Editing Lockheed A-12 (section)

==Operational history==
[[File:LockheedA-12-pilots.jpg|thumb|A-12 pilots and managers: from left to right, Ronald J. "Jack" Layton, Dennis B. Sullivan, Mele Vojvodich Jr, Barrett, Jack W. Weeks, Kenneth B. Collins, Ray, Brig Gen Ledford, Skliar, Perkins, Holbury, Kelly, and squadron commander Col. Slater.]]

Although originally designed to succeed the U-2 overflying the [[Soviet Union]] and [[Cuba]], the A-12 was never used for either objective. After [[1960 U-2 incident|a U-2 was shot down in May 1960]], the Soviet Union was considered too dangerous to overfly except in an emergency (and overflights were no longer necessary,<ref>{{harvnb|McIninch|1996|p=19}}</ref> thanks to [[reconnaissance satellite]]s) and, although crews trained for flights over Cuba, U-2s continued to be adequate there.<ref>{{harvnb|McIninch|1996|p=20}}</ref>

The Director of the CIA decided to deploy some A-12s to Asia. The first A-12 arrived at [[Kadena Air Base]] on [[Okinawa Island|Okinawa]] on 22 May 1967. With the arrival of two more aircraft on 24 May, and 27 May this unit was declared to be operational on 30 May, and it began '''Operation Black Shield'''<!-- BOLDED because a redirect leads here --> on 31 May.<ref>{{harvnb|McIninch|1996|pp=25, 27}}</ref>  [[Mele "Mel" Vojvodich|Mel Vojvodich]] flew the first Black Shield operation, over [[North Vietnam]], photographing [[surface-to-air missile]] (SAM) sites, flying at {{convert|80000|ft|m|abbr=on}}, and at about Mach 3.1. During 1967, the A-12s carried out 22 sorties in support of the [[Vietnam War]] from Kadena Air Base. During 1968 further Black Shield operations were conducted in Vietnam. Additional sorties were carried out during the [[USS Pueblo (AGER-2)|Pueblo Crisis]] with [[North Korea]].{{sfn|McIninch|1996}}

===Mission profile===
Operations and maintenance at Kadena AB began with the receipt of an alert notification. Both a primary aircraft and pilot and a back-up aircraft and pilot were selected. The aircraft were given thorough inspection and servicing, all systems were checked, and the cameras equipped. Pilots received a detailed route briefing in the early evening prior to the day of flight. On the morning of the flight a final briefing occurred, at which time the condition of the aircraft and its systems was reported, last-minute weather forecasts reviewed, and other relevant intelligence communicated, together with any amendments or changes in the flight plan. Two hours prior to take-off the primary pilot had a medical examination, got into his suit, and was taken to the aircraft. If any malfunctions developed on the primary aircraft, the back-up could execute the mission one hour later.

A typical route profile for a mission over North Vietnam included a refueling shortly after take-off, south of Okinawa, the planned photographic pass or passes, withdrawal to a second aerial refueling in the [[Thailand]] area, and return to Kadena. Its turning radius of {{convert|86|miles|km}} was such, however, that on some mission profiles it might intrude into [[China|Chinese]] airspace during the turn.

Once landed, the camera film was removed from the aircraft, boxed, and sent by special aircraft to the processing facilities. Film from earlier missions was developed at the [[Eastman Kodak]] plant in [[Rochester, New York|Rochester]], [[New York (state)|New York]]. Later an Air Force Center in [[Japan]] carried out the processing in order to place the photointelligence in the hands of American commanders in Vietnam within 24 hours of completion of a mission.{{sfn|McIninch|1996}}

===SAM evasion over North Vietnam===
There were a number of reasons leading to the retirement of the A-12, but one major concern was the growing sophistication of Soviet-supplied surface-to-air missile (SAM) sites that it had to contend with over mission routes. In 1967, the vehicle was tracked with acquisition radar over North Vietnam, but the SAM site was unsuccessful with the [[Fan Song]] guidance radar used to home the missile to the target.<ref>{{cite journal |last=Kopp |first=Dr Carlo |title=SNR-75 Fan Song E Engagement Radar / Станция Наведения Ракет СНР-75 Fan Song E |pages=1 |url=http://www.ausairpower.net/APA-SNR-75-Fan-Song.html |publisher=Air Power Australia |date= April 2012 }}</ref> On 28 October, a North Vietnamese SAM site launched a single, albeit unsuccessful, missile. Photography from this mission documented the event with photographs of missile smoke above the SAM firing site, and with pictures of the missile and of its [[contrail]]. [[Electronic countermeasure]]s equipment appeared to perform well against the missile firing.

During a flight on 30 October 1967, pilot Dennis Sullivan detected radar tracking on his first pass over North Vietnam. Two sites prepared to launch missiles but neither did. During the second pass, at least six missiles were fired, each confirmed by missile vapor trails on mission photography. Looking through his rear-view periscope, Sullivan saw six missile contrails climb to about {{convert|90000|ft|m|abbr=on}} before converging on his aircraft. He noted the approach of four missiles, and although they all detonated behind him, one came within {{convert|100|to|200|m|ft|-2|abbr=on|order=flip}} of his aircraft.<ref>{{cite web|title=Pieces of History: Missile Debris from A-12 OXCART|url=https://www.cia.gov/news-information/featured-story-archive/2013-featured-story-archive/pieces-of-history-missile-debris-from-a-12-oxcart.html|archive-url=https://web.archive.org/web/20131028044550/https://www.cia.gov/news-information/featured-story-archive/2013-featured-story-archive/pieces-of-history-missile-debris-from-a-12-oxcart.html|url-status=dead|archive-date=28 October 2013|publisher=Central Intelligence Agency|access-date=2 April 2014}}</ref> Post-flight inspection revealed that a piece of metal had penetrated the lower right wing fillet area and lodged against the support structure of the wing tank. The fragment was not a warhead pellet but may have been a part of the debris from one of the missile detonations observed by the pilot.{{sfn|McIninch|1996}}

The final Black Shield mission over North Vietnam and the [[Demilitarized zone|Demilitarized Zone]] (DMZ) was flown on 8 March 1968. Good quality photography was obtained of [[Khe Sanh Combat Base|Khe Sanh]] and the [[Laos]], [[Cambodia]], and [[South Vietnam]]ese border areas. No usable photography was obtained of North Vietnam due to adverse weather conditions. There was no indication of a hostile weapons reaction and no ECM systems were activated.<ref>{{cite web|title=Black Shield Reconnaissance Missions 1 January – 31 March 1968|url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472531.pdf|publisher=Central Intelligence Agency Document Number 0001472531 page 16|access-date=5 April 2014|archive-date=11 February 2013|archive-url=https://web.archive.org/web/20130211185411/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472531.pdf|url-status=dead}}</ref>{{primary source inline|date=November 2023}}

===Final missions over North Korea===
In 1968, three missions were flown over North Korea. The first mission occurred during a very tense period following seizure of the Navy intelligence ship [[USS Pueblo (AGER-2)|''Pueblo'']] on 23 January. The aim was to discover whether the North Koreans were preparing any large scale hostile move following this incident and to actually find where the ''Pueblo'' was hidden. The ship was found anchored in an inlet in [[Wonsan|Wonsan Bay]] attended by two North Korean patrol boats and guarded by three [[Komar class missile boat]]s.<ref>{{cite web|title=Preliminary Assessment of Black Shield Mission 6847 Over North Korea|url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001474986.pdf|publisher=Central Intelligence Agency Document Number: 0001474986|access-date=4 April 2014|archive-date=17 July 2013|archive-url=https://web.archive.org/web/20130717095625/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001474986.pdf|url-status=dead}}</ref> Chinese tracking of the flight was apparent, but no missiles were fired at the Oxcart.{{sfn|McIninch|1996}}

The second mission on 19 February 1968, was also the first two-pass mission over North Korea. The Oxcart vehicle photographed 84 primary targets plus 89 bonus targets. Scattered clouds covered 20 percent of the area, concealing the area in which the USS ''Pueblo'' was photographed on the previous mission. One new SA-2 site was identified near Wonsan.<ref>{{cite web |title=Black Shield Reconnaissance Missions 1 January – 31 March 1968 |url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472531.pdf |publisher=Central Intelligence Agency Document Number 0001472531 Page 14 |access-date=5 April 2014 |archive-date=11 February 2013 |archive-url=https://web.archive.org/web/20130211185411/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472531.pdf |url-status=dead }}</ref>

===Retirement===
[[File:A12instorage.jpg|thumb|A-12s in storage at Palmdale, note the spurious USAF markings and serial numbers]]

Even before the A-12 became operational, its intended purpose of replacing the U-2 in overflights of the Soviet Union had become less likely. Soviet radar systems increased their [[blip-to-scan ratio]]s, which rendered the A-12 vulnerable.<ref>[http://www.gwu.edu/~nsarchiv/NSAEBB/NSAEBB434/docs/U2%20-%20Chapter%206.pdf "The Oxcart Story"]. CIA, p. 267</ref> In any event, [[John F. Kennedy|President Kennedy]] had stated publicly that the United States would not resume such missions. By 1965, moreover, the [[Reconnaissance satellite|photoreconnaissance satellite]] programs had progressed to the point that crewed flights over the Soviet Union were unnecessary to collect strategic intelligence.<ref name="Robarge 2012 31–38"/>

The A-12 program was ended on 28 December 1966<ref>{{harvnb|McIninch|1996|p=31}}</ref> – even before Black Shield began in 1967 – due to budget concerns<ref name="Robarge 2012 41–44">{{harvnb|Robarge|2012|pp=41–44}}</ref> and because of the SR-71, which began to arrive at Kadena in March 1968.<ref>{{cite web|title=OXCART/SR-71 Information for EXCOM Meeting|url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472041.pdf|publisher=Central Intelligence Agency Document Number: 0001472041|access-date=4 April 2014|archive-date=17 July 2013|archive-url=https://web.archive.org/web/20130717095030/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472041.pdf|url-status=dead}}</ref> The twin-seat SR-71 was heavier and flew slightly lower and slower than the A-12.<ref name="Robarge 2012 41–44"/>

Ronald L. Layton flew the 29th and final A-12 mission on 8 May 1968, over North Korea.<ref>{{cite web|title=Critique for Oxcart Mission Number BX6858|url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001474970.pdf|publisher=Central Intelligence Agency Document Number 0001472531|access-date=5 April 2014|archive-date=17 July 2013|archive-url=https://web.archive.org/web/20130717095849/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001474970.pdf|url-status=dead}}</ref> On 4 June 1968, just {{frac|2|1|2}} weeks before the fleet's retirement, an A-12 from Kadena, piloted by Jack Weeks, was lost over the Pacific Ocean near the Philippines while conducting a functional check flight after the replacement of one of its engines.<ref name="Robarge 2012 41–44"/><ref>{{harvnb|McIninch|1996|p=33}}</ref> Frank Murray made the final A-12 flight on 21 June 1968, to [[Palmdale, California]], storage facility.<ref name="Robarge 2012 42">{{harvnb|Robarge|2012|p=42}}</ref>

On 26 June 1968, Vice Admiral Rufus L. Taylor, the deputy director of Central Intelligence, presented the CIA [[Intelligence Star]] for valor to Weeks' widow and pilots Collins, Layton, Murray, Vojvodich, and Dennis B. Sullivan for participation in Black Shield.<ref name="Robarge 2012 41–44"/><ref>{{harvnb|McIninch|1996|p=34}}</ref><ref>Hayden, General Michael V. [https://web.archive.org/web/20080109060125/https://www.cia.gov/news-information/speeches-testimony/2007/a12-presentation-ceremony.html "General Hayden's Remarks at A-12 Presentation Ceremony."] ''Central Intelligence Agency'', Remarks of Director of the Central Intelligence Agency at the A-12 Presentation Ceremony, 19 September 2007. Retrieved: 10 April 2009.</ref>

The deployed A-12s and the eight non-deployed aircraft were placed in storage at Palmdale. All surviving aircraft remained there for nearly 20 years before being sent to museums around the U.S. On 20 January 2007, despite protests by Minnesota's legislature and volunteers who had maintained it in display condition, the A-12 preserved in Minneapolis, Minnesota, was sent to CIA headquarters to be displayed there.<ref>Karp, Jonathan. [http://www.post-gazette.com/pg/07026/757100-51.stm "Stealthy Maneuver: The CIA Captures An A-12 Blackbird".] ''The Wall Street Journal'', A1, 26 January 2007. Retrieved: 10 April 2009.</ref>

=== A-12 aircraft summary ===
{| class=wikitable style="align: right; text-align: left; font-size:100%; color:black"
|-
!Serial number!!Article!!Model!!Flights!!Hours!!Fate
|-
|60-6924|| 121 || A-12 || 322 || 418.2 || On display at the Air Force Flight Test Center Museum Annex, ''Blackbird Airpark'', at [[Plant 42]], [[Palmdale, California]]
|-
|60-6925|| 122 || A-12 || 161 || 177.9 || On display at the [[Intrepid Sea-Air-Space Museum]], parked on the [[flight deck|deck]] of the [[aircraft carrier]] {{USS|Intrepid|CV-11|6}}, New York City
|-
|60-6926|| 123 || A-12 || 79 || 135.3 || Lost 1963
|-
|60-6927|| 124 || A-12 trainer || 614 || 1076.4 || On display at the [[California Science Center]] in Los Angeles, California<ref>{{cite web |url=http://www.californiasciencecenter.org/Exhibits/AirAndSpace/AirAndAircraft/A12/A12.php |title=A-12 Blackbird|publisher=California Science Center |access-date=9 October 2013 |location=Los Angeles, CA|archive-date=2 March 2013 |archive-url=https://web.archive.org/web/20130302102326/http://www.californiasciencecenter.org/Exhibits/AirAndSpace/AirAndAircraft/A12/A12.php |url-status=dead}}</ref>
|-
|60-6928|| 125 || A-12 || 202 || 334.9 || Lost 1967
|-
|60-6929|| 126 || A-12 || 105 || 169.2 || Lost 1965
|-
|60-6930|| 127 || A-12 || 258 || 499.2 || On display at the [[US Space and Rocket Center|U.S. Space and Rocket Center]], [[Huntsville, Alabama]]
|-
|60-6931|| 128 || A-12 || 232 || 453.0 || On display at the [[George Bush Center for Intelligence]], [[Langley, Virginia]]{{efn|group=N|60-6931 ("Article 128") was unveiled on Wednesday, 19 September 2007, at CIA Headquarters in Langley, Virginia. On hand was Ken Collins, a retired Air Force Colonel, one of only six pilots to have flown the A-12s.}}
|-
|60-6932|| 129 || A-12 || 268 || 409.9 || Lost 1968
|-
|60-6933|| 130 || A-12 || 217 || 406.3 || On display at the [[San Diego Air & Space Museum]], Balboa Park, [[San Diego]], California
|-
|60-6937|| 131 || A-12 || 177 || 345.8 || On display at the [[Southern Museum of Flight]], [[Birmingham, Alabama]]
|-
|60-6938|| 132 || A-12 || 197 || 369.9 || On display at [[Battleship Memorial Park]] ([[USS Alabama (BB-60)#Museum ship|USS ''Alabama'']]), [[Mobile, Alabama]]
|-
|60-6939|| 133 || A-12 || 10 || 8.3 || Lost 1964, crashed on approach to Groom Dry Lake due to hydraulic system failure
|-
|60-6940 || 134 || M-21 || 80 || 123.9 || On display at the [[Museum of Flight]], [[Seattle]], Washington
|-
|60-6941 || 135 || M-21 || 95 || 152.7 || Lost 1966
|-  style="border-top: 2px solid black;" 
|colspan="3"| Total for all aircraft<ref name="crickmore236" />|| 3017 || 5080.9 || 9 on display, 6 lost
|}

===Timeline===
Major events in the development and operation of the A-12 and its successor, the SR-71, include:
* 16 August 1956: Following Soviet protests about U-2 overflights, [[Richard M. Bissell Jr.]] conducts the first meeting on reducing the [[Radar cross-section|radar cross section]] of the U-2. This evolves into [[Project Rainbow]], a bid to prolong the aircraft's operational life through a package of modifications. Called "Trapeze", these added wires and paints impregnated with tiny [[Allotropes of iron|iron ferrite]] beads and [[Electronic countermeasure|ECM]] systems. The modified U-2s were called "Dirty Birds". Ultimately, the program failed to substantially reduce the U-2's RCS, leading to the decision to develop a new aircraft with [[Stealth aircraft|stealth]] characteristics.<ref>{{cite book|last=Brugioni|first=Dino A.|editor-last=Taylor|editor-first=Doris G.|title=Eyes in the sky : Eisenhower, the CIA, and Cold War aerial espionage|year=2010|publisher=Naval Institute Press|location=Annapolis, Md.|isbn=978-1591140825|page=196|url=https://books.google.com/books?id=TCFl1zdYf0oC&pg=PA196|edition=[Online-Ausg.].}}</ref>
* December 1957: Lockheed begins designing subsonic stealthy aircraft under what will become [[Convair Kingfish#Project Gusto|Project Gusto]].
* 24 December 1957: First J-58 engine run.
* 21 April 1958: Kelly Johnson makes first notes on a Mach-3 aircraft, initially called the U-3, but eventually evolving into Archangel I. Kelly noted in his A-12 diary, "I drew up the first Archangel proposal for a Mach&nbsp;3.0 cruise airplane having a {{cvt|4000|nmi|mi km|disp=sqbr}} range at {{convert|90000|to|95,000|ft|m|abbr=on|disp=sqbr|sp=us}}".<ref>{{cite book|last=Crickmore|first=Paul F.|url=https://books.google.com/books?id=8QSGDAAAQBAJ|title=Lockheed Blackbird : beyond the secret missions|publisher=Osprey|year=2004|isbn=1841766941|edition=Rev.|location=Oxford|page=26}}</ref>
* November 1958: The Land panel provisionally selects Convair [[Convair Kingfish#FISH|FISH]] (B-58-launched parasite) over Lockheed's A-3. The A-3 was an unstaged (non-parasite) aircraft that cruised at Mach&nbsp;3.2 at {{convert|95000|ft|m|abbr=on|sp=us}}. The Land Panel favored Convair's design, which had a smaller radar cross section than the A-3. On 22 December, Convair was instructed to continue FISH's development and to plan for production. While Convair struggled with aerodynamic issues, Lockheed pursued its own efforts on high-speed, high-altitude reconnaissance designs, evolving from A-4 through A-11. The first three configurations, A-4 through A-6, were smaller, self-launched aircraft with vertical surfaces hidden above the wing. The aircraft used a variety of propulsion schemes that included [[turbojet]]s, [[ramjet]]s, and [[Rocket engine|rockets]]. None met the required mission radius of {{convert|2000|nmi|mi km|abbr=on}}, leading Lockheed to conclude that maximum performance and low radar cross section were mutually exclusive. The A-10 and A-11 configurations were larger aircraft that also focused on performance at the expense of radar cross section. Lockheed submitted the more refined A-11 at the next Land Panel review.<ref>{{cite web|last=Hehs|first=Eric|title=Code One Magazine: Super Hustler, FISH, Kingfish, And Beyond (Part 2: FISH)|url=http://www.codeonemagazine.com/article.html?item_id=74|publisher=Lockheed Martin Aeronautics Company}}</ref>
* June 1959: The Land panel provisionally selects the A-11 over FISH, instructing both companies to re-design their aircraft. In July, the Land panel rejected both the Convair and Lockheed proposals. The Convair FISH used unproven [[ramjet]] engine technology and would be launched from a modified [[Convair B-58 Hustler|B-58B Hustler]] which was canceled in June. The susceptibility of the A-11 to radar detection was considered too great. On 20 August, both firms provided specifications for their revised proposals.<ref>{{cite book|last=Richelson|first=Jeffrey T.|title=The wizards of Langley : inside the CIA's Directorate of Science and Technology|year=2002|publisher=Westview Press|location=Boulder, Colo.|isbn=0813340594|page=[https://archive.org/details/wizardsoflangley00rich/page/21 21]|url=https://archive.org/details/wizardsoflangley00rich|url-access=registration}}</ref>
[[File:A-12 Nose View.jpg|thumb|Head-on view of an A-12 on the deck of the [[Intrepid Sea-Air-Space Museum]], illustrating the [[Chine (aeronautics)|chines]] ]]
* 14 September 1959: CIA awards antiradar study, aerodynamic structural tests, and engineering designs, selecting the A-12 over rival Convair's [[Convair Kingfish|Kingfish]]. Project ''Oxcart'' established. The A-12 design, a combination of their A-7 and A-11 submissions, emphasized low radar cross section, extremely high altitude and high-speed performance. Earlier, on 3 September, Project GUSTO was concluded and Project OXCART, to build the A-12, was begun.<ref>{{cite book|last=III|first=L. Parker Temple|title=Shades of gray : national security and the evolution of space reconnaissance|year=2004|publisher=American Institute of Aeronautics and Astronautics|location=Reston, Va.|isbn=1563477238|page=112|url=https://books.google.com/books?id=3I8Xki-NiKMC&pg=PA112}}</ref>
* 26 January 1960: The CIA formally placed an order for 12 A-12 aircraft.
* 1 May 1960: [[Francis Gary Powers]] is [[1960 U-2 incident|shot down in a U-2]] over the Soviet Union. He safely ejected and was turned over to Soviet authorities. A well-publicized trial followed and he was sentenced to 10 years "deprivation of liberty," serving three years in prison before being exchanged in 1962 for Soviet spy [[Vilyam Genrikhovich Fisher|Rudolf Abel]]. Upon return he was debriefed extensively.<ref>{{cite web|title=CIA, Debriefing of Francis Gary Powers, February 13, 1962, Top Secret, 31 pp|url=http://www2.gwu.edu/~nsarchiv/NSAEBB/NSAEBB74/U2-10.pdf|publisher=Central Intelligence Agency National Archives}}</ref>
[[File:A-12 Schalk Flight, 1962.jpg|thumb|right|A-12 piloted by Louis Schalk takes off from Groom Lake in 1962.]]
*26 April 1962: First flight of A-12 with Lockheed test pilot Louis Schalk at Groom Lake. The previous day, it had made an unofficial and unannounced flight, in keeping with Lockheed tradition. Schalk flew the aircraft less than two miles (three km), at an altitude of about {{cvt|20|ft|m|0|spell=on|sp=us}}, because of serious wobbling caused by improper hookup of some navigational controls. Instead of circling around and landing, Schalk landed in the lake bed beyond the end of the runway. The next day, the official flight took place with the landing gear down, just in case. The flight lasted about 40 minutes. The takeoff was perfect, but after the A-12 got to about {{cvt|300|ft|m|sigfig=1}} it started shedding all the "pie slice" fillets of titanium on the left side of the aircraft and one fillet on the right. (On later aircraft, those pieces were paired with triangular inserts made of radar-absorbing composite material.) Technicians spent four days finding and reattaching the pieces. Nonetheless, the flight pleased Johnson.<ref name="Robarge 2012 11–17">{{harvnb|Robarge|2012|pp=11–17}}</ref><ref>{{cite web|title=First flight of the A-12 at Groom Lake narrated by its pilot, Lockheed test pilot Lou Schalk| date=August 2010 |url=https://www.youtube.com/watch?v=7diDWBrTjr0| archive-url=https://ghostarchive.org/varchive/youtube/20211117/7diDWBrTjr0| archive-date=2021-11-17 |url-status=live|publisher=Nevada Aerospace Hall of Fame on YouTube}}{{cbignore}}</ref>
* 13 June 1962: SR-71 mock-up reviewed by USAF.
* 30 July 1962: J58 engine completes pre-flight testing.
* October 1962: A-12s first flown with J58 engines
* 28 December 1962: Lockheed signs contract to build six SR-71 aircraft. Earlier in the month, on 17 December the 5th A-12 arrived at Groom Lake and the Air Force expressed an interest in obtaining reconnaissance versions of the Blackbird. Lockheed begins weapons systems development for the [[Lockheed YF-12|AF-12]]. Kelly Johnson obtained approval to design a Mach&nbsp;3 Blackbird fighter/bomber.<ref>{{cite web|last=Hildebrant|first=Don|title=Timeline of the SR-71|url=http://roadrunnersinternationale.com/sr-71timeline.pdf|publisher=(Page 7) Roadrunners Internationale Declassified U-2 A-12 Projects Aquatone OXCART Area 51}}</ref>
* January 1963: A-12 fleet operating with J58 engines
* 24 May 1963: Loss of first A-12 (#60-6926)
* 20 July 1963: First Mach 3 flight tracked by MSQ 39 Radar on an RBS Train stationed at the Army Depot at McAlester, OK. The A-12 flew above 83,000 feet, at 2,250 MPH ground speed.{{citation needed|date=September 2022}}
* 7 August 1963: First flight of the YF-12A with Lockheed test pilot James Eastham at Groom Lake.
* June 1964: Last production A-12 delivered to Groom Lake.
* 25 July 1964: President Johnson makes public announcement of SR-71.
* 29 October 1964: SR-71 prototype (#61-7950) delivered to Palmdale.
* 22 December 1964: First flight of the SR-71 with Lockheed test pilot Bob Gilliland at AF&nbsp;Plant&nbsp;#42. First mated flight of the MD-21 with Lockheed test pilot Bill Park at Groom Lake.
* 28 December 1966: Decision to terminate A-12 program by June 1968.
* 31 May 1967: A-12s conduct Black Shield operations out of Kadena
* 3 November 1967: A-12 and SR-71 conducted a reconnaissance fly-off, codenamed NICE GIRL. Between 20 October and 3 November 1967, A-12s and SR-71s flew three identical routes along the [[Mississippi River]] about one hour apart with their collection systems on. The results were inconclusive. The A-12's camera had a wider swath but the SR-71 collected types of intelligence the A-12 could not of a good quality; however, some sensors would typically be removed to make room for [[Electronic countermeasure|ECM]] gear.<ref>{{harvnb|Robarge|2012|p=52}}</ref> There was little difference in range – the SR-71 carried more fuel – the A-12 had an altitude advantage of from {{cvt|2000|to|5000|ft|m|-2}} over the SR-71 at the same [[Mach number]], being a lighter aircraft. The radar cross section of both aircraft in a clean configuration was relatively low; the SR-71 in a full sensor configuration was somewhat higher due to its larger size and was appreciably larger again with the [[Side looking airborne radar|side-looking radar]] antenna installed.<ref>{{cite web|title=Comparison of SR-71 to A-12 Aircraft|url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001471952.pdf|publisher=Central Intelligence Agency Document Number 0001471952|access-date=15 April 2014|archive-date=20 February 2015|archive-url=https://web.archive.org/web/20150220190055/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001471952.pdf|url-status=dead}}</ref> The A-12 was designed to optionally utilize one of three different types of high resolution cameras; the highest of which provided a {{cvt|63|nmi|mi km}} wide continuous swath of {{convert|1|foot|m|spell=in|frac=3}} resolution. The SR-71 had the simultaneous capability for photography and [[ELINT#Electronic signals intelligence|ELINT]]. Its imagery was one foot resolution of two separate {{convert|5|mile|km|spell=in|abbr=out|adj=on}} swath wide strips positioned up to {{cvt|19.6|mi|km}} apart on either side of the aircraft.<ref>{{cite web|title=Comparison of the Capabilities, Performance, Countermeasures Systems and Operational Status of the A-12 and SR-71|url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472042.pdf|publisher=Central Intelligence Agency Document Number 0001472042|access-date=15 April 2014|archive-date=16 April 2014|archive-url=https://web.archive.org/web/20140416174201/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0001472042.pdf|url-status=dead}}</ref>
* 26 January 1968: North Korea A-12 overflight by Jack Weeks photo-locates the captured [[USS Pueblo (AGER-2)|USS ''Pueblo'']] in Changjahwan Bay harbor.<ref>Jacobsen 2011, p.&nbsp;273.</ref>
* 5 February 1968: Lockheed ordered to destroy A-12, YF-12 and SR-71 tooling.
* 8 March 1968: First SR-71A (#61-7978) arrives at Kadena AB to replace A-12s.
* 21 March 1968: First SR-71 (#61-7976) operational mission flown from Kadena&nbsp;AB over Vietnam.
* 8 May 1968: Jack Layton flies last operational A-12 sortie, over North Korea.
* 5 June 1968: Loss of last A-12 (#60-6932) during Functional Checkout Flight (FCF) flown from [[Kadena Air Base|Kadena]], Jack W. Weeks became the second and last CIA pilot killed in the line of duty during ''Oxcart'' and is so honored in the [[CIA Memorial Wall|"Book of Honor"]] at [[George Bush Center for Intelligence|CIA Headquarters]]. The A-12 had a [[Telemetry|radio telemetry]] system called "Birdwatcher", monitoring the most critical aircraft systems and transmitting data to ground monitoring stations. Following [[aerial refueling]], the ground station was informed via "Birdwatcher" that the starboard engine exhaust gas temperature was in excess of {{convert|1580|F|C|abbr=on}}, the fuel flow on that engine was less than {{convert|7500|lb|kg|abbr=on}} per hour and that the aircraft was below {{cvt|68500|ft|m}}. Several attempts to make contact were made without success. Monitoring continued until the time that the aircraft's fuel would have been depleted. The aircraft was declared missing {{cvt|520|miles|km}} east of the Philippines and {{cvt|625|miles|km|-2}} south of [[Okinawa Prefecture|Okinawa]] in the [[South China Sea]]. The loss was due to an in-flight emergency. To maintain security the official news release identified the loss as an SR-71. An intense air and sea search was conducted but no wreckage of "Article&nbsp;129" was ever recovered. It was presumed totally destroyed at sea. The "Birdwatcher" system provided the only clues to what happened and was the basis for the accident report. It was ascertained that a malfunction involving an engine over-temperature and low fuel flow on the starboard engine had contributed to a catastrophic failure and subsequent aircraft break-up.<ref name="Robarge 2012 42"/><ref>{{cite web|title=CIA Pilot Jack Weeks remembered by family and members|url=http://roadrunnersinternationale.com/weeks.html|publisher=Roadrunners Internationale Declassified U-2 A-12 Projects Aquatone OXCART Area 51}}</ref><ref>{{cite web|title=Tribute to Jack W. Weeks, CIA A-12 Project Pilot for Operation Black Shield|url=http://roadrunnersinternationale.com/weeks_tribute.html|publisher=Roadrunners Internationale Declassified U-2 A-12 Projects Aquatone OXCART Area 51}}</ref>
* 21 June 1968: Final A-12 flight to Palmdale, California.

See [[Lockheed SR-71 Blackbird#Timeline|SR-71 timeline]] for later SR-71 events.