A set of notes in no particular order that other posts refer to, usually so that a term (like "Missed Approach") can be explained here rather than inline. This posting gets updated every so often as required, and isn't really a part of blog itself.

The Hood

See the Cone Of Stupidity.

The Nimitz

Interstate 880 through Oakland -- a major freeway in the area, passing close to Oakland airport -- is known as "The Nimitz" (after Admiral Chester Nimitz, who made a home of the Bay Area during WWII). Anyone who flies VFR out of Oakland North Field more than a couple of times quickly becomes familiar with the ATC instructions "follow the Nimitz...".

There also used to be an aircraft carrier based at Alameda (also within a mile or two of the airport) called The Nimitz (after the same guy, of course). The possibility of confusing one for the other used to be the source of a whole bunch of Bay Area flying lore. But -- being the wet blanket that I am -- I can't help pointing out that either you were local and knew both Nimitz's, or you were from out of town and didn't know either. In the latter case, "Follow the Nimitz..." is just plain incomprehensible.


Outside Air Temperature. Useful to know when flying because it's needed to correct for temperature effects on airspeed and altitude, but also to flag or predict possible icing problems.

In a Cessna 172, OAT is typically measured by a little round gauge above the co-pilot's head.


Notice To Airman. A NOTAM is typically issued by the FAA to inform pilots and others of everything from airspace closures to runway repairs to changes in an instrument procedure. NOTAMs can be associated with a particular airport, facility, or nation-wide.

The formal NOTAM system is probably the poorest implementation of an information dissemination system I've ever seen -- it's unreliable, it's buggy, it's incomprehensible, even the FAA can't use it consistently, and yet if a pilot so much as misses one important NOTAM due to these problems, it's the pilot that suffers or loses a license (or dies).

Missed Approach

If you botch an instrument approach, or (simplifying a little) go to minimums without seeing the airport you're approaching, you have to "go missed". This means following the missed approach procedures, which typically include instructions to climb on certain headings or radials to a particular intersection or fix, then hold until ATC sorts it all out. You can't keep going missed on the same approach (unless you're training); at some point you abandon the attempt completely and / or go to your alternate.

Sometimes you do the missed "as published" (i.e. as spelled out on the approach plate); other times the controller will issue you with missed instructions.


Every instrument approach has a set of "minimums". These spell out the minimum altitude(s) and forward visibility requirements for that approach; if you get to minimum altitude on the approach and you can't see the runway (simplifying a bit), you should go missed. Minimums are tailored to things like surrounding terrain and other obstructions, the type of the approach (precision, non-precision, circling, etc.), and other criteria published by the FAA.


A VOR radial is the virtual straight line from the center of the VOR following a designated (magnetic) heading. If you're on that radial, that radial is your bearing from the VOR station. Things get more complicated when you start adding "inbound" and "outbound" to the equation -- VOR navigation is counter-intuitive for at least the first five minutes, but after that it all clicks.

LDA Approach

A localiser directional aid approach. Basically a localiser (i.e. the azimuth component of an ILS) that's offset by up to 30 degrees from the runway alignment.

Reverse Sensing

Older versions of nav instruments like VOR's, ILS's, and LDA's assume you're tracking in a certain direction in relation to the nav aid (towards it, in the case of ILS's and LDA's). But some approaches -- like Concord's LDA RWY 19R -- often require you to fly a back course in the opposite direction at the beginning of the approach (I'm simplifying here). The older instruments will show you course correction directions that are exactly opposite of what you'd see under normal conditions (i.e. slight turn right when you actually need to turn slightly left). This can be confusing (understatement).