Those speeds gave them that AOA but I don’t know how they knew what speed to hold or if they were using an AOA indicator.
There was no AOA indicator. In fact, there was a "deck angle" indicator (which is not an AOA gauge, but serves as something similar in 1G flight), but it broke during the flight. See:
http://www.oshkosh365.org/saarchive/eaa_articles/1987_02_01.pdffor a description of the flight.
The object, in Voyager's case (or any distance goal) was to fly at the max L/D AOA, which is constant, or the max L/D speed, which changes with weight. If you know how much you weigh, then you know what speed to fly (since L = W). Since Voyager knew how much fuel they were burning, they could estimate their weight at any given time, and thereby know what speed to fly to maximize range. More work, but just as effective, IF you know your weight.
I know there’s a real name for it. There are several distinct AOAs like best L/D etc...
For Voyager (or Global Flyer, or any commercial airliner attempting to maximize range), it's Max. L/D AOA or speed.
With respect to your previous posting's questions, there are really three meaningful AOA's/speeds (and all this is for prop planes, NOT jets - they're slightly different, since their thrust different):
1) Max Endurance speed. This occurs when the power required to stay in the air is a minimum (and so the fuel burn is lowest, so the fuel lasts the longest)
2) Max L/D speed. This occurs at 1.32 * Max Endurance Speed, and is the speed to fly for maximum range. This occurs at the speed at which drag is the lowest. You need more power than the Max. Endurance speed (obviously, since you're going faster), but you pick up a more range by going faster than you lose by burning fuel faster.
3) Carson speed. This occurs at 1.32 * Max L/D speed. This is the "Optimum" cruising speed to fly which optimizes the fuel flow/kt of speed.
For a COZY MKIV (which I fly), the Max Endurance speed is about 75 - 80 kts. The Max L/D (range) speed is about 100 kts. The Carson speed is about 132 kts. Now, these speeds do change with weight, but since I always fly between 1700 - 2100 lb, they don't change much (not like Voyager or Global Flyer, which burned 80-90% of their weights during their flights, or a commercial airliner that might burn 1/2 it's MGW on a flight). It might be a few kts slower at lower speeds to keep the same AOA. Remember that lift is proportional to velocity squared, so a 25% decrease in weight will lead to an 11% decrease in speed for the same AOA.
So my max endurance speed might drop to 70 kts at light weight, etc.
Interestingly enough, since I almost always fly above 7500 ft, my IAS is generally in the 145 kts - 125 kt. range (between 7500 - 13.5K ft). This puts me squarely in the Carson speed area. I'd have to fly a lot higher (with lower IAS's) to get near the Max L/D speed.
If you fly low, you have to slow down a lot to get to the Carson speed, and a LOT to get anywhere near the Max L/D speed.
Here are three articles that explain what's going on in a lot more detail, and with some math if you want it.
http://www.eaa1000.av.org/technicl/perfspds/perfspds.htmhttp://cafefoundation.org/v2/pdf_tech/MPG.engines/AIAA.1980.1847.B.H.Carson.pdfhttp://www.flyingmag.com/very-best-speed-flyPS - still waiting to hear how all of this applies to the Kennedy crash...
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