be seeing landing lights). If we see a single green light, we're looking only at the aircraft's right wingtip, which means the aircraft is crossing from left to right. Most importantly, if we see a green light on our left and a red light on our right, it means we're converging with the traffic head-on.
It's obvious why it's a requirement to have position lights turned on when light conditions are dim or dark. We use position lights not only so we can see other traffic (anti-collision lights and beacons help with this, too), but more importantly so that we can tell which direction the other guy is traveling. During daylight this is easy to do because we're able to see the other guy's wings, nose, and tail. At night the lights have to provide this information.
Some pilots are confused about what the law states regarding when position lights must be illuminated. As the regulation simply states, the lights must be on from sunset to sunrise. Don't confuse this with the FAA's definition of night which is most often used in consideration of one's night currency for passenger carrying (one hour after sunset and one hour before sunrise). Position lights are required to be illuminated for an additional two hours -- one additional hour either side of the definition used for night currency. That means if your airplane isn't equipped with position lights or its position lights are inoperative, you must land before sunset or delay an early morning takeoff until after sunrise.
And one final note. The military occasionally conducts special "lights out" night operations in Military Operations Areas (MOA). That means there are high performance fighter jets flying around with no external lights on, so they're basically impossible to see. That's one more reason to avoid active MOAs when flying VFR at night or at a bare minimum be in contact with air traffic control receiving VFR Flight Following.
Regulation
§ 91.209 Aircraft lights.
No person may:
(a) During the period from sunset to sunrise (or, in Alaska, during the period a prominent unlighted object cannot be seen from a distance of 3 statute miles or the sun is more than 6 degrees below the horizon)—
(1) Operate an aircraft unless it has lighted position lights.
Interpretation
Position lights must be illuminated between sunset and sunrise (except in Alaska). Let's define position lights. Position lights are often referred to by pilots and aircraft manufacturers as navigation lights or "nav" lights. They are the red (left wingtip) and green (right wingtip) lights with white aft sections and sometimes an all white light on the aft empennage.
Explanation
The purpose of position lights is to make aircraft visible to other pilots at night or in reduced visibility and to assist pilots in determining the orientation of nearby traffic. For instance, if we see three dim white lights, that indicates the traffic is most likely moving directly away from us (if they're bright white lights, the opposite might be true because we might be seeing landing lights). If we see a single green light, we're looking only at the aircraft's right wingtip, which means the aircraft is crossing from left to right. Most importantly, if we see a green light on our left and a red light on our right, it means we're converging with the traffic head-on.
It's obvious why it's a requirement to have position lights turned on when light conditions are dim or dark. We use position lights not only so we can see other traffic (anti-collision lights and beacons help with this, too), but more importantly so that we can tell which direction the other guy is traveling. During daylight this is easy to do because we're able to see the other guy's wings, nose, and tail. At night the lights have to provide this information.
Some pilots are confused about what the law states regarding when position lights must be illuminated. As the regulation simply states, the lights must be on from sunset to sunrise. Don't confuse this with the FAA's definition of night which is most often used in consideration of one's night currency for passenger carrying (one hour after sunset and one hour before sunrise). Position lights are required to be illuminated for an additional two hours -- one additional hour either side of the definition used for night currency. That means if your airplane isn't equipped with position lights or its position lights are inoperative, you must land before sunset or delay an early morning takeoff until after sunrise.
And one final note. The military occasionally conducts special "lights out" night operations in Military Operations Areas (MOA). That means there are high performance fighter jets flying around with no external lights on, so they're basically impossible to see. That's one more reason to avoid active MOAs when flying VFR at night or at a bare minimum be in contact with air traffic control receiving VFR Flight Following.
Thursday, July 23, 2009
Reg Review #1
I'm going to try something new. A couple of times each week I'm going to make a post reviewing long forgotten or rarely discussed regulations. Some of the regulations I'll review will be rather trivial , some significant, and some will be a clarification of widely misinterpreted regulations. I understand that the human brain only opens its intake filter for content it deems important and useful, so I'll explain the reason behind each regulation I review. If I don't know the reason, I'll give you my best educated guess. Because regulations are important to pilots for several reasons (enforcement action, safety, operational requirements), I think this new column will be helpful to readers. I'll also occasionally throw in guidance topics from the Aeronautical Information Manual (AIM) and FAA Advisory Circulars (AC). It will be a good review for me, too!
Let's get started with the first review.
Topic
Advisory Circular 91-36D, VFR Flight Near Noise-Sensitive Areas
"This Advisory Circular (AC) encourages pilots making VFR flights near noise-sensitive areas to fly at altitudes higher than the minimum permitted by regulation and on flight paths that will reduce aircraft noise in such areas." (See AC document for complete details.)
Interpretation
VFR aircraft are requested to fly at least 2,000 feet above ground level (AGL) over designated national wildlife refuge areas and other noise-sensitive areas. We know where these areas are located by finding them on VFR navigational charts (TAC, SAC, or WAC). We can compute the minimum requested mean sea level (MSL) altitude which will yield 2,000 feet AGL by decoding the terrain elevation color shown on the map (refer to the map legend for color-to-number translation) and adding 2,000. Add another five hundred feet to give yourself a margin for altitude drift and nonuniform terrain elevation. For an easier method, add 2,000 to the Maximum Elevation Figure (MEF) shown on the chart, plus a five hundred foot margin. This method won't work in extremely rugged terrain or where there are unusually high obstacles around (i.e. a tethered weather balloon) because the MEF might apply to an area miles away from the noise-sensitive area and might put you much higher than 2,000-3,000 feet AGL.
Explanation
The government wants to limit noise pollution in these areas. Airplanes are noisy, especially when they're less than 2,000 feet away. Think about it... Ground vehicles are restricted in these areas, and air vehicles are too. That's why they call these areas refuges. The idea here is to protect these nature areas from the nuisance of aircraft engine noise so that people and animals can enjoy them.
Let's get started with the first review.
Topic
Advisory Circular 91-36D, VFR Flight Near Noise-Sensitive Areas
"This Advisory Circular (AC) encourages pilots making VFR flights near noise-sensitive areas to fly at altitudes higher than the minimum permitted by regulation and on flight paths that will reduce aircraft noise in such areas." (See AC document for complete details.)
Interpretation
VFR aircraft are requested to fly at least 2,000 feet above ground level (AGL) over designated national wildlife refuge areas and other noise-sensitive areas. We know where these areas are located by finding them on VFR navigational charts (TAC, SAC, or WAC). We can compute the minimum requested mean sea level (MSL) altitude which will yield 2,000 feet AGL by decoding the terrain elevation color shown on the map (refer to the map legend for color-to-number translation) and adding 2,000. Add another five hundred feet to give yourself a margin for altitude drift and nonuniform terrain elevation. For an easier method, add 2,000 to the Maximum Elevation Figure (MEF) shown on the chart, plus a five hundred foot margin. This method won't work in extremely rugged terrain or where there are unusually high obstacles around (i.e. a tethered weather balloon) because the MEF might apply to an area miles away from the noise-sensitive area and might put you much higher than 2,000-3,000 feet AGL.
Explanation
The government wants to limit noise pollution in these areas. Airplanes are noisy, especially when they're less than 2,000 feet away. Think about it... Ground vehicles are restricted in these areas, and air vehicles are too. That's why they call these areas refuges. The idea here is to protect these nature areas from the nuisance of aircraft engine noise so that people and animals can enjoy them.
Thursday, July 16, 2009
Traffic Advisories
"Citation One Charlie Mike, traffic twelve o'clock, five miles, southwestbound, level six thousand, a Gulfstream," transmitted the controller. "Uh, One Charlie Mike, yeah, we got 'em on TCAS," responded the pilot. A moment later the controller transmitted an updated traffic advisory, "November One Charlie Mike, that traffic's now one o'clock and three miles, six thousand." The Citation pilot responded, "Charlie Mike's got 'em on the box." I would imagine at this point the controller rolled his eyes and went on about his business, monitoring his sector and watching for traffic conflicts. What the Citation pilot didn't understand was why the controller was issuing him a traffic advisory and what the controller needed to hear to take further action.
Situations like this hypothetical event occur everyday. In this case, imagine that the Citation was level at seven thousand, his course converging with the Gulfstream one thousand feet below. The Citation needed lower because he was nearing his destination. The controller must separate the aircraft by three to five miles laterally, depending on the type of radar being used. If the airplanes are closer together than this in terms of lateral distance, the controller must separate them by one thousand feet vertically (or less in some situations). However, when visual meteorological conditions exist the controller may employ visual separation when the airplanes see each other. Have you ever heard a controller say to you, "Maintain visual separation with that traffic"? That means he's using visual separation procedures and the vertical and lateral spacing requirements are waived. When visual separation is being used as long as no one exchanges paint, controllers (and pilots) are happy. In order for a controller to employ visual separation, though, the pilots of the conflicting aircraft must report each other in sight. In the case of the Citation, the controller was attempting to initiate visual separation in order to expedite the airplane's descent as opposed to waiting until the Citation was three to five miles on the other side of the Gulfstream below. But since the Citation pilot didn't make much of an effort to find the other traffic, he denied himself the benefits of visual separation and the increased flexibility it unlocks.
You see, controllers follow complex sets of rules (just like pilots) that guide and dictate their decisions. When a controller issues a traffic advisory in an effort to initiate visual separation procedures, his rules tell him that the pilots must see each other with their eyeballs before they're permitted to penetrate each other's separation bubbles. Seeing another aircraft on a Traffic Collision Avoidance System (TCAS), or Traffic Information/Advisory Service (TIS/TAS) in the case of a light airplane, is not sufficient for the allowance of the reduced spacing visual separation provides. The FAA only trusts your eyeballs for that. When you tell a controller you've "got them on TCAS" you're wasting his time. He'll just filter those words out and translate them into his own controller language: "He doesn't have the other traffic in sight. That means I can't use visual separation." TCAS isn't approved for use in visual separation because, after all, it's not visual. It's a computer system. The controller already knows you probably see the other guy on TCAS, and he's not interested in that. He's only interested in whether or not you see him out the window. That's what is operationally significant to him. Think of it this way, imagine you said to the controller, "We've got 'em on TCAS." The controller then replied, "Yeah, and I've got you both on radar. That's not what I'm getting at." If two big, fast, shiny flying machines are going to whisk past each other in flight, the FAA insists that the pilots must primarily be relying on their eyeballs and not technology. That makes sense.
Remember, everything a controller does is for a reason. He's at work. He's got a job to do, and he's being guided by logical rules and procedures at all times. Whenever a controller gives you an instruction, try to figure out the reason for the instruction. Be curious about the operational significance of what he's asking of you. Whenever a controller talks to me on frequency, my mind automatically envisions him sitting in front of a big black radar scope with green blips and data tags watching for traffic conflicts, planning ahead about what each aircraft needs and keeping it all straight in his mind. Controllers call this "the flick." It's a fun term for situational awareness. Taking a tour of an air traffic control facility can be an amazingly beneficial activity for any pilot. Learn as much about the air traffic control system as you can, and it will serve you more pleasantly and effectively. And next time a controller gives you a traffic advisory, make both of your lives easier and find the other aircraft with your eyes. Your aviation medical examiner didn't certify your vision for nothing. You've got the gift of sight, use it!
Situations like this hypothetical event occur everyday. In this case, imagine that the Citation was level at seven thousand, his course converging with the Gulfstream one thousand feet below. The Citation needed lower because he was nearing his destination. The controller must separate the aircraft by three to five miles laterally, depending on the type of radar being used. If the airplanes are closer together than this in terms of lateral distance, the controller must separate them by one thousand feet vertically (or less in some situations). However, when visual meteorological conditions exist the controller may employ visual separation when the airplanes see each other. Have you ever heard a controller say to you, "Maintain visual separation with that traffic"? That means he's using visual separation procedures and the vertical and lateral spacing requirements are waived. When visual separation is being used as long as no one exchanges paint, controllers (and pilots) are happy. In order for a controller to employ visual separation, though, the pilots of the conflicting aircraft must report each other in sight. In the case of the Citation, the controller was attempting to initiate visual separation in order to expedite the airplane's descent as opposed to waiting until the Citation was three to five miles on the other side of the Gulfstream below. But since the Citation pilot didn't make much of an effort to find the other traffic, he denied himself the benefits of visual separation and the increased flexibility it unlocks.
You see, controllers follow complex sets of rules (just like pilots) that guide and dictate their decisions. When a controller issues a traffic advisory in an effort to initiate visual separation procedures, his rules tell him that the pilots must see each other with their eyeballs before they're permitted to penetrate each other's separation bubbles. Seeing another aircraft on a Traffic Collision Avoidance System (TCAS), or Traffic Information/Advisory Service (TIS/TAS) in the case of a light airplane, is not sufficient for the allowance of the reduced spacing visual separation provides. The FAA only trusts your eyeballs for that. When you tell a controller you've "got them on TCAS" you're wasting his time. He'll just filter those words out and translate them into his own controller language: "He doesn't have the other traffic in sight. That means I can't use visual separation." TCAS isn't approved for use in visual separation because, after all, it's not visual. It's a computer system. The controller already knows you probably see the other guy on TCAS, and he's not interested in that. He's only interested in whether or not you see him out the window. That's what is operationally significant to him. Think of it this way, imagine you said to the controller, "We've got 'em on TCAS." The controller then replied, "Yeah, and I've got you both on radar. That's not what I'm getting at." If two big, fast, shiny flying machines are going to whisk past each other in flight, the FAA insists that the pilots must primarily be relying on their eyeballs and not technology. That makes sense.
Remember, everything a controller does is for a reason. He's at work. He's got a job to do, and he's being guided by logical rules and procedures at all times. Whenever a controller gives you an instruction, try to figure out the reason for the instruction. Be curious about the operational significance of what he's asking of you. Whenever a controller talks to me on frequency, my mind automatically envisions him sitting in front of a big black radar scope with green blips and data tags watching for traffic conflicts, planning ahead about what each aircraft needs and keeping it all straight in his mind. Controllers call this "the flick." It's a fun term for situational awareness. Taking a tour of an air traffic control facility can be an amazingly beneficial activity for any pilot. Learn as much about the air traffic control system as you can, and it will serve you more pleasantly and effectively. And next time a controller gives you a traffic advisory, make both of your lives easier and find the other aircraft with your eyes. Your aviation medical examiner didn't certify your vision for nothing. You've got the gift of sight, use it!
Monday, July 13, 2009
AWE1549 CVR
If you haven't yet seen the Cactus 1549 cockpit voice recorder (CVR) transcript, check this out. Being a stickler for detail, and learning that Captain Sullenberger is too, I was surprised when I first heard the ATC tapes that Sully didn't use the "distress emergency" (indicating life is presently in jeopardy) radio transmission of "Mayday. Mayday. Mayday." It turns out, I was wrong. He did use it, and I'm not surprised. The first part of his distress transmission was blocked by New York Departure, but it was captured by the CVR. A minor detail, but just one more piece of evidence to indicate Sully's impeccable airmanship.
Below I've listed a link to an NSTB video including the approximate flight path of the Airbus and the ATC audio overlaid with the CVR transcript. "HOT-1" is Sully, "HOT-2" is First Officer Skiles, "CAM" means "cockpit area microphone" (which means the voice was either Sully or Skiles), and "RDO-1" is Sully transmitting on the radio. You'll also see messages from "GPWS." These are aural alerts from the aircraft's Ground Proximity Warning System that automatically alert the crew to terrain threats when certain parameters are exceeded.
Both Sully and Skiles are the definition of honorable pilots. Notice that they kept working all the way down to the water. They didn't freeze, they didn't panic, they stayed present and in command until the airplane wasn't flying anymore. Notice Skiles running the QRH (Quick Reference Handbook--you'll see Sully mention this after the bird strikes), reading and responding to each checklist item in an orderly and thorough manner all the way down. I believe Skiles even selected the "ditch switch" at a mere one hundred feet above the Hudson. You'll see Skiles refer to "* * Switch" on the CVR, the asterisks indicating an unknown word. I believe this was Skiles confirming with Sully the need to activate the ditch switch before impact, which sends a command to close the aircraft's pressurization outflow valve, pack flow control valves, and a couple other systems in order to enhance the airplane's ability to float. Once in the water, Skiles remained alone on the flight deck running the evacuation checklist while Sully made his way to the cabin to assist with the evacuation.
Sully and Skiles stayed active and calm all the way down to the Hudson. They certainly have my respect, admiration, and gratitude for their handling of that difficult emergency and for saving all those lives. The cabin crew (flight attendants) did a wonderful job, too. When asked by an interviewer if the flight attendants called the cockpit to see what was happening, one of them said, "No. We knew they were very busy. We knew they'd let us know when and if they got the time." That's the kind of response that gives me goosebumps. These ladies definitely know how pilots operate. And the flight crew never did get time to explain. The only thing the cabin crew heard from the cockpit was Sully's brace command, and they immediately began yelling their verbal commands from their jumpseats, "Brace! Brace! Heads down, stay down!" They performed their duties admirably as well.
So, without further ado, here's the link to the video. An excellent display of superior airmanship.
http://www.youtube.com/watch?v=5S5hRRio-E8
Below I've listed a link to an NSTB video including the approximate flight path of the Airbus and the ATC audio overlaid with the CVR transcript. "HOT-1" is Sully, "HOT-2" is First Officer Skiles, "CAM" means "cockpit area microphone" (which means the voice was either Sully or Skiles), and "RDO-1" is Sully transmitting on the radio. You'll also see messages from "GPWS." These are aural alerts from the aircraft's Ground Proximity Warning System that automatically alert the crew to terrain threats when certain parameters are exceeded.
Both Sully and Skiles are the definition of honorable pilots. Notice that they kept working all the way down to the water. They didn't freeze, they didn't panic, they stayed present and in command until the airplane wasn't flying anymore. Notice Skiles running the QRH (Quick Reference Handbook--you'll see Sully mention this after the bird strikes), reading and responding to each checklist item in an orderly and thorough manner all the way down. I believe Skiles even selected the "ditch switch" at a mere one hundred feet above the Hudson. You'll see Skiles refer to "* * Switch" on the CVR, the asterisks indicating an unknown word. I believe this was Skiles confirming with Sully the need to activate the ditch switch before impact, which sends a command to close the aircraft's pressurization outflow valve, pack flow control valves, and a couple other systems in order to enhance the airplane's ability to float. Once in the water, Skiles remained alone on the flight deck running the evacuation checklist while Sully made his way to the cabin to assist with the evacuation.
Sully and Skiles stayed active and calm all the way down to the Hudson. They certainly have my respect, admiration, and gratitude for their handling of that difficult emergency and for saving all those lives. The cabin crew (flight attendants) did a wonderful job, too. When asked by an interviewer if the flight attendants called the cockpit to see what was happening, one of them said, "No. We knew they were very busy. We knew they'd let us know when and if they got the time." That's the kind of response that gives me goosebumps. These ladies definitely know how pilots operate. And the flight crew never did get time to explain. The only thing the cabin crew heard from the cockpit was Sully's brace command, and they immediately began yelling their verbal commands from their jumpseats, "Brace! Brace! Heads down, stay down!" They performed their duties admirably as well.
So, without further ado, here's the link to the video. An excellent display of superior airmanship.
http://www.youtube.com/watch?v=5S5hRRio-E8
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