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3.1.2. TLO Module 

The PEP module, dedicated to takeoff performance computation and takeoff chart (RTOW) production, is called TLO (Takeoff and Landing Optimization). TLO is an interface common to all aircraft types, which facilitates the management of takeoff input and output data. On the other hand, the calculation program used for the performance determination depends on the aircraft type. It is called: 

TLC (or TCP) for A300, A310 and A3201 

OCTOPUS for A318, A319, A320, A321, A330 and A340 

Therefore, as two different calculation programs exist, different RTOW formats are obtained (see Figures J18 and J19).

Figure J18 : TLC takeoff chart example 

Figure J19 : OCTOPUS takeoff chart example 

3.1.2.1. TLC program 

The first optimization tool, developed by an aircraft manufacturer in the early 1980’s, was the Airbus TLC (Takeoff and Landing Computation) program based on tabulated data of the AFM. During optimization, the TLC interpolates the different 1 some A320 models are certified with TLC, others with OCTOPUS. Limitations in tables and returns the MTOW and associated speeds. The TLO performance database is a “picture” of the performance charts, that were used in conventional paper flight manuals. The TLC has been designed to replace the long and tedious calculation process that was done manually, based on tables and graphs. It was also designed to facilitate Airline Flight Operations’ work by reducing the production time and the risk of errors. 

3.1.2.2. OCTOPUS program 

The next step in the performance calculation process, referred to as OCTOPUS (Operational and Certified Takeoff and landing Universal Software), not only offers the same advantages as TLC but also drastically changes the performance calculation method. It is no longer based on pre-computed data, but uses the “first principle” mode that allows a real on-time computation to benefit from a higher takeoff weight. Instead of smoothed pre-computed performance results, the OCTOPUS performance database contains all the airplane and engine characteristics, enabling performance computation based on physics equations. In addition, OCTOPUS introduces a new and improved takeoff chart format, with its use of multi-configurations and influences. 

3.2. Less Paper Cockpit (LPC) 

This new concept based on onboard computations, using a laptop in the cockpit, represents the ultimate performance computation method. This program, which replaces paper charts, reduces flight preparation time and the risk of error. It suppresses the interpolations and method errors, while providing quick results for real external conditions. As a result, the performance obtained (MTOW or flexible temperature) is the best possible one, thus leading to improved profit. 

The computation is based on the same performance software as TLO (i.e. TLC, or OCTOPUS depending on the aircraft type: Figure J20). 

4. APPENDIX 4 : ABBREVIATIONS 

Greek letters 

α ( alpha ) Angle of attack 

γ ( gamma ) Climb or descent angle 

δ ( delta ) Pressure ratio = P / P0 . 

△( DELTA ) Parameters’ variation (ex : △ISA, △P)

φ ( phi ) Bank angle

μ ( mu ) Runway friction coefficient

θ( theta ) Aircraft attitude

ρ ( rho ) Air density

ρ0 ( rho zero ) Air density at Mean Sea Level

σ ( sigma ) Air density ratio = ρ / ρ0

A 

a Sound velocity

A0 Sound velocity at sea level 

AC Advisory Circular (FAA)

ACJ Advisory Circular Joint (JAA)

ADIRS Air Data / Inertial Reference System

AFM Aircraft Flight Manual

ALD Actual Landing Distance

AMC Acceptable Means of Compliance (JAA)

AMJ Advisory Material Joint (JAA)

AOM Airline Operation Manual 

APM Aircraft Performance Monitoring (program)

ASD Accelerate-Stop Distance 

ASDA Accelerate-Stop Distance Available 

ATC Air Traffic Control 

C 

CD Drag coefficient 

CL Lift coefficient 

CAS Calibrated Air Speed

CDL Configuration Deviation List 

CG Center of gravity

CI Cost Index 

CL Climb throttle position 

CWY Clearway 

D 

DA Drift Angle 

DGAC Direction Générale de l’Aviation Civile 

DOC Direct Operating Cost 

DOW Dry operating weight 

E 

ECON Economic (minimum cost) speed 

EGT Exhaust Gas  Temperature