Are there barometric and gps altimeters on these planes too? Maybe inertial guidance systems? Hard to believe they’d rely on a single source. And the rate of change should have to make sense too. I’m sure there’s a good answer. Thank you for a great article!
Great question--they actually have both! The barometric altimeter gives them altitude above sea-level because it uses the ambient air pressure. This is really helpful, but it won't tell the pilots how high off the ground they are if what they're flying over is above sea-level. That is where the radar altimeters come in, and why they're especially important for landing. Radar altimeters work best under 5,000 feet, so they are critical for knowing how high above the ground you are during landing.
Are there barometric and gps altimeters on these planes too? Maybe inertial guidance systems? Hard to believe they’d rely on a single source. And the rate of change should have to make sense too. I’m sure there’s a good answer. Thank you for a great article!
Great question--they actually have both! The barometric altimeter gives them altitude above sea-level because it uses the ambient air pressure. This is really helpful, but it won't tell the pilots how high off the ground they are if what they're flying over is above sea-level. That is where the radar altimeters come in, and why they're especially important for landing. Radar altimeters work best under 5,000 feet, so they are critical for knowing how high above the ground you are during landing.
Thanks Matthew for providing the insight into a hot topic.
As usual, an excellent article. In this day and age it is refreshing to get the facts without the hysteria. Now if COVID abates I can fly again!