So, instead of boring you with lame attempts to explain the importance of angle of attack, I will just point you to where I got this viral idea. My only hope is to raise awareness of this way of flying and how it will affect your virtual missions, from cruising to the objective through the final gun run.
The book "Stick and Rudder" by Wolfgang Langewiesche is the premier source for all this angle of attack mambo-jambo. Ed Kolano has a nice article about the basics of angle of attack here.
The basics are as follows:
- You select an angle of attack to fly by using the horizontal stabilizer
- The angle of attack determines your airspeed
- From a selected angle of attack (and thereby airspeed) you can climb, descend or fly level by adjusting power
So, let's fly the Hog above the Nevada desert and let's see what it can do without touching the stick. The airplane will point its nose down or up depending on your throttle setting. At a certain throttle setting, the aircraft achieves steady flight. In this case is around 270 knots, but that varies depending on loading and altitude.
|The angle of attack (AoA) indicator reads 14. This is an indication of the angle of attack that the aircraft reaches without any input from the stick.|
|A quick glance at the instruments reveals that each engine of the Hog is consuming around 2,200 pounds of fuel per hour. Assuming a total fuel load of 9,600 pounds, we have around 2 hours of flight left.|
So, let's now increase our angle of attack a little bit. That's done by pushing the stick backwards. For long periods of time, it's kind of difficult (and exhausting) to keep your stick input consistent and even. That's why we have the trim! Yeah! Let's trim the nose up one or two notches. I know that as I do this, the aircraft will be trimmed for a larger angle of attack and a lower airspeed, so I don't need that much power now to keep flying straight and level and thereby reduce my throttle a bit.
|I have trimmed the aircraft's nose one or two notches up and reduced throttle until achieving level flight. I am now flying at around 200 knots. Nose up -> more angle of attack -> less airspeed.|
|The angle of attack (AoA) indicator now reads 16. Angles of attack between 15 and 16 are used to do some cruising in the Hog.|
|Just with two notches of nose up trim, we decreased the fuel consumption and increased our flying time by one hour. Calculation above assumes a total of 9600 pounds of fuel available.|
Let's go loco and trim the nose up one or two notches more. I have the Hog now trimmed for a higher angle of attack and thus a lower airspeed, so I ease the throttle a bit until I get into level flight again.
|More nose up trimming. My aircraft is now trimmed for an airspeed around the 170's.|
|The angle of attack of indicator (AoA) now reads 18. Angles of attack of 17 and 18 are used for endurance or maximum loitering time. See next screenshot.|
|We may be flying slower now, but look at our endurance!|
The moral of this blog entry: watch for your tim/angle of attack! After a long commute to the kill zone, you may be arriving with a Hog trimmed for something else than a gun run. This may not kill you but the aircraft will be heavy to maneuver. In case of doubt, neutralize trim before the bomb/gun run.
Some useful values (please remember that the Hog's AoA indicator has values in arbitrary units, not real/physical angles):
- AoA for cruising: 15-16
- AoA for maximum endurance: 17-18 (may come in handy for loitering)
- AoA for landing approaches: 19-20-21
This blog was never in the tutorial business, but my inability to properly explain this angle of attack-based form of flying has me very frustrated. I can only wish that this blog entry will spark some interest in the topic among you virtual pilots.