Note : Do not use this NNC for annunciated smoke, fire or fumes events, such as engine and APU fire, cargo fire, wheel well fire, window arcing or lavatory smoke. for the latter however, consider accomplishing this checklist too !
PILOT FLYING
It is suggested that the left hand seat pilot becomes the PF :
- Electrical smoke may cause partial loss of flight instruments ; the left hand seat instruments have standby electrical power.
- In case of air conditioning smoke the right hand seat pilot (with oxygen mask and goggles on) is best seated to operate the air conditioning panel
TYPE OF SMOKE
The new NNC no longer requires the crew to determine the difference between electrical smoke and air conditioning smoke by sense of smell, density or color. The following paragraph is for background info only :
AIR CONDITIONING SMOKE
Can be identified as white or gray dense smoke entering the passenger cabin or flight deck from the air conditioning system via cabin ceiling, air conditioning outlets or individual nozzles. Air conditioning smoke can be caused by a malfunction of the system itself. however, a recirculation fan causing smoke due to an electrical short circuit may inadvertently be interpreted as air conditioning smoke.
The following may also cause smoke or fumes via the air conditioning system :
- An engine wash during the preceding layover may cause heavy smoke when applying takeoff thrust, especially if maintenance did not perform an engine run. This smoke smells like soap and disappears shortly after takeoff. If during preflight you find a maintenance ATL entry for an engine wash, discuss with your fellow pilot whether or not you will reject takeoff for this.
- Overservicing of hydraulic reservoirs can cause hydraulic fluid to enter the air conditioning system via the pneumatic duct. This is confirmed by a full quantity indication and a recent servicing entry in the ATL.
- De-icing fluid sprayed into the APU inlet may also cause dense and irritating smoke in the air conditioning system, especially during a No Bleed Takeoff. Reconfigure the Bleed ON and select Packs HIGH as soon as possible. If company SOP do not allow a No Bleed Takeoff after de-icing, change to unpressurized takeoff to increase performance.
ELECTRICAL SMOKE
Electrical smoke or fumes can be identified by a typical odor of burned insulation material and bluish color. It can be toxic and cause itching to eyes. The smoke source can often visually be identified, such as coming from the instrument panel, circuit breakers panels, the flight deck door locking system, galley equipment, lighting or in-flight entertainment.
CHECKLIST PHILOSOPHY
The NNC actions are divided into initial steps and remaining steps. The initial steps isolate potential sources of the problem and are accomplished without time consuming analysis or troubleshooting. These steps are based on historical fleet data and are reversible at the captain's discretion.
Equipment or events that in the past have caused smoke or fire onboard include lavatory waste bin fire (cigarettes), galley and lavatory water heaters, toilet flush, flammable liquids in carry-on baggage, equipment cooling fans, fluorescent lights, portable DVD players, windshield wipers, door heaters (as installed), electrical bus short circuit.
The decision to divert is taken immediately after the initial steps.
Diversion may be needed
This text is intended to establish a mindset that a diversion may be required soon, however, it does not yet direct the crew to divert! An immediate diversion to a suitable airport is always required, except if the smoke, fire of fumes source is visually identified, the source is visually confirmed to be extinguished and smoke and fumes are dissipating.
If conditions deteriorate and risks associated with the approach or landing are exceeded by the risk of the onboard situation, the flight crew must land immediately, including landing overweight, landing with tailwind, an off-airport landing or ditching.
The time from first indication of smoke to an out-of-control situation can be a matter of minutes !
Accomplish the NNC [Smoke or fumes Removal] only after the fire has been extinguished or if the smoke or fumes present the greatest threat to flight safety. Keep in mind that smoke removal may change airflow and make the situation worse by fanning the source. Or it may even mask the source, leading you to think that the fire is out while it is still smoldering!
However, for an evacuation, make sure the cabin outflow valve is open, except for ditching, where it is recommended to have the outflow valve closed to prevent water from entering the airplane -> open the window.
- Do not reset any tripped! If smoke is coming from electrical or instrument panels and smoke does not reduce after the NNC actions, consider further powering down the electrical system, such as removing a generator from bus.
- Do not supply oxygen to the passengers in case of smoke !
SMOKE ON TAKEOFF
MAN [Rejected Takeoff] - Smoke is not literally listed as a mandatory reason to reject takeoff. Sound judgment is required to abort or to continue.
If an immediate turnback to the departure airfield is decided and there is not enough time to accomplish the NNC, take 10 seconds to blindly switch-off all fans (equipment cooling + recirculation) and utilities (entertainment, galley power). If you remain below 3,000 feet AAL, even switch-off the Packs! This double-quick action eliminates 60% of all systems that showed to be the smoke source in the past.