Carb ice ?
After over 5 years of happy RV12 flying we seem to have all problems this year.
We have two RV12 and on both we had engine problems and critical emergency landings.
PH-SEP hobbs 600 5 years in use :
We did an extensive annual a month ago and as the 5 years had past we replaced all rubber hoses and components as per Rotax schedule.
We had a Rotax dealer rebuild the carbs and replace the fuel pump both due at 600 hours.
We did a 30 minute testfligth after all the work and all seems perfect.
Today we did a first 45 minute overland without any problems.
On the return fligth however it was very difficult to reach rotation speed untill we noticed the engine did only 3800 rpm but we had to depart as the end of the short grass strop was near. We got up to 300 ft and the engine shaked and ran very rough and we barely managed to go around and land. Pfffff
We called the local Rotax engineer which did a lot of checks but found nothing.
After a succesful testflight we returned to our airport without any problems.
In all cases the engine was ran for a good warm-up before departure. Humidity was quite high and temp 50 F. Both fuel pumps on.
We analysed the Dynon log files and all readings are normal with exception of the two right hand EGT's were 300 deg F lower than left and varying up/down.
The experts concluded short of fuel caused by carb ice !
I was always made to believe as we have no airbox the carbs always get warm air from inside the cowl and therefore heating not required.
I must also say in 850 RV12 Rotax hours we never had ice and flew in all kind of temperatures and humidities.
Also never heard any RV12 owner about this.
What say and are there carb ice exoeriences ?
PH-SEP and PH-SES
RV12 #120519 and #120790
Hobbs 700+ hours and 400+ hours
Dual SV1000 Skyview 15, Pocket FMS and Powerflarm 6.0 (ADSB)