Friday, May 6, 2016

Summer Breeze

Oil pressure sender.
More than one sensor was providing out of limit alerts. CHT was just out of range, but an extra long wait on the ground might justify that one. Fuel pressure low right after take off was bothersome, but did not recur during the climb or leveling at cruise altitude. EGT happened once. The real problem was oil pressure low. It would usually happen during the take off roll, then subside during climb out. After 20 minutes of flight it would sound off again. Each fluctuation would trigger it and the frequency of alerts would increase over time. By the time I got to Sebring the oil pressure indicator was flat lined. No vibration or temperature rise, no other visible indication that anything was wrong. We sent my D120 to Dynon for analysis. Lockwood lent me a spare that they had sitting on the shelf.

The D120 is an amazing piece of equipment. It turns out you just can't pop one out and slap another in. It has to know the fuel status and that takes calibration, two gallons at a time (for each tank.) It also knows each senor and what the limits are to trigger an alert. It also knows the Hobbs time. All of this information (and more) is customized for each airframe. So work had to be done for the loaner, then redone when my box returned. I spent Tuesday in Sebring getting this work done. Fortunately the IAC trials were going on so I got to watch some great performances while the tanks were being calibrated.

Rwy 23 at KVDF
While at Sun 'n Fun I discussed my problem and all of the experts had the same conclusion: bad oil pressure sender unit. So in addition to replacing a card in the D120, I also replaced the sensor. The flight home on Tuesday was uneventful (Yes!)

Wednesday was a washout. A cold front with driving rain came through the area. Thursday I went out to KVDF to preflight for a validation flight. Choppy, gusty winds were forecast for the afternoon. We took off by 9:00am. The cold front had left us with beautiful blue skies and puffy scattered clouds at 4000ft. We would stay at 1500ft to stay under the Tampa Class B shelf and head west to the gulf.

I4 & Rt 301
It was already getting bumpy. The autopilot would occasionally have problems holding heading. The little arrow on my display showed 20kts from the west. It was choppy but not as bad as one might expect. The trip down the gulf coast was fun. On a calm day I would fly down to the Sunshine Skyway Bridge, but not today. We settled for over flying Clearwater Airpark (which was pretty busy with two in the pattern and a Helicopter preparing to join them). We departed to the north and made the 20 minute trip back to Tampa Executive. 310@14G22

A routine flight. No sensors reported out of limits.

Video notes: Florida Scenery

Virb Edit  3.5.2

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