Lecture 13 (emily) Flashcards
What is roll subsidence mode
How aircraft deals with disturbance from roll
Is roll subsidence mode oscillatory
no
How long does dutch roll tend to last?
10-15 sec
In dutch roll what’s the relationship between roll and yaw
they do the same thing but roll is phase delayed
What causes dutch roll? [4]
turblent, swept wing, control system, pilot
Is dutch roll oscillatory
yes
Is spiral mode oscillatory?
no just one real root
What is typical time period of spiral mode?
100 sec
How many modes will a well designed aircraft have?
8
Describe the modes a well designed aircraft will have
Phgoid- 2
short period- 2
roll- 1
spiral- 1
dutch roll 2
how do you damp dutch roll?
with a large tail fin
how to you stop spiral
sufficiently long tail arm
Which two modes don’t have to be stable
phugoid and spiral
