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  • #31
    Originally posted by Airbus_A320
    But all the is beside the point.

    Yeah, because you completely missed it. I could pick apart your post and show you exactly why, but I really don't feel like it.

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    • #32
      Originally posted by Airbus_A320
      But all the is besides the point. We are talking about the fact that highly experienced pilots got a plane into the air in the alloted amount of runway and why this was somehow an unsafe operation.
      Pleas answer this question:

      Taking into account that from the point where the pilot decides to start the rotation to the point where the airplane actually lifts off there are several feet and a few seconds and that the exact ammount of feet and seconds are function of aircraft weight, airspeed, acceleration, runway slope, wind speed, density altitude, pitch-up rate and engine performance, all figures that are subject to errors and variation between the value that is measured, computed, aimed or assumed and the actual value at the moment of take off, what precision (in feet) would you say is reliabily achivable arround a target "unstick" point, for a "highly experienced pilot"?

      --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
      --- Defend what you say with arguments, not by imposing your credentials ---

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      • #33
        Originally posted by Gabriel
        Pleas answer this question:

        Taking into account that from the point where the pilot decides to start the rotation to the point where the airplane actually lifts off there are several feet and a few seconds and that the exact ammount of feet and seconds are function of aircraft weight, airspeed, acceleration, runway slope, wind speed, density altitude, pitch-up rate and engine performance, all figures that are subject to errors and variation between the value that is measured, computed, aimed or assumed and the actual value at the moment of take off, what precision (in feet) would you say is reliabily achivable arround a target "unstick" point, for a "highly experienced pilot"?
        Ok, I posted and ran, and see quite the debate here over whether the pilots are flying reasonably or not.

        Yes, while there is agreement that it's ok have an extended takeoff roll, it sure looks like these planes were pushed a bit farther than reasonable common sense would suggest.

        So, I'd only suggest that we may not know the exact height, the true liftoff point, and true distances from the end of the runway and might be seeing an optical illusion.

        And, Airbus: 1) To hell with common sense, What does the letter of the law say about how much runway not to use on takeoff? That's an interesting and valid question...how would you prohibit someone from using the runway, how do you regulate common sense, and is "legal right up to the moment of impact" adequate? You have a point as I don't know how one might regulate that.

        However, 2) Don't pretend that it's 200% safe to literally lift off between the piano keys and the threshold line...a misjudgement of your rotation rate, a wind gust, or several other things could put you in the approach lights with some ruined expensive tires and lights, or conceivably worse!

        Still- did these photographers capture pilots pusing takeoff roll farther than common sense would dictate, or are we seeing exagerated perspective effects?
        Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

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        • #34
          Originally posted by 3WE
          And, Airbus: 1) To hell with common sense, What does the letter of the law say about how much runway not to use on takeoff? That's an interesting and valid question...how would you prohibit someone from using the runway, how do you regulate common sense, and is "legal right up to the moment of impact" adequate? You have a point as I don't know how one might regulate that.
          That's a point. Yet, you always have the provisions of the "careless and reckless flying" as a last resource, if the FAA thinks (they don't need to "prove" it) that the pilot decided to take a risk with no good reason. You won't find in the FAR's something like "No flight crew member shall attempt to reach the certified ceiling in vertical speed mode and disregard all cues that the airplane is about to stall" either.

          Unless you busted the tire speed limit, in which case you are in vioation of the approved envelope.
          Still- did these photographers capture pilots pusing takeoff roll farther than common sense would dictate, or are we seeing exagerated perspective effects?
          The second photo is pretty more suggestive than the first one. And the video of the Russian cargo in "that thread", well, you saw it, no further comments needed.

          --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
          --- Defend what you say with arguments, not by imposing your credentials ---

          Comment


          • #35
            Originally posted by 3WE
            Ok, I posted and ran, and see quite the debate here over whether the photos are reasonable or not.

            Yes, while there is agreement that it's ok have an extended takeoff roll, it sure looks like these planes were pushed a bit farther than reasonable common sense would suggest.

            So, I'd only suggest that we may not know the exact height, the true liftoff point, and true distances from the end of the runway and might be seeing an optical illusion.

            And, Airbus: 1) To hell with common sense, What does the letter of the law say about how much runway not to use on takeoff? That's an interesting and valid question...how would you prohibit someone from using the runway, how do you regulate common sense, and is "legal right up to the moment of impact" adequate? You have a point as I don't know how one might regulate that.

            However, 2) Don't pretend that it's 200% safe to literally lift off between the piano keys and the threshold line...a misjudgement of your rotation rate, a wind gust, or several other things could put you in the approach lights with some ruined expensive tires and lights, or conceivably worse!

            Still- did these photographers capture pilots pusing takeoff roll farther than common sense would dictate, or are we seeing exagerated perspective effects?
            Good points. And yes, it's not 200% safe, but what is, after all you're hurling yourself through the air in a metal tube.

            What I'm trying to say is that I look at this as a precise operation performed by skilled pilots, not as something that's ridiculous, fishy, etc. I have barely any flight experience (compared to some of the people on here), but I try not to be one of those who calls anything that doesn't look "normal" automatically unsafe without knowing the details and not giving the benefit of the doubt that the pilots know what they are doing. From the limited expereince that I do have, I have found that many things that I would have believed to be unsafe before I started flying can actually be accomplished safetly as long as done carefully and with precision.

            And the viewing angle/optical illusion thing you bring up, is what I mentioned before. It's hard to tell how high or low it actually is.

            Comment


            • #36
              Originally posted by Gabriel
              As an addition: Do you know why GA flying is not remotely as safe as commercial flying? Because we at GA don't have the requirements of training, safety margin, redundancy and mistake proofing that those at the airline have. It's up to the pilot/operator to make some of that. Pilots that are well trained, put redundancy in their planes, and use their own operational limitations with margin over what the book say the airplane can do, tend to have far less accidents than those who just comply with the minimum requirements.
              I think you're putting too much water in the "mistake proofing" bucket and less in the training. Yes there is a lot of "child proof" things built into the aircraft...but in my admittedly brief career as a pilot, I can't think of a single time that one of these devices has saved me from having an accident. You make it sound like we're a bunch of monkeys swinging gear handles, banking crazily, and regularly flying too fast. Yes these protections are important and HAVE saved lives, but its just another way to cover holes in the swiss cheese theory. Training is the most important part.

              And last of all...none of us were there...none of us has any idea actually how high the airplane is over the runway. Nor do we know how heavy the payload, what the required flap settings, or anything about the crew and their abilities. As was stated before, transport category aircraft are required to be 35ft above the end of the runway should the lose an engine...in the grand scheme of things, that really isn't that high.
              Last edited by screaming_emu; 2008-05-22, 03:52.

              Comment


              • #37
                Originally posted by screaming_emu
                I think you're putting too much water in the "mistake proofing" bucket and less in the training. Yes there is a lot of "child proof" things built into the aircraft...but in my admittedly brief career as a pilot, I can't think of a single time that one of these devices has saved me from having an accident. You make it sound like we're a bunch of monkeys swinging gear handles, banking crazily, and regularly flying too fast. Yes these protections are important and HAVE saved lives, but its just another way to cover holes in the swiss cheese theory. Training is the most important part.

                And last of all...none of us were there...none of us has any idea actually how high the airplane is over the runway. Nor do we know how heavy the payload, what the required flap settings, or anything about the crew and their abilities. As was stated before, transport category aircraft are required to be 35ft above the end of the runway should the lose an engine...in the grand scheme of things, that really isn't that high.
                I agree with both things you say.

                Training is a main factor in safety. But training alone is not enough because it doesn't prevent a skilled but human pilot from making a critical mistake. Most of the times the mistake could be catched by the pilot himself with no additional help. But when you are talking about a single digit of accidents per million of departures, mistake-proofing becomes critical. How many millions of departures have you already made? Now, as I explained, if you relayed on mistake-proofing features as the single mean to prevent a mistake, it would be bad, as it would be bad to rely only on trained pilots not making the mistake. Is the very low probability that both the well trained pilot and the mistake proofing feature fail at the same time what makes it work in the low PPM range. Not that it has never happened or won't happen again, though.

                I also agree that we don't know exactly what was going on there. I started my first post saying what made me feel "uncomfortable" about those photos for what they loked, and on the following posts I oppined why it's not acceptable to intentionaly lift off the ground on the very last feet of the runway. If that's not what happened, then great.

                --- Judge what is said by the merits of what is said, not by the credentials of who said it. ---
                --- Defend what you say with arguments, not by imposing your credentials ---

                Comment


                • #38
                  The one thing that every one seems to assume is that the A/C used the entire length of the runway. Now this may be a hunch on my part but is it possible that the crew was asked by ATC to start the takeoff from mid runway and the crew accepted the request?

                  It is hard to say exactly what happened unless you were there and saw the entire event.
                  Robin Guess Aviation Historian, Photographer, Web Designer.

                  http://www.Jet-Fighters.Net
                  http://www.Jet-Liners.Net

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                  • #39
                    Originally posted by Jet-fighters.Net
                    The one thing that every one seems to assume is that the A/C used the entire length of the runway. Now this may be a hunch on my part but is it possible that the crew was asked by ATC to start the takeoff from mid runway and the crew accepted the request?

                    It is hard to say exactly what happened unless you were there and saw the entire event.
                    I don't belive that that is allowed. Even if it were I don't think most pilots would do it.
                    Signatures are overrated

                    Comment


                    • #40
                      Originally posted by Airfoilsguy
                      I don't belive that that is allowed. Even if it were I don't think most pilots would do it.
                      Actually it is, though mostly used in the other direction (13L), regionals regularly use twy Kilo to enter 13L for takeoff, but on occasion larger jets too if they are in a hurry and load is light. 31R/13L is 12000 ft long, using K still leaves about 9500. Tecnically the same thing is possible, using twy Xray, however takeoffs on 31R are very rare due to noise abatement, 99% of takeoffs in 31 direction will be from 31L. Exceptions are if a very long takeoff roll is needed, or the other runway is closed for any reason.

                      I'm not aware of any RWY closures on the 15th, so the crew likely have requested 31R takeoff because 31L would have been too short. The flight was to Bagram AFB, Afghanistan, they were probably close to mtow. Noise abatement procedures require reaching 2000' by DME 3.5 (and hefty fines if somebody misses the target) so it is quite concievable that the crew elected to use the maximum runway available to gain speed for rate of climb. However I do agree that it looks a bit too tight. The photo was indeed taken from the tower, but there is no optical illusion, it is just off the ground. However you can see that the main gears are already beginning to retract, so it must have been in the air for at least several seconds.
                      another ADC refugee

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                      • #41
                        Originally posted by andrasz
                        Actually it is, though mostly used in the other direction (13L), regionals regularly use twy Kilo to enter 13L for takeoff, but on occasion larger jets too if they are in a hurry and load is light. 31R/13L is 12000 ft long, using K still leaves about 9500. Tecnically the same thing is possible, using twy Xray, however takeoffs on 31R are very rare due to noise abatement, 99% of takeoffs in 31 direction will be from 31L. Exceptions are if a very long takeoff roll is needed, or the other runway is closed for any reason.

                        I'm not aware of any RWY closures on the 15th, so the crew likely have requested 31R takeoff because 31L would have been too short. The flight was to Bagram AFB, Afghanistan, they were probably close to mtow. Noise abatement procedures require reaching 2000' by DME 3.5 (and hefty fines if somebody misses the target) so it is quite concievable that the crew elected to use the maximum runway available to gain speed for rate of climb. However I do agree that it looks a bit too tight. The photo was indeed taken from the tower, but there is no optical illusion, it is just off the ground. However you can see that the main gears are already beginning to retract, so it must have been in the air for at least several seconds.
                        Well I stand corrected. It just seem strange to me that a pilot would cut him self short like that. Maybe I am too careful but I would always rather have extra runway in front of me in case of a problem then cut my taxi time short.
                        Signatures are overrated

                        Comment


                        • #42
                          Originally posted by andrasz
                          However you can see that the main gears are already beginning to retract, so it must have been in the air for at least several seconds.

                          Wouldn't the main gear/nose gear doors have opened then? Or be in the process of opening?

                          It does look like the main gears are pulling up and this is probably before the nose doors opened, so the lever was probably lifted.

                          N305FE. McDonnell Douglas DC-10-30(F). JetPhotos.com is the biggest database of aviation photographs with over 5 million screened photos online!

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                          • #43
                            Originally posted by Leftseat86
                            Wouldn't the main gear/nose gear doors have opened then? Or be in the process of opening?

                            It does look like the main gears are pulling up and this is probably before the nose doors opened, so the lever was probably lifted.

                            http://www.jetphotos.net/viewphoto.p...199230&nseq=75
                            On the DC-10, the main gear doors must open before the gear will begin to retract. The nose and center gear doors operate with the movement of the gear. The main gear doors are in the opening cycle, the gear has unlocked, therefor the gear handle has been raised.

                            Where I work, gear up is not called until positive rate has been called. How these guys work is unknown.
                            Don
                            Standard practice for managers around the world:
                            Ready - Fire - Aim! DAMN! Missed again!

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                            • #44
                              Originally posted by Dmmoore
                              Where I work, gear up is not called until positive rate has been called. How these guys work is unknown.
                              Maybe it's a special procedure to get them out of the way of the approach lights ...
                              another ADC refugee

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                              • #45
                                Originally posted by Dmmoore
                                On the DC-10, the main gear doors must open before the gear will begin to retract. The nose and center gear doors operate with the movement of the gear. The main gear doors are in the opening cycle, the gear has unlocked, therefor the gear handle has been raised.

                                Where I work, gear up is not called until positive rate has been called. How these guys work is unknown.

                                Thats what I thought. Thanks for the info. In any case that looks like a VERY early retraction.

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