0:02
whether you're an aviation student
0:04
technician pilot or simply passionate
0:07
about aircraft this video will give you
0:09
a clear understanding of the different
0:11
types of propellers used in aviation
0:13
from basic fixed pitch designs to
0:15
advanced constant speed and feathering
0:17
systems we'll break down how they work
0:20
where they're used and why they're
0:25
started first a quick refresher a
0:28
propeller is essentially a rotating wing
0:30
its blades are shaped like air foils and
0:33
generate thrust by accelerating a mass
0:35
of air rearward creating a forward
0:37
reaction force based on Newton's third
0:39
law the efficiency and performance of a
0:42
propeller depend heavily on its design
0:44
which is why different types exist for
0:46
different aircraft and mission profiles
0:53
let's start with the fixed pitch
0:54
propeller the simplest type of propeller
0:57
design fixed pitch propellers are
0:59
designed for best efficiency at one
1:01
rotational and forward speed that means
1:04
they're optimized for a specific
1:05
combination of aircraft and engine
1:07
speeds and any change from those
1:09
conditions reduces the efficiency of
1:11
both the propeller and the engine these
1:14
propellers are commonly found on
1:16
aircraft of low power speed range or
1:19
altitude like the Cessna 150 or Piper
1:22
Cub they're ideal for training aircraft
1:25
or recreational flyers because of their
1:29
operation one of their biggest
1:31
advantages is that they don't require
1:33
any control input from the pilot during
1:35
flight just throttle control that
1:38
simplicity translates to fewer
1:39
maintenance needs and lower operational
1:46
a test club is used specifically for
1:49
ground testing and braking and
1:51
reciprocating engines it's not designed
1:53
to produce thrust instead it creates the
1:56
right amount of load on the engine
1:58
during the test period these propellers
2:00
are essential tools for engine shops and
2:02
maintenance facilities to safely test
2:04
performance and reliability before
2:06
engines are installed in aircraft
2:13
next up is the ground adjustable
2:15
propeller which operates just like a
2:17
fixed pitch propeller during flight the
2:19
difference the blade angle can be
2:21
adjusted but only on the ground when the
2:23
engine is not running this adjustment is
2:26
made by loosening the clamping mechanism
2:28
that holds the blades in place once the
2:31
desired pitch is set and the mechanism
2:33
is tightened the blades are locked in
2:35
position and cannot be changed in flight
2:37
to meet varying performance needs
2:40
because of this limitation ground
2:42
adjustable propellers are rarely used on
2:45
modern aircraft you might still find
2:47
them on some light sport or experimental
2:53
planes a controllable pitch propeller
2:56
allows the pilot to change the blade
2:58
angle while the propeller is spinning
3:00
this means the propeller can be adjusted
3:02
in flight to match different performance
3:04
needs the number of pitch settings may
3:07
be limited such as in a two-position
3:09
propeller or more flexible with multiple
3:12
blade angles available between minimum
3:15
settings unlike constant speed props
3:18
where a governor automatically adjusts
3:20
pitch to maintain engine RPM the
3:23
controllable pitch propeller requires
3:25
the pilot to manually select the blade
3:27
angle it stays at that setting until the
3:29
pilot changes it again these types of
3:31
propeller are not in wide use today
3:40
a constant speed propeller automatically
3:42
adjusts the blade pitch to maintain a
3:44
selected engine RPM no matter the flight
3:47
condition it uses a governor to increase
3:50
or decrease blade angle as needed
3:52
optimizing both performance and
3:54
efficiency at low speeds or high power
3:57
the blades move to a fine pitch for
3:59
better acceleration and climb at higher
4:02
speeds or during cruise they shift to a
4:04
course pitch to reduce engine RPM and
4:08
fuel this system gives pilots better
4:11
control over engine performance while
4:13
reducing workload fuel consumption and
4:15
engine wear it's widely used in modern
4:18
general aviation and commercial
4:24
aircraft a feathering propeller is a
4:26
type of constant speed propeller used
4:28
mainly on multi-engine aircraft it's
4:31
designed to reduce drag in the event of
4:34
failure when an engine fails and can't
4:37
turn the propeller the blades can be
4:39
rotated to a feathered position about
4:42
90° to the plane of rotation this aligns
4:45
the blades with the air flow greatly
4:47
reducing drag and preventing
4:50
windmilling feathering helps maintain
4:52
better control of the aircraft after an
4:54
engine failure once in feather the
4:57
blades are held in place by aerodynamic
4:59
forces keeping them from turning and
5:01
allowing the aircraft to fly more
5:03
efficiently on the remaining
5:10
engine some advanced propellers mainly
5:12
on turborop aircraft feature a reverse
5:15
pitch function to improve ground
5:17
handling and braking performance these
5:19
are usually part of feathering propeller
5:21
systems a reverse pitch propeller is a
5:24
controllable propeller that can change
5:26
the blade angle to a negative value
5:28
generating thrust in the opposite
5:30
direction of normal flight this is
5:32
especially useful during landing after
5:35
touchdown the pilot can set the blades
5:37
to reverse pitch generating reverse
5:40
thrust that slows the aircraft quickly
5:42
shortens the landing roll and reduces
5:50
modern propeller designs include
5:52
simmer-shaped blades and composite
5:54
materials to improve performance and
5:57
reduce noise sim propellers get their
5:59
name from their curved swept back shape
6:02
which helps reduce drag and increase
6:04
efficiency especially at higher speeds
6:07
composite propellers are made from
6:09
advanced materials like carbon fiber
6:11
making them lighter stronger and more
6:13
resistant to fatigue than traditional
6:15
metal blades they also allow for more
6:19
shapes these innovations are widely used
6:22
in both general aviation and commercial
6:24
turbo props offering better performance
6:27
fuel savings and a quieter
6:34
ride some aircraft employ specialized
6:37
propeller designs tailored to specific
6:39
performance demands for example
6:41
contraotating propellers like those on
6:43
the TU95 and advanced UAVs feature two
6:47
coaxial sets of blades spinning in
6:49
opposite directions to increase thrust
6:52
and eliminate torque effects duct fan
6:54
propellers commonly used in VTOL and
6:57
EVTOL aircraft offer compact efficient
7:00
thrust with enhanced control and safety
7:03
and multi-blade propellers with four to
7:05
eight blades are designed to absorb
7:08
greater engine power while reducing
7:09
noise vibration and overall aerodynamic
7:13
stress these innovations are pushing the
7:15
boundaries of what propellers can
7:17
achieve in modern and future aviation
7:22
so to summarize aircraft propellers come
7:24
in many types fixed pitch test club
7:28
ground adjustable constant speed
7:30
feathering reverse pitch controllable
7:32
pitch and composite and similar designs
7:35
each type has specific advantages
7:37
depending on the aircraft's mission
7:39
engine type and operational requirements
7:42
if you found this breakdown helpful give
7:44
it a like and subscribe for more
7:45
detailed videos on aircraft
7:48
systems thanks for watching
