Folks,
I was out flying a couple weeks ago during our first hot humid day in NH. Flew to a local airport for a T&G at 2K then climbed up to 5K to go shoot an ILS at Lebanon NH. About 10 miles from the IAF I started feeling a slight engine surge then the tach showed about a 100 RPM swing (50 above and 50 below my power setting). I doubted carb ice (which I've not experienced in 400 hours in an Archer) but put it on and that didn't make any difference. I was already leaned but brought that forward with no difference.
Slowed to 90 KTS, started the approach but wasn't comfortable so discontinued it and told tower I was going to keep it high to the field. Did a space shuttle approach and parked to discuss it with the folks at Granite Air FBO. They took it out, ran it up brought it back in the hangar and took the cowl off and checked everything. Nothing found (very nice FBO and mechs though and no charge)
I did another perfect run-up and departed for home at 3K. I encountered the same issue, turned on carb heat, altered mixture and after about 2 minutes it cleared up and the engine ran fine the remaining 30 minutes home. Wrote up my experiences and sent it to the club members.
I was the 2nd flight after maint and the mags were rebuilt, oil changed and that was about it engine-wise
I flew again this last Monday and didn't experience anything unusual.
One of the other club members (an experienced commercial pilot) flew it down to Nantucket yesterday and experienced what I did IMC but only on the approach into the field.
Thoughts? It's not bad but it's not what I expect either. We were thinking maybe the prop is out of balance? Been quit a while since we did that.
I was out flying a couple weeks ago during our first hot humid day in NH. Flew to a local airport for a T&G at 2K then climbed up to 5K to go shoot an ILS at Lebanon NH. About 10 miles from the IAF I started feeling a slight engine surge then the tach showed about a 100 RPM swing (50 above and 50 below my power setting). I doubted carb ice (which I've not experienced in 400 hours in an Archer) but put it on and that didn't make any difference. I was already leaned but brought that forward with no difference.
Slowed to 90 KTS, started the approach but wasn't comfortable so discontinued it and told tower I was going to keep it high to the field. Did a space shuttle approach and parked to discuss it with the folks at Granite Air FBO. They took it out, ran it up brought it back in the hangar and took the cowl off and checked everything. Nothing found (very nice FBO and mechs though and no charge)
I did another perfect run-up and departed for home at 3K. I encountered the same issue, turned on carb heat, altered mixture and after about 2 minutes it cleared up and the engine ran fine the remaining 30 minutes home. Wrote up my experiences and sent it to the club members.
I was the 2nd flight after maint and the mags were rebuilt, oil changed and that was about it engine-wise
I flew again this last Monday and didn't experience anything unusual.
One of the other club members (an experienced commercial pilot) flew it down to Nantucket yesterday and experienced what I did IMC but only on the approach into the field.
Thoughts? It's not bad but it's not what I expect either. We were thinking maybe the prop is out of balance? Been quit a while since we did that.
