It is noon on Mother’s Day. Geico’s advertising airplane has been circling my house for the last hour. It ‘s pulling a giant advertising banner against the relentless San Francisco wind. I can’t hear myself think.
This is the un-cropped frame from a Canon 400 mm lens with a 1.4 teleconverter, yielding an effective lens length of 560 mm (or 576 mm if the 1.4x converter is actually a 1.44x converter as I suspect). At 1.4x, the effective angular width across the diagonal of a frame (35 mm full frame body) is 4.4 degrees.
This aircraft looks to me to be a late 1950s Piper PA-18-150 Super Cub, having a wingspan of 35 feet. With some arithmetic, I can calculate how far away this aircraft is. The plane isn’t directly above me. The shot’s about 15 degrees off vertical (perhaps more, but I’ll be conservative for calculations, erring in Geico’s favor). It’s wingspan occupies 0.39 of the diagonal image, meaning the full diagonal span of this photo is 90 feet. If I’m right about the aircraft model, that means this airplane is 1170 feet away from me. I shot the picture from the 9th floor of a building, 90 feet above ground. Ground elevation is 10 feet.
So the maximum altitude for this aircraft - assuming 35 foot wingspan - is 1270 feet. Given that the photo angle is about 15 degrees from vertical, it’s altitude is more likely about 100 feet lower. Trigonometry-aware readers will note that you can adjust for both the departure from vertical and the departure from perpendicularity of the wingspan by about sin(15) squared = .93, yielding a likely elevation of 1180 feet above sea level.
My reading of Federal Aviation Regulations, title 14, Part 91.119 (Minimum Safe Altitudes) specifies a minimum distance over congested areas of 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet of the aircraft. The residential building at One Rincon Hill is over 600 feet high, above a base at elevation around 100 feet, so it tops out at over 700 feet above sea level. One Rincon is about 800 feet north from where I shot this picture.
Based on my math above and my reading of FAR 91.119, Geico’s airplane should be flying at an altitude of at least 1700 feet. It’s clearly well below that – my math can’t be that far off. And if I’m missing some exemption to the FAR that allows Geico to buzz my patio on Mother’s Day for more that an hour straight, Geico is still bunch of bastards with very bad manners.