Stephen Larew

personal website — updated sporadically

Mission, Design, and Planning

One of the first suggestions one receives when choosing a design is to define and prioritize the missions for the aircraft. My two missions in order are:

  1. Fly locally for fun: hop around among the airports, enjoy the views, and go fast or slow as I please.
  2. Spend vacations adventuring away from home base: comfortable cross-country flight, reliable systems, suitable baggage capacity, journey is the vacation.

The CH 650 is an excellent design for both missions. The bubble canopy grants magnificent views. Its stall speeds are VS=44 kn and VS0=38 kn and my build should cruise at 108-120 kn CAS. Autopilot and modern glass VFR avionics will make cross-country flying a joy. For about $5K, the new Garmin GPS 175 would enable legal IFR flight for brief light IMC conditions.

While top-notch, most of the planes from Vans are excessive for my needs and constraints (airspeed, build time and skills, cost) except the RV-12. I chose the CH 650 over the RV-12 because it affords broader design choices (motor, prop, avionics, kit options) while being about the same (or less) in near-term costs.

Preliminary Design

I am building a ZODIAC CH 650 B with the following options:

  • Long range fuel tank (increases fuel capacity from 24 to 30 gallons).
  • AeroLED nav/strobe/position lights.
  • AeroLED landing light.
  • Wing locker kit.
  • Upholstery kit.
  • Aileron trim tab kit.

I am still researching the motor and avionics options.


I am leaning towards the UL350i. It is a lightweight modern fuel injected engine with a FADEC. The UL350iS increases power from 118 HP to 130 HP but also increases the minimum MOGAS octane level. The lower octane limit of 91 AKI (easier to find) drives me to the UL350i.


I want a clean glass VFR panel with remote components. Major components include

  • GRT Horizon 10.1 EFIS
  • TRIG TY91 VHF COMM (remote)
  • GRT SafeFly ADS-B RX
  • TRIG TT22 transponder (remote)

If I want to add IFR capabilities, I believe I could add an IFR GPS navigator (e.g., Garmin GPS 175) and a NAV radio (e.g., VAL Avionics NAV-2KR) to the GRT EFIS.


  • Is the cheaper Viking engine a good bet?
  • Install a NAV antenna for future use?
  • Second EFIS display for right seat or as MFD?
  • Experimental SDR installation what/where/why/how?

Planning for the Mission

I believe I can begin flying before 2021 ends. My tentative (and admittedly aggressive) timeline is:

January 2021
Start work once kit arrives.
May 2021
Finalize motor and avionics plans. Order avionics and electrical systems.
June 2021
Order motor.
July 2021
Complete major component assembly. Move project to hangar.
August 2021
Receive motor and begin firewall forward.
October 2021
Receive airworthiness and begin Phase I flight testing.