''Light Heart'' was a

balloon A balloon is a flexible membrane bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. For special purposes, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), ...

constructed by

Colonel Colonel ( ; abbreviated as Col., Col, or COL) is a senior military Officer (armed forces), officer rank used in many countries. It is also used in some police forces and paramilitary organizations. In the 17th, 18th, and 19th centuries, a colon ...

Thomas Leigh Gatch Jr., USAR (13 September 1925 – disappeared 19 February 1974) for an unsuccessful attempt at the first crossing of the

Atlantic Ocean The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

by balloon. Gatch was the son of Vice Admiral

Thomas Leigh Gatch Thomas Leigh Gatch (August 9, 1891 – December 16, 1954) was an American naval officer and attorney in the 20th century. A native of Oregon, and grandson of educator Thomas Milton Gatch, he served in the United States Navy as a ship commander d ...

(1891–1954) and grandson of photographer Helen Gatch (1862–1942).

Balloon design

The balloon consisted of a sealed and pressurized envelope suspended from a cluster of ten

helium Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...

balloons. Each of these was a

superpressure balloon A superpressure balloon (SPB) is a style of aerostatic balloon where the volume of the balloon (aircraft), balloon is kept relatively constant in the face of changes in ambient pressure outside the balloon, and the temperature of the contained li ...

(also known as a constant pressure or positive pressure balloon.) In theory, such a balloon can retain a constant altitude over very long-distance flights of several days' duration, since the volume of the envelope remains relatively constant over time. Changes in the pressure of the gas due to heating and cooling are accommodated by mitigating the temperature changes and using an inelastic envelope. The sealed and insulated gondola, which Gatch constructed at home, was designed to maintain the same partial pressure of oxygen as at sea level (40% oxygen at 0.5 atmospheres).

Flight plan

Gatch intended to fly the Atlantic (solo) from Harrisburg Airport,

Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...

, to somewhere in

Western Europe Western Europe is the western region of Europe. The region's extent varies depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to the Western half of the ancient Mediterranean ...

in a little over two days. The theory underlying this plan was that he would be able to maintain a constant altitude of 12,000m (39,000 ft); at this altitude the

jet stream Jet streams are fast flowing, narrow thermal wind, air currents in the Earth's Atmosphere of Earth, atmosphere. The main jet streams are located near the altitude of the tropopause and are westerly winds, flowing west to east around the gl ...

should carry his aircraft from North America to Europe in the time planned.

Flight and disappearance

''Light Heart'' took off from Harrisburg Airport at 19:29 hours on 18 February 1974. By 21:00 the balloon was reported to have stabilized at 10,200m (33,500 ft), having passed over

Dover, Delaware Dover ( ) is the List of capitals in the United States, capital and the List of municipalities in Delaware, second-most populous city of the U.S. state of Delaware. It is also the county seat of Kent County, Delaware, Kent County and the princ ...

, and

Atlantic City, New Jersey Atlantic City, sometimes referred to by its initials A.C., is a Jersey Shore seaside resort city (New Jersey), city in Atlantic County, New Jersey, Atlantic County, in the U.S. state of New Jersey. Atlantic City comprises the second half of ...

. Gatch reported that one of the ten helium balloons had burst during the ascent (at 20:45). While the balloon was able to continue in this condition, he had been forced to jettison water ballast to continue climbing and he was now able to cruise at no more than 11,000m (36,000 ft), rather than the 12,000m (39,000 ft) he had originally intended. For the next sixteen hours Gatch maintained radio contact with passing airliners (at least two of which were diverted to avoid his craft). His last radio contact was at 12:50 on Tuesday, 19 February, with

BOAC British Overseas Airways Corporation (BOAC) was the British state-owned national airline created in 1939 by the merger of Imperial Airways and British Airways Ltd. It continued operating overseas services throughout World War II. After the ...

Flight 583. At that point, the balloon was 1,490 km (925 miles) northeast of

San Juan, Puerto Rico San Juan ( , ; Spanish for "Saint John the Baptist, John") is the capital city and most populous Municipalities of Puerto Rico, municipality in the Commonwealth (U.S. insular area), Commonwealth of Puerto Rico, an unincorporated territory of the ...

. ''Light Heart'' continued to drift southwards out of the main transatlantic airways, far south of Gatch's plotted course. No further radio transmissions were received from ''Light Heart''. The

Liberia Liberia, officially the Republic of Liberia, is a country on the West African coast. It is bordered by Sierra Leone to Liberia–Sierra Leone border, its northwest, Guinea to Guinea–Liberia border, its north, Ivory Coast to Ivory Coast–Lib ...

n freighter ''Ore Meridian'' reported sighting the balloon just after dawn on 21 February. At that point, the balloon was at an altitude of about 305 m (1000 ft), approximately 1,610 km (1,000 miles) west of the

Canary Islands The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...

and drifting towards Africa. According to this report, eight of the ten balloons remained inflated. The gondola was designed to float in the event of a water landing and to be radar reflective. Notwithstanding this (or conjectures that the balloon might have landed in the

Spanish Sahara Spanish Sahara (; ), officially the Spanish Possessions in the Sahara from 1884 to 1958, then Province of the Sahara between 1958 and 1976, was the name used for the modern territory of Western Sahara when it was occupied and ruled by Spain bet ...

) no confirmed trace of ''Light Heart'' or Gatch was ever found, after the ''Ore Meridians reported sighting on 21 February. The

US Department of Defense The United States Department of Defense (DoD, USDOD, or DOD) is an executive department of the U.S. federal government charged with coordinating and supervising the six U.S. armed services: the Army, Navy, Marines, Air Force, Space Force, ...

and the

Spanish Army The Spanish Army () is the terrestrial army of the Spanish Armed Forces responsible for land-based military operations. It is one of the oldest Standing army, active armies – dating back to the late 15th century. The Spanish Army has existed ...

conducted extensive search operations both at sea off

West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...

and in the

. Search operations were called off in mid-March 1974.

References

{{Reflist 1970s missing person cases Aviation accidents and incidents in 1974 Aviation accidents and incidents in the Atlantic Ocean Individual balloons (aircraft) Missing aircraft People lost at sea Transatlantic flight Aircraft first flown in 1974 Aircraft flown once

Balloon design

Flight plan

Flight and disappearance

See also

References