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Flying By The Numbers is my #1 Life Preserver

Pilot Tips

Pilot Tips Sometimes it has taken me years to realize the errors of my ways. All those hours in training and in flying my Seawind failed to prepare me for optimal safe flight. My flight instructors taught me what they had been taught. Takeoffs, landings, straight and level VFR, IFR, and on and on, but no one taught me the best numbers to remember.

Further in Pilot Tips, instructors were focused on piston performance, but N71RJ was no piston engine and the numbers I learned were largely useless for taming a turbine. For starters, what torque setting yields the best efficiency? Best cruise power? Best rates of climb and descents? What does wing loading and power loading tell me about performance and how can I use these numbers to optimize my flight? What Is my Carson Index and how do I calculate it? Equally important, what are the effects of takeoff and landing weights on roll distances? For an experimental airplane, these numbers had to be tested by me, the builder/manufacturer, on land, in water, and in the air.

To accomplish that, I needed to know all the numbers I had not been taught, burn them into my brain and revise my Pilot Operating Handbook, POH. A simple truth surfaced: I could not fly my Super Seawind well without adding these numbers to all the others and employing them for best performance. So, let me share a little story that reflected my ignorance.

REAL LIFE STORY

On a 2020 trip flying my Super Seawind from Massachusetts to Florida, I positioned the throttle to get the speed I desired. However, this told me nothing about drag eating up more fuel than the plane should have. Had I known a few key numbers before the engine start, for example, if I knew the torque setting and fuel consumption that would allow a perfectly trimmed airplane to give me a certain indicated airspeed, IAS, then I could achieve it. If not, I would know I have excess drag. As I later discovered my rudder was out of trim and the autopilot had corrected and compensated with aileron trimming – further increasing drag. Flying 600 NM legs, reduced my range because I used increased power and fuel-burn to reach the desired speed instead of torque and NF.

CONCLUSION

What combination of all these numbers yields the best possible flight? Answer: I did not know. What did I need to do to get the most from every flight and make each one safer too? Answer: Record these numbers and calculate performance expected prior to every flight. The numbers will tell the story of what should happen.

If I do not see these performance numbers in flight, I will immediately know there is a problem that I need to address ASAP. For instance, what weight numbers and what flight configuration do I need to know to clear 50’ trees at the end of a 2500’ runway in July? This number alone could be a lifesaver. Take-off ground roll to lift off point would tell me when to abort a flight if this number is not attained as expected.

It is burned into my brain at least a day before I get into any airplane. Not acting appropriately on this number has needlessly caused many pilot and passenger tragedies. By making a preflight cheat sheet with all these numbers, I am highly motivated to avoid another number; 6 feet under.

  • NF is fuel flow.
  • N1 is compressor speed.
  • N2 is propeller speed.
  • Torque
  • FP is fuel pressure.
  • Oil pressure
  • Oil temperature
  • Inter-turbine temperature
  • Voltage
  • Amperage
  • Take-off weight and balance
  • Takeoff and landing rolls in feet.
  • Lift-off speed
  • Vx: Best angle of climb
  • Vy: Best rate of climb
  • Rate of climb, ROC
  • Flap positions
  • VFe is Flap speeds
  • Landing gear retraction and extension speeds
  • Cruise settings for Carson speed and for high performance
  • Expected fuel consumption.
  • Wind directions and speeds at various altitudes
  • True Air Speed, TAS expected.
  • Calculated range, aka endurance.

Now I know that flying my Seawind is all about how all the numbers tell a story I need to listen to.

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