More "things we won't do"

The following article appeared in the December 2021 edition of the American Bonanza Society Magazine - www.bonanza.org

In the September 2021 ABS Magazine, Tom Turner wrote about training in multiengine aircraft. He brought up a list of things we as BPPP instructors will not do and highlighted some personal instructor minimums we all abide by in order to make the instructional environment as safe as possible. 

Many of us BPPP instructors add additional personal minimums to this list. When flying multiengine aircraft, I introduce the following additional personal minimum into all of my multiengine training flights – especially in aircraft that I have never flown before:

Actual engine shutdowns will occur no lower than 5,000 feet and will occur within 10 miles of an airport with a runway of at least 4,000 feet length.

This may seem overly cautious, but as is typical, many personal minimums are born out of past experiences, and this one is no different.

A few years ago I was flying with a student, preparing him for a commercial checkride. I mentioned that we would be performing an actual engine shutdown as an examiner would expect on the checkride. I wanted to ensure the pilot knew the checklist and was able to experience the sight, sounds, and feel of the aircraft when truly running on only one engine. I also wanted to do this with the student, because it wasn’t clear whether he ever performed an engine shutdown when he transitioned to this aircraft. His previous experience was in a Diamond Twin Star. Either way, experiencing this in a Baron for the first time on a checkride is not a good idea. 

We climbed to altitude and talked through the checklist once again before performing the actual shutdown. We then took up an easterly heading so the sun wouldn’t be in our eyes and pulled out the checklist. The student started to complete each item in the Securing Engine checklist. When we got to the Propeller-Feather item, the student smoothly brought the propeller lever to feather. 

The plane started to yaw just a little less, and the dead engine was slowly coming to a stop as the propeller blades started to move to the feather position. The thing was, it was sure taking a long time for the propeller to completely go into feather. Three seconds turned into five seconds, turned into 10 seconds...and I started to wonder: “Why isn’t this propeller feathering?” It seemed like it was almost there, but it wasn’t fully feathered. The mostly windmilling propeller would fight the engine compression and spin a little faster, then slow almost to a stop, then continue the cycle again. At this point I had seen enough and asked the student to advance the propeller control, hoping we could get things back to normal.

To my delight we came out of "partial-feather" and were able to start the engine without further fanfare. What seemed like many minutes were only really a few moments, but during that time I started to think about what could have happened. What if something happened that wouldn't allow the propeller to come out of that partially feathered position? Would we be making a single-engine landing, but with a partially feathered propeller? What would that performance look like? Where is my nearest airport, and does it have enough runway length to make me comfortable with a non-standard single-engine approach? 

These questions rushed through my mind in an instant and caused me to think about the potential situations we could have encountered. We terminated the training session and landed. I had the pilot call maintenance to get the feathering problem figured out before the next flight since our inability to feather that engine would certainly be an issue if we needed to feather it at a critical phase of flight, such as shortly after takeoff on climb-out.

Our friends at a shop in Kalamazoo, Michigan, were able to make some adjustments to the feathering mechanism in the engine compartment. It needed to be re-adjusted to allow the propeller to completely feather. We tested the ability to feather this engine again on our next flight, as well as the other engine, both successfully feathering. 

Another notable observation came out of this experience. The propeller exercise we do before the first flight of the day doesn’t really check for the ability to fully feather. It did exactly what we expected it to do that afternoon on our Before Takeoff checklist. There was no indication of problems when we pulled the propeller control into feather and then returned it to high RPM. We let the prop speed drop a couple hundred RPM before advancing the propeller control, which only tells us that the propeller governor is attempting to feather. But there are no guarantees.

Everything eventually worked great, and I signed him off to take his commercial checkride. Not only did a new personal minimum come out of this experience, but I also work with pilots to encourage them to get with their favorite multiengine instructor and feather each of their engines on occasion just to make sure they actually feather.