Question: What company had an aviation business arrangement where two or more airlines share the same flight on flight LH2420

Context articles: Luxair Flight 9642
Partnership taxation in the United States
Capital Airlines Flight 67
Codeshare agreement
Northwest Airlines Flight 253
Aloha Airlines Flight 243
1985 in aviation
Ukrainian Aviation Group
Regis de Ramel
AMR Corporation

Luxair Flight 9642 was a scheduled international passenger flight flying from Berlin Tempelhof Airport, Germany, to Luxembourg Findel Airport, Luxembourg.
 The flight carried 19 passengers and 3 crew members.
 The flight was operated by Luxair, the flag carrier (national airline) of Luxembourg.
 The plane was a Fokker 50 and registered as LX-LGB.
 Lufthansa had a codeshare on the flight as LH2420.
 On 6 November 2002, the flight crashed while on final approach to Luxembourg Findel Airport about 6 nautical miles (11 km) short of the runway while trying to land in fog.
 20 out of the 22 passengers and crew perished
The rules governing partnership taxation, for purposes of the U.S. Federal income tax, are codified according to Subchapter K of Chapter 1 of the U.S. Internal Revenue Code (Title 26 of the United States Code).
 Partnerships are "flow-through" entities.
 Flow-through taxation means that the entity does not pay taxes on its income.
 Instead, the owners of the entity pay tax on their "distributive share" of the entity's taxable income, even if no funds are distributed by the partnership to the owners.
 Federal tax law permits the owners of the entity to agree how the income of the entity will be allocated among them, but requires that this allocation reflect the economic reality of their business arrangement, as tested under complicated rules.
Capital Airlines Flight 67 was domestic scheduled passenger flight operated by Capital Airlines that crashed on final approach to Freeland, Michigan, USA, during a severe snowstorm on April 6, 1958.
 The flight was en route from Flint-Bishop Airport to the Freeland-Tri City Airport (now MBS International Airport) when it crashed.
 Flight 67 was the first of four fatal crashes in the space of two years involving Capital Airlines Vickers Viscounts; the others were Capital Airlines Flight 300 (May 1958), Capital Airlines Flight 75 (May 1959) and Capital Airlines Flight 20 (January 1960).
A codeshare agreement, also known as codeshare, is an aviation business arrangement where two or more airlines share the same flight.
 Sharing, in this sense, means that each airline publishes and markets the flight under its own airline designator and flight number as part of its published timetable or schedule.
Northwest Airlines Flight 253 was an international passenger flight from Amsterdam Airport Schiphol in Haarlemmermeer, Netherlands, to Detroit Metropolitan Wayne County Airport in Romulus, Michigan, United States.
 The flight was the target of a failed al-Qaeda bombing attempt on Christmas Day, December 25, 2009, in which a passenger tried to set off plastic explosives sewn to his underwear.
 There were 290 people on board the aircraft—an Airbus A330-323E operated by Northwest Airlines, which had merged with Delta Air Lines the year before.
 Had the attempt succeeded, it would have surpassed American Airlines Flight 191 as the deadliest aviation occurrence on U.S. soil and tied Iran Air Flight 655 as the eighth-deadliest of all time.
 The incident was also the second in 2009 involving an Airbus A330, after the crash of Air France Flight 447 on June 1.
 This was also the final accident/incident involving Northwest Airlines as it closed down a month later when it merged with Delta Air Lines.
Aloha Airlines Flight 243 (AQ 243, AAH 243) was a scheduled Aloha Airlines flight between Hilo and Honolulu in Hawaii.
 On April 28, 1988, a Boeing 737-297 serving the flight suffered extensive damage after an explosive decompression in flight, but was able to land safely at Kahului Airport on Maui.
 There was one fatality, flight attendant Clarabelle "C.B." Lansing, who was ejected from the airplane.
 Another 65 passengers and crew were injured.
 The safe landing of the aircraft despite the substantial damage inflicted by the decompression established Aloha Airlines Flight 243 as a significant event in the history of aviation, with far-reaching effects on aviation safety policies and procedures.
This is a list of aviation-related events from 1985.
 It remains one of the deadliest years in aviation history for aviation disasters, including the crash of Japan Airlines Flight 123, bombing of Air India Flight 182, crash of Arrow Air Flight 1285, crash of Aeroflot Flight 7425, crash of Iberia Airlines Flight 610, Delta Air Lines Flight 191, Galaxy Airlines Flight 203, and British Airtours Flight 28M, a mid-air collision between Aeroflot Flight 8381 and a Soviet Air Forces transport aircraft, the hijacking of Egyptair Flight 648, and various crashes and other incidents with under 50 fatalities.
 August 1985 remains the worst single month for commercial aviation fatalities in history.
The Ukrainian Aviation Group was a Ukrainian informal monopoly alliance of three airlines owned by Privat Group and led by Ihor Kolomoyskyi.
 The group was founded in 2007 by combining Dniproavia, Aerosvit and Donbassaero; these airlines often provide each other with the opportunity to use each other's aircraft, with flights more than often being operated for Aerosvit (the alliance's largest carrier).
 When Privat Group acquired Ukraine's largest airline Ukraine International Airlines in February 2011 Privat Group had a near monopoly on the aviation business in Ukraine.
Regis Antonin de Ramel (born August 20, 1974) is an aviation business owner and philanthropist.
 He is the owner of an aircraft management, maintenance, charter and flight training services company with locations in Wilmington, Delaware (ILG); Blue Bell, Pennsylvania (LOM); and Lancaster, Pennsylvania (LNS).
 He also owns an air taxi operation servicing the mid-Atlantic and Northeast United States.
 All four are marketed under the unifying brand of flyADVANCED.
AMR Corporation was a commercial aviation business and airline holding company based in Fort Worth, Texas, which was the parent company of American Airlines, American Eagle Airlines, AmericanConnection and Executive Airlines.
 AMR filed for Chapter 11 bankruptcy in November 2011, and merged with US Airways Group on December 9, 2013 to form American Airlines Group, Inc.