Flight Training - June 2015 - 42

TECHNIQUE

CONSTANT-SPEED PROPELLER

One propeller, many options
ยป

By Ian J. Twombly

ILLUSTRATION BY KEVIN HAND

CONFUSION ABOUT OPERATION of a constant-speed propeller no doubt begins with the name. Although the intent is
to optimize the propeller's efficiency to maintain constant rpm, it's done by varying the pitch of the blades.
A fixed-pitch propeller operates at peak performance in only one phase of flight-usually climb, cruise, or
something in between. Selecting one requires tradeoffs from the others. Not so with a constant-speed propeller, which utilizes a central hub that connects the individual blades. Inside the hub, oil is used to provide
pressure against a cylinder and spring mechanism that either increases or decreases the pitch of each
blade. Operating a constant-speed propeller is only slightly more challenging than operating a fixedpitch propeller, and it can be easily learned with only an hour or two of training.

CONTROLS
Throttle (left)-Just as with a fixed-pitch propeller, throttle controls the amount of fuel going into
the engine, which either increases (by pushing
forward) or decreases (by pulling back) the power.
Power is measured by a manifold pressure gauge,
graduated in inches of mercury.
Propeller (center)-Pull back and the blades increase in pitch, which lowers rpm.
Push forward and they go flat, which increases rpm. In a multiengine airplane, if you
pull the propeller control back all the way the blades will feather, or go horizontal, to
reduce drag. Mixture-Controls the fuel/air mixture, just as in a fixed-pitch airplane.

1. RUNUP
Taking a constant-speed airplane through its pre-takeoff
routine is a bit more involved.
The propeller control must
be pulled back all the way at
least once, and more may be
required to check manifold pressure, rpm, and oil pressure-all
of which will change as the propeller pitch changes.
2. TAKEOFF
Assuming a normally aspirated
engine, the engine controls
will almost always be full
forward for takeoff. The fuel
flow gauge should be added to
the scan to ensure the airplane
is developing full power.

42 /

FLIGHTTRAINING.AOPA.ORG


http://FLIGHTTRAINING.AOPA.ORG

Flight Training - June 2015

Table of Contents for the Digital Edition of Flight Training - June 2015

Contents
Flight Training - June 2015 - Cover1
Flight Training - June 2015 - Cover2
Flight Training - June 2015 - Contents
Flight Training - June 2015 - 2
Flight Training - June 2015 - 3
Flight Training - June 2015 - 4
Flight Training - June 2015 - 5
Flight Training - June 2015 - 6
Flight Training - June 2015 - 7
Flight Training - June 2015 - 8
Flight Training - June 2015 - 9
Flight Training - June 2015 - 10
Flight Training - June 2015 - 11
Flight Training - June 2015 - 12
Flight Training - June 2015 - 13
Flight Training - June 2015 - 14
Flight Training - June 2015 - 15
Flight Training - June 2015 - 16
Flight Training - June 2015 - 17
Flight Training - June 2015 - 18
Flight Training - June 2015 - 19
Flight Training - June 2015 - 20
Flight Training - June 2015 - 21
Flight Training - June 2015 - 22
Flight Training - June 2015 - 23
Flight Training - June 2015 - 24
Flight Training - June 2015 - 25
Flight Training - June 2015 - 26
Flight Training - June 2015 - 27
Flight Training - June 2015 - 28
Flight Training - June 2015 - 29
Flight Training - June 2015 - 30
Flight Training - June 2015 - 31
Flight Training - June 2015 - 32
Flight Training - June 2015 - 33
Flight Training - June 2015 - 34
Flight Training - June 2015 - 35
Flight Training - June 2015 - 36
Flight Training - June 2015 - 37
Flight Training - June 2015 - 38
Flight Training - June 2015 - 39
Flight Training - June 2015 - 40
Flight Training - June 2015 - 41
Flight Training - June 2015 - 42
Flight Training - June 2015 - 43
Flight Training - June 2015 - 44
Flight Training - June 2015 - 45
Flight Training - June 2015 - 46
Flight Training - June 2015 - 47
Flight Training - June 2015 - 48
Flight Training - June 2015 - 49
Flight Training - June 2015 - 50
Flight Training - June 2015 - 51
Flight Training - June 2015 - 52
Flight Training - June 2015 - 53
Flight Training - June 2015 - 54
Flight Training - June 2015 - 55
Flight Training - June 2015 - 56
Flight Training - June 2015 - Cover3
Flight Training - June 2015 - Cover4
https://www.nxtbook.com/nxtbooks/aopa/ft_202108
https://www.nxtbook.com/nxtbooks/aopa/ft_202107
https://www.nxtbook.com/nxtbooks/aopa/ft_202106
https://www.nxtbook.com/nxtbooks/aopa/ft_202104
https://www.nxtbook.com/nxtbooks/aopa/ft_202105
https://www.nxtbook.com/nxtbooks/aopa/ft_202103
https://www.nxtbook.com/nxtbooks/aopa/ft_202101
https://www.nxtbook.com/nxtbooks/aopa/ft_202011
https://www.nxtbook.com/nxtbooks/aopa/ft_202009
https://www.nxtbook.com/nxtbooks/aopa/ft_202008
https://www.nxtbook.com/nxtbooks/aopa/ft_202007
https://www.nxtbook.com/nxtbooks/aopa/ft_202006
https://www.nxtbook.com/nxtbooks/aopa/ft_202005
https://www.nxtbook.com/nxtbooks/aopa/ft_202004
https://www.nxtbook.com/nxtbooks/aopa/ft_202003
https://www.nxtbook.com/nxtbooks/aopa/ft_202001
https://www.nxtbook.com/nxtbooks/aopa/ft_201912
https://www.nxtbook.com/nxtbooks/aopa/ft_201911
https://www.nxtbook.com/nxtbooks/aopa/ft_201910
https://www.nxtbook.com/nxtbooks/aopa/ft_201909
https://www.nxtbook.com/nxtbooks/aopa/ft_201908
https://www.nxtbook.com/nxtbooks/aopa/ft_201907
https://www.nxtbook.com/nxtbooks/aopa/ft_201906
https://www.nxtbook.com/nxtbooks/aopa/ft_201905
https://www.nxtbook.com/nxtbooks/aopa/ft_201904
https://www.nxtbook.com/nxtbooks/aopa/ft_201903
https://www.nxtbook.com/nxtbooks/aopa/ft_201902
https://www.nxtbook.com/nxtbooks/aopa/ft_201901
https://www.nxtbook.com/nxtbooks/aopa/ft_201812
https://www.nxtbook.com/nxtbooks/aopa/ft_201811
https://www.nxtbook.com/nxtbooks/aopa/ft_201810
https://www.nxtbook.com/nxtbooks/aopa/ft_201809
https://www.nxtbook.com/nxtbooks/aopa/ft_201808
https://www.nxtbook.com/nxtbooks/aopa/ft_201807
https://www.nxtbook.com/nxtbooks/aopa/ft_201806
https://www.nxtbook.com/nxtbooks/aopa/ft_201805
https://www.nxtbook.com/nxtbooks/aopa/ft_201804
https://www.nxtbook.com/nxtbooks/aopa/ft_201803
https://www.nxtbook.com/nxtbooks/aopa/ft_201802
https://www.nxtbook.com/nxtbooks/aopa/ft_201801
https://www.nxtbook.com/nxtbooks/aopa/ft_201712
https://www.nxtbook.com/nxtbooks/aopa/ft_201711
https://www.nxtbook.com/nxtbooks/aopa/ft_201710
https://www.nxtbook.com/nxtbooks/aopa/ft_201709
https://www.nxtbook.com/nxtbooks/aopa/ft_201708
https://www.nxtbook.com/nxtbooks/aopa/ft_201707
https://www.nxtbook.com/nxtbooks/aopa/ft_201706
https://www.nxtbook.com/nxtbooks/aopa/ft_201705
https://www.nxtbook.com/nxtbooks/aopa/ft_201704
https://www.nxtbook.com/nxtbooks/aopa/ft_201703
https://www.nxtbook.com/nxtbooks/aopa/ft_201702
https://www.nxtbook.com/nxtbooks/aopa/ft_201701
https://www.nxtbook.com/nxtbooks/aopa/ft_201612
https://www.nxtbook.com/nxtbooks/aopa/ft_201611
https://www.nxtbook.com/nxtbooks/aopa/ft_201610
https://www.nxtbook.com/nxtbooks/aopa/ft_201609
https://www.nxtbook.com/nxtbooks/aopa/ft_201608
https://www.nxtbook.com/nxtbooks/aopa/ft_201607
https://www.nxtbook.com/nxtbooks/aopa/ft_201606
https://www.nxtbook.com/nxtbooks/aopa/ft_201605
https://www.nxtbook.com/nxtbooks/aopa/ft_201604
https://www.nxtbook.com/nxtbooks/aopa/ft_201603
https://www.nxtbook.com/nxtbooks/aopa/ft_201602
https://www.nxtbook.com/nxtbooks/aopa/ft_201601
https://www.nxtbook.com/nxtbooks/aopa/ft_201512
https://www.nxtbook.com/nxtbooks/aopa/ft_201511
https://www.nxtbook.com/nxtbooks/aopa/ft_201510
https://www.nxtbook.com/nxtbooks/aopa/ft_201509
https://www.nxtbook.com/nxtbooks/aopa/ft_201508
https://www.nxtbook.com/nxtbooks/aopa/ft_201507
https://www.nxtbook.com/nxtbooks/aopa/ft_201506
https://www.nxtbook.com/nxtbooks/aopa/ft_201505
https://www.nxtbook.com/nxtbooks/aopa/ft_201504
https://www.nxtbook.com/nxtbooks/aopa/ft_201503
https://www.nxtbook.com/nxtbooks/aopa/ft_201502
https://www.nxtbook.com/nxtbooks/aopa/ft_201501
https://www.nxtbook.com/nxtbooks/aopa/ft_201412
https://www.nxtbook.com/nxtbooks/aopa/ft_201411
https://www.nxtbook.com/nxtbooks/aopa/ft_201410
https://www.nxtbook.com/nxtbooks/aopa/ft_201409
https://www.nxtbook.com/nxtbooks/aopa/ft_201408
https://www.nxtbook.com/nxtbooks/aopa/ft_201407
https://www.nxtbook.com/nxtbooks/aopa/ft_201406
https://www.nxtbook.com/nxtbooks/aopa/ft_201405
https://www.nxtbook.com/nxtbooks/aopa/ft_201404
https://www.nxtbook.com/nxtbooks/aopa/ft_201403
https://www.nxtbook.com/nxtbooks/aopa/ft_201402
https://www.nxtbook.com/nxtbooks/aopa/ft_201401
https://www.nxtbook.com/nxtbooks/aopa/ft_201312
https://www.nxtbook.com/nxtbooks/aopa/ft_201311
https://www.nxtbook.com/nxtbooks/aopa/ft_201310
https://www.nxtbook.com/nxtbooks/aopa/ft_201309
https://www.nxtbook.com/nxtbooks/aopa/ft_201308
https://www.nxtbook.com/nxtbooks/aopa/ft_201307
https://www.nxtbook.com/nxtbooks/aopa/ft_201306
https://www.nxtbook.com/nxtbooks/aopa/ft_201305
https://www.nxtbook.com/nxtbooks/aopa/ft_201304
https://www.nxtbook.com/nxtbooks/aopa/ft_201303
https://www.nxtbook.com/nxtbooks/aopa/ft_201302
https://www.nxtbook.com/nxtbooks/aopa/ft_201301
https://www.nxtbook.com/nxtbooks/aopa/ft_201212
https://www.nxtbook.com/nxtbooks/aopa/ft_201211
https://www.nxtbook.com/nxtbooks/aopa/ft_201210
https://www.nxtbook.com/nxtbooks/aopa/ft_201209
https://www.nxtbook.com/nxtbooks/aopa/ft_201208
https://www.nxtbook.com/nxtbooks/aopa/ft_201207
https://www.nxtbook.com/nxtbooks/aopa/ft_201206
https://www.nxtbook.com/nxtbooks/aopa/ft_201205
https://www.nxtbook.com/nxtbooks/aopa/ft_201204
https://www.nxtbook.com/nxtbooks/aopa/ft_201203
https://www.nxtbook.com/nxtbooks/aopa/ft_201202
https://www.nxtbook.com/nxtbooks/aopa/ft_201201
https://www.nxtbook.com/nxtbooks/aopa/ft_201112
https://www.nxtbook.com/nxtbooks/aopa/ft_201111
https://www.nxtbook.com/nxtbooks/aopa/ft_201110
https://www.nxtbook.com/nxtbooks/aopa/ft_201109
https://www.nxtbook.com/nxtbooks/aopa/ft_201108
https://www.nxtbook.com/nxtbooks/aopa/ft_201107
https://www.nxtbook.com/nxtbooks/aopa/ft_201106
https://www.nxtbook.com/nxtbooks/aopa/ft_201105
https://www.nxtbook.com/nxtbooks/aopa/ft_201104
https://www.nxtbook.com/nxtbooks/aopa/ft_201103
https://www.nxtbookmedia.com