''Light Heart'' was a

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

constructed by

Colonel Colonel (abbreviated as Col., Col or COL) is a senior military 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 colonel was typically in charge of ...

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 oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

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 du ...

(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 el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...

balloons. Each of these was a

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

(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 (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...

, to somewhere in

Western Europe Western Europe is the western region of Europe. The region's countries and territories vary depending on context. The concept of "the West" appeared in Europe in juxtaposition to "the East" and originally applied to 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, meandering thermal wind, air currents in the Atmosphere of Earth, atmospheres of some planets, including Earth. On Earth, the main jet streams are located near the altitude of the tropopause and are west ...

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 capital and second-largest city of the U.S. state of Delaware. It is also the county seat of Kent County and the principal city of the Dover, DE, Metropolitan Statistical Area, which encompasses all of Kent County and is part of ...

, and

Atlantic City, New Jersey Atlantic City, often known by its initials A.C., is a coastal resort city in Atlantic County, New Jersey, United States. The city is known for its casinos, boardwalk, and beaches. In 2020, the city had a population of 38,497.

. 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 11,000,m (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 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 passi ...

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

San Juan San Juan, Spanish for Saint John, may refer to: Places Argentina * San Juan Province, Argentina * San Juan, Argentina, the capital of that province * San Juan, Salta, a village in Iruya, Salta Province * San Juan (Buenos Aires Underground), ...

, Puerto Rico. ''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 its north, Ivory Coast to its east, and the Atlantic Ocean ...

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 (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...

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 ( es, Sahara Español; ar, الصحراء الإسبانية, As-Sahrā'a Al-Isbānīyah), officially the Spanish Possessions in the Sahara from 1884 to 1958 then Province of the Sahara between 1958 and 1976, was the name used f ...

) 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 branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secu ...

and the

Spanish Army The Spanish Army ( es, Ejército de Tierra, lit=Land Army) is the terrestrial army of the Spanish Armed Forces responsible for land-based military operations. It is one of the oldest active armies — dating back to the late 15th century. The ...

conducted extensive search operations both at sea off

West Africa West Africa or Western Africa is the westernmost region of Africa. The United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Ghana, Guinea, Guinea-Bissau, Ivory Coast, Liberia, Mali, Maurit ...

and in the Spanish Sahara. 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

Balloon design

Flight plan

Flight and disappearance

See also

References