AOPA Pilot Magazine - January 2025 - 83

range. In a strong headwind,
for example, a
faster-than-best-glide
airspeed will reduce
the amount of time the
airplane is subjected
to a headwind and
reduce the resulting
loss of glide distance.
Similarly, with a tailwind,
pilots should fly
a slower indicated airspeed
than best glide to
maximize the duration
of nature's push and
increase gliding distance.
Garmin air data
computers know and
constantly update wind
strength and direction-
yet the company doesn't
use that information to
adjust the manufacturer-supplied bestglide
speed for current conditions.
Dynon
Dynon added an " Emergency Glide " feature
SkyView HDX update on August 20, 2024,
that engages the autopilot to fly directly to
the nearest suitable airport at best-glide
speed. It shows a green glide-range ring on
the moving map. The Dynon glide ring is
circular at all times and its shape changes
to account for mountainous terrain-but
Emergency Glide takes terrain elevation
into account when selecting target airports.
I made a series of flights in my Dynon
SkyView-equipped Van's Aircraft RV-4
and set up each glide in the same way:
an altitude of 4,000 feet or above, airport
barely within the graphical glide ring.
Then I'd engage Emergency Glide (by
holding down the NRST button for two
seconds or more) and let the airplane turn
directly to the airport at idle power and the
prop in its full high-pitch/low-rpm setting.
Dynon requires pilots of airplanes
registered in the experimental/amateurbuilt
category (such as the RV-4) to set
their airplane's glide ratio and rate of
descent because each aircraft is likely to
vary, and sometimes they vary widely.
Van's Aircraft doesn't provide glide
ratios, so I turned to pilots and builders
of similar airplanes who provided
must pick an off-airport
landing site.
There's no reason
Dynon's Emergency Glide draws a green circle with the aircraft in the center to show glide
range, and that circle accounts for wind but not terrain. Here, the airplane is flying at 7,000
feet, about five miles from Palm Springs International Airport (PSP), and the green circle
shows the airport is within glide range.
guestimates of about 9:1. My airplane's
real-world, idle-power performance was
closer to 8:1 with a 950-foot-per-minute
rate of descent. Those stubby, low-aspectratio
wings just aren't efficient gliders.
One glide-ring characteristic that
became clear during the Dynon/RV-4
glide flights was that headwinds at cruise
altitude are far more likely to result in successfully
reaching airports than tailwinds.
That seems counterintuitive but headwinds
are almost certain to diminish as a gliding
airplane descends to lower altitude-and
that reduced headwind increases glide
range. Similarly, a tailwind at cruise altitude
is also likely to diminish during a descent.
That decreasing push leads the glide rings
to rapidly constrict-and that makes it less
likely a gliding airplane will reach its target.
During headwinds or tailwinds of 10 knots
or more, my airplane's glide performance
was noticeably better when I adjusted the
best-glide speed while hand flying instead
of using autopilot.
Conclusions
The main benefit of glide rings is that
they constantly give pilots this bit of
unsettling news: We're seldom within
gliding distance to an airport, even at
normal cruise altitudes above populated
regions. In a real engine-out emergency,
glide rings show pilots instantly that they
to waste precious time
with distractions such as
searching for and choosing
a nearby airport,
turning in its direction,
changing radio
frequencies, and estimating
whether or not you'll
be able to glide there. You
won't, don't bother trying.
The trickiest aspect
of glide rings is that they
give the appearance
of omniscience when
they're really just living
in the moment. They
make constant calculations
and update the pilot
every three seconds-yet
they don't predict how much the wind is
going to shift in speed or direction at lower
altitudes, and they don't show the pilot
the optimal speed to fly to maximize glide
range based on current conditions.
For pilots who begin a glide to an airport
that appears within glide range only to
see it slip away as the rings constrict during
descent, the sense of betrayal is severe.
After all, as an airplane flies in the direction
of a suddenly out-of-reach airport, it's
likely heading toward a more developed
area with fewer suitable off-field landing
sites. Pilots can find out for themselves
by practicing power-off glides in various
wind conditions to determine whether
their anticipated glide range is accurate.
Pilots also can improve glide performance
by moving constant-speed propellers to
the high pitch/low rpm setting; pitching
up momentarily to stop props from adding
drag by windmilling; flying faster than the
published best-glide speed in a headwind
and slower with a tailwind.
Glide rings provide a great deal of
potentially life-saving information at a
glance. When linked to an autopilot, they
reduce pilot workload and avoid potential
losses of aircraft control at critical
moments. Like other safety tools, however,
understanding what goes into them
is the key to getting the most out of them.
dave.hirschman@aopa.org
AOPA PILOT / January 2025
83

AOPA Pilot Magazine - January 2025

Table of Contents for the Digital Edition of AOPA Pilot Magazine - January 2025

Contents
AOPA Pilot Magazine - January 2025 - Intro
AOPA Pilot Magazine - January 2025 - Cover1
AOPA Pilot Magazine - January 2025 - Cover2
AOPA Pilot Magazine - January 2025 - Contents
AOPA Pilot Magazine - January 2025 - 2
AOPA Pilot Magazine - January 2025 - 3
AOPA Pilot Magazine - January 2025 - 4
AOPA Pilot Magazine - January 2025 - 5
AOPA Pilot Magazine - January 2025 - 6
AOPA Pilot Magazine - January 2025 - 7
AOPA Pilot Magazine - January 2025 - 8
AOPA Pilot Magazine - January 2025 - 9
AOPA Pilot Magazine - January 2025 - 10
AOPA Pilot Magazine - January 2025 - 11
AOPA Pilot Magazine - January 2025 - 12
AOPA Pilot Magazine - January 2025 - 13
AOPA Pilot Magazine - January 2025 - 14
AOPA Pilot Magazine - January 2025 - 15
AOPA Pilot Magazine - January 2025 - 16
AOPA Pilot Magazine - January 2025 - 17
AOPA Pilot Magazine - January 2025 - 18
AOPA Pilot Magazine - January 2025 - 19
AOPA Pilot Magazine - January 2025 - 20
AOPA Pilot Magazine - January 2025 - 21
AOPA Pilot Magazine - January 2025 - 22
AOPA Pilot Magazine - January 2025 - 23
AOPA Pilot Magazine - January 2025 - 24
AOPA Pilot Magazine - January 2025 - 25
AOPA Pilot Magazine - January 2025 - 26
AOPA Pilot Magazine - January 2025 - 27
AOPA Pilot Magazine - January 2025 - 28
AOPA Pilot Magazine - January 2025 - 29
AOPA Pilot Magazine - January 2025 - 30
AOPA Pilot Magazine - January 2025 - 31
AOPA Pilot Magazine - January 2025 - 32
AOPA Pilot Magazine - January 2025 - 33
AOPA Pilot Magazine - January 2025 - 34
AOPA Pilot Magazine - January 2025 - 35
AOPA Pilot Magazine - January 2025 - 36
AOPA Pilot Magazine - January 2025 - 37
AOPA Pilot Magazine - January 2025 - 38
AOPA Pilot Magazine - January 2025 - 39
AOPA Pilot Magazine - January 2025 - 40
AOPA Pilot Magazine - January 2025 - 41
AOPA Pilot Magazine - January 2025 - 42
AOPA Pilot Magazine - January 2025 - 43
AOPA Pilot Magazine - January 2025 - 44
AOPA Pilot Magazine - January 2025 - 45
AOPA Pilot Magazine - January 2025 - 46
AOPA Pilot Magazine - January 2025 - 47
AOPA Pilot Magazine - January 2025 - 48
AOPA Pilot Magazine - January 2025 - 49
AOPA Pilot Magazine - January 2025 - 50
AOPA Pilot Magazine - January 2025 - 51
AOPA Pilot Magazine - January 2025 - 52
AOPA Pilot Magazine - January 2025 - 53
AOPA Pilot Magazine - January 2025 - 54
AOPA Pilot Magazine - January 2025 - 55
AOPA Pilot Magazine - January 2025 - 56
AOPA Pilot Magazine - January 2025 - 57
AOPA Pilot Magazine - January 2025 - 58
AOPA Pilot Magazine - January 2025 - 59
AOPA Pilot Magazine - January 2025 - 60
AOPA Pilot Magazine - January 2025 - 61
AOPA Pilot Magazine - January 2025 - 62
AOPA Pilot Magazine - January 2025 - 63
AOPA Pilot Magazine - January 2025 - 64
AOPA Pilot Magazine - January 2025 - 65
AOPA Pilot Magazine - January 2025 - 66
AOPA Pilot Magazine - January 2025 - 67
AOPA Pilot Magazine - January 2025 - 68
AOPA Pilot Magazine - January 2025 - 69
AOPA Pilot Magazine - January 2025 - 70
AOPA Pilot Magazine - January 2025 - 71
AOPA Pilot Magazine - January 2025 - 72
AOPA Pilot Magazine - January 2025 - 73
AOPA Pilot Magazine - January 2025 - 74
AOPA Pilot Magazine - January 2025 - 75
AOPA Pilot Magazine - January 2025 - 76
AOPA Pilot Magazine - January 2025 - 77
AOPA Pilot Magazine - January 2025 - 78
AOPA Pilot Magazine - January 2025 - 79
AOPA Pilot Magazine - January 2025 - 80
AOPA Pilot Magazine - January 2025 - 81
AOPA Pilot Magazine - January 2025 - 82
AOPA Pilot Magazine - January 2025 - 83
AOPA Pilot Magazine - January 2025 - 84
AOPA Pilot Magazine - January 2025 - 85
AOPA Pilot Magazine - January 2025 - 86
AOPA Pilot Magazine - January 2025 - 87
AOPA Pilot Magazine - January 2025 - 88
AOPA Pilot Magazine - January 2025 - 89
AOPA Pilot Magazine - January 2025 - 90
AOPA Pilot Magazine - January 2025 - 91
AOPA Pilot Magazine - January 2025 - 92
AOPA Pilot Magazine - January 2025 - 93
AOPA Pilot Magazine - January 2025 - 94
AOPA Pilot Magazine - January 2025 - 95
AOPA Pilot Magazine - January 2025 - 96
AOPA Pilot Magazine - January 2025 - 97
AOPA Pilot Magazine - January 2025 - 98
AOPA Pilot Magazine - January 2025 - 99
AOPA Pilot Magazine - January 2025 - 100
AOPA Pilot Magazine - January 2025 - 101
AOPA Pilot Magazine - January 2025 - 102
AOPA Pilot Magazine - January 2025 - 103
AOPA Pilot Magazine - January 2025 - 104
AOPA Pilot Magazine - January 2025 - Cover3
AOPA Pilot Magazine - January 2025 - Cover4
https://www.nxtbook.com/nxtbooks/aopa/pilot_202502
https://www.nxtbook.com/nxtbooks/aopa/pilot_202501
https://www.nxtbook.com/nxtbooks/aopa/pilot_202412
https://www.nxtbook.com/nxtbooks/aopa/pilot_202411
https://www.nxtbook.com/nxtbooks/aopa/pilot_202410
https://www.nxtbook.com/nxtbooks/aopa/pilot_202409
https://www.nxtbook.com/nxtbooks/aopa/pilot_202408
https://www.nxtbook.com/nxtbooks/aopa/pilot_202407
https://www.nxtbook.com/nxtbooks/aopa/pilot_202406
https://www.nxtbook.com/nxtbooks/aopa/pilot_202405
https://www.nxtbook.com/nxtbooks/aopa/pilot_202404
https://www.nxtbook.com/nxtbooks/aopa/pilot_202403
https://www.nxtbook.com/nxtbooks/aopa/pilot_202402
https://www.nxtbook.com/nxtbooks/aopa/pilot_202401
https://www.nxtbook.com/nxtbooks/aopa/pilot_202312
https://www.nxtbook.com/nxtbooks/aopa/pilot_202311
https://www.nxtbook.com/nxtbooks/aopa/pilot_202310
https://www.nxtbook.com/nxtbooks/aopa/pilot_202309
https://www.nxtbook.com/nxtbooks/aopa/pilot_202308
https://www.nxtbook.com/nxtbooks/aopa/pilot_202307
https://www.nxtbook.com/nxtbooks/aopa/pilot_202306
https://www.nxtbook.com/nxtbooks/aopa/pilot_202305
https://www.nxtbook.com/nxtbooks/aopa/pilot_202304
https://www.nxtbook.com/nxtbooks/aopa/pilot_202303
https://www.nxtbook.com/nxtbooks/aopa/pilot_202302
https://www.nxtbook.com/nxtbooks/aopa/pilot_202301
https://www.nxtbook.com/nxtbooks/aopa/pilot_202212
https://www.nxtbook.com/nxtbooks/aopa/pilot_202211
https://www.nxtbook.com/nxtbooks/aopa/pilot_202210
https://www.nxtbook.com/nxtbooks/aopa/pilot_202209
https://www.nxtbook.com/nxtbooks/aopa/pilot_202208
https://www.nxtbook.com/nxtbooks/aopa/pilot_202207
https://www.nxtbook.com/nxtbooks/aopa/pilot_202206
https://www.nxtbook.com/nxtbooks/aopa/pilot_202205
https://www.nxtbook.com/nxtbooks/aopa/pilot_202204
https://www.nxtbook.com/nxtbooks/aopa/pilot_202203
https://www.nxtbook.com/nxtbooks/aopa/pilot_202202
https://www.nxtbook.com/nxtbooks/aopa/pilot_202201
https://www.nxtbook.com/nxtbooks/aopa/pilot_202112
https://www.nxtbook.com/nxtbooks/aopa/pilot_202111
https://www.nxtbook.com/nxtbooks/aopa/pilot_202110
https://www.nxtbook.com/nxtbooks/aopa/pilot_202109
https://www.nxtbook.com/nxtbooks/aopa/pilot_202108
https://www.nxtbook.com/nxtbooks/aopa/pilot_202107
https://www.nxtbook.com/nxtbooks/aopa/pilot_202106
https://www.nxtbook.com/nxtbooks/aopa/pilot_202105
https://www.nxtbook.com/nxtbooks/aopa/pilot_202104
https://www.nxtbook.com/nxtbooks/aopa/pilot_202103
https://www.nxtbook.com/nxtbooks/aopa/pilot_202102
https://www.nxtbook.com/nxtbooks/aopa/pilot_202101
https://www.nxtbook.com/nxtbooks/aopa/pilot_202012
https://www.nxtbook.com/nxtbooks/aopa/pilot_202011
https://www.nxtbook.com/nxtbooks/aopa/pilot_202010
https://www.nxtbook.com/nxtbooks/aopa/pilot_202009
https://www.nxtbook.com/nxtbooks/aopa/pilot_202008
https://www.nxtbook.com/nxtbooks/aopa/pilot_202007
https://www.nxtbook.com/nxtbooks/aopa/pilot_202006
https://www.nxtbook.com/nxtbooks/aopa/pilot_202005
https://www.nxtbook.com/nxtbooks/aopa/pilot_202004
https://www.nxtbook.com/nxtbooks/aopa/pilot_202003
https://www.nxtbook.com/nxtbooks/aopa/pilot_202002
https://www.nxtbook.com/nxtbooks/aopa/pilot_202001
https://www.nxtbook.com/nxtbooks/aopa/pilot_201912
https://www.nxtbook.com/nxtbooks/aopa/pilot_201911
https://www.nxtbook.com/nxtbooks/aopa/pilot_201910
https://www.nxtbook.com/nxtbooks/aopa/pilot_201909
https://www.nxtbook.com/nxtbooks/aopa/pilot_201908
https://www.nxtbook.com/nxtbooks/aopa/pilot_201907
https://www.nxtbook.com/nxtbooks/aopa/pilot_201906
https://www.nxtbook.com/nxtbooks/aopa/pilot_201905
https://www.nxtbook.com/nxtbooks/aopa/pilot_201904
https://www.nxtbook.com/nxtbooks/aopa/pilot_201903
https://www.nxtbook.com/nxtbooks/aopa/pilot_201902
https://www.nxtbook.com/nxtbooks/aopa/pilot_201901
https://www.nxtbook.com/nxtbooks/aopa/pilot_201812
https://www.nxtbook.com/nxtbooks/aopa/pilot_201811
https://www.nxtbook.com/nxtbooks/aopa/pilot_201810
https://www.nxtbook.com/nxtbooks/aopa/pilot_201809
https://www.nxtbook.com/nxtbooks/aopa/pilot_201808
https://www.nxtbook.com/nxtbooks/aopa/pilot_201807
https://www.nxtbook.com/nxtbooks/aopa/pilot_201806
https://www.nxtbook.com/nxtbooks/aopa/pilot_201805
https://www.nxtbook.com/nxtbooks/aopa/pilot_201804
https://www.nxtbook.com/nxtbooks/aopa/pilot_201803
https://www.nxtbook.com/nxtbooks/aopa/pilot_201802
https://www.nxtbook.com/nxtbooks/aopa/pilot_201801
https://www.nxtbook.com/nxtbooks/aopa/pilot_201712
https://www.nxtbook.com/nxtbooks/aopa/pilot_201711
https://www.nxtbook.com/nxtbooks/aopa/pilot_201710
https://www.nxtbook.com/nxtbooks/aopa/pilot_201709
https://www.nxtbook.com/nxtbooks/aopa/pilot_201708
https://www.nxtbook.com/nxtbooks/aopa/pilot_201707
https://www.nxtbook.com/nxtbooks/aopa/pilot_201706
https://www.nxtbook.com/nxtbooks/aopa/pilot_201705
https://www.nxtbook.com/nxtbooks/aopa/pilot_201704
https://www.nxtbook.com/nxtbooks/aopa/pilot_201703
https://www.nxtbook.com/nxtbooks/aopa/pilot_201702
https://www.nxtbook.com/nxtbooks/aopa/pilot_201701
https://www.nxtbook.com/nxtbooks/aopa/pilot_201612
https://www.nxtbook.com/nxtbooks/aopa/pilot_201611
https://www.nxtbook.com/nxtbooks/aopa/pilot_201610
https://www.nxtbook.com/nxtbooks/aopa/pilot_201609
https://www.nxtbook.com/nxtbooks/aopa/pilot_201608
https://www.nxtbook.com/nxtbooks/aopa/pilot_201607
https://www.nxtbook.com/nxtbooks/aopa/pilot_201606
https://www.nxtbook.com/nxtbooks/aopa/pilot_201605
https://www.nxtbook.com/nxtbooks/aopa/pilot_201604
https://www.nxtbook.com/nxtbooks/aopa/pilot_201603
https://www.nxtbook.com/nxtbooks/aopa/pilot_201602
https://www.nxtbook.com/nxtbooks/aopa/pilot_201601
https://www.nxtbook.com/nxtbooks/aopa/pilot_201512
https://www.nxtbook.com/nxtbooks/aopa/pilot_201511
https://www.nxtbook.com/nxtbooks/aopa/pilot_201510
https://www.nxtbook.com/nxtbooks/aopa/pilot_201509
https://www.nxtbook.com/nxtbooks/aopa/pilot_201508
https://www.nxtbook.com/nxtbooks/aopa/pilot_201507
https://www.nxtbook.com/nxtbooks/aopa/pilot_201506
https://www.nxtbook.com/nxtbooks/aopa/pilot_201505
https://www.nxtbook.com/nxtbooks/aopa/pilot_201504
https://www.nxtbook.com/nxtbooks/aopa/pilot_201503
https://www.nxtbook.com/nxtbooks/aopa/pilot_201502
https://www.nxtbook.com/nxtbooks/aopa/pilot_201501
https://www.nxtbook.com/nxtbooks/aopa/pilot_201412
https://www.nxtbook.com/nxtbooks/aopa/pilot_201411
https://www.nxtbook.com/nxtbooks/aopa/pilot_201410
https://www.nxtbook.com/nxtbooks/aopa/pilot_201409
https://www.nxtbook.com/nxtbooks/aopa/pilot_201408
https://www.nxtbook.com/nxtbooks/aopa/pilot_201407
https://www.nxtbook.com/nxtbooks/aopa/pilot_201406
https://www.nxtbook.com/nxtbooks/aopa/pilot_201405
https://www.nxtbook.com/nxtbooks/aopa/pilot_201404
https://www.nxtbook.com/nxtbooks/aopa/pilot_201403
https://www.nxtbook.com/nxtbooks/aopa/pilot_201402
https://www.nxtbook.com/nxtbooks/aopa/pilot_201401
https://www.nxtbook.com/nxtbooks/aopa/pilot_201312
https://www.nxtbook.com/nxtbooks/aopa/pilot_201311
https://www.nxtbook.com/nxtbooks/aopa/pilot_201310
https://www.nxtbook.com/nxtbooks/aopa/pilot_201309
https://www.nxtbook.com/nxtbooks/aopa/pilot_201308
https://www.nxtbook.com/nxtbooks/aopa/pilot_201307
https://www.nxtbook.com/nxtbooks/aopa/pilot_201306
https://www.nxtbook.com/nxtbooks/aopa/pilot_201305
https://www.nxtbook.com/nxtbooks/aopa/pilot_201304
https://www.nxtbook.com/nxtbooks/aopa/pilot_201303
https://www.nxtbook.com/nxtbooks/aopa/pilot_201302
https://www.nxtbook.com/nxtbooks/aopa/pilot_201301
https://www.nxtbook.com/nxtbooks/aopa/pilot_201212
https://www.nxtbook.com/nxtbooks/aopa/pilot_201211
https://www.nxtbook.com/nxtbooks/aopa/pilot_201210
https://www.nxtbook.com/nxtbooks/aopa/pilot_201209
https://www.nxtbook.com/nxtbooks/aopa/pilot_201208
https://www.nxtbook.com/nxtbooks/aopa/pilot_201207
https://www.nxtbook.com/nxtbooks/aopa/pilot_201206
https://www.nxtbook.com/nxtbooks/aopa/pilot_201205
https://www.nxtbook.com/nxtbooks/aopa/pilot_201204
https://www.nxtbook.com/nxtbooks/aopa/pilot_201203
https://www.nxtbook.com/nxtbooks/aopa/pilot_201202
https://www.nxtbook.com/nxtbooks/aopa/pilot_201201
https://www.nxtbook.com/nxtbooks/aopa/pilot_201112
https://www.nxtbook.com/nxtbooks/aopa/pilot_201111
https://www.nxtbook.com/nxtbooks/aopa/pilot_201110
https://www.nxtbook.com/nxtbooks/aopa/pilot_201109
https://www.nxtbook.com/nxtbooks/aopa/pilot_201108
https://www.nxtbook.com/nxtbooks/aopa/pilot_201107
https://www.nxtbook.com/nxtbooks/aopa/pilot_201106
https://www.nxtbook.com/nxtbooks/aopa/pilot_201105
https://www.nxtbook.com/nxtbooks/aopa/pilot_201104
https://www.nxtbook.com/nxtbooks/aopa/pilot_201103
https://www.nxtbook.com/nxtbooks/aopa/pilot_201103_test
https://www.nxtbook.com/nxtbooks/aopa/pilot_201102
https://www.nxtbook.com/nxtbooks/aopa/pilot_201011demo
https://www.nxtbook.com/nxtbooks/aopa/pilot_201011
https://www.nxtbook.com/nxtbooks/aopa/pilot0308
https://www.nxtbookmedia.com