It was very fun flying with you Ben! I pushed a little more aggressively than I should have getting on the pine nuts and some inconveniently located strong sink forced me to divert towards minden where I had to dump my ballast to scrape back up. Congratulations on the great flight!
Thanks! The oxygen is necessary because I'm flying at high altitude, where there isn't enough oxygen in the air. It's not because of any medical condition.
At 18,000ft and above, you set your altimeter to 29.92 in mg and keep it there. So the floor of class A is at 18,000ft pressure altitude at standard atmospheric pressure. If you want to get close to class A but not go into it, you need to have the altimeter set to 29.92.
@@BenHirashima 14 cfr 71.33 (class A airspace areas) says class A airspace includes "That airspace of the United States, including that airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States, from 18,000 feet MSL to and including FL600 excluding the states of Alaska and Hawaii." Saying 18,000 feet MSL without any additional qualifiers means true altitude. Further, 14 cfr 91.121 (altimeter settings) has a table of the "minimum usable flight level" based on the current altimeter setting on the ground, which supports my interpretation. For example, if the altimeter setting is "28.91 through 28.42", then the minimum usable flight level is 195 according to the table, because as soon as you pass 18,000 feet true altitude, you increase the kollsman window setting to 29.92, which causes the indicated altitude to jump up to about 19,500 (in other words, class A airspace starts at about 19,500 pressure altitude on that day). If your interpretation was correct, then flight levels starting from 180 would always be usable because class A airspace would always start at 18,000 pressure altitude, but the table contradicts this. For a more in-depth discussion search "stackexchange which altimeter setting airspace boundary" on google (youtube won't let me link it)
I did some research on this subject, and it was not easy to find a definitive answer to the question of what the legal definition of the class A floor is. Beware of discussions on Stack Exchange and the like, because they are just random people's opinions, not legal definitions. I dug through the CFRs but could not find a clear definition of the class A floor. I did find this, which is illuminating: "It starts at 18,000 feet mean sea level (MSL) and goes up to and including Flight level (FL) 600 (or 60,000 feet MSL). But wait, it’s not quite that simple. In the case of Class A airspace, and ONLY Class A airspace, the identifier isn’t based on local barometric pressure. Pilots fly in Class A using the “Standard Datum Plane”. We will get more into this a little later, but for the purposes of identifying Class A a pilot enters 29.92 in Hg into their Kollsman Window. This means that technically Class A does not start at 18,000 feet MSL exactly, but rather 18,000 feet MSL from a theoretical point near the surface that measures 29.92 inches of Mercury." From bobbielind.com/understanding-class-a-airspace/ This is not definitive, because it's just somebody's opinion. However, it makes sense to me. I think to definitively answer the question, we'd need lawyers. What IS clear though, is that if you want to avoid getting hit by an airliner, you should set your altimeter to 29.92 because that is what the airliners have theirs set to.
Such a fascinating hobby, this planet is just amazing for all the incredible riches it provides.
It was very fun flying with you Ben! I pushed a little more aggressively than I should have getting on the pine nuts and some inconveniently located strong sink forced me to divert towards minden where I had to dump my ballast to scrape back up. Congratulations on the great flight!
Congrats on winning the day! You overcame that early setback and flew a great flight.
Love the naration and graphics. Thanks.
Great flight, Ben!
That was awesome
No need for Oxygen ?
sorry I see you are using Oxygen, great footage!
Thanks! The oxygen is necessary because I'm flying at high altitude, where there isn't enough oxygen in the air. It's not because of any medical condition.
Class A boundary is determined by true altitude MSL, not pressure altitude :O
At 18,000ft and above, you set your altimeter to 29.92 in mg and keep it there. So the floor of class A is at 18,000ft pressure altitude at standard atmospheric pressure. If you want to get close to class A but not go into it, you need to have the altimeter set to 29.92.
@@BenHirashima 14 cfr 71.33 (class A airspace areas) says class A airspace includes "That airspace of the United States, including that airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States, from 18,000 feet MSL to and including FL600 excluding the states of Alaska and Hawaii." Saying 18,000 feet MSL without any additional qualifiers means true altitude.
Further, 14 cfr 91.121 (altimeter settings) has a table of the "minimum usable flight level" based on the current altimeter setting on the ground, which supports my interpretation. For example, if the altimeter setting is "28.91 through 28.42", then the minimum usable flight level is 195 according to the table, because as soon as you pass 18,000 feet true altitude, you increase the kollsman window setting to 29.92, which causes the indicated altitude to jump up to about 19,500 (in other words, class A airspace starts at about 19,500 pressure altitude on that day). If your interpretation was correct, then flight levels starting from 180 would always be usable because class A airspace would always start at 18,000 pressure altitude, but the table contradicts this.
For a more in-depth discussion search "stackexchange which altimeter setting airspace boundary" on google (youtube won't let me link it)
I did some research on this subject, and it was not easy to find a definitive answer to the question of what the legal definition of the class A floor is. Beware of discussions on Stack Exchange and the like, because they are just random people's opinions, not legal definitions. I dug through the CFRs but could not find a clear definition of the class A floor. I did find this, which is illuminating:
"It starts at 18,000 feet mean sea level (MSL) and goes up to and including Flight level (FL) 600 (or 60,000 feet MSL). But wait, it’s not quite that simple. In the case of Class A airspace, and ONLY Class A airspace, the identifier isn’t based on local barometric pressure. Pilots fly in Class A using the “Standard Datum Plane”. We will get more into this a little later, but for the purposes of identifying Class A a pilot enters 29.92 in Hg into their Kollsman Window. This means that technically Class A does not start at 18,000 feet MSL exactly, but rather 18,000 feet MSL from a theoretical point near the surface that measures 29.92 inches of Mercury."
From bobbielind.com/understanding-class-a-airspace/
This is not definitive, because it's just somebody's opinion. However, it makes sense to me. I think to definitively answer the question, we'd need lawyers. What IS clear though, is that if you want to avoid getting hit by an airliner, you should set your altimeter to 29.92 because that is what the airliners have theirs set to.
@@BenHirashimait's such a specific and grey area I would just stay a little bit away from fl 180. Maybe 170