4 ms·

While some base to final stall accidents are as simple as you make it sound a good chunk of them happen when you try to come OUT of the turn at an already slow

While some base to final stall accidents are as simple as you make it sound a good chunk of them happen when you try to come OUT of the turn at an already slow speed increasing the angle of attack on one wing alone. The stall and subsequent spin catches the pilot entirely surprised unaware of why they’re even stalling and with very little escape bandwidth. The FAA has been trying for better angle of attack instrumentation but what I described above isn’t an easy fix with technology. When you talk to pilots who inadvertently stall spin and lived to tell the tale most of them will tell you they didn’t even recognize that they were in a stall. That’s where the problem starts.

aeternum 2y ago
Right but I don't know of any GA stall/spin warning system that takes into account pilot input. Even simple sensors are lacking, for example accelerometers are nearly free yet GA planes give you no warning that you're in a skid. Similarly given yoke input, bank angle and speed you could warn of an impending stall well before it actually happens with a few position encoder sensors. As you point out, the current system relies on pilots recognizing a stall which is a foolish thing to rely on and almost all GA stall warning sensors are only on one of the wings and require actual airflow disruption to work. In many cases that is already too late or the other wing could stall first. The calculation doesn't even have to be perfect since most pilots want plenty of margin of safety on a base to final turn. I'd much rather have a false alarm + go-around than an inadvertent spin. The collision thing is also ridiculously irrational. The FAA requires drones over half a pound to continually transmit their location yet somehow considers it sufficiently safe for planes to fly without a radio nor transponder around most of the airports in the US relying only on pilots looking out the window. It's just disappointing that the vast majority of GA accidents could be completely avoided with slightly better avionics.
- nradov 2y ago
  Civilian drones are fairly new. There are century old GA aircraft still flying around. I'm sure the FAA would love to require them all to carry radios and transponders but it's technically and politically difficult to impose new requirements on old certified aircraft. Some owners can barely afford to fly as it is so they'll resist any new mandates.
  - aeternum 2y ago
    This is a common argument but makes little sense because the accident and loss rates of GA is so incredibly high. The cost of an ADS-B receiver for example is only $200. Full transceivers are a few thousand. Aircraft owners are already paying well over that as insurance rates yearly because of all the accidents, so total cost to fly would likely decrease by mandating things that actually move the needle on safety, especially ADS-B and fuel alerts.
- sokoloff 2y ago
  > the vast majority of GA accidents could be completely avoided with slightly better avionics. Reading accident reports or the annual summary McSpadden Report (previously called the Nall Report), I get a different view: if pilots would keep fuel in the airplane and flowing to the engine(s), not fly into weather beyond the capability of the airplane and crew, and divert or not takeoff at the onset of signs that an aircraft is not airworthy, would reduce serious accidents by half or more. Better avionics has relatively little to do with that (other than the proper use of a fuel totalizer or better). Complacency kills more pilots than weak avionics.
  - aeternum 2y ago
    Most cars give you significant warnings that you're about to run out of gas and as a result very few people do. Improved avionics could warn you that you're flying into a storm or that the airplane is not airworthy or that you are converging with other traffic. Complacency kills because it sneaks up on pilots, but it doesn't have to be that way. We should not accept that the FAA's answer is an IMSAFE checklist. Pilots should not have to die simply because they didn't realize they were feeling slightly stressed or emotional prior to takeoff and forgot to check a single one of the 40+ items on the preflight/runup/takeoff checklists. Of course good pilots should check it all anyway but just as NHTSA requires safety warnings for cars, we could save many more lives if we required low fuel warnings, terrain warnings, gear warnings, speed warnings, etc. in aircraft avionics.
    - sokoloff 2y ago
      I agree there is room for improvement and smarter airplane equipment is undoubtedly part of that. I do not believe that “slightly better avionics will completely avoid the vast majority of GA accidents.”
    - NovemberWhiskey 2y ago
      >Most cars give you significant warnings that you're about to run out of gas and as a result very few people do. You will see accident reports where the problem is that the pilot just completely failed to put enough fuel in the airplane and then flew it until it ran out; but that's not the typical thing. What's much more common is that the pilot takes off with what seems like ample fuel, gets halfway there, discovers weather that is worse than expected, has to fly lower than planned, burns a lot more fuel as a result, discovers that they will have to refuel, can't find an airport with good weather at which to land, and ends up flying a graveyard spiral into a fatal crash caused by disorientation in conditions for which they are not trained. The majority of accidents are traceable to poor planning or decision-making once airborne; and I tend to agree with the other poster that improved avionics are not going to make a really big difference.
- FabHK 2y ago
  > GA planes give you no warning that you're in a skid. "The ball" will show you that you're in a skid. https://en.wikipedia.org/wiki/Turn_and_slip_indicator https://en.wikipedia.org/wiki/Turn_and_slip_indicator
lovecg 2y ago
That makes a lot of sense, interested to learn more about this, any statistics you’re aware of on this topic?
- danielschonfeld 2y ago
  I don’t have those I’m sorry. Not that much into it. If you need a better understanding look for a video of a pilot I think in South Africa or Australia who took a cameraman and his wife and stalled shortly after takeoff. It’s interesting to see how many warning signs throughout the whole video are glaring at him yet he keeps flying all the way into the crash. What’s also interesting is that that’s it. Just warning signs but if you really try to put yourself in his shoes it’s entirely hard to accept the warnings as everything on surface level understanding seems normal, controlled and flat. Very very very flat. I think the biggest problem with real life stalls as compared to training world ones are that they are either more benign or entirely out of left field and believing you’re about to go into one doesn’t even begin to enter the pilot’s mind let alone correct recovery techniques.
  - lovecg 2y ago
    Thanks, by the way if that’s the same video I’m thinking of the problem there was gross incompetence - he tied the door wide open to the wing strut! Another piece of statistics I recently learned is that most stalls occur on departure or go arounds, and classic base to final are relatively rare. Maybe those have been successfully trained out.
bombcar 2y ago
The FAA also has the NTSB investigate every crash and accident, and if it was something as simple as "change the airport patterns to be larger and faster" or "make more airports straight in" it would have already been done. Fancier aeronautics has a way of letting the plane get ahead of the pilot even faster.

aeternum 2y ago

Right but I don't know of any GA stall/spin warning system that takes into account pilot input. Even simple sensors are lacking, for example accelerometers are nearly free yet GA planes give you no warning that you're in a skid. Similarly given yoke input, bank angle and speed you could warn of an impending stall well before it actually happens with a few position encoder sensors. As you point out, the current system relies on pilots recognizing a stall which is a foolish thing to rely on and almost all GA stall warning sensors are only on one of the wings and require actual airflow disruption to work. In many cases that is already too late or the other wing could stall first. The calculation doesn't even have to be perfect since most pilots want plenty of margin of safety on a base to final turn. I'd much rather have a false alarm + go-around than an inadvertent spin. The collision thing is also ridiculously irrational. The FAA requires drones over half a pound to continually transmit their location yet somehow considers it sufficiently safe for planes to fly without a radio nor transponder around most of the airports in the US relying only on pilots looking out the window. It's just disappointing that the vast majority of GA accidents could be completely avoided with slightly better avionics.

nradov 2y ago
Civilian drones are fairly new. There are century old GA aircraft still flying around. I'm sure the FAA would love to require them all to carry radios and transponders but it's technically and politically difficult to impose new requirements on old certified aircraft. Some owners can barely afford to fly as it is so they'll resist any new mandates.
- aeternum 2y ago
  This is a common argument but makes little sense because the accident and loss rates of GA is so incredibly high. The cost of an ADS-B receiver for example is only $200. Full transceivers are a few thousand. Aircraft owners are already paying well over that as insurance rates yearly because of all the accidents, so total cost to fly would likely decrease by mandating things that actually move the needle on safety, especially ADS-B and fuel alerts.
sokoloff 2y ago
> the vast majority of GA accidents could be completely avoided with slightly better avionics. Reading accident reports or the annual summary McSpadden Report (previously called the Nall Report), I get a different view: if pilots would keep fuel in the airplane and flowing to the engine(s), not fly into weather beyond the capability of the airplane and crew, and divert or not takeoff at the onset of signs that an aircraft is not airworthy, would reduce serious accidents by half or more. Better avionics has relatively little to do with that (other than the proper use of a fuel totalizer or better). Complacency kills more pilots than weak avionics.
- aeternum 2y ago
  Most cars give you significant warnings that you're about to run out of gas and as a result very few people do. Improved avionics could warn you that you're flying into a storm or that the airplane is not airworthy or that you are converging with other traffic. Complacency kills because it sneaks up on pilots, but it doesn't have to be that way. We should not accept that the FAA's answer is an IMSAFE checklist. Pilots should not have to die simply because they didn't realize they were feeling slightly stressed or emotional prior to takeoff and forgot to check a single one of the 40+ items on the preflight/runup/takeoff checklists. Of course good pilots should check it all anyway but just as NHTSA requires safety warnings for cars, we could save many more lives if we required low fuel warnings, terrain warnings, gear warnings, speed warnings, etc. in aircraft avionics.
  - sokoloff 2y ago
    I agree there is room for improvement and smarter airplane equipment is undoubtedly part of that. I do not believe that “slightly better avionics will completely avoid the vast majority of GA accidents.”
  - NovemberWhiskey 2y ago
    >Most cars give you significant warnings that you're about to run out of gas and as a result very few people do. You will see accident reports where the problem is that the pilot just completely failed to put enough fuel in the airplane and then flew it until it ran out; but that's not the typical thing. What's much more common is that the pilot takes off with what seems like ample fuel, gets halfway there, discovers weather that is worse than expected, has to fly lower than planned, burns a lot more fuel as a result, discovers that they will have to refuel, can't find an airport with good weather at which to land, and ends up flying a graveyard spiral into a fatal crash caused by disorientation in conditions for which they are not trained. The majority of accidents are traceable to poor planning or decision-making once airborne; and I tend to agree with the other poster that improved avionics are not going to make a really big difference.
FabHK 2y ago
> GA planes give you no warning that you're in a skid. "The ball" will show you that you're in a skid. https://en.wikipedia.org/wiki/Turn_and_slip_indicator https://en.wikipedia.org/wiki/Turn_and_slip_indicator

lovecg 2y ago

That makes a lot of sense, interested to learn more about this, any statistics you’re aware of on this topic?

danielschonfeld 2y ago
I don’t have those I’m sorry. Not that much into it. If you need a better understanding look for a video of a pilot I think in South Africa or Australia who took a cameraman and his wife and stalled shortly after takeoff. It’s interesting to see how many warning signs throughout the whole video are glaring at him yet he keeps flying all the way into the crash. What’s also interesting is that that’s it. Just warning signs but if you really try to put yourself in his shoes it’s entirely hard to accept the warnings as everything on surface level understanding seems normal, controlled and flat. Very very very flat. I think the biggest problem with real life stalls as compared to training world ones are that they are either more benign or entirely out of left field and believing you’re about to go into one doesn’t even begin to enter the pilot’s mind let alone correct recovery techniques.
- lovecg 2y ago
  Thanks, by the way if that’s the same video I’m thinking of the problem there was gross incompetence - he tied the door wide open to the wing strut! Another piece of statistics I recently learned is that most stalls occur on departure or go arounds, and classic base to final are relatively rare. Maybe those have been successfully trained out.

bombcar 2y ago

The FAA also has the NTSB investigate every crash and accident, and if it was something as simple as "change the airport patterns to be larger and faster" or "make more airports straight in" it would have already been done. Fancier aeronautics has a way of letting the plane get ahead of the pilot even faster.