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  • Some new questions

    Hello!
    Some of the questions I couldn't find in question bank :
    wording uncertain in addition to my poor English.
    1 what initial indications when encountering down draft:
    increase/decrease headwind and inc/dec tailwind (doesn't say if its in front or behind of the aircraft)
    2 what happens when engine inlet probe icing occurs: (one to choose)
    - A/P disconnecting, A/T reducing and disconnecting
    - engine stall
    - A/T retarding
    - ?
    3 Can a flight be conducted to an airport ILS II equipped if one of two rad alts fails? One out of four answers (which I cant recollect) to choose
    there was 3 other questions asking about ILS2 with connection to 2 rad alts
    4 This is my favourite, cant recollect exact wording, but it was VERY technical:
    Which is one of he ground (school?) based requirements for pilots studying instrument rating?
    - additional requirements for LVO with D/H above 250 ft
    - requirements for LVO with D/H below 800ft
    - requirements for LVO with D/H below 550 ft
    - additional requirements for LVO above 500 ft
    this one is as close to the exam question as I can remember.
    5 Can a flight be conducted if one of the pilots fail LVO recurrent due to flight sim failure?
    - yes if the RVR at the destination is above 300m
    - yes if MD/MDA below ceiling
    - no - and that seems to be correct
    - yes if the pilot with current LVP is the pilot flying
    I also found that some of the questions has 2 or more points mark. Otherwise with 8 out of 45 questions wrong I wouldn't get 73% correct answers. According to my calculations it is 82.2%! But I can be wrong. Just to let you know I got to the stage when I could answer 100 random questions from question bank in 40 minutes with average 95% correct answers. I've also read thru Aviation Exam questions on the subject which seems to have some of the older questions, unfortunately still not enough. At my last sitting there was about 60% questions I haven't seen before.
    Hoping this post going to help somebody.
    Seb
    Last edited by Korick; 11-04-2019, 04:29.

  • #2
    Seb, sorry for the delay

    Here are some thoughts:

    1. Downdraft/updraft ... initial effect
    In level (non turning) flight, an aircraft is flown at a pitch attitude which provides for an angle of attack (α) of the wing appropriate to the airspeed. The relationship between the angle of attack and the airspeed assumes that the air is striking the leading edge of the wing horizontally (i.e. negligible upward or downward component). But, if an aircraft then flies into a downdraft or updraft, the air is no longer striking the wing horizontally but at a small angle to the horizontal which depends on the relative magnitudes of the airspeed and the vertical component of the wind (downdraft or updraft). Hence, the angle of attack has effectively been changed without any change in the pitch attitude.

    As in the case of a change in airspeed due to horizontal wind shear, a change in angle of attack due to a downdraft/updraft is a transient change pending the restoration of the original angle of attack. A downdraft causes a transient reduction in angle of attack which in turn causes a reduction in lift and disturbs the equilibrium of forces acting on the aircraft. The reduction in lift causes a resultant force acting below the intended flight path. An updraft acts in the opposite sense. A downdraft thus has the same initial effect on an aircraft as a decreasing headwind or increasing tailwlnd and an updraft the same initial effect as an increasing headwind or decreasing tailwind. However, the downdraft/updraft effect is due to a transient change in angle of attack whilst the headwind/tailwind effect is due to a transient change in airspeed.

    Once established in a downdraft/updraft
    Once inside the vertical shaft of the downdraft core (in a microburst?) the aircraft descends at the speed of the downdraft (i.e. "drifting " downwards in the new vertical wind regime in a manner similar to lateral drift in crosswinds, although the downdraft case will of course be far more severe). To counter the steady downdraft it is necessary to generate an equivalent rate of climb by increasing thrust and pitch attitude .

    Exiting a downdraft
    As the aircraft exits the down burst, the down draft is replaced by an increasing tailwind which causes a decrease in airspeed and a further deterioration in the flight path.


    2. The thrust produced by a jet engine is measured by the acceleration of a mass of air, it is determined by the mass flow through the engine and the difference between inlet and exhaust velocities. An accurate measurement of thrust can be made from the engine pressure ratio (EPR).

    EPR = Turbine Outlet Pressure / Compressor Inlet Pressure

    A simple EPR indicator would therefore have two pressure sensors. One upstream of the compressor inlet and the other downstream of the turbine outlet.

    Some high bypass ratio engines use a series of probes throughout the engine to produce an integrated EPR (IEPR).

    Compressor inlet pressure sensors can be blocked by ice. Exactly what happens will depend on the throttle setting and the situation at which the pressure sensor ices up - what we can say is that the EPR reading will become unreliable.

    In one case, the No 2 inlet sensor (B737) iced up on the ground, when the throttles were then set for take-off the No 2 EPR gauge over read and insufficient thrust was be set for take-off (the aircraft crashed https://www.youtube.com/watch?v=eNPRrLuvPyY )

    Another answer COULD be that the A/T retards; this has occurred, but it covered a specific scenario at cruise.


    3. Looking for a good reference on this, which I can t find at the moment.


    Airbus MEL gives the answer;

    34.40.03 Radio Altimeter System
    Repair interval .... Nbr installed .... Nbr required .... Procedure
    ........ C ........................ 2 ........................ 1 ................... (O)

    FLIGHT PREPARATION/LIMITATIONS
    Maximum landing capability is CAT 2.

    In other words, with only one radalt, CAT II is the limit.

    4. Wording and answer options uncertain, but if we look at the definitions below, the only option that make sense (aeroplanes) is additional requirements for LVO with RVR below 550 m

    low visibility take off (LVTO) means a take off with an RVR lower than 400 m but not less than
    75 m;

    category I (CAT I) approach operation means a precision instrument approach and landing using
    an instrument landing system (ILS), microwave landing system (MLS), GLS (ground-based
    augmented global navigation satellite system (GNSS/GBAS) landing system), precision approach
    radar (PAR) or GNSS using a satellite-based augmentation system (SBAS) with a decision height
    (DH) not lower than 200 ft and with a runway visual range (RVR) not less than 550 m for
    aeroplanes and 500 m for helicopters;

    category II (CAT II) operation means a precision instrument approach and landing operation
    using ILS or MLS with:
    (a) DH below 200 ft but not lower than 100 ft; and
    (b) RVR of not less than 300 m;

    5. Annex V Part SPA LVO

    SUBPART E: LOW VISIBILITY OPERATIONS (LVO)

    Both crew members must be qualified and current


    I will get these questions on the QB!

    Tom
    Last edited by Tom; 17-04-2019, 11:15.

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    • #3
      Thank you Tom!

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