4 ms·

The article states that the pilot awoke mid-recovery and increased to 9.1G

Declanomous 10y ago
I wonder if the 5G limitation on the avoidance system is to allow pilot a chance to recover from GLOC, or if it is due to other concerns like the structural integrity of the aircraft or more unpredictable handling at more than 5Gs. Can more than 5 sustained Gs kill someone if they aren't conscious and able to counteract the blood pooling in their lower extremities?
- trentnelson 10y ago
  5G is definitely more tolerable than 9G, especially in a GLOC situation, yet still allows for a pretty aggressive avoidance maneuver. The 5G limit is going to be decided in concert with the minimum altitude and an upper speed limit. GLOC would be most common at the merge, where they'll be at corner speed (the speed that allows them to get the tightest turning radius whilst bleeding the least amount of energy) and need to instantaneously load to 9Gs. So from an engineering perspective, I'm sure they massaged the G limit, minimum recovery altitude and maximum likely speed into the most optimal set of parameters, with 5G offering a good trade-off between minimum recovery altitude and pilot comfort. The planes themselves are G-rated to 9Gs, which is entirely a flight control system limit, because the bag of bones in the front seat tends not to do so well over 9Gs for sustained periods -- but the actual airframe will be able to sustain much higher before structural failures will start occurring.
- amargherio 10y ago
  The maximum g-load for an F-16 carrying external fuel tanks or air-to-ground ordinance is 5G and is enforced by the flight computer to prevent the extra weight on the wing hardpoints from causing structural damage to the air frame. Within the cockpit, on the left side, there's a CAT switch that's used to switch between CAT-I (lighter loadouts, such as A-A) which permits more G-intensive maneuvering, and CAT-III (external tanks or A-G ordinance). As far as sustained loads higher than 5G's, I could see the potential to kill someone, but I would also guess that the more immediate threat after G-LOC is probably the ground.

I wonder if the 5G limitation on the avoidance system is to allow pilot a chance to recover from GLOC, or if it is due to other concerns like the structural integrity of the aircraft or more unpredictable handling at more than 5Gs. Can more than 5 sustained Gs kill someone if they aren't conscious and able to counteract the blood pooling in their lower extremities?

trentnelson 10y ago
5G is definitely more tolerable than 9G, especially in a GLOC situation, yet still allows for a pretty aggressive avoidance maneuver. The 5G limit is going to be decided in concert with the minimum altitude and an upper speed limit. GLOC would be most common at the merge, where they'll be at corner speed (the speed that allows them to get the tightest turning radius whilst bleeding the least amount of energy) and need to instantaneously load to 9Gs. So from an engineering perspective, I'm sure they massaged the G limit, minimum recovery altitude and maximum likely speed into the most optimal set of parameters, with 5G offering a good trade-off between minimum recovery altitude and pilot comfort. The planes themselves are G-rated to 9Gs, which is entirely a flight control system limit, because the bag of bones in the front seat tends not to do so well over 9Gs for sustained periods -- but the actual airframe will be able to sustain much higher before structural failures will start occurring.
amargherio 10y ago
The maximum g-load for an F-16 carrying external fuel tanks or air-to-ground ordinance is 5G and is enforced by the flight computer to prevent the extra weight on the wing hardpoints from causing structural damage to the air frame. Within the cockpit, on the left side, there's a CAT switch that's used to switch between CAT-I (lighter loadouts, such as A-A) which permits more G-intensive maneuvering, and CAT-III (external tanks or A-G ordinance). As far as sustained loads higher than 5G's, I could see the potential to kill someone, but I would also guess that the more immediate threat after G-LOC is probably the ground.