Configuration Checklists

[Bob Axsom]

I have a racing configuration and a traveling configuration for my RV-6A. The temptation is to not make the complete switchover when changing the mission. I will list only the reversable racing changes and you will know the travel configuration is the opposite:

- Tip tanks removed
- Stock tips replaced by three inch custom tips
- Blocking plates installed over the heater and blast tube ports in rear baffle
- Lock down the intake filter bypass door

The wing configuration change takes about a day and a half and involves a lot of wiring and two fuel lines. With so many fasteners it would be very easy to get distracted and not install them correctly. Since I use knife splices, it would be easy to not sleeve one properly and lead to a short, or miswire them and the lights or fuel sensor not work. A fuel leak or a completly unconnected tip tank would be at least quite a mess (I worked for Douglas in Long Beach when A DC-9 was fueled for delivery to Hawaii without the ferry tank system properly configured and the fuel poured out on the ramp).

In a trip from Fayetteville, Arkansas to Baltimore, Maryland last week I made the change to the travel configuration. As we crossed over the mountains west of Maryland we were in IMC and started picking up light ice. The airspeed indicator started dropping off and as it was was passing through 100 kts I turned on the pitot heat and it recovered. Ice started forming on the windshield I opened the heat and serial windshield defroster ports and the ice stopped accumulating there. I had not thought to remove the filter by-pass lock down but I gave induction icing considerable thought at that time during the flight.

If you do this kind of configuration change there is considerable risk and you probably should develop a itemized checklist that includes functional testing where possible.

Bob Axsom