EC-135/Emergency Procedures
SECTION 3. EMERGENCY PROCEDURES
Contents
- 1 GENERAL
- 2 SINGLE ENGINE FAILURE
- 3 ENGINE FIRE
- 4 DOUBLE ENGINE FAILURE (OGE)
- 5 DOUBLE ENGINE FAILURE (IGE)
- 6 FADEC FAILURE
- 7 ELECTRICAL FAILURE - BUS SHORT
- 8 PFD FAILURE
- 9 TAIL ROTOR FAILURE
- 10 ENGINE CHIP INDICATION
- 11 TRANSMISSION OR TAIL ROTOR CHIP INDICATION
- 12 LOW-RPM CONDITION
- 13 VORTEX RING STATE
1 GENERAL
This section describes recommended procedures for managing various types of emergency conditions. Although these procedures are considered the best available, they are not a substitute for the sound judgement of the pilot. In general, for any emergency, the pilot should keep in mind three basic rules:
- Maintain aircraft control
- Analyze the situation
- Take proper action
Many easy to manage emergencies become more critical due to the pilot's failure to analyze options before acting, or the pilots failure to maintain control due to becoming fixated on the emergency.
1.1 URGENCY OF LANDING
The following terms are use to describe the urgency of landing in response to an emergency:
- LAND IMMEDIATELY - Extremely high urgency to land. Focus is on the survival of the occupants. Landing in unsuitable areas (water, trees, etc.) considered only as last resort.
- LAND AS SOON AS POSSIBLE - Land without delay at nearest suitable site (e.g., open field) at which a safe landing can be made.
- LAND AS SOON AS PRACTICABLE - Landing is at discretion of pilot. Flight beyond nearest point where assistance can be found is not recommended.
2 SINGLE ENGINE FAILURE
Indications:
- Loss of power
- Split torque needles on FLI
- ENGINE FAIL indication on CAD
Procedure:
- Failed Engine - Identify (Falling N2 or torque)
- ENG (failed engine) - Open guard and OFF
- Fuel Cutf-Off - If engine fire is a possibility, open guard and press the fuel-cut off button.
- Fuel Quantity - Check
Restart Attempt:
- FUEL PRIME - ON (affected engine)
- ENG MAIN - IDLE (affected engine)
- ENG MAIN - FLY (once N2 reaches 70%)
- FUEL PRIME - OFF
Single Engine Flight:
- Collective - Monitor torque on the FLI and observe the OEI (One Engine Inoperative) limitations as marked.
- LAND - AS SOON AS PRACTICABLE.
3 ENGINE FIRE
Indications:
- FIRE indication on warning panel
- Warning alarm
- Loss of power
- Split torque needles on FLI
- ENGINE FAIL indication on CAD
Procedure:
- Failed Engine - Identify (“FIRE” indication on warning panel)
- Fuel Cut-Off - PRESS (fire extinguisher will engage)
- ENG (failed engine) - Open guard and OFF
- Collective - Monitor torque on the FLI and observe the OEI (One Engine Inoperative) limitations as marked.
If fire indication light is off
- LAND - AS SOON AS POSSIBLE.
If fire indication light remains on
- LAND - IMMEDIATELY.
4 DOUBLE ENGINE FAILURE (OGE)
For double engine failure in cruise flight or in an out of ground effect hover.
Indications:
- Total loss of power
- Decreasing rotor RPM
- Low RPM Warning horn
- ENGINE FAIL indication in both system on CAD
Procedure:
- Collective - Lower completely.
- Rotor RPM - Monitor in descent and raise collective slightly if rotor RPM becomes too high.
- Right Pedal - Apply as necessary to compensate for reduction in torque from the engine.
- LAND - IMMEDIATELY.
- Forward Speed 50-60 knots until approximately 50 feet AGL.
- At 50 feet AGL Begin a cyclic flare by pulling back on the cyclic.
- At 10 feet AGL Level the helicopter and pull collective to slow down the descent.
5 DOUBLE ENGINE FAILURE (IGE)
For double engine failure in an in ground effect hover.
Indications:
- Total loss of failure
- Decreasing rotor RPM
- Low RPM Warning horn
- ENGINE FAIL indication in both system on CAD
Procedure:
- Right Pedal Apply to maintain heading
- Collective Hold until helicopter begins to sink
- Slowly apply full up when helicopter begins to sink
- After landing Lower collective once helicopter is fully on the ground
6 FADEC FAILURE
Indications:
- FADEC FAIL indication on CAD
- Failure of system to maintain engine RPM
Procedure:
- Affected Engine - Identify (unstable N2 or torque, FADEC FAIL indication on CAD)
- FADEC - OFF (affected engine)
- Collective - Small movements only
- Throttle - Adjust as necessary to keep rotor RPM in green band.
- LAND - AS SOON AS PRACTICABLE.
7 ELECTRICAL FAILURE - BUS SHORT
Indications:
- All electrical systems dark
Procedure:
- BAT and GEN - Check ON
If systems still failed:
- BUS TIE(both) - EMER
- Identify - Failed Bus. If short is only in one bus, systems on good bus will come back on. INP FAIL indication may also show in CAD for the bad bus.
- BUS TIE(good bus) - NORM
- GEN (failed bus) - OFF
8 PFD FAILURE
Indications:
- FAIL indication on affected PFD
- PFD fails to indicate aircraft state
Procedure:
- Control - Maintain using other PFD or backup flight instruments
- LAND - AS SOON AS PRACTICABLE.
9 TAIL ROTOR FAILURE
Indications:
- Sudden uncontrolled yaw to the right.
- Lack of response from anti-torque pedals.
Procedure:
- Autorotation Establish
- LAND - IMMEDIATELY.
10 ENGINE CHIP INDICATION
Indications:
- ENGINE CHIP indication on CAD
Procedure:
- Affected Engine - Shut down
- OEI Procedures - Establish
- LAND - AS SOON AS PRATICABLE.
11 TRANSMISSION OR TAIL ROTOR CHIP INDICATION
Indications:
- XMSN CHIP or TRGB CHIP indication on CAD
Procedure:
- LAND - AS SOON AS POSSIBLE.
12 LOW-RPM CONDITION
Low rotor RPM is a dangerous condition that can occur when RPM is not carefully monitored or maximum power limitations are not observed. If the RPM is allowed to decay too far, recovery may be impossible. This aircraft is equipped with a low RPM warning system consisting of a warning light and a horn. The light and horn will activate when rotor RPM is below 93% whenever the collective is not full down. In the event of a low RPM condition, the pilot should lower the collective until normal RPM is achieved. If the helicopter is too low or over unsuitable terrain, the pilot can attempt to "milk" the collective, with small up-down movements of the collective in an attempt to recover rotor RPM. However, the best approach is to not get into a low RPM condition in the first place.
13 VORTEX RING STATE
Vortex ring state occurs when a helicopter descends into its own downwash resulting in a loss of lift. It can occur when attempting to apply power during a vertical descent. To recover, the pilot should lower the collective and apply forward cyclic to regain airspeed. Since the recovery can require a significant loss of altitude, the best practice is to avoid encountering this condition, particularly when close to the ground. Practice vortex ring state recovery should be performed with sufficient altitude to be able to complete the maneuver. See the SL Helicopter Flying Handbook for a more complete description of vortex ring state.