Patent AU-2021211996-A1 (AU)
Title: A system and method for determining the real-time effect of ice accumulation on aircraft surfaces on angle of attack during flight
Inventor: BETUSH WILLIAM
IPC: G08B21/18
Filed: 2021-08-03
Abstract: A SYSTEM AND METHOD FOR DETERMINING THE REAL-TIME EFFECT 
OF ICE ACCUMULATION ON AIRCRAFT SURFACES ON ANGLE OF 
ATTACK DURING FLIGHT 
5 
ABSTRACT OF THE DISCLOSURE 
A system includes a plurality of sensors along a 
surface of an airfoil operable to measure a first set of 
ice thickness values at a first time and a second set of 
10 ice thickness values at a second time. The system 
further includes a processor configured to determine a 
first plurality of lift calculation variables and a 
second plurality of lift calculation variables. The 
processor also generates a threshold angle of attack 
15 value and updates the threshold angle of attack value at 
the second time, based on one or more differences between 
the first and second sets of ice thickness values and the 
first and second plurality of lift calculation variables.  
The processor is further configured to send, to a 
20 display, based on the updated threshold angle of attack, 
one or more changes to flight data to adjust the actual 
angle of attack of the airfoil.
200 2/3 Apply signal averaging for each ice 218 
START thickness value within the second set 
oficethicknessvalues 
Generate, by a plurality of sensors along 2 220 
a surface of an airfoil, a first set of ice Determine, based on a measured flight 
thickness values corresponding to data, a second plurality of lift 
a first time calculation variables 
204 
Filter each ice thickness value within 222 
the first set of ice thickness values Difference 
with digital signal processing between first set of 
NO ice thickness values and first 
206 plurality of lift calculation 
Apply signal averaging for each ice variables and second 
thickness value within the first set of set? 
ice thickness values 
208 224 
Determine, based on a measured flight Compare the second set of ice thickness 
data, a first plurality of lift values with the second plurality of lift 
calculation variables calculation variables against a data table 
210 
Compare the first set of ice thickness Update at the second time, based on one 226 
values with the first plurality of lift or more differences between the first 
calculation variables against a data table and second sets of ice thickness values 
and the first and second plurality of lift 
212 calculation variables, the threshold 
Generate, based on at least the first set k angle of attack 
of ice thickness variables and the first 
plurality of lift calculation variables, a 228 
threshold angle of attack value Send , to a display screen, based on the 
updated angle of attack, one or more 
214 changes to the flight data to adjust 
Generate, by a plurality of sensors along the actual angle of attack 
a surface of an airfoil, a second set of 
ice thickness values corresponding to 
a first time 230 
216 angle of attack NO 
Filter each ice thickness value within the above the 
threshold? 
second set of ice thickness values with 
digital signal processing 
YES 232 
Generate a warning signal 
FIG.2 REPEAT