4 ms·

Concrete Arrows and the U.S. Airmail Beacon System (2013)

35 points by RyanShook 4y ago

dang 4y ago
Related: The Remains of the US Airmail Beacon System - https://news.ycombinator.com/item?id=24961102 https://news.ycombinator.com/item?id=24961102 - Nov 2020 (14 comments)
duxup 4y ago
Very interesting. Even with the lights having to just trust that you will spot the next light sometime soon and wait for it to appear seems like a nightmare. Reminds me of the Brazilian flight that among a series of errors decided to follow a river to their destination, but it wasn’t the river they thought it was. https://en.m.wikipedia.org/wiki/Varig_Flight_254 https://en.m.wikipedia.org/wiki/Varig_Flight_254
- tjohns 4y ago
  Student pilots today are still taught to navigate via dead reckoning (compass and stopwatch) and pilotage (looking out the window and identifying prominent landmarks). Even at night, a pilot would have a pretty good idea where they were before they saw the light. Also, you can see pretty far at altitude. Flying at 10,000 feet, I can see the San Francisco bay all the way from Lake Tahoe. Fun fact: There's an airway beacon on top of Mount Diablo in San Francisco, but it's only lit a couple times a year for special occasions: https://www.dreamsmithphotos.com/arrow/States/ca/mt_diablo.html https://www.dreamsmithphotos.com/arrow/States/ca/mt_diablo.h... https://www.danvillesanramon.com/news/2022/11/28/pearl-harbor-day-beacon-lighting-returns-to-mount-diablo https://www.danvillesanramon.com/news/2022/11/28/pearl-harbo...
  - kqr 4y ago
    I've only flown in simulators, but the effectiveness of dead reckoning and pilotage really surprised me as I started getting used to them. Even when I'd accidentally taken a wrong turn twice and only realised much later, I managed to figure out from direction, speed, and time approximately where on the map I was, and then from there lakes and train tracks helped me pinpoint my location exactly enough to draw a new heading to my destination. I also didn't expect that pilotage would be an incremental process. Sometimes the things I see outside could be any of a number of things on the map, but as I continue to fly in any direction and more landmarks reveal themselves, the selection of possibilities narrow until I know where I am. I have no idea if any of this is relevant to real flight, of course.
  - kqr 4y ago
    I doubt airmail ever flew at 10,000 feet in the pre-radio navaid era. It shocks me how low these people flew. I suppose part of it was for weather/cloud/temperature reasons, and maybe that it somehow felt safer to be closer to the threat (i.e. ground) but the number of stories of airmail pilots flying into trees and buildings and whatnot makes me shiver.
    - perilunar 4y ago
      Some of the early airmail planes couldn't even reach 10,000 feet. e.g. the JN-1 had a ceiling of 6,500 ft.
      - aidenn0 4y ago
        How did airmail cross the continental divide?
        Oxidation 4y ago
        The first trancontinental routes crossed via Rock Springs (6388 ft) and Rawlins (6834 ft). It's not immediately clear to me which planes they used, but that's over the Curtiss JN-4B service ceiling. The route was originally surveyed in 1920 by 3 cutting-edge Junkers-Larsen JL-6s, an American-built F13 (only 8 JL-6s were ever made!). Bert Acosta flew one of them. Map of the 1924 route: https://en.wikipedia.org/wiki/United_States_airmail_service#/media/File%3ATranscontinental_Air_Mail_Map_1924.jpg https://en.wikipedia.org/wiki/United_States_airmail_service#...
  - throw0101c 4y ago
    > Student pilots today are still taught to navigate via dead reckoning (compass and stopwatch) and pilotage (looking out the window and identifying prominent landmarks). The first license anyone gets, the "PPL", Private Pilot's License, only allows for flying under VFR/VMC—i.e., nice weather: > In aviation, visual meteorological conditions (VMC) is an aviation flight category in which visual flight rules (VFR) flight is permitted—that is, conditions in which pilots have sufficient visibility to fly the aircraft maintaining visual separation from terrain and other aircraft. They are the opposite of instrument meteorological conditions (IMC). The boundary criteria between IMC and VMC are known as the VMC minima and are defined by: visibility, cloud ceilings (for takeoffs and landings), and cloud clearances. * https://en.wikipedia.org/wiki/Visual_meteorological_conditions https://en.wikipedia.org/wiki/Visual_meteorological_conditio... * https://en.wikipedia.org/wiki/Visual_flight_rules https://en.wikipedia.org/wiki/Visual_flight_rules So you kind of have to know where are and where you're going by sight, and every pilot learns it, even if they eventually may move on if they're planning on making a career of it. The next step is generally getting a rating to be able to fly by instruments: * https://en.wikipedia.org/wiki/Instrument_flight_rules https://en.wikipedia.org/wiki/Instrument_flight_rules
    - kqr 4y ago
      VFR doesn't imply actively using dead reckoning and pilotage, though. Many people fly VFR and still navigate by radio navaids, or these days, GPS.
      - ericpauley 4y ago
        Agreed. Further, VMC doesn’t always imply necessary ground visibility for pilotage. It’s perfectly legal to fly VFR above a cloud deck with no ground visibility, for instance.
zabzonk 4y ago
doesn't everyone know that they are keys to superman's fortress of solitude?

35 points by RyanShook 4y ago

dang 4y ago

Related: The Remains of the US Airmail Beacon System - https://news.ycombinator.com/item?id=24961102 https://news.ycombinator.com/item?id=24961102 - Nov 2020 (14 comments)

duxup 4y ago

Very interesting. Even with the lights having to just trust that you will spot the next light sometime soon and wait for it to appear seems like a nightmare. Reminds me of the Brazilian flight that among a series of errors decided to follow a river to their destination, but it wasn’t the river they thought it was. https://en.m.wikipedia.org/wiki/Varig_Flight_254 https://en.m.wikipedia.org/wiki/Varig_Flight_254

tjohns 4y ago
Student pilots today are still taught to navigate via dead reckoning (compass and stopwatch) and pilotage (looking out the window and identifying prominent landmarks). Even at night, a pilot would have a pretty good idea where they were before they saw the light. Also, you can see pretty far at altitude. Flying at 10,000 feet, I can see the San Francisco bay all the way from Lake Tahoe. Fun fact: There's an airway beacon on top of Mount Diablo in San Francisco, but it's only lit a couple times a year for special occasions: https://www.dreamsmithphotos.com/arrow/States/ca/mt_diablo.html https://www.dreamsmithphotos.com/arrow/States/ca/mt_diablo.h... https://www.danvillesanramon.com/news/2022/11/28/pearl-harbor-day-beacon-lighting-returns-to-mount-diablo https://www.danvillesanramon.com/news/2022/11/28/pearl-harbo...
- kqr 4y ago
  I've only flown in simulators, but the effectiveness of dead reckoning and pilotage really surprised me as I started getting used to them. Even when I'd accidentally taken a wrong turn twice and only realised much later, I managed to figure out from direction, speed, and time approximately where on the map I was, and then from there lakes and train tracks helped me pinpoint my location exactly enough to draw a new heading to my destination. I also didn't expect that pilotage would be an incremental process. Sometimes the things I see outside could be any of a number of things on the map, but as I continue to fly in any direction and more landmarks reveal themselves, the selection of possibilities narrow until I know where I am. I have no idea if any of this is relevant to real flight, of course.
- kqr 4y ago
  I doubt airmail ever flew at 10,000 feet in the pre-radio navaid era. It shocks me how low these people flew. I suppose part of it was for weather/cloud/temperature reasons, and maybe that it somehow felt safer to be closer to the threat (i.e. ground) but the number of stories of airmail pilots flying into trees and buildings and whatnot makes me shiver.
  - perilunar 4y ago
    Some of the early airmail planes couldn't even reach 10,000 feet. e.g. the JN-1 had a ceiling of 6,500 ft.
    - aidenn0 4y ago
      How did airmail cross the continental divide?
      - Oxidation 4y ago
        The first trancontinental routes crossed via Rock Springs (6388 ft) and Rawlins (6834 ft). It's not immediately clear to me which planes they used, but that's over the Curtiss JN-4B service ceiling. The route was originally surveyed in 1920 by 3 cutting-edge Junkers-Larsen JL-6s, an American-built F13 (only 8 JL-6s were ever made!). Bert Acosta flew one of them. Map of the 1924 route: https://en.wikipedia.org/wiki/United_States_airmail_service#/media/File%3ATranscontinental_Air_Mail_Map_1924.jpg https://en.wikipedia.org/wiki/United_States_airmail_service#...
- throw0101c 4y ago
  > Student pilots today are still taught to navigate via dead reckoning (compass and stopwatch) and pilotage (looking out the window and identifying prominent landmarks). The first license anyone gets, the "PPL", Private Pilot's License, only allows for flying under VFR/VMC—i.e., nice weather: > In aviation, visual meteorological conditions (VMC) is an aviation flight category in which visual flight rules (VFR) flight is permitted—that is, conditions in which pilots have sufficient visibility to fly the aircraft maintaining visual separation from terrain and other aircraft. They are the opposite of instrument meteorological conditions (IMC). The boundary criteria between IMC and VMC are known as the VMC minima and are defined by: visibility, cloud ceilings (for takeoffs and landings), and cloud clearances. * https://en.wikipedia.org/wiki/Visual_meteorological_conditions https://en.wikipedia.org/wiki/Visual_meteorological_conditio... * https://en.wikipedia.org/wiki/Visual_flight_rules https://en.wikipedia.org/wiki/Visual_flight_rules So you kind of have to know where are and where you're going by sight, and every pilot learns it, even if they eventually may move on if they're planning on making a career of it. The next step is generally getting a rating to be able to fly by instruments: * https://en.wikipedia.org/wiki/Instrument_flight_rules https://en.wikipedia.org/wiki/Instrument_flight_rules
  - kqr 4y ago
    VFR doesn't imply actively using dead reckoning and pilotage, though. Many people fly VFR and still navigate by radio navaids, or these days, GPS.
    - ericpauley 4y ago
      Agreed. Further, VMC doesn’t always imply necessary ground visibility for pilotage. It’s perfectly legal to fly VFR above a cloud deck with no ground visibility, for instance.

zabzonk 4y ago

doesn't everyone know that they are keys to superman's fortress of solitude?