Method for determining the total temperature of an airflow surrounding an aircraft

1. A method for determining the total temperature of the air stream surrounding an aircraft, comprising:

measuring a static temperature,

measuring a total temperature,

determining a value of speed of the air stream,

determining a computed total temperature from the measured static temperature and measured total temperature as a function of an acceleration or deceleration phase of the aircraft and the speed of the air stream.

2. A method according to claim 1 , wherein the computed total temperature corresponds to the measured total temperature or to the measured static temperature, corrected if necessary according to a law of convergence applied as a function of the acceleration or deceleration phase of the aircraft.

3. A method according to claim 2 , wherein the law of convergence differs as a function of the airspeed.

4. A method according to claim 2 , wherein, at low speed, the computed total temperature corresponds to the measured static temperature.

5. A method according to claim 2 , wherein, at high speed, the computed total temperature corresponds to the measured total temperature.

6. A method according to claim 2 , wherein, at intermediate speed the computed total temperature is corrected by a difference between the measured total temperature and the measured static temperature at a given point in time.

7. A method according to claim 6 , wherein, in the acceleration phase of the aircraft, the total computed temperature is TAT computed (t)=TAT measured (t)−ΔT vo *(V 1 −CAS(t))/(V 1 −V 0 ), where ΔT vo =TAT measured (t vo )−TAT computed (t vo ),

where:

V 0 and V 1 are transition speeds of airflow relative to the aircraft,

TAT measured (t) is the measured total temperature,

TAT measured (t vo ) is the measured total temperature at transition speed V 0 ,

TAT computed (t vo ) is the total computed temperature at transition speed V 0 , and

CAS(t) is the speed of the aircraft at time t.

8. A method according to claim 6 , wherein, in the deceleration phase of the aircraft, the total temperature computed is TAT computed (t)=SAT measured (t)−ΔTv2*(t−tV 2 )T convergence , where ΔTv2=SAT measured (t v2 )−TAT computed (T v2 ),

where:

V 2 is a transition speed of airflow relative to the aircraft,

SAT measured is the measured static temperature,

tV 2 is the time that the aircraft is at the transition speed V 2 , and

T convergence is the duration of convergence toward the measured static temperature.

9. An aircraft comprising a system implementing the method of claim 1 .