Black Boxes

The Flight Data and Cockpit Voice Recorders (so called 'black-boxes' even though they are actually orange) provide invaluable information to investigators as they try to piece together the sequence of events leading up to an accident.  

CAR 605.33 Flight Data Recorder and Cockpit Voice Recorder Requirements

• FDR: required for multi-engine turbine aircraft (see regulation for specifics and variations based on passenger configurations)
• CVR: required for multi-engine turbine aircraft configured for 6 or more passengers and two pilots

CAR 605.34 Use of Flight Data Recorders and Cockpit Voice Recorders

• Operation 
• FDR: continuously from take-off to landing
• CVR: continuously from application of electrical power prior to flight until removal of electrical power following flight
• Without a MEL, either the FDR or CVR may be unserviceable for up to 90 days after day of failure, as long as the other one is serviceable, and the date of failure is recorded in the aircraft technical records. 

Pressurization

Reference Turbine Pilot's Flight Manual Chapter 5

HOW DOES IT WORK?
Bleed air from the engines is continually distributed to the cabin.  Outflow valves modulate the exhaust of cabin air to obtain the desired level of pressurization.  

DEFINITIONS

• Maximum Differential (max diff): the maximum ratio of cabin pressure to outside (ambient) air pressure that the aircraft can sustain.
• Positive Pressure Relief Valves (Safety Valves): vent excess pressure overboard if max diff is exceeded (prevents overpressurization)
• Negative Pressure Relief Valves: ensure cabin never falls below ambient pressure
• Dump Valves: allow pilots to manually vent in an emergency (i.e. smoke)

• Squat Switch: ensures aircraft is depressurized on the ground

Air Law Potpourri

I went through some practice questions about Air Law this morning and it emphasized my need to study even more!  Here are some things I'd forgotten:

TRAINING

• Instrument Training
• CAR 425.21: with a CPL or ATPL, you may give a licensed pilot instrument training towards an IFR rating provided you have and instrument rating and:
• instructor rating OR
• 500 hours PIC of which 100 must be on the same group of aircraft used for training (and for Group 1, at least 10 hours on the type used for training)

AIRSPACE

• Class F Restricted
• CAR 601.04: A pilot may fly through an active area:
• if authorized by appropriate person
• if it doesn't pose hazard to aircraft
• if it doesn't jeopardize national security

• CAR 602.145: VFR Flight in ADIZ
• VFR flight within or into the ADIZ requires a Defense Flight Plan or Defense Flight Itinerary to be filed.
• Must revise time/point of entry if more than +/- 5 minutes or 20 NM.

AIRPORTS

• Take-off Alternates (i.e. weather is above take-off minima but below landing minima for that aerodrome):
• CAR 704.26 Commuter: if authorized on air operator certificate
• CAR 705.34 Airline: within 60 minutes with OEI (twin) or 120 minutes with OEI (three or four engines or ETOPS)

• Dispatch Limitations:
• CAR 704.49 and CAR 705.60: must be able to land at destination and alternate within
• Turbo-jets: 60% of landing distance available (LDA)
• Turbo-props: 70% of LDA
• must be suitable runway for aircraft and conditions, and can't take credit for more than 50% of anticipated headwind or less than 150% of tailwind
• CAR 704.50 and CAR 705.61: for turbo-jets, if wet runway expected, the calculated runway requirement must be increased by an additional 15%. (Can be less if AFM includes info, but not shorter than what is required by 704.49 / 705.60).

SYSTEMS

• Altitude Alerting System or Device
• CAR 605.36: required for turbo-jets, with these exceptions:
• MEL, or if no MEL, being ferried to location with device
• flight tests, PPCs, training
• if failure after TO, until it reaches location where it can be repaired

• GPWS
• CAR 605.37: required for 704 and 705 turbo-jets with MCTOW of more than 15000 kg (33069 lbs) and authorized to carry more than 10 passengers (exception - MEL). 

• Standby Attitude Indicator
• CAR 605.41: required for Part VII turbo-jets (some exceptions).  Required for Part VII turbo-props configured for 10 or more passengers.
• CAR 625.41: must be installed on turbojet aircraft, and operate for 30 minutes in the event of a complete electrical system malfunction

Turbine Engines

Suck, squeeze, bang, blow... intake, compression, power, exhaust.  The basic sequence of events on a gas turbine is the same as on the 4-cycle reciprocating engines we learned about in Private Pilot ground school.  But the components are different and turbine engines are much more efficient due to continuous flow conditions.  

INTAKE

COMPRESSION

Two types of compressors:

• axial-flow (more efficient)
• rotor blades: air deflected in direction of rotation
• stator vanes: direct and compress the flow of air
• centrifugal-flow (more durable)
• impeller: air directed towards center, then slung outward to diffuser
• diffuser: converts high velocity airflow into high pressure airflow for delivery to combustion section

POWER

Combustion is continuous and self-sustaining

EXHAUST

Turbines are turned by escaping gases, and in turn, drive the compressors through shafts.

Definitions

• bypass ratio: relationship between the mass flow of cold air through the fan to the mass flow of the hot air through the turbine
• engine pressure ratio (EPR): the ratio of turbine discharge total pressure to the total pressure at the compressor inlet (OUT / IN)
• free turbine: there are two separate shafts - one to drive the compressor section and the other to transmit power to the reduction gearbox and thus turn the propeller
• waste gate: controls the amount of exhaust gas which enters the turbine section of a turbo-charger
• flex temperature: the assumed temperature used in calculating the reduced thrust settings for take-off

Lots of systems material to cover... more to come!