AOPA Pilot Magazine - October 2019 - 89

EXPLORING VARIOUS PROCEDURES
I used my own airplanes to explore various emergency descent techniques. Included are the published procedure
and the flight test data. A video detailing this experiment can be found at aceaerobaticschool.com/videos.
Cessna 152 Aerobat (CE-A152)
POH: The handbook for the Cessna listed no procedure but recommended an airspeed of 85 knots (VFE but no
mention of flap use is made). This profile resulted in a descent rate of about 1,000 fpm.
AIRSPEED

FLAPS (DEG)

BANK ANGLE
(DEG)

COORDINATION

GEAR

DESCENT RATE (FPM)

VFE

Coordinated

Down

1,500

VFE

Coordinated

Down

1,000

Coordinated

Down

1,800

Slip

Down

1,800

VNO

Coordinated

Down

2,500

Beechcraft Bonanza (BE-E33C)
POH: power-idle, propeller-high rpm, landing gear-down, airspeed 154 knots (VLO/VLE)
AIRSPEED

FLAPS (DEG)

BANK ANGLE
(DEG)

COORDINATION

GEAR

DESCENT RATE (FPM)

VFE

Coordinated

Down

2,700

Slip

Down

1,700

Coordinated

Down

2,700

VLO/VLE

Coordinated

Down

5,900

VNO

Coordinated

3,000

advance and let both pilots verify the aircraft is in the proper configuration before
commencing a maneuver. Since the vertical
speed indicator isn't reliable for accurate
descent rates, record the time t (in minutes)
it takes to descend through a 1,000-foot altitude block. The descent rate is then 1,000
divided by t. I tested a Cessna 152 Aerobat
and a Beechcraft Bonanza to generate procedures for my own aircraft (see "Exploring
Various Procedures," this page).
I must say that the emergency descent
procedure for the Cirrus SR20 and SR22
caught my attention. Risks of exceeding
VNE include parts leaving the airplane and

aerodynamic flutter that may cause catastrophic structural failure. Personally,
taking any airplane to VNE would require
me to get my courage up in a way that
is incompatible with aviating. But I had
to know more, so I turned to Cirrus aficionado Max Trescott for his take on
the procedure. He was kind enough to
make a video (youtu.be/fp3s-VOm3IQ)
that demonstrates that a power-off dive
in the SR20 at VNO provides a 4,000 fpm
descent rate-and I can only imagine the
eye-watering descent rate that VNE must
produce. If you own such a model, I do
not advocate testing the POH procedure

and consider using it only during an
emergency in smooth air.
I'm a fan of making my own aircraft
checklists as the process makes me read my
operating manual with a critical eye. While
the likelihood of needing such a maneuver is
remote, waiting for a true emergency to consult your checklist would be a mistake. Find
and include the procedure(s) you deem best
in your own emergency checklist.
AOPA
CATHERINE CAVAGNARO is an aerobatics

instructor (aceaerobaticschool.com) and
professor of mathematics at Sewanee: The
University of the South.

aopa.org/pilot AOPA PILOT | 89

http://www.aceaerobaticschool.com/videos https://www.youtube.com/watch?v=fp3s-VOm3IQ&t=3s http://www.aceaerobaticschool.com http://www.aopa.org/pilot

AOPA Pilot Magazine - October 2019

Table of Contents for the Digital Edition of AOPA Pilot Magazine - October 2019