AOPA Pilot Magazine - April 2017 - 20

SAFETY SPOTLIGHT

Stabilized approach
economics

BY MAX TRESCOTT

Unstable approaches can be expensive

MAX TRESCOTT

20 | AOPA PILOT April 2017

away. While many factors contributed to this fatal
accident, two stood out. The clouds at Akron were
600 feet overcast, and the pilots apparently spent
time discussing whether clouds are measured from
the ground or sea level. With more than 9,000 hours
in flying time between the two pilots, I was surprised
they didn't know unquestionably that clouds are measured from the ground. If you ever forget, just think
about a METAR for 1,000-foot clouds over Denver.
Could they possibly be 4,000 feet below the ground?
Obviously not, which confirms that cloud heights are
reported in agl, not msl.
Another major factor was that the Hawker was
not on a stabilized approach. One of the pilots apparently said to the other, "You're diving. You're diving.
Don't dive-2,000 feet per minute, buddy! Two thousand feet per minute! Don't go 2,000 feet per minute!"
Soon after, the aircraft broke out of the clouds, but
the pilots didn't arrest their high descent rate and
crashed into the ground, killing all on board.
So what is a stabilized approach, and why does
it matter? Cirrus Aircraft's flight operations manual gives a good description: "A stabilized approach
is characterized by a constant angle and constant
rate of descent approach profile ending near the
touchdown point. Stabilized approach criteria
apply to all approaches including practice power-off
approaches."
It goes on to say that for VFR landings, an
approach is considered stabilized when all of the following criteria are achieved by 500 feet agl:
* Proper airspeed,
* Correct flight path,
* Correct aircraft configuration for phase of flight,
* Appropriate power setting for aircraft configuration,
* Normal angle and rate of descent,
* Only minor corrections are required to correct deviations. "A go-around must be executed if the above
conditions are not met, and the aircraft is not stabilized by 500 feet agl," it said.
Undoubtedly, all the pilots in these incidents
knew they should have gone around, or executed a
missed approach. But none did. For all of them, it
was a costly lesson on the economics of unstable
approaches.
AOPA

JASON DOIY

is a Platinum Cirrus
Standardized
Instructor Pilot and
the 2008 National
Certificated Flight
Instructor of the
Year.

MOST PILOTS HAVE HEARD of a stabilized approach
and know it's helpful to have one while on approach
to landing. But many pilots don't know all the elements of a stabilized approach, or the potential
expense of an unstable approach. In 2016, two pilots
I know dug deeply into their wallets to pay for damage resulting from poor landings following unstable
approaches. Both considered going around, but neither did. The pilots of an IFR charter fight into Akron,
Ohio, in November 2015 weren't so lucky; everyone died in the crash resulting from their unstable
approach.
The first incident involved a pilot recently
checked out in a Diamond DA40. He flew a few hours
to Southern California, but was tired when he arrived.
On final, he knew he was high and fast, but felt he
could still make the landing work. After landing long,
he applied the brakes hard and stopped before the
end of the runway.
I was the next person to fly the airplane. Before
climbing into the rental aircraft with a client, I rolled
it forward to inspect the main tires for flat spots. In
the process, we discovered both tires had the largest
flat spots I'd seen in my long flying career. That pilot
paid $800 for new tires and labor to change them.
The second pilot didn't fare as well. After not flying for a month, he flew his Cessna 182 to a nearby
airport to practice landings. After a few good landings at Half Moon Bay Airport, he returned to the
airport in Palo Alto, California. Approaching the field,
he relaxed because he was returning to his "home
field," with which he was very familiar. Ironically,
relaxing was the wrong thing to do. Palo Alto's runway is among the shortest many pilots will encounter.
Like the first pilot, he was high and fast. He considered going around, but felt he could save the
landing. He landed long and hard, and bounced. The
aircraft then contacted the runway in a nose-low attitude, and the nose gear collapsed as it skidded to a
stop. The cost to replace a near-TBO engine, propeller,
a wing tip, and the bottom of the engine compartment
will exceed $100,000. Like the first incident, this one
could have been avoided by a timely go-around.
On November 10, 2015, a chartered Hawker
departed Dayton, Ohio, for Akron, about 30 minutes

Table of Contents for the Digital Edition of AOPA Pilot Magazine - April 2017