Aircraft accidents aren't evenly spread across the terrain. Often they form clusters. Around 2005, I analyzed all of the fatal accidents, about 100 of them, that occurred in the prior 10 years in the S.F. Bay area, which I defined as the area from Petaluma in the north, to Salinas in the South and Tracy to the east. That's a huge area, yet fully 50% of all night and weather related fatal accidents were clustered in one spot: the Livermore Valley.
The reason is obvious. The Livermore Valley is completely surrounded by mountains. PIlots fly in and out of this area using passes at Castro Valley, Sunol and Altamont. But as the picture above of the Sunol Pass shows, these passes used by pilots to get home are the same ones that the marine layer moves through as it reforms on most nights. Any time you cannot clearly see through one of these passes, you need to make a 180 degree turn and land at Livermore, Stockton, Modesto or some other airport where it's clear.
I recently overnighted at Livermore. As I was paying my $6 parking fee the next morning, the guy collecting my money mentioned a student pilot he’d just met who had bought a Bonanza. Asked why he would buy a Bonanza, the student pilot replied, “So that I can stay ahead of the weather.”
That’s wishful thinking for sure. And if that’s the full extent of the pilot’s contingency planning, someday he’s going to encounter weather and have to make up a plan on the spot for dealing with it. Unfortunately, that type of last minute contingency planning is often fatal. Why? It’s hard to explore the full range of options when you encounter unexpected weather and have seconds to make a decision. It’s far better to plan your alternatives ahead of time from the comfort of your easy chair while you’re relaxed and more likely to make better decisions.
All pilots flying in the S.F. Bay area need a Plan B for dealing with the marine layer. To not consider alternatives ahead of time is reckless: the marine layer is a fact of life and if you fly long enough, eventually it will impede your flying.
If you’re instrument rated in an instrument capable airplane, you have more options. Recently I was returning from having spent the day on Don Pedro Reservoir in my non-instrument capable seaplane. So flying an instrument approach into Palo Alto was not an option. Instead, I executed one version of a plan B I formulated decades ago and have taught to many of my students: I landed at Livermore and walked to a nearby motel. It was simple and easy with a guaranteed safe outcome.
Years ago, I developed the plan by investigating which airports in California have motels on or close to the airport. These became my “go-to airports” if I’m tired or weather intervenes. Scoping these airports out ahead of time makes in-flight decision making easy. For example, given the choice of staying overnight at Stockton or Modesto, I’d choose Modesto, which has many more motels within a couple of miles of the airport. Some airports with motels on or adjacent to the field are Fresno, Visalia, Santa Maria and Concord.
One of the scenarios I developed for my Night Flying presentation goes as follows: You’re flying through the Livermore Class D at 1600 feet on your way home to Palo Alto. There’s an overcast above you and it’s just after sunset so it’s not totally dark. As you look toward Sunol Pass, you can’t tell if you can see through the pass over I-680. If you’re non-instrument rated, what should you do?
In most cases, the best option is to land at Livermore and then phone a friend to come get you, or to take a 5-minute walk to a nearby motel and spend the night. I always tell clients that they can call me and I’ll pick them up at Livermore…but it won’t be a free ride!
For instrument rated pilots, the scenario answer is the same: land at Livermore. Why? Because at 1600 feet, you’re way below NorCal’s MVA (minimum vectoring altitude) which is 4,000 feet above the Livermore Airport. So if you try to get a pop-up clearance, NorCal will ask you if you can maintain your own terrain clearance until you reach 4,000 feet. It’s much safer to just land at Livermore, then file IFR on the ground and fly the IFR clearance you’ll receive, which involves a departure procedure that climbs you to point where NorCal can see you and issue vectors.
A series of things delayed my return from Don Pedro to Palo Alto Airport. Over Oakdale Airport around 9 PM, I learned that the last ATIS for Palo Alto was 900 feet scattered. As I approached Livermore, I could see a nearly solid marine layer, so I queried NorCal. Oakland and Hayward were both below VFR minimums, and San Jose International was overcast at 1,400 feet. ATIS reports for RHV and PAO were both more than an hour old. The odds of going on top and finding a hole at PAO seemed remote. When Hayward is reporting a ceiling at 1,000 feet, it’s highly unlikely that the Sunol pass is flyable. So with clouds forming in front of me and Livermore reporting 1,600 feet overcast, it was a no brainer: descend prior to the clouds and fly the last 6 or 7 miles to land straight in on runway 25R.
I was careful not to descend until I was over the lighted portion of the Livermore Valley. Descending over the dark hills of the Altamont Pass at night could have been fatal. If I had doubt at any time, I would climb and fly to Modesto, as the entire central valley was clear.
Spending the night at Livermore was easier than I imagined. After tying up the plane, I checked my iPhone and saw that the Extended Stay America was the closer of two motels. It cost $72 plus tax. If you want to stay at the fancier Hampton, you’d need to walk to the north side of I-580. It was a 5-minute walk to the Extended Stay, and it took us right by a Starbucks, 7-11 and a Carl’s Junior.
As we walked back to the airport the next morning, we stopped in the Starbucks, which fueled us for the trip home. Livermore was overcast at 1,800 and we had no trouble getting through the Sunol Pass—which was much easier to see in the daytime. After tying up the plane, I still had a few sips of my Grande left for the drive home. Not a bad way to start the day!