Unicom

February 2017 Issue




Fate Can Be The Hunter

Kudos to Robert Wright on achieving 50 years of accident/incident free flying and receiving the FAA’s Master Pilot Award (“50 Years a Pilot,” September 2016). I too have reached that milestone, but not without accident nor incident in my 6100-plus hours of private pilot flying, most of which has been recreational. My incidents occurred despite what I believed to have been reasonable risk management:

As a student pilot with approximately 20 hours, I landed a Cessna 150 four minutes behind a DC-6 on a calm evening on a runway too short to land beyond his touchdown point. I was caught in the DC-6’s reverse-thrust vortex, striking the prop and both wing tips.

ernest k. gann fate is the hunter

Smoke filled the cabin of a Cessna 180 on skis shortly after takeoff, resulting in dead-stick landing. The smoke likely was due to oil spilled on the engine in 30-degree-below-zero weather.

I also entered a sudden snow squall in hilly terrain, reversed course into intensifying snow and rapidly deteriorating visibility. I performed a precautionary landing on a road and snapped unseen telephone wire, tearing the trailing edges of extended flaps and blowing out the rear window.

I experienced a forced, dead-stick landing on a switch-back logging road while crossing the height of the Canadian Rockies 70 miles west of Calgary. The Cessna 177 Cardinal’s engine suffered total failure due to broken sprocket jamming the oil pump.

In flight following a quick fuel stop 15 minutes after takeoff, I discovered fuel being forcibly ejecting from the underwing vent due to bumblebee plugging another vent.

And I lost airspeed indication one minute after departing a short mountain airstrip in a narrow valley—another bee had impaled itself firmly over the pitot tube.

As Mr. Wright says, flying “is as safe as you want to make it” but in my case, fate has been the hunter, despite what I believe to have been reasonable measures to mitigate risk. I don’t qualify for the award, and there is such a thing as bad luck, but at least I’m still flying.

All the risk management in the world will not eliminate the possibility of all the accidents and incidents that may befall those who fly.

Morton Doran
Fairmont, B.C., Canada

Bob Wright’s achievement is well-deserved, but your career seems to have exposed you to more and different risks than many other contemporary pilots, ourselves included. Fate may have played a role in preventing you from obtaining that award, but we’d guess skill also played a role, since you’re still around to talk about it. Luck and fate aren’t binary, on/off, either/or things; they’re infinitely variable.

Energy Equation

I just finished reading the two articles on flight energy management (“Energy Management Basics,” November 2016, and “Mismanaging Flight Energy,” December 2016) by Micheal Banner. I agree with the vast majority of Dr. Banner’s presentation but, being an engineer, I am driven to take issue with the equation: “Energy state = (EKIN + EPOT) - Drag.” My first problem here is that equations need to be dimensionally homogeneous and this one is not. EKIN and EPOT are both energy quantities and, of course, have energy units. Drag is not energy. It is a force and carries force units. We can’t just add a force quantity to an energy quantity and expect to have a meaningful result.

If we want to express the effect of drag on energy state, we might try multiplying drag (D) by velocity (V). The product D*V carries units of energy per unit time and represents the rate at which drag is trying to diminish energy. But, to get a complete picture, we also need to consider thrust (T). The product T*V represents that rate at which thrust is trying to increase energy. For steady state flight (equilibrium) thrust and drag are numerically equal so they cancel each other and energy does not change. If thrust exceeds drag, energy will increase. If drag exceeds thrust, energy will decrease. In equation form, we might express it this way: Rate of change of Energy = (T - D)*V.

Donald A. Moen
Mayville, North Dakota