Friday, December 31, 2010

...and It Was Good

As anticipated in the previous posting, yesterday's flight from KBDR in Connecticut down to KVKX in the DC area was pleasant and uneventful. For most of the trip N631S and I cruised under altostratus layers a couple of thousand fee above us, mostly in temperatures above freezing. The photo below is typical.

We did come upon a cold (27F) cloud layer at 8,000 feet MSL just north of Lancaster (KLNS). I requested a descent to 6,000 in expectation of warmer air. The descent, quickly approved by Harrisburg approach, also put us below the clouds, and that was the extent of IMC for the day.

Here's the track for the flight, courtesy of FlightAware.com:

I'd be remiss if I neglected to report an embarrassing moment that occurred prior to departure. I am theological about leaning the fuel mixture going to N631S's big O-470U engine aggressively right after start. I go to full-rich for the run-up and leave it thus for takeoff. Leaning for ground op's keeps the spark plugs from fouling and is generally good for the engine. Here is an excerpt from the gospel according to Capt. John Deakin (Pelican's Perch #77):

Running [very] lean (lean of peak power) on the ground also absolutely prevents you from taking off with the mixture leaned. This is not true if you take half-measures: Either do it this way, or leave it full rich. I don't care how faithfully you use checklists, you will someday attempt a takeoff with the mixture leaned. If you have properly leaned for taxi, the engine will simply wheeze and lose power, making it very obvious you're not going anywhere...

Lean it aggressively on the ground, or not at all!

Well, this was the time I forgot to go to full rich for the run-up. I am now able to offer personal testimony that an aggressively leaned Continental O-470U will not keep running if one mag is shut off. I re-started immediately...maybe nobody noticed?


== T.J.== said...

I have heard the same preaching (from other sources) about leaning for ground ops... I too do it religiously!

Frank Van Haste said...

Thanks for reading, T.J. As the man said, it's a good thing to do but you need to do it aggressively!

BTW, all of Capt. Deakin's old columns for AvWeb are chock full of wisdom...highly recommended.