BI 7
1.  Discuss:

    a.  Inverter failure

        Failure of inverter No. 1 or inverter No. 2 will be indicated by a flashing MASTER CAUTION light, illumination of the INVERTER annunciator light, and loss of all ac-powered instruments and equipment.

NOTE - If the 115-Vac, 1-amp circuit breaker pops, resetting this circuit breaker will provide power to the FWD and AFT cockpit attitude instruments regardless of inverter selected.  If the 115-Vac, 1-amp circuit breaker cannot be reset, the front cockpit attitude instruments will operate normally when inverter No. 2 is selected.

        1)  Cycle electrical control transfer/TAKE COMMAND switch
 
        If annunciator remains illuminated:
        2)  Switch to the other inverter
        3)  Check inverter control relay circuit breaker - IN

WARNING - A popped 115-Vac, 1-amp circuit breaker will cause the loss of certain 115-Vac instruments depending on the cockpit and the inverter selected.  Instrument flight is not possible with a complete loss of ac power.  Indications are as follows:

1.  Front cockpit:  No. 1 inverter selected - Flashing MASTER CAUTION,
                    INVERTER annunciator lights and loss of attitude gyro and
                    turn needle.
                    No. 2 inverter selected - No indications.

2.  Rear cockpit:   No. 1 inverter selected - Flashing MASTER CAUTION,
                    INVERTER annunciator lights and loss of attitude gyro.
                    No. 2 inverter selected - Loss of attitude gyro and turn
              needle.

    b.  Generator failure

        If the generator becomes inoperative, indications will be flashing MASTER CAUTION light and an illuminated GENERATOR annunciator.

        1)  Starter switch - OFF (both cockpits)
        2)  Generator switch - ON (reset)

        If annunciator remains illuminated:
        3)  Cycle electrical control transfer/TAKE COMMAND switch
        4)  Generator switch - ON (reset)
 
        If generator does not return to line:
        5)  Reduce all nonessential electrical loads
        6)  Land as soon as practical
 
 
 
 
 
 

    c.  Gyro failure

        Partial panel flight begins upon failure of the primary attitude instrument, the attitude gyro.  The flight must now be continued and the aircraft attitude controlled by referring to the remaining instruments only.  The loss of the gyro can occur in various ways:

        1)  the failure or tumbling of the gyro itself

        2)  An inverter (AC power) failure (115 Vac)

        Failure of the gyro itself would be recognized by an OFF flag in the instrument.  The indication of a RMI failure would be a red flag on the indicator.

NOTE - In the T-34C, ACTUAL instrument flight would NOT be possible with an AC power failure.  Practice partial panel will be utilized simulating the turn needle as a DC powered instrument.

    d.  Partial panel

        When an AC power failure is recognized:
        1)  Continue to fly the aircraft.

        2)  Execute INVERTER FAILURE procedures.

        3)  Continue the maneuver.

        If the gyro still shows an OFF flag:
        1)  Smoothly level the wings with coordinated rudder and aileron
 
        2)  Reposition the nose to the straight and level flight attitude by cross checking the VSI and altimeter for level flight nose attitude.

        3)  Check the turn needle and balance ball for the wings level balanced flight condition.

        4)  When established and TRIMMED in straight and level flight, initiate PARTIAL PANEL SCAN including the turn needle and balance ball for roll and yaw control; also VSI and altimeter for pitch control.  Report:

        ICS “I HAVE AN AC POWER FAILURE; EMERGENCY PROCEDURES COMPLETED WITH
            NEGATIVE RESULTS; ON PARTIAL PANEL SCAN.”

    e.  Limited use of magnetic (wet) compass

        The instrument has a pronounced turning and pitching error during any change of attitude.  These errors appear as tendencies for the compass card to “lag” or “lead” the aircraft heading during the turn and to swing unpredictably in turbulent air.  Only when the airplane is in straight and level, balanced flight in relatively smooth air, can you rely on the indication of this compass.
 
 

 
        In extreme latitudes near the magnetic poles, the instrument oscillates and swings unpredictably, and without proper correction, it is useless for heading indications.  Under certain conditions, the magnetic compass will indicate accurately in attitudes other than straight and level flight.  These instances are:

        1)  When turning through a heading of East or West with the AOB less than 18 degrees.

        2)  When accelerating or decelerating, climbing or descending at a pitch angle of not more than 18 degrees, on a heading of North or South.

2.  Introduce:

    a.  Unusual attitudes partial panel (UA-PP)

        It is of extreme importance during actual instrument flight that the pilot not allow himself to get into a situation which could result in an unusual attitude on partial panel.  It is sometimes difficult to visualize, through the partial panel instruments, either the nose attitude or the wing position.  For example, beyond a two-needle-width turn where the needle is pegged, there may exist a higher rate of turn or a continuous roll.

        The unusual attitudes will be entered in a smooth and coordinated manner from normal cruise (150 kts).  The instructor will not exceed the following limitations on entry:

        1)  50 degrees nose high
        2)  40 degrees nose low
        3)  A two-needle-width deflection on the turn needle

        Recovery procedures:

        1)  HOLD THE STICK PRESSURE as you recognize whether nose high or nose low by the actions of the airspeed indicators; wing position by the turn needle.
        2)  If the airspeed is approaching 200 kts, reduce power to idle, cross check the altimeter and VSI.
        3)  Using smooth coordinated rudder and aileron, center the ball, then level the wings on the turn needle.
        4)  Smoothly and slowly relax stick pressure as necessary to stop the airspeed as you keep the ball centered and wings level.
        5)  When the airspeed has stopped accelerating, shift your scan to the turn needle and balance ball, as well as VSI.  Keep the ball centered and the wings level as you adjust nose position until the VSI stabilizes at “O.”  If you had previously reduced the power on recovery (nose low), reset normal cruise approaching 150 kts.

NOTE - Wingover (90 degree bank) recoveries will not be performed.
 

        Common errors:

        1)  Rolling wings level rapidly and over banking in the opposite direction.  Remember to “lead” the turn needle by stopping the wings prior to the needle completely centering.
        2)  Not stopping the airspeed.
        3)  Not allowing the VSI and altimeter to stabilize prior to making the next nose correction.
        4)  Chasing the altimeter and VSI.
        5)  Forgetting to reset normal cruise power if you had previously reduced to idle during nose low recovery.

3.  Practice:

    a.  ICA
    b.  Approach pattern
    c.  S-1 pattern
    d.  Partial panel straight and level
    e.  Partial panel timed turns
    f.  Partial panel en route descent
    g.  Penetration maneuver
    h.  BAC maneuver
    i.  Direct to a VOR or TACAN