Friday, October 3, 2014

Knowledge Test Supplement - Watch the Scale!

Earlier this year the FAA updated the Private Pilot Test Supplement. This is the book that contains all the figures and charts that are referenced in the Private Pilot Knowledge Test. This introduced a number of issues. One issue is that the scale on the sectional chart excerpts does not match the scale on a real chart and consequentially your plotter can’t be used to directly measure distance. The previous test supplement, although it didn’t match perfectly, was relatively close. On the new test supplement, figure 21 is significantly different than the normal scale. You can see in this picture that if you used your plotter, a distance of 10 NM on the figure would be measured as only 7 NM as shown on a plotter. This would be enough to throw any calculations off and lead to answering the test question incorrectly. Each figure has a unique scale on the side of the chart that must be carefully checked in order to determine the accurate distance.

Friday, September 26, 2014

Letter "L"

It is intriguing what landmarks are charted on our sectional charts. On the San Francisco sectional chart in the northern area toward the coast, I found this interesting landmark. Normally you will see notes like settlement, ranch, sawmill, etc. But I haven't seen anything like this before.

This is what is found at this location.... Yep, that is an "L" marked on the ground. Now the mystery is why is it there. Well that is another story.

Friday, September 19, 2014

Interesting class B airspace

I ran across an interesting notation for the floor of a class B airspace. It is common to see notation that use "-" to indicate that a class D airspace goes up to but does not include an altitude. An example of this is KSQL class D airspace on the east side of the airport. It has a designation of [-15] which indicates that the Delta airspace goes up from the surface up to but not including 1500 MSL. It is also common to see "T" used for the ceiling of class C airport to indicate that the ceiling extends to the top of the overlying airspace. This is used in the KOAK class C airspace.

In the New York area, I ran across a unique notation that I hadn't seen before. One of the shelves of the class B had a notation of "+" for floor of the airspace. In the chart to the right, you can see the +05. This indicates that the floor of this airspace starts "above" 500 MSL but does not include 500 MSL.

Friday, June 6, 2014

PIREPS Remarks

If you are checking PIREPS on a regular basis you might notice some interesting text in the RM portions of a PIREP. Here is an example:


In this case the RM section has the text “AWC”. This is an indication that the PIREP was reported by a pilot that has taken the SkySpotter training. The following comes from the FAA:

The "SKYSPOTTER" program is a result of a recommendation from the Safer Skies FAA/INDUSTRY Joint Safety Analysis and Implementation Teams. The term "SKYSPOTTER" indicates that a pilot has received specialized training in observing and reporting inflight weather phenomenon, pilot weather reports, or PIREPs. When a PIREP from a pilot identifying themselves as a "SKYSPOTTER" aircraft is received, the additional comment "/AWC" must be added at the end of the remarks section of the PIREP.

You can find the AOPA SkySpotter course here:

Friday, November 1, 2013

Windy out there

A windy evening this last Sunday. Winds at KSQL were 20+KTS and KSFO were 27G40. These high winds were due to a strong pressure gradient in the area as observed by very closely spaced isobar lines on this surface analysis chart.Each line represents a 4 mb difference in pressure. ATIS reports between KSFO and KSAC were confirming that large difference in pressure. KSFO 29.75 vs KSAC 29.58. Converting that to millibar (mbar) yields a 5.8 mbar difference. The delta between KHAF and KSAC was even larger at 7.5 mbar. The NWS aviation forecaster had this to say: IMPRESSIVE SURFACE GRADIENTS LOCALLY SFO-SAC RANGING FROM 5 TO 5.7 MB AND HAF-SFO 2.7 MB THIS EVE. SLIGHTLY LARGER SCALE PRESSURE GRADIENTS ACROSS THE AREA ARE NOT SUPPORTIVE OF PRESENT MEASURED WIND SPEEDS SO THE TREND HAS BEEN FOR LOW TO MID LEVEL WINDS TO LINK UP TO SURFACE WINDS BRINGING STRONG WIND GUSTS DOWN TO THE SURFACE.  VICINITY OF KSFO...IMPRESSIVE WIND GUSTS PEAKING NEAR 50 MPH THIS EVE.

Friday, October 18, 2013

Antennas - VOR in particular

I have flown mostly in 172s that all have two communication radios and two navigation radios. I have been accustomed to noting that there were two communication radio antennas on top of the aircraft and what I thought were two navigation radio antennas in a V-shape on the vertical stabilizer, i.e. one antenna for each Nav radio. A few weeks back I was looking at a 152 and its antennas. The 152 had one comm radio and one nav radio. Correspondingly it had only one comm antenna mounted on top of the aircraft but it still had the two antennas on the vertical stabilizer in a V-shape. I originally thought that maybe these antennas were installed in the case that an additional nav radio might be installed. After doing some additional research I found that the V shaped antenna is actually not two separate antennas but one antenna called a dipole. The dipole is a specific design for an antenna that consists of two identical elements that are joined in the center and feed a single radio or in the case of the 172s with two nav radios the antenna feeds both nav radios.
Comm Antennas
Nav Antennas

Friday, October 11, 2013

What is missing?

As part of the pre-flight you open the access door in the engine cowling to check the oil quantity and quality. As you glance in to the engine compartment you see this picture. Is there something wrong?