Page 12 of 12 FirstFirst ... 2101112
Results 221 to 227 of 227

Thread: Pitot Tube Failure

  1. #221
    Senior Member 3WE's Avatar
    Join Date
    Jan 2008
    Posts
    5,093

    Default

    Quote Originally Posted by Gabriel View Post
    If you want to get higher you have to climb so "climb" has to be at least related with an intermediary goal. But "climb" by itself is insufficient (as a goal or as a mean to achieve it).

    If you are driving North and want to go West, you just turn West? (and bump into a fence for not doing it in a corner or lose control for applying just 1/8 of the steering wheel travel at 100 MPH?).
    C-172M Memory Checklist for Climb

    -AIRSPEED, ATTITUDE AND ALTITUDE APPROPRIATE FOR FLIGHT AND CLIMB...CONFIRM
    -SIMULTANEIOUSLY ADJUST POWER, ATTITUDE AND AIRSPEED TO VALUES KNOWN FOR CLIMB
    -MAINTAIN ATTITUDE AND AIRSPEED TO COUNTERACT DREADED PHUGOID BEHAVIOR
    -ADJUST MIXTURE WHEN ABOVE 3000 FEET AGL[/SIZE]

    I suppose that 172 S and A300 memory checklist might suggest an aggressive 1.5G 6000 ft pull ups with no attention to airspeed at all whatsoever. But I dunno, in my cowboy improvisational mind, significant attitude adjustments with unreliable airspeed seems like a bad idea.
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

  2. #222
    Senior Member Evan's Avatar
    Join Date
    Jan 2008
    Posts
    6,734

    Default

    Quote Originally Posted by ATLcrew View Post
    Which is why that's what Airbus actually preaches...
    Wait a tick ATL... This IS the procedure from the BEA report that AF447 had onboard.

    Click image for larger version. 

Name:	annexe.06.jpg 
Views:	19 
Size:	193.7 KB 
ID:	27379

    There are two options:

    1) Memory items 'if the safe conduct of the flight is impacted'
    2) Instructions to level off if 'the safe conduct of the flight' is not impacted.

    There is no 'do nothing' here. Option 2 still instructs pilots to use 'PITCH/THRUST FOR INITIAL LEVEL OFF' by following a reference table with specific values. That is a procedure involving a pilot doing A instead of B (improvising).

    Certainly, as this is not a memory procedure, if the pilots have been too lax to learn the QRH procedure, they will have to do something before this procedure is called and followed, and that something is what I'm getting at. It shouldn't be left to personal improvisation. It should also be a memorized procedure (even if it instructs them to remain at the current or typical pitch and power but not their current flight level).

    Case in point AF447:

    Pitch 5 secs before the autopilot disconnect (2h 10min 00) : 1.8 deg (let's consider this 'typical pitch' for this phase of flight).
    Altitude 5 secs before the autopilot disconnect (2h 10 min 00): 35,024.
    Vertical Speed 5 secs before the autopilot disconnect (2h 10 min 00): 0 +/-.
    Normal Acceleration 5 secs before the autopilot disconnect (2h 10 min 00): 1G +/-.

    Pitch at the time of the autopilot disconnect (2h 10min 05): 0 deg.
    Altitude reading just after autopilot disconnect (2h 10min 09): 34,664.
    Vertical Speed reading just after autopilot disconnect (2h 10min 07): -400 fpm (estimated from the FDR).
    Normal Acceleration just after autopilot disconnect (2h 10min 05): .7G +/-.

    Now, If your improvised airmanship goal was to 'level off', given the apparent descent depicted by your instruments (along with 8.4 deg of roll and turbulence), and you consider level flight to be FL350 with approximately 2 deg of pitch, wouldn't leveling off lead you to pull up slightly?

    If so, now you've added pitch that wasn't needed (due to deception from misleading instrument readings) and this will result in you leaving level flight and slowing down.

    Now, let's say you aren't skilled with manual flight at this speed/flight level. Isn't it possible to overcontrol a bit there?

    Maximum Normal Acceleration during the first 5 secs after autopilot disconnect: 1.25G.
    Pitch attitude 5 seconds after the loss of autopilot (2h 10mins 10): 4-5 deg .
    Stall warning threshold: 4 deg +/- AoA

    The thing you must keep in mind is that I'm ONLY talking about the intial actions needed to stabilize long enough to get to the QRH. Those critical moments when a memory procedure would be very helpful...

    (At about 2h 10min 10, I suspect the intention to ascend took hold. That's another matter.)

  3. #223
    Senior Member 3WE's Avatar
    Join Date
    Jan 2008
    Posts
    5,093

    Default

    I’ll try to remember all that next time I ride a bike.
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

  4. #224
    Member ATLcrew's Avatar
    Join Date
    Sep 2013
    Posts
    959

    Default

    Quote Originally Posted by Evan View Post
    Certainly, as this is not a memory procedure, if the pilots have been too lax to learn the QRH procedure, they will have to do something before this procedure is called and followed, and that something is what I'm getting at. It shouldn't be left to personal improvisation. It should also be a memorized procedure (even if it instructs them to remain at the current or typical pitch and power but not their current flight level).
    Still waiting for that open mind. I don't need a written memory item to know what pitch and power settings are safe for my airplane. If it will give you some sort of warm and fuzzies for Airbus to put them out on a piece of paper with the words "Memory Item" on top, I guess I don't have a problem with that. My point remains, however, that any pilot who doesn't know those already won't be saved by a memory item either.

  5. #225
    Senior Member Gabriel's Avatar
    Join Date
    Jan 2008
    Location
    Buenos Aires - Argentina
    Posts
    6,994

    Default

    Quote Originally Posted by ATLcrew View Post
    Still waiting for that open mind. I don't need a written memory item to know what pitch and power settings are safe for my airplane. If it will give you some sort of warm and fuzzies for Airbus to put them out on a piece of paper with the words "Memory Item" on top, I guess I don't have a problem with that. Our point remains, however, that any pilot who doesn't know those already won't be saved by a memory item either.
    Fixed, and I guess you can start with whatever you had at that time and work from there. 12 degrees higher is possibly not a good target.

    --- 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 ---

  6. #226
    Senior Member Evan's Avatar
    Join Date
    Jan 2008
    Posts
    6,734

    Default

    Quote Originally Posted by ATLcrew View Post
    Still waiting for that open mind. I don't need a written memory item to know what pitch and power settings are safe for my airplane. If it will give you some sort of warm and fuzzies for Airbus to put them out on a piece of paper with the words "Memory Item" on top, I guess I don't have a problem with that. My point remains, however, that any pilot who doesn't know those already won't be saved by a memory item either.
    Still waiting for you to read my words and respond to my actual concern. I've already said that I don't doubt that you know what pitch and power settings are safe. This is about doing that vs doing something else, such as attempting to regain flight level after an upset or attempting to transit to a higher one. To the crew of AF447, there was no memorized procedure to maintain safe pitch and power vs regain altitude or arrest vertical rate. There was only a written procedure (never pulled out) to level off with prescribed pitch and power settings. Therefore, everything in that moment was left to personal pilot judgment and improvisation in a deceptive environment. And look what happened.

    AFAIK, procedurally, nothing has changed as a result.

  7. #227
    Senior Member 3WE's Avatar
    Join Date
    Jan 2008
    Posts
    5,093

    Default

    Quote Originally Posted by Evan View Post
    To the crew of AF447, there was no memorized procedure to maintain safe pitch and power vs regain altitude or arrest vertical rate.
    I firmly believe there are all sorts of memory procedures to climb, descend, level, speed up, slow down, go left, go right...

    AS WELL AS TO CONTINUE STRAIGHT AHEAD IN LEVEL, FAT, DUMB AND HAPPY FLIGHT.

    And, I firmly believe there is a reasonable memory procedure on how to stall a plane...unfortunately that was the memory procedure that was chosen.
    Les règles de l'aviation de base découragent de longues périodes de dur tirer vers le haut.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •