What Would You Do ? (3)

[Big Pistons Forever]

I followed the shore line back towards the airport as the Nanchang is well suited to ditching as it has a low wing, retractable gear, and a full sliding canopy and I was wearing a PFD. However the siren call of the nice big runway prompted me to turn away from the shoreline and line up with the runway before I was in gliding range of the runway. This of course is when the engine quit as described in post #9. At this point I made a vary poor decision. Instead of immediately turning back to the shoreline I continued towards the runway. The engine needed to run for about another minute and a half to get me to the runway, which it did, but I had eliminated almost all of my options for that period and luckily for me I got away with it as the engine continued running until I closed the throttle in the flare when it quit again. I allowed the lure of the runway just about there to overcome good decision making which is a lesson I take very much to heart.

Needing to be lucky rather than good is not a place where you should be...


Some general thoughts

1) I have been flying for over 40 years, have 8000 hrs and 68 types in my log book. During that time I have had to deal with a variety of aircraft failures, but I can honestly say that this event was the one I had the hardest time with. If the engine had just quit I would have know exactly what to do. If I was able to get power back by identifying what caused the engine to quit, I would have known exactly what to do. But having an engine that was obviously unwell with no indications of what the problem was can paralyze thinking, especially when you are "almost" home.

2) I continue to believe that other than going to full rich mixture, ( carb air temp was 18 deg so carb heat was not selected) not touching anything else was the correct move until something changed. It turned out the problem was a failing carb diaphragm. A significant change of throttle position may have shut down the engine with no recovery possible.

3) A review of flight safety data implies that partial engine failures are more common than total engine failures, possibly as much as 3 times more likely. Having a decision tree sorted before you get one is a really good idea, rather than when the pressure is on. A good starting point is to know what the minimum power is required to maintain safe level flight. If you don't have that power available than you can immediately move to the forced landing plan if you do have that you then you have more options. My experience is most pilots don't know the minimum RPM or min MP at full fine needed.

4) The way flight training teaches the engine failure scenario is IMO opinion fatally flawed. When the instructor reaches over and pulls the throttle back and says "simulated engine failure" the scenario is effectively an airplane that had a full preflight inspection with no faults found, had completed runup with no faults found, completed a normal takeoff, and is flying with normal engine and fuel indications, suddenly has the engine suffer a complete and instantaneous failure. If you look at the accidents record this scenario is the least likely example of what could happen to you. Far more likely it will fail because of something you are in control of (eg carb ice, fuel management) or will give some warning like my example in the first what would you do post. Discussion of examples of pilot induced engine failures and forced landing exercises that start with a partial failure is almost never taught in flight training. The systems checks conducted right after the engine fails are also usually glossed over but can often restore power if done correctly.

As a final thought and a bit off topic, I remember reading a accident report in Pilot magazine about a Pa 28 which had an engine failure and conducted a forced approach. The were no good fields in range but the pilot conducted a successful forced approach into the best place which resulted in no injures but substantial damage to the aircraft. This successful outcome required skillful flying. The report noted that the attributed his success to the fact that he regularly practiced forced approaches. The engine was test run with no fault found. Given that the temp was +5 C with a small temp dew point spread the cause of the engine failure was deemed to be carb icing.

The pilot can always prevent the engine from failing due to carb icing with early recognition and prompt action, even in the worst possible carb icing conditions, I would suggest that if the pilot had spent a little less time practicing forced approaches and more time practicing engine monitoring and strategies to recognize and take action on aircraft indications that could be the precursors to engine failure, there would be one more Piper flying today.....