The Power of 25

Think of it as a crash course in aeronautical trivia.

A Boeing 767-300 lands on Los Angeles International Airport’s runway 25L. (Sam Chui)
Air & Space Magazine

A 25th anniversary collection of tidbits, tales, and trivia from around the world of air and space to help you win that next bar bet. (There--we said it in 25 words.)

From This Story

— The Editors

By the Rules
Without Part 25 of the Federal Aviation Regulations, airline passengers might feel a little less confident in the safety of their ride. You may be relieved to know, for example, that each critical “removable bolt, screw, nut, pin, or other removable fastener” on your airliner “must include two separate locking devices.” The FARs are rules that govern all aviation activity—from commercial airliners to model rockets—in the United States. In covering airworthiness standards for transports with a maximum takeoff weight greater than 12,500 pounds, Part 25 applies to Boeing’s 737 and later types, and the Airbus A300 series, airliners certified since February 1, 1965, when most of the FARs were instituted.

The 25th Pilot
We’re not certain who made the 25th airplane flight. Trying to find out would probably just lead to arguments about who flew how far and when, who was there to observe it, and what qualifies as an airplane anyway. But we do know who got the 25th pilot’s license in the United States: Phil Parmelee, a member of the Wright brothers’ exhibition team, who was issued license no. 25 by the Aero Club of America in 1910, before government agencies required official certification for airplane pilots.

When NASA Grew Like Kudzu
NASA’s head count hit 25,000 in 1963, during Project Mercury. Just five years earlier, when its predecessor, the National Advisory Committee for Aeronautics, was created, it had only 8,000 employees. NASA reached its peak employment in 1967 with 35,800 workers and 375,000 contractors for the Apollo moon landing program. Today, the space agency employs 18,000, with a contractor force of about 40,000.

Crowded Field
In 1928, 25 years after the first airplane flight, aircraft were being mass-produced around the world. Here are 25 of the manufacturers:

Albatros-Flugzeugwerke (Germany), Blériot-Aéronautique (France), Boeing (U.S.), Breguet (France), Bristol Aeroplane (U.K.), Caproni (Italy), Consolidated Aircraft (U.S.), Curtiss (U.S.), de Havilland (U.K.), Douglas (U.S.), Fairey Aviation (U.K.), Farman (France), Fokker (Germany), Gotha (Germany), Handley Page (U.K.), Hawker (U.K.), Junkers (Germany), Morane-Saulnier (France), Nieuport (France), North American (U.S.), Polikarpov (Soviet Union), Short Brothers (U.K.), Supermarine Aviation Works (U.K.), Travel Air (U.S.), Vickers (U.K.)

It’s Elemental
Manganese, a silver-gray brittle metal, is the 25th chemical in the periodic table of elements. When small amounts of manganese are combined with aluminum—a lightweight metal ideal for the construction of aircraft—the resulting aluminum-manganese alloy has a much higher tensile strength than pure aluminum, so it is ideal for standing up to aerodynamic stresses. Manganese also makes aluminum less vulnerable to corrosion. The manganese-aluminum alloy, which first appeared in airplane production around 1917, has been used frequently in the manufacture of aircraft fuel tanks, fairings, and oil tanks.

You’re Cleared for Runway 25
If you’re flying to Los Angeles, Anchorage, Moscow, or Karachi, you’ll find the number 25 at the airport: All of those cities have airports with southwest- heading runways. Runways are numbered according to their compass heading divided by 10; for example, a runway pointed due north (360 degrees) is numbered 36. Runways numbered 25 are at 250 degrees on the compass, between due south (180) and due west (270). These airports have parallel left and right runway 25s:

Los Angeles International, California (International Air Transport Association identifier LAX), Hong Kong International/Chek Lap Kok, China (HKG), Phoenix Sky Harbor International, Arizona (PHX), Phoenix Deer Valley, Arizona (DVT), Daugherty Field, Long Beach, California (LGB), Brussels, Belgium (BRU), McCarran, Las Vegas, Nevada (LAS), Livermore Municipal, California (LVK), Ted Stevens Anchorage International, Alaska (ANC), Frankfurt am Main, Germany (FRA), Addis Ababa Bole International, Ethiopia (ADD), Daytona Beach International, Florida (DAB), Barcelona/El Prat, Catalonia, Spain (BCN), Tan Son Nhut International, Ho Chi Minh City, Vietnam (SGN), Soekarno-Hatta, Jakarta, Indonesia (GCK), Sheremetyevo International, Moscow, Russia (SVO), Compton/Woodley, Compton, California (CPM), General Mitchell International, Milwaukee, Wisconsin (MKE), Jinnah International, Karachi, Pakistan (KHI)

Comment on this Story

comments powered by Disqus