Editing Boeing B-47 Stratojet (section)

===Flight test phase===
The XB-47 prototype flew its first flight on 17 December 1947 (the anniversary of the [[Wright Brothers]]' first four flights on 17 December 1903), with test pilots Robert Robbins and Scott Osler at the controls. It lasted 27 minutes, flying from [[Boeing Field]] in [[Seattle]] to [[Grant County International Airport|Moses Lake Airfield]] in central [[Washington (state)|Washington state]].<ref name="Yenne p158">Yenne 2002, p. 158.</ref><ref name="Peacock AE p34">Peacock 1989, p. 34.</ref> While not experiencing major problems, the emergency hot wire system was needed to raise the flaps and the engine fire warning indicators falsely illuminated. Robbins stated that it had good flight characteristics.<ref name="Natola 1724">Natola 2002, pp. 17–24.</ref>

Robbins had been skeptical about the XB-47, saying that before his first flight he had prayed, "Oh God, please help me through the next two hours." Robbins soon realized that he had an extraordinary aircraft.<ref name="Natola 1724"/> [[Chuck Yeager]] also flew the XB-47, noting it was so aerodynamically clean that he had difficulty landing on the [[Edwards Air Force Base|Edwards lakebed]].<ref name="Yeager 177178">Yeager 1985, pp. 177–178.</ref> In February 1949, Russ Schleeh and Joe Howell "broke all coast-to-coast speed records" flying from [[Larson Air Force Base|Moses Lake AFB]] to [[Andrews Air Force Base|Andrews AFB]], averaging {{convert|607.8|mph|kn km/h}}.<ref name="Natola 3436">Natola 2002, pp. 34–36.</ref> During an early test flight, the canopy came off at high speed, killing pilot Scott Osler; the aircraft was safely landed by the copilot.<ref name="Flight Journal">Boyne, Walter J. "Flying the B-47: An inside look at the USAF's first jet bomber".''Flight Journal'', April 2002. Retrieved 31 March 2010.</ref> The accident resulted in a canopy redesign and the hiring of pilot [[Alvin M. Johnston|Tex Johnston]] as chief test pilot.<ref>Johnston 2000, p. 135.</ref>

The second XB-47 (46-066) prototype first flew on 21 July 1948 and, following its delivery to the USAF in December of that year, served as a flying test bed until 1954. Its final destination was [[Chanute Air Force Base|Chanute AFB]] where it was used as a maintenance and familiarization aircraft.<ref>{{Cite web |url=http://b-47.com |title=The B-47 Stratojet Association |website=The B-47 Stratojet Association |language=en-US |access-date=8 December 2016}}</ref> The second prototype was equipped with more powerful General Electric [[General Electric J47|J47-GE-3]] turbojets with {{convert|5200|lbf|kN|abbr=on|lk=in}} of static thrust each.<ref name="Yenne p165">Yenne 2002, p. 165.</ref><ref name=tjpwpwr>{{cite news |url=https://news.google.com/newspapers?id=XsxeAAAAIBAJ&sjid=szIMAAAAIBAJ&pg=6446%2C3174477 |work=Lewiston Morning Tribune |location=(Idaho) |agency=Associated Press |title=Boeing turbo-jet packed with power |date=October 9, 1949 |page=1}}</ref> The J47 or "TG-190" was a redesigned version of the TG-180/J35; the first prototype was later retrofitted with these engines.{{Citation needed|date=August 2019}}

Flight testing of the prototypes was careful and methodical since the design was new in so many ways. They initially suffered from "[[Dutch roll]]", an instability that caused it to weave in widening "S" turns, remedied by the addition of a "[[yaw damper]]" control system to automatically deflect the [[rudder]] to damp out the weaving motion. Wind tunnel tests had shown it would pitch up at maximum speed due to wing stall on the outboard section of the wing. This was confirmed during flight tests so small vanes called "[[vortex generator]]s" were added to prevent [[Flow separation|airflow separation]].<ref>The Road to the 707 The Inside Story of Designing the 707, William H. Cook 1991, {{ISBN|0 9629605 0 0}}, p.194-198</ref>

Both XB-47 prototypes were test flown at Edwards AFB; the first XB-47 (46-065) was disassembled and scrapped in 1954, making the second prototype (46-066) the sole surviving XB-47. Upon retirement, XB-47 (46-066) was restored and placed on display at the [[Octave Chanute Aerospace Museum]] in [[Rantoul, Illinois]], remaining there until the museum announced its closure due to financial difficulties in April 2015.<ref>{{Cite web |url=http://www.paxtonrecord.net/news/politics-and-government/2015-04-23/chanute-air-museum-closing-rantoul.html |title=Chanute Air Museum closing in Rantoul {{!}} Paxton Record |website=paxtonrecord.net |access-date=8 December 2016 |archive-date=31 October 2016 |archive-url=https://web.archive.org/web/20161031172922/http://www.paxtonrecord.net/news/politics-and-government/2015-04-23/chanute-air-museum-closing-rantoul.html |url-status=dead }}</ref> In late 2015, the Flight Test Historical Foundation<ref>{{Cite web |url=http://afftcmuseum.org/foundation/ |title=Flight Test Historical Foundation |access-date=8 December 2016 |archive-url=https://web.archive.org/web/20160911190328/http://afftcmuseum.org/foundation/ |archive-date=11 September 2016 |url-status=dead }}</ref> began fundraising to purchase XB-47 (46-066) for relocation to the [[Air Force Flight Test Museum|Flight Test Museum]] at Edwards AFB. The purchase was completed in August 2016 and on 21 September 2016 the aircraft arrived at Edwards AFB for reassembly, restoration and eventual display at the Flight Test Museum.<ref>{{Cite news |url=https://www.edwards.af.mil/News/Article-Display/Article/951797/experimental-bomber-returns-home-after-six-decades/ |title=Experimental bomber returns home after six decades |newspaper=Edwards Air Force Base |access-date=8 December 2016}}</ref>