Monday, September 26, 2011

Oil Pressure


Dale starts every flight with a prayer, and yesterday morning he prayed for good judgment. We were headed out to explore the local grass strips in the Ercoupe.

We flipped a coin to see who got the left seat, and I won. Last time we flew together he got the left seat, so I figure he'll get it for our next flight.

Our first stop was the beautiful Rainbow Ranch and its lovely turf. Dale did a nice landing and as we rolled out I scanned the obstacles to the West: the East is a small ridgeline, more than the 'Coupe can outclimb. I took the controls and we taxied back to the far end. "Tail in the Weeds!"

Throttle in and we're rolling. Airspeed alive. Check the engine gauges.

What?? Why is the oil pressure so low?? I aborted.

We taxied away from the owner's home so I could do a runup. We had oil pressure but less than desired. The temperature was rock steady and not too high.

What had we prayed for?

That killed the plan for exploring grass strips. We would either stay at Rainbow Ranch, or fly home. Which? This was on the edge: we had oil pressure, it was steady, and the oil temperature wasn't rising. Perhaps a stuck relief valve? Grounding the airplane at RR was an unattractive option, but not doing so required judgment.

We had enough runway and were surrounded by excellent landing fields, so an engine failure on takeoff wasn't that big a deal. We would climb out at Vx, watch the temp and pressure, and fly home a little higher to increase our landing options. We would not overfly the one town between the RR and home. There were dozens of fields in which to land, almost too many.

It was my takeoff and we launched. The pressure held steady and we climbed to altitude. The air was so smooth that I flew hands off, but more so I could focus on the terrain around us.

Quite soon home was in sight. The wind was calm, so we could choose the better way to land. If the engine quit landing north, we would be in the Walmart parking lot, but if it quit landing south we would be on the empty golf course. An easy choice.

I entered the pattern high to double check the sock. The pressure held steady. I flew a close-in downwind and announced a landing point about 1/3 of the way down the runway, aiming a little long on purpose.

We landed on the spot.

Now to figure out what's wrong.

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Saturday, March 29, 2008

Smoke in the Cockpit (almost)

Dennis has had some bad luck with the flying schedule. First we took off into what was supposed to have been a 1500 foot ceiling, which would have been plenty for ground reference maneuvers, but in fact the ceiling was at about 500 feet, so we flew the one pattern and called it good. I suppose that the ceiling was 1500 at the ASOS station behind us.

A few days later, we pulled the airplane out of the hangar after a quick check of the radar, because the forecast called for snow showers. There was one big shower that was clearly going to pass east of the field. By the time we got the doors open and the airplane pulled out, though, the sky to the southwest had become dark and swirly. We watched a little as the storm approached with the airport boresighted, and I made the decision to lickety-split put the airplane away. The line crew was tied up playing tiddlywinks, so I just muscled it in as the snow started to fly, big sideways flakes getting into my ears.    Now the radar showed that the shower really had passed to the east, but had expanded while it did so.

Today the weather was way better than forecast and the airplane was available, so I called Dennis and we hustled out the field. We had briefed this flight several times, so we got in the air pretty quickly. We started with a climb under the hood, then some turns and a good stretch of straight-and-level, which went pretty well. The most annoying part was a new loud buzz in the intercom until we passed the localizer antenna. You know the kind of buzz: It's the "alternator failure" buzz.  I made a mental note.

We're still exanding his stall envelope.  We did clearing turns and the first stall went pretty well, although he almost got a secondary stall.  But it didn't smell right. Something on the ground, I thought. since we were downwind of a town. A couple of more stalls; the smell reappeared when the power was pulled back. I did not like the smell but he didn't smell it yet. Whatever it was was coming from the airplane. I turned off the landing light, and then the heat, but as soon as the power went to idle the smell came back. We turned back to the airport and landed.

There was no smoke. I have seen smoke in a 172 cockpit, thankfully on the ground just before takeoff, and was pleased not to see it again. But I sure was looking for it!

So Dennis has had more than the usual exposure to what the FAA calls "Aeronautical Decision Making": several instances of weather worse than advertised and a genuine "system and equipment malfunction." We had a good discussion about instruments and systems and what you lose when you turn off the master, with the added sensory input of the burn in the back of our throats from the ozone.



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