In recognition of Armed Forces Day (May 16) and Memorial Day (May 25), I thought it appropriate to revisit a story from my USAF days. While much less life-altering and traumatic than recent global military actions, it’s more like the majestic flying described in High Flight.
Once in high school my English teacher had me “write sentences” as a punishment. You know, write 100 times: “I will not talk out of turn in class?” I’d been caught throwing (who’d-a-guessed) a paper airplane in class. If I hadn’t constructed it so well, it may not have been airborne long, and my transgression would have gone undetected. It was, however, and remained aloft long enough to be seen by all. I was already learning to fly real airplanes by this point in High School, and all of my classmates knew it. So my response to the teacher’s query drew quite a cheer, despite his angst.
I’m a Test Pilot
Being the wise guy that I sometimes still am today, my response to his question of “Why’d you throw that?” was proudly, “I’m a Test Pilot.” Yep, I had to write 500 times by tomorrow “I-am-a-Test-Pilot.” No contraction and use capitals in the title. One hundred sentences was the norm, but he was upset with me to the 500-sentence level. Now that I think about it, I had to write sentences a lot in school. I enjoyed writing them. Some kind of psychological thing is still with me today: fill in lines in the logbook, track stocks, make lists and check things off, write stories. Motivational speakers tell you if you say something positive about yourself over and over, it will help keep you motivated until you get to that goal. I didn’t need the 500 sentences to motivate me, but they didn’t hurt. Glad he didn’t have me write: “Flying Costs Too Much.”
Fast forward: Visibility today is at least 100 miles. Looking out the side of the tinted canopy, I watch as the airport below me drops away at over 50,000 feet per minute. The distant horizon is in view beyond the mountains of Vegas within two seconds of the 6G pull I had initiated a moment ago and 90 degrees from its previous position. Glancing at the artificial horizon, the airplane symbol is fixed in the little round section that shows straight up – the exact center of the blue. I’m by myself in the most modern single-seat, single-engine jet in the world, letting more than 25,000 pounds of thrust push me up, for the moment, faster than the Shuttle and faster than Apollo. My thrust-to-weight ratio today is almost 1:1. I’m in a vertical climb and barely decelerating. Talk about making the sun rise and set with my gloved hand. Is this fun or what!
Twist My Arm
Despite the motivational 500-sentences, this day, I’m not a test pilot; I’m the squadron FCF Pilot (Functional Check Flight Pilot). I fly with the 430th Tactical Fighter Squadron Tigers, 474th Tactical Fighter Wing, Nellis Air Force Base, Nevada. This F-16A has a newly installed motor from Pratt, and it needs somebody to wring it out. Twist my arm. Fifteen seconds ago, I had pushed the single throttle forward to MIL power, checked the gauges, then rotated it slightly outboard and shoved it the rest of the way to full AB. That’s the way fighter guys say it, by the way. MIL is short for Military and pronounced “mill” as in sawmill, and A-B (said as two letters) is Afterburner. MIL is full power and AB is full power plus a bunch of raw fuel dumped into the exhaust section just after the last turbine section, then lit on fire. At night you can see a 30-foot plume, and the sound is…the sound of freedom.
The F-16 has five stages of AB and one of my jobs today is to make sure all five will light. It happens fast, so you have to know what to listen for and, more accurately, feel for. Five distinct kicks in the hind end. The only indications in the cockpit are the exhaust nozzle position going full open and the fuel flow gauge pegging off-scale high – close to 60,000 pounds per hour. At $5.00 per gallon, that’s about $12.30 per second.
Going Straight Up Over Government Property
Somewhere close to 150 knots I apply very slight back pressure on the side stick (that only moves a half-inch total), and the jet’s in the air as I reach for the gear handle. I release the back pressure on the stick so little that it’s more like a thought than action. I’m level at 20 feet, gear up, accelerating above the hot desert runway; I can see the heat waves. If I let it continue, I’ll be supersonic by a half-mile off the end of the runway and out of fuel in seven minutes. Not today, though. For this takeoff my goal is to get some energy as quickly as possible in case something bad happens and keep me, my jet, and its pieces-parts on government property if it does. At 350 KIAS, I pull back on the stick again – this time to 6G’s. The back pressure on the stick to get to 6 G’s is less than five pounds. I’m going straight up over government property.
By the time I’ve watched the altimeter spin for eight seconds, it’s time to pull over onto my back at 15,000 feet then roll upright. I pull the throttle out of AB, check the engine gauges again, point my nose toward the MOA and slow my climb to 8,000 feet per minute. I’m headed for the FCF area and a working altitude of 25,000 feet. I’ll cruise out there at about 350 KIAS. So far, I’m one minute into the flight. Another five and I’ll be in the MOA at altitude. This new motor is awesome.
Now, there is something you have to know about these FCF flights. Remember the scenes from the movie “Apollo Thirteen” where they’re trying to power up the spacecraft and get it oriented for re-entry after being cold-soaked for three days? Hundreds of checklist steps all done in a precise order? That’s kind of the way the FCF profile goes. You have about 10,000 things to do and check, and you’ve already used up a third of your gas just getting off the ground and to the test area.
Most Never Get North of Mach 2
As soon as you hit the test corridor, you plug it back into burner and do the speed check. By the time you get to fly the F-16, you’ve already been supersonic a few times so that’s no big deal. Most pilots never get north of Mach 2, however, except FCF pilots. The actual speed I’m checking is classified, but it’s on the checklist to verify that you can get to it. The new motor does it easily. It’s also at these speeds that the stabilator starts to work as a “taileron” taking over from the flaperons.
Now, for you aero folks (short for aerospace engineers) and RC builders, the stabilator vs. elevon vs. taileron debate is ongoing. We F-16 guys used to say stabilator when the true engineering name would be elevon. In the 16, the “horizontal tail” is actually a combination elevator, stabilizer, and aileron. So taileron, elevon, and stabilator all are correct. In any case, whatever it’s called, it’s a “made-up” word. Made up by you aero people.
In the style of professor William Strunk Jr., who coined the word “studentry” over student body, I thought maybe I’d make up a new word to describe the horizontal tail functions: Staba-later-on. Pronounced Stabalator with “on” added to the end. Take the hyphens out when you quote me. “I respect a man who knows how to spell a word more than one way.” (Mark Twain) The rudder isn’t like a Bonanza rudervator, though. The F-16 has a “mostly” normal rudder. It’s controlled by the computer, including correcting for yaw when you shoot the gun.
The next test is one we used to call a “gut-check.” If the test fails, you have to restart the motor – if it will start. The engine has some self-protection features to prevent it from “blowing out” if the commanded fuel flow drops off while the airflow is still large. At Mach 2 plus, the airflow is large. The test is to briskly pull the throttle all the way from full AB to idle. If it blows out, you wait until you’re subsonic and restart it…maybe. Or worse, if the IGV’s (inlet guide vanes) “flat plate” and severely limit airflow through the engine, you will kind of explode due to the back pressure in the long inlet to the motor. Today it works. Thank you, Lord.
Stay tuned for “Paper Airplanes – Reloaded” Part II in the June issue…
