Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: CN aboard a Cessna 172
    From: Frank Reed
    Date: 2010 Jan 31, 17:23 -0800

    I got back to Chicago two weeks ago, but I've been busy "putting out brush fires" ever since so sorry for my late reply on this.

    I thoroughly enjoyed meeting Mike and Greg out in southern California three weeks ago, and it was great seeing Gary again. At Camarillo Airport, Gary showed us several of his bubble sextants and Mike and Greg had theirs, too. Gary showed me some details on the use of these averagers that I had never understood before. The simple "pencil" averager on the early bubble sextant he showed us was really interesting.

    We had great flying weather, smooth air. The Moon was lost in thin clouds and even the Sun became difficult for a while. I sat in the back and recorded GPS coordinates from my cell phone on Greg's and Mike's flights. Yes, I had both GPS signals and cell phone signals on my phone during the flight. We even received a text notification of a NavList message in-flight.

    During my flight, we lost one averaging run because I didn't know how to use the averager yet. On the next run, we had to maneuver to avoid other traffic (it's a popular and busy area for general aviation) which had me wondering for a moment why the Sun was suddenly accelerating to the right. And on my best run, the Sun looked like a cotton ball, very nearly lost in the clouds. The results were mediocre (13' error in the LOP), but fascinating nonetheless, and it was easy to imagine doing much better with better conditions and just a little practice. Gary was an excellent pilot and a fine instructor. Lots of fun!

    We sat and talked for an hour over lunch about the observations and Gary showed us his model Bygrave. We all agreed that this was something that had to be done to be understood. When you shoot altitudes with a bubble sextant in such a light plane, you understand that the Sun dances around over a broad area. It was not unusual to find the Sun drifting off as much as two degrees from the bubble. But the averaging process cancels out most of this. Gary also mused about the Coriolis force (grrr... one day I'll learn 'im!). Later that evening, I visited Greg's floating celestial navigation laboratory (his boat) at the Channel Islands Marina, and we did some more sights with his bubble sextant. I shot Capella by making contact with the upper edge of the bubble, then the lower edge, and averaging the times and angles. That gave us an LOP within two nautical miles so quite good (this was with the bubble sextant hand-held, from his boat moored to the dock in very slight swells in the marina).

    On Sunday, Greg took me and Gary and his wife for a little "sail" out on the Pacific swells. There was impressive surf just south of the entrance to the marina. We had no wind so there was no real sailing, but it was lovely weather, and we did some more navigation experiments. As he handed me one of his sextants to use, I asked whether we were close to LAN and as it turned out it was right then, so I shot a quick altitude of the Sun, and Gary noted down the time. The result was within a nautical mile or so. Nothing surprising there, but that was my very first latitude determined in the Pacific Ocean! It struck me how different the experience was from shooting the Sun in the air just the previous day. On the swells, of course, you wait for that moment when the boat is up top and the horizon is clear, and then quickly adjust for the best possible altitude swinging the arc if there's enough time. The sight is over in a second. Then the calculation is done at leisure. By contrast, in the air, you begin shooting at an exact time, the top of the minute, and continue aiming at the Sun as best you can for the full duration of the averager's two-minute run. Though we didn't do it, it was clear that the best way to analyze the sight would be to compare it against a pre-calculated altitude right away. Even in a slow-moving light plane, your sight data has a short shelf-life.

    So many thanks to Gary LaPook and Greg Rudzinski for their aerial and marine hospitality respectively, and many thanks to Mike Burkes for joining us. My road trip was a lot of fun, and I saw parts of the country that I've never seen before. I drove just about 7,000 miles all told and averaged 6.5 hours of driving every day.

    Here's a summary of from my trip (I won't dig out the "slide projector" to show you the 1240 photos I took, but it's tempting!):

    The weather was wonderful. I tossed my coat in the trunk of my car one day out from Chicago and only wore it once (on the rim of the Grand Canyon) until I entered Illinois again two weeks later. Miserable weather arrived in southern California just days later so the timing was great.

    Some highlights:
    * USS Razorback in Little Rock, a veritable time capsule of submarine history.
    * A friend I haven't heard from in years phoned me by chance from Austin, Texas when I was only two hours away (so I drove up for a beer --you can't ignore a coincidence like that... what our the odds?? I've never set foot in Texas before and someone I know calls out of the blue when I've been there for just 24 hours). Also saw one more submarine in Galveston --not worth the trip.
    * Beautiful night sky above western Texas. Navigating by Deneb on the black, empty highway leading to Pecos, Texas. The stars at night... are big and bright... down there...
    * Carlsbad Caverns the next day in NM. As impressive as you might imagine and blissfully uncrowded in early January. Sunny weather and cactus in the craggy canyon above the caverns.
    * On to Arizona. Outside Tucson, the Pima Air & Space Museum has at least one of everything (three B-52s on display), and they offer tours of the "boneyard" of thousands of mothballed and derelict aircraft at Davis-Monthan AFB. Back underground again, visited the Titan Missile museum, home to a retired nuclear missile.
    * And then southern California. Had breakfast by the extraordinary Salton Sea, and lunch in the strange desert to its west.
    * Drove up Mount Palomar to see the famous 200-inch telescope. Beautiful and sweet-smelling mountain air. Great views along the winding mountain road.
    * On to San Diego where the city is beautiful and yet odd: filled with palm trees, wonderful architecture, ships of all kinds, and the biggest population of people living on the streets I've ever seen.
    * Visited the San Diego Maritim Museum. Great ships. Two more submarines (a Russian Foxtrot and USS Dolphin, a medium-sized USN research sub retired just a few years ago and open to the public less than one year ago). Their exhibits included a small but remarkably accurate account of lunars, both use and history, in one of their display cases.
    * Another Foxtrot Russian sub in Long Beach, nestled right next to the giant Queen Mary. This Russian sub is considerably better presented and interpreted than the one in San Diego.
    * Beaches and more beaches with great surf. And the strange, famous spectacle of Venice Beach including shops openly selling marijuana (unique in the USA).
    * Traffic on the L.A. freeways... awful, just like in the movies! Stores near Beverly Hills intended for people far, far wealthier than me.
    * FLYING on January 9 with Gary at the controls. Beautiful views and a fascinating experience using a bubble sextant in a light plane. Sun barely visible through thickening clouds during my run so my result was off by about 13'. That's mediocre, but it's easy to imagine better results with better conditions and a little more practice.
    * Great conversations with Gary, Greg, and Mike Burkes before and after our flights.
    * More celestial experiments aboard Gary Rudzinski's boat. Averaged sights of Capella with his bubble sextant accurate to about 1'.
    * SAILING on January 10 on Greg's boat. Not a bit of wind but big swells and great surf off the Channel Islands Harbor marina. Somme more fun with sextants: just by chance I got a LAN sight giving our latitude to about a mile. First latitude I've ever measured in the Pacific Ocean (I don't count the sights at the pier in the harbor the previous night).
    * Amazing breaking waves along the coast. Saw signs announcing "significant fines" for turning over starfish in tidepools near Malibu.
    * A quick drive up to San Francisco for lunch and one more submarine.
    * Back to L.A. A visit to Hollywood Boulevard and Griffith Park Observatory for some very touristy views (fun --and beautiful weather). And I spent a late afternoon climbing Vasquez Rocks where many B-movies and old tv shows were filmed (e.g., Captain Kirk invents gunpowder to defeat a guy in a lizard suit). Sure enough, they were filming some bad movie there.
    * And then it got cold for an afternoon when I drove up to the Grand Canyon. Always beautiful and the little bit of snow just added to it.
    * A nice evening in Flagstaff, AZ, finally taking a break for a real meal (I averaged $5 daily for food on all but two days).
    * Meteor Crater. It's a pilgrimage I can't skip.
    * Got off the interstate shortly after Winslow and spent four hours driving with almost no signs of civilization and no cell phone signal (GPS ok though). Very nearly ran out of gas but my car rather miraculously got 42 mpg on that leg (normally 35).
    * Just before sunset: the VLA radio observatory on the plains west of Socorro, New Mexico. Quite a sight. Lots of cows, too. No people.
    * Muskogee, Oklahoma. Visited the submarine USS Batfish at its home high and dry in a grassy field, as if dropped there by space aliens. A nice little museum. Also visited Tahlequah, the capital of the Cherokee Nation.
    * A long drive back north through Oklahoma, Missouri, and then Illinois (with a half-mile jaunt into Kansas just to say I had been there). The ground in Illinois was white with snow, trees frosted white from a recent ice storm, and the sky grey with dense fog, too. It was a world without color and an amazing contrast from the sweet smells, warm sun, flowers, blue ocean, and palm trees of California. But all is not lost, as soon as I entered Chicago, the sky cleared, and it was beautiful blue again above the skyline and Lake Shore Drive.


    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site