Test Pilot

GENERAL

1. Helium provides buoyancy and maintains the shape of a blimp (as it does a child’s balloon). As a blimp climbs, helium—like any gas—expands. What prevents the expanding helium from excessively pressurizing and damaging a blimp? (Note: Helium is not dumped overboard because it is expensive and is needed during the descent when gas contracts.)
2. Why is that lifesaving device called a parachute?
3. What is the V-speed that represents the minimum indicated airspeed at which an airplane can be made to lift from a runway?
4. From reader Brian Korney: With the exception of Rogers (Dry) Lake at Edwards Air Force Base in Southern California, which is several miles long, what is the longest paved runway in the United States, and how long is it?
5. From reader Phil Koch: While decelerating on the runway after landing, the reverse thrust used to assist in slowing jet aircraft typically is reduced or canceled at an indicated airspeed of approximately 60 to 80 knots. Why is reverse thrust not used below this speed?
6. The pilot of a Lockheed SR–71 Blackbird is performing a preflight inspection and notes that fuel is dripping incessantly from all six fuel tanks. Why is this considered normal?
7. A pilot makes a forced landing somewhere in the Northern Hemisphere and is uncertain of his position. He sights along the long edge of his plotter and notes from a plumb bob hanging from the center of the plotter that Polaris, the North Star, is 37 degrees above the horizon. What is the pilot’s latitude?

MULTIPLE CHOICE

8. Orville and Wilbur Wright are among history’s most famous brothers, but how many Wright brothers were there?
   1. two
   2. three
   3. four
   4. five
9. Who originated the name Powder-Puff Derby when referring to the Women’s Transcontinental Air Derby?
   1. Arthur Godfrey
   2. Paul Harvey
   3. Howard Hughes
   4. Will Rogers
10. A pilot initiates a normal glide at 10,000 feet msl and maintains the published (best) glide speed throughout his descent. As altitude decreases, the rate of descent will _____ and the glide angle (or ratio) will _____.
    1. increase, increase
    2. increase, decrease
    3. decrease, increase
    4. decrease, decrease
    5. None of the above

TRUE OR FALSE

11. When a Mooney pilot applies nose-up trim, the vertical stabilizer simultaneously moves (sweeps) forward.
12. A pilot holding a no-wind heading determines that his aircraft is drifting 10 degrees right of his desired course. If he turns 10 degrees left, this will result in the aircraft’s exactly paralleling the desired course.
13. Landing on a runway coated with wet ice requires more distance than landing on a runway coated with ice that is dry.

ANSWERS

1. There are two large air-filled bags, called ballonets, inside the blimp. During climb, air is ported overboard from the ballonets, which then contract to make room for the expanding helium. When the helium contracts during descent, ram-air pressure refills the ballonets to maintain constant helium pressure.
2. Literally translated from French, parachute means to guard against a fall.
3. V _MU, or the minimum-unstick speed. V _MU can be determined in a lightplane using a procedure similar to that of a soft-field takeoff.
4. Runway 13R/31L at New York’s John F. Kennedy International Airport is 14,572 feet long, and the runway at the Kennedy Space Center at Cape Canaveral, Florida, is 15,000 feet long.
5. At low airspeeds, the turbulent airflow of reversed air can reenter the engine inlet, which can cause a compressor stall and engine damage. Depending on engine location, low-speed reversing increases the likelihood of ingesting foreign objects on the runway. Also, thrust reversing loses effectiveness at lower speeds.
6. Components of the SR–71 (including its fuel tanks) fit loosely when the aircraft is on the ground. At cruise speeds of 2,000 kt, air friction increases skin temperature to as high as 600 degrees Fahrenheit. Such heating causes components to expand, thereby sealing the fuel tanks and preventing in-flight leakage.
7. 37 degrees north. Latitude is equal to the altitude (angular elevation) of Polaris above the horizon. When the observer is at the North Pole (90 degrees north latitude), Polaris is directly overhead (90 degrees above the horizon), and when at the equator (zero degrees latitude), Polaris is on the horizon (zero degrees of elevation).
8. (c) Orville (born 1871) and Wilbur (1867) had two older brothers, Reuchlin (1861) and Lorin (1863)—and a younger sister, Katharine (1874). (There also were twins, who died in infancy.)
9. (d) The famous humorist and Wiley Post were killed in a seaplane accident near Point Barrow, Alaska, in 1935.
10. (e) Although sink rate decreases with a decrease in altitude, true airspeed reduces proportionately, which results in a constant glide ratio.
11. True. The trimmable horizontal stabilizer and the vertical stabilizer move as a single unit in response to pitch-trim input. Similarly, the vertical fin moves (sweeps) aft when nose-down trim is applied.
12. False. The new heading results in the aircraft heading more into the wind, and the new drift angle will be ever so slightly different. For practical purposes, however, drift angle and wind-correction angle are considered to be the same.
13. True. Ice covered with water is more slippery and offers less frictional resistance than dry ice. Ice melting under the blades of ice skates allows skaters to achieve greater speeds than if such frictional melting did not occur.