The first OLS was the mirror landing aid, one of several British inventions made after the Second World War revolutionising the design of aircraft carriers. The others were the steam catapult and the angled flight deck. The Mirror Landing Aid was invented by Nicholas Goodhart. It was tested on the carriers HMS Illustrious and HMS Indomitable before being introduced on British carriers in 1954 and on US carriers in 1955.
The mirror landing aid was a gyroscopically-controlled concave mirror on the port side of the flight deck. On either side of the mirror was a line of green coloured "datum lights". A bright orange "source" light was shone into the mirror creating the "ball" (or "meatball" in later USN parlance) which could be seen by the aviator who was about to land. The position of the ball compared to the datum lights indicated the aircraft's position in relation to the desired glidepath: if the ball was above the datum, the plane was high; below the datum, the plane was low; between the datum, the plane was on glidepath. The gyro stabilisation compensated for much of the movement of the flight deck due to the sea, giving a constant glidepath.
Initially, the device was thought able to allow the pilot to land without direction from the LSO. However, accident rates actually increased upon the system's initial introduction, so the current system of including the LSO was developed. This development, along with the others mentioned, contributed to the US carrier landing accident rate plummeting from 35 per 10,000 landings in 1954 to 7 per 10,000 landings in 1957.
The LSO, who is a specially qualified and experienced Navy pilot, provides additional input to the pilot via radios, advising of power requirements, position relative to glide path and centerline. The LSO can also use a combination of lights attached to the OLS to indicate "go around" using the bright red, flashing wave off lights. Additional signals, such as "cleared to land," "add power," or "divert" can be signaled using with a row of green "cut" lights or a combination thereof.
Read more about this topic: Optical Landing System
Famous quotes containing the words mirror, landing and/or aid:
“Women ... are completely alone, though they were born and bred upon this soil, as if they belonged to another class in creation.”
—“Jennie June” Croly 1829–1901, U.S. founder of the woman’s club movement, journalist, author, editor. F, Demorest’s Illustrated Monthly Mirror of Fashions, pp. 363-4 (December 1870)
“I foresee the time when the painter will paint that scene, no longer going to Rome for a subject; the poet will sing it; the historian record it; and, with the Landing of the Pilgrims and the Declaration of Independence, it will be the ornament of some future national gallery, when at least the present form of slavery shall be no more here. We shall then be at liberty to weep for Captain Brown. Then, and not till then, we will take our revenge.”
—Henry David Thoreau (1817–1862)
“Manners aim to facilitate life, to get rid of impediments, and bring the man pure to energize. They aid our dealing and conversation, as a railway aids travelling, by getting rid of all avoidable obstructions of the road, and leaving nothing to be conquered but pure space.”
—Ralph Waldo Emerson (1803–1882)