Saturday, June 20, 2015

Marginal

A sport pilot may not act as pilot in command of a light-sport aircraft:
  • When the flight or surface visibility is less than 3 statute miles.
  • Without visual reference to the surface. 
Cloud Clearance - Class E - Less than 10,000 feet msl:
  • 3 statute miles
  • 500 feet below
  • 1,000 feet above
  • 2,000 feet horizontal
MVFR means Minimum or Marginal Visual Flight Rules. MVFR criteria means a ceiling between 1,000 and 3,000 feet and/or 3 to 5 miles visibility.

Max. Demonstrated Headwind:
  • 24 KTS
Max. Demonstrated Crosswind:
  • 12 KTS
For most training flights my personal limits are 3000', 8 statute miles visibility and gusting winds less than 12 Kts. There are of course exceptions and that's what makes it interesting.

I stared at the computer. 0700 was time for my daily weather brief. There were a mix of red, blue and green dots sprinkled across the local area. The METARs ranged from 500' overcast to 1500' scattered to clear skies. Visibility was less than 6 miles in most cases. A few isolated showers were present. The winds were not a factor yet, but could be later in the day. A slow moving cold front was making its way across western Pennsylvania bringing unstable air along with it. Airports in the middle of the state were reporting gust up to 14kts, but it was calm here.

Its the marginal decisions that are the tough ones. We could go but not do all of the lesson plan. We could accomplish something but would it be enough to be a valuable lesson?  At this stage of training I wanted a clear horizon to practice basic airwork and although experiencing marginal conditions would be useful it was just too early for this student to struggle with poor conditions. In end, I cancelled. (...and then I questioned my decision for the rest of the day.)

I went out to the airport anyway. Sally hadn't been cleaned in awhile so I took this opportunity to work on her. Belly wash and wheel pants first. Extra time spent on the canopy inside and and out. Then my attention went to all of the leading surfaces to remove the squashed bugs. Its still early in the season so that part really wasn't too bad. I noticed that the gas caps had some brownish stains around the edges. Meguiar's Clear Plastic Polish cleaned off about 90% of the stains.

It only took a few hours and Sally looked great. We were ready for the Discovery flight scheduled for the following day.

I stared at the computer. 0700 was time for my daily weather brief. Marginal (at best). Canc-Wx.

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