Always be learning

As the saying goes, a pilot certificate is a license to learn.

And today, I learned something.

It happened while reading the Feb. 22, 2024, edition of Flying Lessons by Thomas P. Turner. If you don’t subscribe, you should. And not just subscribe, but read.

This week’s lessons and discussion came as a result of a fatal crash of a parachute-equipped Sling TSi.

I’ve had the good fortune to make several flights aboard various Cirrus Aircraft models. All were outfitted with CAPS, the Cirrus Airframe Parachute System. I can remember each pilot briefing the passengers on CAPS, including when it can be used and how.

In Flying Lessons, instructor Mike Radomsky wrote about an acronym I hadn’t heard, Cdh, which stands for CAPS Decision Height.

As noted, Cdh is “either 500 feet or 600 feet AGL, depending on the Cirrus model.”

Other acronyms I hadn’t seen before were:

• Pdh (Parachute Decision Height)
• GAGL (Global Positioning System Above Ground Level)
• EFATO (Engine Failure After Take-Off)

While Pdh makes sense now that I’ve seen Cdh, I don’t see a need for EFATO. In the age of GPS generated altitude, GAGL is useful, if a bit of a stretch.

As Tom points out, “An important note: knowing your approximate height above ground level (AGL) is important in aircraft not equipped with whole-airplane parachutes as well. If you find yourself in an engine-out glide you need to know your height AGL so you can determine how much maneuvering you can do and still make it to your chosen landing spot.“

Further down the newsletter, Ed Wischmeyer adds that the Sling accident “strongly suggests that the significant part of the flight path might have been a descending spiral and not a stall/spin.”

Ed includes a link to a YouTube video that includes a descending spiral with a not great ending.

I don’t recall learning about a maneuver called a descending spiral. But my primary flight training was last century.

Thankfully Tom included a link to an article he write about “Avoiding Airframe Failure” published in Aviation Safety.

The article explains spiral tendency and recovery and how they relate to airframe failure.

While I recall my training on steep turns, a maneuver that may lead to a descending spiral, I don’t recall them being called descending spirals.

Anyway, this morning was a productive one. I learned a few new-to-me acronyms and brushed up on some concepts and maneuvers I haven’t thought about in years — all from the safety and comfort of my home.

Always be learning.

And seriously, go to https://thomaspturner.com/ and click the Subscribe button in the upper right to start receiving Flying Lessons. (There is no charge for the email subscription, but he does accept donations.)