RPMR EPS (9.14-9.21)

  1. Decreasing % RPMR Warning

    G t E L t o a p d n r M F F o N l.
    %R R w d b n o r i M F F o N l a e.
    • Going to ECU LOCKOUT to obtain additional power does not remove Maximum Fuel Flow or Ng limits.
    • %RPM R will decrease below normal operating range if Maximum Fuel Flow or Ng limits are exceeded.
  2. Decreasing % RPMR Caution

    W e i c w E P C l i L, e r i m f a T l s i i.
    C m b t n t e T l a k % R R a % R 1 a 2 i o r.
    • When engine is controlled in LOCKOUT, engine response is much faster and TGT limiting system is inoperative.
    • Take care not to exceed TGT limits and keeping % RPM R and % RPM 1 and 2 in operating range.
  3. Decreasing % RPMR Note

    I %R d f xx% t xx-xx% d s f, c t.
    I t a e a b M T A, a t i % R R w E R t s.
    • If % RPM R drops from 100% to 95-96% during steady flight, check torque 1/2.
    • If torque are equal and below Maximum Torque Available, attempt to increase % RPM R with ENG RPM (INCR/DECR) trim switch.
  4. Decreasing % RPM R.
    Def'n, Steps

    D
    I a e c u f t t l s a t o e i u t p s t, % R R w d.

    Steps
    C - A t c % R R.
    E a s-e a. M % T a xx% b o e.
    E P C l (l % T/T T e) -  L.
    L a s a p.
    If an engine control unit fails to the low side and the other engine is unable to provide sufficient torque, % RPM R will decrease.

    • Steps
    • Collective - Adjust to control % RPM R.
    • Establish a sing-engine airspeed.
    • ENG POWER CONT lever (low % TRQ/TGT TEMP engine) -  LOCKOUT. Maintain % TRQ approximately 10% below other engine.
    • Land as soon as practicable.
  5. Increasing % RPM R.
    Def'n, Steps
    % R R i w r f a e c s f t t h s. 
    % R 1 a 2 (N) w i w t r % R R. 

    1. E (h % T/ T e) - R, m % T ~xx% b o e.
    2. L.

    I a e d n r t E m b/t f a i, H m b m i.
    3. E s e a.
    4. P E E S (?)
    5. R t s e e.
    % RPM R increasing will result from an engine control system failing to the high side.  % RPM 1 and 2 (Np) will increase with the rotor % RPM R. 

    • 1. EPLC (high % TQ/ TGT engine) - Retard, maintain % TRQ ~10% below other engine.
    • 2. Land as soon as practicable.

    If affected engine does not respond to EPCL movement b/t fly and idle, HMU may be malfunctioning internally.

    • 3. Establish single engine airspeed.
    • 4. Perform Emergency Eng Shutdown (affected engine)
    • 5. Refer to single engine ep.
  6. %RPMR Increasing/Decreasing (Oscillation)

    I i p f a m t o t c c t a e t o. 
    T o e w r t t c i p b a o, o w s a.

    1. E s e a.
    2. S r E o t s e.

    I O s:
    3. P t e i L a m c p.
    4. L a s a p.

    I o c:
    5. P E b t F a r E o t o e.
    6. P t e i L, m c t p.
    7. L a s a p.
    It is possible for a malfunction to occur that can cause the affected engine to oscillate.  The other engine will respond to the changes in power by also oscillated, often with smaller amplitudes.

    • 1. Estb single engine airspeed.
    • 2. Slowly retard EPLC of the suspected engine.
    • If Oscillation stops:
    • 3. Place that engine in Lockout and manually control power.
    • 4. Land as soon as practicable.

    • If oscillation continues:
    • 5. Place EPCL back to Fly and retard EPCL of the other engine.
    • 6. Place the engine in Lockout, manually control the power.
    • 7. Land as soon as practicable.
  7. Trq split bt engines 1 & 2.
    • 1. If TGT temp of one engine exceeds 850'c, retard EPCL on that engine to reduce TGT.  Retard EPCL to maintain tq ~10% below other engine.
    • 2. If TGT temp limit of either engine is not exceeded, retard EPCL on high %tq and observe tq of low power engine.
    • 3. If %tq of low power engine increases, EPCL on high power engine - retard to tq~10%b.
    • 4. If %tq of other engine does not increase, or RPMR decreases, EPCL - return to fly.
    • 5. If add'l power is required, low power EPCL, momentarily move to lockout and tq~10%b.
    • 6. Lasa prac.
  8. LDS malfunction
    Conditions
    Steps
    • On ground:
    • EPCL in Idle - Ng 3-4% higher than normal.
    • EPCL in Fly - Tq split (single engine malfunction)

    • In flight:
    • Initial takeoff (during collective increase) - Increased tq split (single engine malfunction)
    • Low power descent (lowering collective to minimum) - Rapid rise in engine %RPM and %RPMR

    • On ground:
    • Shut down and consult maint

    • In flight:
    • Lasa Prac.
    • 1. Perform a normal approach, avoiding low 2. power autorotative descents.
  9. Engine Compressor Stall

    N r b a n b o p n a p a y.
    N a b r i i T a f i N S, % T, a % R r f t a e.

    1. C - R

    I c p:
    2. E (a e) - R, T S d.
    3. E (a e) - F

    I s c r:
    4. E s e a.
    5. E e s (a e)
    6. R t s e f E.
    • Normally recognized by a noticable bang or popping noise and possible acft yaw.
    • Normally accompanied by rapid increase in TGT and fluctuations in Ng Speed, % TRQ, and % RPM remaining for the affected engine.

    • 1. Collective - Reduce
    • 2. EPCL (affected engine) - Retard, TGT Should decrease.
    • 3. EPCL (affected engine) - Fly

    • If stall condition recurs:
    • 4. Estb single engine airspeed.
    • 5. Emergency eng shutdown (affected engine)
    • 6. Refer to single engine failure EP.
  10. #1 Oil filter bypass or #2 Oil filter bypass caution appears.
    • 1. EPCL - Retard
    • 2. Lasa Prac
  11. #1/#2 Engine Chip, #1/2 Engine Oil Press, #1/#2 Engine Oil Temp Cautions

    1. E s e a.
    2. E (?) -R, t r t.

    I o p i b m l o i o t r a m l.
    3. E e s (a e)
    4. R t s e f E.
    • 1. Establish single engine airspeed.
    • 2. EPCL (affected engine) -Retard, to reduce torque.

    • If oil pressure is below minimum limits or if oil temperature remains above max limits.
    • 3. Emergency engine shutdown (affected engine)
    • 4. Refer to single engine failure EP.
  12. 9.20
    Engine high-speed shaft failure.

    P f: l h-s r a v f e a.
    C f: l b a s %T d t z o t a e. 
    %R o a e w i u o s i a.

    1. C - a.
    2. E s e a.
    3. E e s (a e) d n a r.
    4. R t s-e f e.
    • Partial failure: loud high-speed rattle and vibration from engine area.
    • Complete failure: loud bang and sudden %TRQ decrease to zero on the affected engine. 
    • %RPM of affected engine will increase until overspeed system is activated.

    • 1. Collective - adjust.
    • 2. Estb single engine airspeed.
    • 3. Emergency engine shutdown (affected engine) do not attempt restart.
    • 4. Refer to single-engine failure ep.
  13. 9.21
    Lightning Strike Warning
    L s m r i l o a f c f, e c, a/o e p.
    Lightning strikes may result in loss of automatic flight control functions, engine controls, and/or electric power.
  14. 9.21
    Lightning Strike

    M c o o b e t i p m p w n T l o o p.
    S i m a b i. 
    I t o, f c w h t a E a r t c %R b s a f. 
    I p, p s r s t xx k t r c o m xx% r s.

    1. E(?) - a a r t c % R
    2. L a s a p
    • May cause one or both engines to immediately produce maximum power with no TGT limiting or overspeed protection.
    • System instruments may also be inop. 
    • If this occurs, flight crew would have to adjust EPCLs as required to control %RPM by sound and feel. 
    • If pratical, pilot should reduce speed to 80 kts to reduce criticality of maintaining 100% rotor speed.

    • 1. EPCLs - adjust as required to control % RPMR
    • 2. Possible
Author
walterm
ID
259864
Card Set
RPMR EPS (9.14-9.21)
Description
(Decreasing RPMR) 9.14 - 9.21 (Lightning Strike)
Updated