Attitude Indicator and Stalls.

Discussion in 'Cleared for the Approach' started by luvflyin, Sep 29, 2019.

  1. luvflyin

    luvflyin Final Approach

    Joined:
    May 8, 2015
    Messages:
    7,186
    Location:
    Vancouver, WA
    Display Name:

    Display name:
    Luvflyin
    I posted this, "As I recall, the only thing that could have resolved the problem was the Attitude Indicator. Put the wings so many bar widths above the horizon and hold it there regardless of what the other instruments were saying," in a thread about auto pilots that led to the Air France accident. Didn't get any response and I want to know, so starting this thread about it in particular. Youse big iron guys, is this part of emergency training? When everything else goes nips up and starts lying to you, just hold an 'attitude.'
     
  2. MauleSkinner

    MauleSkinner Final Approach

    Joined:
    Oct 25, 2005
    Messages:
    6,212
    Location:
    Wichita, KS
    Display Name:

    Display name:
    MauleSkinner
    Pitch plus power still equals performance.
     
    Hacker and denverpilot like this.
  3. Larry in TN

    Larry in TN Cleared for Takeoff

    Joined:
    Nov 16, 2013
    Messages:
    1,325
    Location:
    Nashville, TN
    Display Name:

    Display name:
    Larry in TN
    It is part of the Airspeed Unreliable checklist on the 737 as a memory item.

    Flaps extended ... 10° ANU and 80% N1
    Flaps up ... 4° ANU and 75% N1
     
    denverpilot, Stickman and Eric Stoltz like this.
  4. luvflyin

    luvflyin Final Approach

    Joined:
    May 8, 2015
    Messages:
    7,186
    Location:
    Vancouver, WA
    Display Name:

    Display name:
    Luvflyin
    N1?? What exactly are the words in ANU?
     
  5. luvflyin

    luvflyin Final Approach

    Joined:
    May 8, 2015
    Messages:
    7,186
    Location:
    Vancouver, WA
    Display Name:

    Display name:
    Luvflyin
    Performance, pershmorfance. Just tryin to stay in the air here.
     
  6. MauleSkinner

    MauleSkinner Final Approach

    Joined:
    Oct 25, 2005
    Messages:
    6,212
    Location:
    Wichita, KS
    Display Name:

    Display name:
    MauleSkinner
    Ok...pitch plus power still allows you to stay in the air because you’re not clueless as to what your airplane is doing.
     
  7. Larry in TN

    Larry in TN Cleared for Takeoff

    Joined:
    Nov 16, 2013
    Messages:
    1,325
    Location:
    Nashville, TN
    Display Name:

    Display name:
    Larry in TN
    N1 is the speed of the fan (low-speed spool) in percentage. It is the primary power indication for each engine. We also have an indication of N2 which is the speed of the high-speed or core spool. N2 is not generally used for setting power settings.

    ANU is Aircraft Nose Up. Pitch attitudes below the horizon are AND.
     
    denverpilot likes this.
  8. luvflyin

    luvflyin Final Approach

    Joined:
    May 8, 2015
    Messages:
    7,186
    Location:
    Vancouver, WA
    Display Name:

    Display name:
    Luvflyin
    Yeah. Gotcha.
    Flaps extended ... 10° ANU and 80% N1
    Flaps up ... 4° ANU and 75% N1
    That is pitch plus power
     
  9. luvflyin

    luvflyin Final Approach

    Joined:
    May 8, 2015
    Messages:
    7,186
    Location:
    Vancouver, WA
    Display Name:

    Display name:
    Luvflyin
    What about power? If the engine instruments aren’t passing the logic check like what happened to Air Florida into the Potomac, is there a default setting? Like say 4” short of full throttle or something like that?
     
  10. MauleSkinner

    MauleSkinner Final Approach

    Joined:
    Oct 25, 2005
    Messages:
    6,212
    Location:
    Wichita, KS
    Display Name:

    Display name:
    MauleSkinner
    Yes.
     
    Eric Stoltz likes this.
  11. Sluggo63

    Sluggo63 Line Up and Wait

    Joined:
    Oct 9, 2013
    Messages:
    893
    Display Name:

    Display name:
    Sluggo63
    No. Nothing like that.

    Air Florida was using EPR (Engine Pressure Ratio) which can be affected by things like probes icing over. N1, unless the transmitter fails, will give a true representation of thrust.

    Air Florida crashed because those guys had no idea how to do winter operations.
     
  12. Larry in TN

    Larry in TN Cleared for Takeoff

    Joined:
    Nov 16, 2013
    Messages:
    1,325
    Location:
    Nashville, TN
    Display Name:

    Display name:
    Larry in TN
    If the problem was a failure in the engine instrumentation then we'd set the power to achieve the desired airspeed. We have three independent airspeed indicating systems.

    I've had an unreliable airspeed once in the 737. It took about five seconds to compare the three readings and determine which one was bad.
     
    denverpilot and Eric Stoltz like this.
  13. aterpster

    aterpster Pattern Altitude

    Joined:
    Apr 15, 2011
    Messages:
    2,485
    Display Name:

    Display name:
    aterpster
    We always used EPR for power settings.
     
  14. Doc Holliday

    Doc Holliday Line Up and Wait

    Joined:
    Dec 9, 2016
    Messages:
    670
    Location:
    Tombstone
    Display Name:

    Display name:
    Doc Holliday
    EPR is the primary, but should be backed up with N1 and fuel flow.
     
    Eric Stoltz likes this.
  15. dtuuri

    dtuuri En-Route

    Joined:
    Apr 21, 2011
    Messages:
    3,735
    Location:
    Madison, OH
    Display Name:

    Display name:
    dtuuri
    Well, the EPR probes were full of deice fluid. Then, the copilot, who was making the takeoff, was complaining to the Captain that the thrust levers didn't "feel right" (not pushed far enough forward), but in ambiguous language. In response, the captain referenced the EPR gauges and insisted the thrust was correctly set. See my post in the Marine crash thread re: the conservative response to challenge. They ought to have aborted to find the cause of their disagreement.
     
  16. Doc Holliday

    Doc Holliday Line Up and Wait

    Joined:
    Dec 9, 2016
    Messages:
    670
    Location:
    Tombstone
    Display Name:

    Display name:
    Doc Holliday
    After the AF crash airlines began adding N1 setting to the TOLD card in addition to target EPR. Trust, but verify.
     
    denverpilot and dtuuri like this.
  17. Sluggo63

    Sluggo63 Line Up and Wait

    Joined:
    Oct 9, 2013
    Messages:
    893
    Display Name:

    Display name:
    Sluggo63
    It wasn't deice fluid on the probes, it was ice. These guys used reverse on the ground to help the pushback (throwing ice and slush forward into the engine), they never turned the engine anti-ice on in heavy snow and freezing temperatures, they got close to an aircraft in front of them in an attempt to melt the ice off their own leading edges (which had the opposite effect of melting the snow and having it refreeze on the LE), then they attempted to take off with snow and ice adhering to the wing and finally they either (a) didn't reject the takeoff or (b) push the thrust levers up when they got the stick shaker.
     
  18. dtuuri

    dtuuri En-Route

    Joined:
    Apr 21, 2011
    Messages:
    3,735
    Location:
    Madison, OH
    Display Name:

    Display name:
    dtuuri
    You don't know that for a fact. We do know that deicing personnel were observed shining their pressure washers onto inlet cowls where the EPR probes were located, IIRC. As to some of your other comments, after every accident those with an agenda start citing their pet causes in "Never waste a crisis," fashion. EPR probes can fail and aircraft can usually takeoff with some contamination on the wings, a lot of others did that day. You wouldn't blame the crew if it was simply a mechanical EPR indication failure, I bet, using your same logic. But the result would have still been a crash.You will never convince me the real root cause wasn't the lack of communication between the pilots regarding the true nature of the copilot's concern. That and, as you did mention, not hitting the iron stops with the thrust levers when faced with stall warnings. That isn't necessarily emphasized enough during training, or at least wasn't back then.
     
    Last edited: Sep 30, 2019
  19. luvflyin

    luvflyin Final Approach

    Joined:
    May 8, 2015
    Messages:
    7,186
    Location:
    Vancouver, WA
    Display Name:

    Display name:
    Luvflyin
    Is N1 something
    I was wondering if they had that N1 thing back then. Guess so. What exactly is it?
     
  20. Doc Holliday

    Doc Holliday Line Up and Wait

    Joined:
    Dec 9, 2016
    Messages:
    670
    Location:
    Tombstone
    Display Name:

    Display name:
    Doc Holliday
    N1 refers to turbine rpm in percent. And yes, they had it on the 737-200 (P&W JT-8D).

    From Wikipedia:

    [​IMG]
    The blue area is N1, and the yellow area is N2.

    When calculating TO thrust for a certain runway using temperature and wind, plus any runway contamination (water, slush, ice) an EPR number is derived, plus a target N1 number to crosscheck the EPR setting.
     
    Last edited: Sep 30, 2019
  21. Larry in TN

    Larry in TN Cleared for Takeoff

    Joined:
    Nov 16, 2013
    Messages:
    1,325
    Location:
    Nashville, TN
    Display Name:

    Display name:
    Larry in TN
    The CFMs (GE) don't have EPR like the Pratts did. Can't remember if Rolls engines have EPR.

    Doesn't really matter, though. The "top gauge" is the primary for setting power.
     
  22. Stickman

    Stickman Pre-takeoff checklist

    Joined:
    Mar 10, 2018
    Messages:
    214
    Location:
    0AK1 Wasilla, AK
    Display Name:

    Display name:
    Stickman
    Similar on the MD-11.
     
  23. Doc Holliday

    Doc Holliday Line Up and Wait

    Joined:
    Dec 9, 2016
    Messages:
    670
    Location:
    Tombstone
    Display Name:

    Display name:
    Doc Holliday
    RR RB-211's were "triple spool" engines and had EPR for power settings.
     
  24. Larry in TN

    Larry in TN Cleared for Takeoff

    Joined:
    Nov 16, 2013
    Messages:
    1,325
    Location:
    Nashville, TN
    Display Name:

    Display name:
    Larry in TN
    That's a tall stack.

    EPR
    N1
    EGT
    N2
    N3
     
  25. Doc Holliday

    Doc Holliday Line Up and Wait

    Joined:
    Dec 9, 2016
    Messages:
    670
    Location:
    Tombstone
    Display Name:

    Display name:
    Doc Holliday
    Yep. B757 with RR RB-211's

    [​IMG]
     
  26. Larry in TN

    Larry in TN Cleared for Takeoff

    Joined:
    Nov 16, 2013
    Messages:
    1,325
    Location:
    Nashville, TN
    Display Name:

    Display name:
    Larry in TN
    Hey! Your CWS switches are missing!
     
  27. Sluggo63

    Sluggo63 Line Up and Wait

    Joined:
    Oct 9, 2013
    Messages:
    893
    Display Name:

    Display name:
    Sluggo63
    What’s up with those tiny little TVs and all those clocks?
    FD461AAD-3965-44EC-AAFA-93B4A79EB266.jpeg
     
  28. NoHeat

    NoHeat En-Route

    Joined:
    Jul 27, 2009
    Messages:
    3,731
    Location:
    Iowa City, IA
    Display Name:

    Display name:
    17
    I like the first officer's turn coordinator.
    Screen Shot 2019-09-30 at 11.02.54 PM.png
     
    N1120A and Sluggo63 like this.
  29. Doc Holliday

    Doc Holliday Line Up and Wait

    Joined:
    Dec 9, 2016
    Messages:
    670
    Location:
    Tombstone
    Display Name:

    Display name:
    Doc Holliday
    Fedex 767 cockpit?
     
  30. Sluggo63

    Sluggo63 Line Up and Wait

    Joined:
    Oct 9, 2013
    Messages:
    893
    Display Name:

    Display name:
    Sluggo63
    757. The 76s have the larger displays.
     
  31. denverpilot

    denverpilot Tied Down

    Joined:
    Nov 8, 2009
    Messages:
    50,546
    Location:
    Denver, CO
    Display Name:

    Display name:
    DenverPilot
    Shouldn’t they have done that all the way back at Air Florida dunking themselves in a river?
     
  32. Sluggo63

    Sluggo63 Line Up and Wait

    Joined:
    Oct 9, 2013
    Messages:
    893
    Display Name:

    Display name:
    Sluggo63
    AF = Air Florida
     
  33. aterpster

    aterpster Pattern Altitude

    Joined:
    Apr 15, 2011
    Messages:
    2,485
    Display Name:

    Display name:
    aterpster
    Yes indeed.
     
  34. Pugs

    Pugs Pre-takeoff checklist

    Joined:
    Oct 24, 2018
    Messages:
    221
    Location:
    Maryland
    Display Name:

    Display name:
    Pugs
    Cross-cockpit experience gradient.... Yep, abort and work it out. One of our case studies from safety school.
     
  35. denverpilot

    denverpilot Tied Down

    Joined:
    Nov 8, 2009
    Messages:
    50,546
    Location:
    Denver, CO
    Display Name:

    Display name:
    DenverPilot
    LOL crap. I read it as [US]AF.
     
  36. neilki

    neilki Pre-Flight

    Joined:
    Jul 11, 2014
    Messages:
    93
    Location:
    New York
    Display Name:

    Display name:
    neilki
    The Airbus has Memory Items for Stall Indictions on takeoff and other phases of flight. It's simply a pitch and power combination.
    Most of my operators aircraft have the Backup Speed System (BUSS):) that replaces Airspeed with AoA data and GPS derived Altitude
     

    Attached Files: