Announcement

Collapse
No announcement yet.

Greenland Dash 8 guides Twin Cessna to safety

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Originally posted by Evan View Post
    Where did you read that? All I'm seeing is that they were "having problems with their navigational equipment". The altimeters were were apparently working just fine, as was whatever form of GPS they had. Maybe these were the newer breed of magenta line pilots and had a modern glass nav system installed, and when that failed, had no idea what the old VOR and the ADF needles were for, and they didn't have database or charts for the nearby airstrips. Dunno...
    Oha. Let me write that again, 'the newer breed of magenta line pilots'. Probably I should virtually kiss you for these words. Not really. But. I know what you mean.


    I don't know much about colors of lines in a Dash 8, but as I sometimes do, I took out my ruler. 252 nmi for the Dash 8, from take off to touchdown, as originally planned. And I assume that a Dash 8 has TCAS.
    So, imho, it was professional and a good thing that the Dash 8 crew helped the Cessna.

    And it was a bit of luck, too. Both a/c are twin-engine propellers? So, they operate with approx. the same speed? Good.
    A cool action by the Dash 8.

    What could a 744 have done in this case? Probably not as much as Air Greenland. Narsarsuaq is not part of every database, afaik. But, what strikes me, the twin Cessna was flown, without that somebody on board knew how to operate a VOR?!

    Gabriel, help us, is that possible?
    The German long haul is alive, 65 years and still kicking.
    The Gold Member in the 747 club, 50 years since the first LH 747.
    And constantly advanced, 744 and 748 /w upper and lower EICAS.
    This is Lohausen International airport speaking, echo delta delta lima.

    Comment


    • #17
      Originally posted by Evan View Post
      Where did you read that? All I'm seeing is that they were "having problems with their navigational equipment". The altimeters were were apparently working just fine, as was whatever form of GPS they had. Maybe these were the newer breed of magenta line pilots and had a modern glass nav system installed, and when that failed, had no idea what the old VOR and the ADF needles were for, and they didn't have database or charts for the nearby airstrips. Dunno...
      Maybe they didn't have an old VOR and ADF with needles. If they had a G1000, they would just have 2 tubes plus backup artificial horizon, backup airspeed indicator, backup altimeter, plus magnetic compass. That's it. A total electrical failure or total G1000 failure would mean no PFD, no nav, no comm, no transponder. Of course that would be the case too in an old panel with a total electrical failure, except they typically would have the vacuum driven artificial horizon and gyro compass. The GPS could have been any handheld device, from an iPad to a Huawei cellphone.

      Click image for larger version

Name:	cessnaSkyhawkPanel.jpg
Views:	1
Size:	651.3 KB
ID:	1015212

      --- 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


      • #18
        Originally posted by Gabriel View Post
        Maybe they didn't have an old VOR and ADF with needles. If they had a G1000, they would just have 2 tubes plus backup artificial horizon, backup airspeed indicator, backup altimeter, plus magnetic compass. That's it. A total electrical failure or total G1000 failure would mean no PFD, no nav, no comm, no transponder. The GPS could have been any handheld device, from an iPad to a Huawei cellphone.

        [ATTACH=CONFIG]6842[/ATTACH]
        Good Evening, Buenos Aires.

        No PFD? You make an 'almost senior' (defined during the last US election as 'men, older than 40') shiver!
        And No COM? But the twin Cessna did communicate that they had problems, or not? Ah, "would" or "if" is the keyword. If the twin Cessna had lost all its electricity, they also would've lost COM. Do you have to mention such nightmares in the middle of the night? For me, it is 0329 am!

        Nevertheless, dearest greetings to... interesting 747 destinations.

        PS: And with an operator of a semipro LH-B744 simulator, you shouldn't make bad jokes in the middle of the night. 'they didn't have an old VOR and ADF'. I don't know the exact Cessna type, but some twin Cessnas are built since the mid-1960's, so, with, so to say, more experience as we both could ever deliver, even if we were able to deliver live aviation experience since our dob, which indeed is not the case.

        SO, I take for granted that the twin Cessna, e.g. a Cessna 411, provides "OLD" VOR and ADF needles,
        as, btw, my avatar!
        Old. The Cessna 411 is born in 1962. Don't mention that word in presence of the on duty US-President Obama.

        Probably Joe Sutter (1921-2016) was older than both of us when he tried to sell the 748i at his 90th birthday.
        But really really old?
        Last edited by LH-B744; 2016-11-18, 02:58. Reason: Old?
        The German long haul is alive, 65 years and still kicking.
        The Gold Member in the 747 club, 50 years since the first LH 747.
        And constantly advanced, 744 and 748 /w upper and lower EICAS.
        This is Lohausen International airport speaking, echo delta delta lima.

        Comment


        • #19
          Hey LH. A twin Cessna can be anything from a Cessna 310 to a Citation XLS. And right, the scenario I posted would mean no comm but they were communicated (although this could have been through a handheld radio), but I was just explaining a scenario, not that I believe that this is what happened.

          If you asked me, they had some relatively minor failure. They had transponder and radio, probably also a legacy VOR. And no reason to believe they lost any of the flight instruments. Maybe they had a GPS with moving map and were too reliant on that so when they lost it they suddenly didn't know where they were. Child of the magenta line.

          --- 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


          • #20
            Originally posted by Gabriel View Post
            Hey LH. A twin Cessna can be anything from a Cessna 310 to a Citation XLS. And right, the scenario I posted would mean no comm but they were communicated (although this could have been through a handheld radio), but I was just explaining a scenario, not that I believe that this is what happened.

            If you asked me, they had some relatively minor failure. They had transponder and radio, probably also a legacy VOR. And no reason to believe they lost any of the flight instruments. Maybe they had a GPS with moving map and were too reliant on that so when they lost it they suddenly didn't know where they were. Child of the magenta line.
            Don't you mention the word magenta line in combination with the word child. Both of us are old enough so that we could have a son that might be named 'son of the magenta line'.

            And the word old. Did you completely read my edited #18?

            Cessna 411: older than a quite prominent US-guest today in Germany. Cessna 310 (*1953)? The older the better, at least if we talk about VOR knowledge.

            Old. I like to replace that word by 'experience'. Joe Sutter was not old when he died at 95 this year. But he provides a unique heritage, as both, the engineer father, and the grandfather of 'not yet old aviation enthusiasts'... :
            the 747 experience.

            Btw, I sometimes use a Baron 58 (*1969) on my computer. With 'old' VOR needles. And, as I mentioned, Sutters B744 (invented 1989) also provides (two) VOR receivers. You only have to know where they are hidden, and, of course, what it means if you read 'radial 311 DUS'.

            Still hard to believe for me, that a twin engine propeller pilot (i.e. advanced?) forgot the VOR. But IFR is not mandatory for twin engine propeller pilots.

            As you sometimes wonder in your car, where have all the people learned to... fly. Obviously not with you in the cockpit.
            The German long haul is alive, 65 years and still kicking.
            The Gold Member in the 747 club, 50 years since the first LH 747.
            And constantly advanced, 744 and 748 /w upper and lower EICAS.
            This is Lohausen International airport speaking, echo delta delta lima.

            Comment


            • #21
              Originally posted by LH-B744 View Post
              And it was a bit of luck, too. Both a/c are twin-engine propellers? So, they operate with approx. the same speed? Good.
              Unclear what Dash 8 this was but the report states that they had to deploy flaps to drag it down to the Cessna approach speed. The Q300-400 approach speed is not so far below a 737 classic, and let's not forget about that added 15-20kt margin with anti-ice if the situation calls for it. Flying 3000' above the Cesnna, they had to bring out significant drag to stay with it.

              Comment


              • #22
                Evan, drag is not the issue. You can also decrease thrust.

                The problem is to keep lift up without nearing too much to the stall, since the lift goes with the square of lift and you need to keep it equal to the wight by increasing the AoA and/or deploying high lift devices.

                --- 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


                • #23
                  Originally posted by Gabriel View Post
                  Evan, drag is not the issue. You can also decrease thrust.

                  The problem is to keep lift up without nearing too much to the stall, since the lift goes with the square of lift and you need to keep it equal to the wight by increasing the AoA and/or deploying high lift devices.
                  So, maintaining about 3000' vertical seperation without descending or stalling or overflying the Cessna on final, they had to deploy flaps. Decreasing thrust isn't going to work there.

                  Comment


                  • #24
                    I meant if what you wanted was more drag (as you said in the previous post), then you could reduce thrust instead for the same effect (instead of more drag you have less thrust, for the same effect).
                    But the intention when they extended the flaps was not to add drag but to improve lift availability at low speed (increase CLmax or, in other words, reduce the 1G stall speed), and of course reducing power won't help there.

                    --- 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


                    • #25
                      [QUOTE=LH-B744;644198]And it was a bit of luck, too. Both a/c are twin-engine propellers? So, they operate with approx. the same speed?/QUOTE]

                      As usual!

                      Comment


                      • #26
                        Originally posted by Gabriel View Post
                        Evan, drag is not the issue. You can also decrease thrust.

                        The problem is to keep lift up without nearing too much to the stall, since the lift goes with the square of lift and you need to keep it equal to the wight by increasing the AoA and/or deploying high lift devices.
                        To Evan (not Gabe).

                        Your black and white thinking again betrays you.

                        "Flaps increase drag and reduce stall speed" (If you have to say in one sentence what flaps do, that would be it).

                        BUT, in the fuzzy gray realm, the first 25% or so of flap deployment increases wing area, increases available lift, and decreases stall speed markedly with relatively small increases in drag.

                        The final 33% (or Lord knows what number as there are too many variables) markedly increases drag with somewhat less effect on lift and stall speed.
                        Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                        Comment


                        • #27
                          Originally posted by Gabriel View Post
                          ...If you asked me, they had some relatively minor failure. They had transponder and radio, probably also a legacy VOR. And no reason to believe they lost any of the flight instruments. Maybe they had a GPS with moving map and were too reliant on that so when they lost it they suddenly didn't know where they were. Child of the magenta line...
                          There's plenty of unknowns here, and I might suggest we lay off of the Child of the magenta line stereotype.

                          Indeed ITS would handle an engine failure with a compass, stopwatch and a map, and navigate with pure genius, with no assistance whatsoever to the destination (and probably ask the Dash-8 to follow him so he could impart valuable airmanship wisdom via a Morse code flashlight to them along the way).

                          At the other end of the spectrum is that 'traditional' light twins are probably the highest workload planes there are...Throttle, mixture, props, cowl-flaps for temperature management, and at the extreme, maybe even carburetor heat. No Airbus auto throttle, no auto rudder trim, limited (or no) autopilot, have to fumble through an inch-thick book to look up your approach plate, no hydraulically assisted controls and generally not as much slop factor with respect to extra power.

                          This could have been a very OK pilot, who made the classic mistake of not being totally prepared for an engine failure and was pretty tied up aviating. If I am not mistaken, he was continuing his flight, and talking with ATC.

                          This might have been a very simple save...Dash-8, "Hey, you might want to go land here instead of there, and you know what, want to just follow me there?"

                          If you heard that, the best CRM decision might be, "Yes, I would LOVE to follow you there...it's really kind of awkward to look at this hand-held GPS while holding hard rudder and aileron inputs for the asymmetric thrust.

                          Regarding my earlier rants- this is clearly too complicated for the press to handle (they generally screw up much simpler incidents just fine). I will still chuckle at the information flow...Lost all instruments, well they had a GPS...oh and by the way, they lost an engine...Maybe that engine failure needed to be the lead. "Airliner helps guide aircraft with engine and navigation problems to alternate airport!!!!"....Yeah, not sexy at all.
                          Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                          Comment


                          • #28
                            Originally posted by Gabriel View Post
                            I meant if what you wanted was more drag (as you said in the previous post), then you could reduce thrust instead for the same effect (instead of more drag you have less thrust, for the same effect).
                            But the intention when they extended the flaps was not to add drag but to improve lift availability at low speed (increase CLmax or, in other words, reduce the 1G stall speed), and of course reducing power won't help there.
                            Originally posted by AVherald
                            The Dash 8 followed 3000 feet above the Cessna with flaps extended to slow the aircraft down and match their speed with the Cessna, there was sufficient fuel on board so that this was not a concern to the Dash.
                            ...implying that the flap configuration would result in increased fuel burn. Why?

                            Comment


                            • #29
                              Originally posted by Evan View Post
                              ...implying that the flap configuration would result in increased fuel burn. Why?
                              Originally posted by Evan
                              they had to deploy flaps to drag it down to the Cessna approach speed
                              Flaps do increase drag. They didn't extend the flaps to increase the drag, that was a side effect in this case.
                              More drag increases fuel consumption, as it does to rendezvous with another airplane at low altitude drifting away of your intended route and away from your intended destination.

                              --- 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


                              • #30
                                Originally posted by 3WE View Post
                                ...the first 25% or so of flap deployment increases wing area, increases available lift, and decreases stall speed markedly with relatively small increases in drag....
                                A good, broad fundamental procedure when you need to fly kind of slow.

                                Increases your margin above stall speed.

                                I guess they left that out on the Dash-8 QRH under the heading "Helping a Small, Slow Twin with Navigation Issues", and we cannot refer to QRH's from a 737-200 nor 737-236A for general reference.

                                Originally posted by Evan
                                they had to deploy flaps to drag it down to the Cessna approach speed
                                Wrong...

                                They reduced power and trimmed nose up* and let total drag (induced + parasite) reduce airspeed.

                                As they slowed to where the margin between their speed and their stall speed became small enough to be 'significant', they added flaps to lower stall speed. [drag increased a small amount as 'approach' flaps were deployed, power would have been increased to counteract the slight additional drag).

                                Not unlike any instance of descending and slowing for landing, and to some extent- speed and flap settings are even specified in procedures.

                                *This does not mean the attitude moved nose up- as they also appear to have descended.
                                Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

                                Comment

                                Working...
                                X