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The final information on the crash almost reads like they hit the very top of the mountain - according to NTSB, they were about 200-250 ft from the summit, so

The final information on the crash almost reads like they hit the very top of the mountain - according to NTSB, they were about 200-250 ft from the summit, so it is possible they did still have visual with the airport until right before the impact. Whether or not GPS could've helped with this, I'm not sure - it might've allowed them to see where they were relative to the mountain better, since it was the middle of the night and so they probably couldn't see the mountain very well..

colechristensen 1mo ago
Your GPS enabled flight computer will indeed yell at you VERY LOUDLY if you're about to hit a mountain. It will not allow you to get particularly close to terrain without noticing.
- inigyou 1mo ago
  You say GPS-enabled. What about a GPS-jammed flight computer? Can that do it too?
  - colechristensen 1mo ago
    GPS + a topo map yelling at you for being too close to the ground is extremely simple, a very basic feature. Dead reckoning (keeping track of position over time without an external source of truth) and radar altimeters are high level features that some avionics do have, but these are expensive and not expected to always be present. Inertial navigation systems you'd find on missiles are precise enough that if you leave one running on a table in the upper floor of the building you can track the rise and fall of the building as it heats up and grows because of thermal expansion throughout the day (in other words, they are extremely precise). So it depends.
- deleted 1mo ago
  [deleted]
- MSFT_Edging 1mo ago
  I'm wondering what they could have done differently here. The report said it was a 0% moonlight night, extremely dark. No exact position from GPS, and visuals on the landing strip. That mountain peak would have likely been invisible from the pilot's seat. What would have been the "skill issue" difference people keep mentioning? It's getting really frustrating how reckless the US military is with the skies. They keep putting people in danger. I can't help but think about the DCA crash due to the continuity of government drills. There's no reason they should have been flying dark for a drill that night.
  - sokoloff 1mo ago
    This is a judgment issue more than a skill issue. GPS NOTAM'd as unreliable on a dark, moonless night? Fly the ILS approach (or fly a visual approach along the track of the ILS approach backing up your visual with the radio signals). That will give you terrain and obstacle clearance all along the route using locally generated navigation signals that will be entirely unaffected by GPS jamming. https://aeronav.faa.gov/d-tpp/2607/06922IL24.PDF https://aeronav.faa.gov/d-tpp/2607/06922IL24.PDF
    - plorg 1mo ago
      Per other comments the ILS approach was not available due to the local weather service being NOTAM'd as unavailable, couldn't set local altitude. The judgment call was effectively whether to take the flight at all, as there was effectively no instrument approach available and the visual conditions precluded VFR.
      - sokoloff 1mo ago
        The ILS approach being not legally usable as an approach due to a missing local altimeter setting does not make it unusable to back up a visual approach [or VFR arrival]. I would 100% (and have) take center's altimeter setting and fly the track of an ILS or localizer rather than "whelp, nothing can be done..." This was VMC; you don't need a local altimeter setting to be safe using the radio navaids; you would need it to legally fly the approach as an ILS approach.
- voidUpdate 1mo ago
  "TOO LOW – TERRAIN" vwoop vwoop

colechristensen 1mo ago

Your GPS enabled flight computer will indeed yell at you VERY LOUDLY if you're about to hit a mountain. It will not allow you to get particularly close to terrain without noticing.

inigyou 1mo ago
You say GPS-enabled. What about a GPS-jammed flight computer? Can that do it too?
- colechristensen 1mo ago
  GPS + a topo map yelling at you for being too close to the ground is extremely simple, a very basic feature. Dead reckoning (keeping track of position over time without an external source of truth) and radar altimeters are high level features that some avionics do have, but these are expensive and not expected to always be present. Inertial navigation systems you'd find on missiles are precise enough that if you leave one running on a table in the upper floor of the building you can track the rise and fall of the building as it heats up and grows because of thermal expansion throughout the day (in other words, they are extremely precise). So it depends.
deleted 1mo ago
[deleted]
MSFT_Edging 1mo ago
I'm wondering what they could have done differently here. The report said it was a 0% moonlight night, extremely dark. No exact position from GPS, and visuals on the landing strip. That mountain peak would have likely been invisible from the pilot's seat. What would have been the "skill issue" difference people keep mentioning? It's getting really frustrating how reckless the US military is with the skies. They keep putting people in danger. I can't help but think about the DCA crash due to the continuity of government drills. There's no reason they should have been flying dark for a drill that night.
- sokoloff 1mo ago
  This is a judgment issue more than a skill issue. GPS NOTAM'd as unreliable on a dark, moonless night? Fly the ILS approach (or fly a visual approach along the track of the ILS approach backing up your visual with the radio signals). That will give you terrain and obstacle clearance all along the route using locally generated navigation signals that will be entirely unaffected by GPS jamming. https://aeronav.faa.gov/d-tpp/2607/06922IL24.PDF https://aeronav.faa.gov/d-tpp/2607/06922IL24.PDF
  - plorg 1mo ago
    Per other comments the ILS approach was not available due to the local weather service being NOTAM'd as unavailable, couldn't set local altitude. The judgment call was effectively whether to take the flight at all, as there was effectively no instrument approach available and the visual conditions precluded VFR.
    - sokoloff 1mo ago
      The ILS approach being not legally usable as an approach due to a missing local altimeter setting does not make it unusable to back up a visual approach [or VFR arrival]. I would 100% (and have) take center's altimeter setting and fly the track of an ILS or localizer rather than "whelp, nothing can be done..." This was VMC; you don't need a local altimeter setting to be safe using the radio navaids; you would need it to legally fly the approach as an ILS approach.
voidUpdate 1mo ago
"TOO LOW – TERRAIN" vwoop vwoop