Airport of the Week: KHAF - The Bay's Coziest Fog Trap

Welcome back to another installment of Airport of the Week, where I explore some of the most fascinating, challenging, and downright interesting US airports. This time it’s the beautiful, and often moody, California coast to visit Half Moon Bay Airport (KHAF). Side note, this airport was renamed to Eddie Andreini Sr. Airfield in honor of the late Eddie Andreini Sr in December 2015, but the FAA still has it listed as the Half Moon Bay.

The Postcard and The Punchline

Half Moon Bay Airport is, without a doubt, stunning. Nestled just a stone's throw from the Pacific, about 20 miles south of San Francisco, it boasts a 5,000-foot runway (12/30) and views that can make even the most jaded pilot swoon. On a clear day, the approach over the rugged coastline and the iconic Highway 1 is pure aviation bliss. You can grab a bite at the nearby Pilot Light Cafe and feel like you're in a flying movie.

But KHAF has a mischievous side, a personality quirk well-known to local pilots. This brings me to a gem I stumbled upon on Reddit, a comment that perfectly encapsulates the Half Moon Bay experience:

"KSQL-KHAF is the shortest 24 hour round trip in the bay."

For the uninitiated, KSQL (San Carlos Airport) is a mere 12 nautical miles east of Half Moon Bay. On a clear day, it's a quick, breathtakingly scenic hop over the hills. You take off, climb over the ridge, and boom, you're practically on final. The flight time? About 15 minutes.

So why the "24-hour round trip"? The answer is as simple as it is humbling: fog.

That beautiful marine layer that gives the California coast its mystique can roll in with the stealth of a ninja. Many pilots have made that quick flight over from the sunny side of the peninsula, only to find themselves staring at a solid white wall of IFR conditions that decided to park itself over the airport. You can see the sun shining just a few miles east, but you're not going anywhere. You've been caught in the cozy coastal trap. Enjoy your unexpected overnight stay!

The County of San Mateo has a nice quality public webcam where you can check out the current conditions (obviously, not for flight planning purposes!). Did you notice the small toy airplane? See if you can find it in the picture below.

A Look at the Fog

The weather at KHAF is a masterclass in microclimates. While it might be CAVU (Ceiling and Visibility Unlimited) just over the hills in San Carlos or Palo Alto, KHAF can be a completely different world.

I'm going to take a look at a real-time TAF (Terminal Aerodrome Forecast) for KHAF to see what I mean.

KHAF 230107Z 2301/2324 33011KT 4SM HZ BKN008 FM230600 VRB05KT 4SM HZ BR OVC005 FM231800 25008KT 4SM HZ BR OVC010

I'll break this down for the student pilots, with the help of your trusty (or future) PaperMETAR device:

• KHAF 230107Z 2301/2324: This is the forecast for KHAF, issued on the 23rd of the month at 0107 Zulu time, and it's valid for 24 hours.
• 33011KT: Initially, the wind is from 330 degrees at 11 knots. A nice little crosswind for Runway 30.
• 4SM HZ BKN008: Here's where it gets interesting. Visibility is 4 statute miles in haze, with a broken ceiling at just 800 feet. That's getting low for VFR flight, especially with the surrounding terrain.
• FM230600 VRB05KT 4SM HZ BR OVC005: From 0600Z, things get even grimier. The wind becomes variable at 5 knots, visibility holds at 4 miles with haze and mist (BR), and the ceiling drops to overcast at 500 feet (OVC005). This is solid IFR. If you were planning a VFR departure around this time, you'd be grounded. This is the part of the forecast that creates those "24-hour round trips."
• FM231800 25008KT 4SM HZ BR OVC010: By 1800Z the next day, the forecast shows slight improvement. The wind shifts to 250 degrees at 8 knots, but the overcast ceiling is only expected to lift to 1,000 feet. Still marginal VFR at best.

The rapid change and the low ceilings are the name of the game at Half Moon Bay. It’s a place that demands respect, a solid weather briefing, and maybe a packed overnight bag, just in case.

Finally, here are some YouTube videos of people flying in and out of this airport.

1. Outside the Cockpit – Half Moon Bay Airport (KHAF) | WHERE’S TRANSIENT PARKING | Half Moon Bay, California
2. Jack Breslin – Unedited: Approach and landing into Half Moon Bay, California KHAF (4/7/2021). Shows a nice cloud cover, and haze.
3. Misha Tyukin - Instrument approach into Half Moon Bay!. Shows the low cloud cover and haze.

So, here's to KHAF! An airport that offers both some of the most beautiful flying in California and a valuable, sometimes humorous, lesson in coastal weather. Fly safe, keep an eye on that weather, and maybe think twice before that "quick" hop over the hills!