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.