XS-1 Credit - NASA

Also known as the X-1. This rocket plane was the first aircraft to break the sound barrier, and the first in a line of X- aircraft leading to the space shuttle. Due to the press of war work, Bell Aircraft was the only company that would take on the project in 1944. German swept-wing research being unknown, the configuration developed was a thin, straight-winged aircraft with a bullet-shaped fuselage. The XS-1 began flight test in 1946 and Chuck Yeager flew it through the sound barrier on October 14, 1947.

Main Engine: XLR-11. Main Engine Propellants: Lox/Alcohol.

• 1943 December 1 - NACA rocket program. -
  The rocket aircraft research program conceived by NACA's John Stack, to investigage the flight characteristics of an airplane flying beyond the speed of sound or Mach 1.

• 1944 January 1 - Bell Aircraft begins work on the XS-1 rocketplane. -
  Due to the press of war work, Bell Aircraft was the only company that would take on the XS-1 rocketplane project. This would produce the X-1, the first aircraft to break the sound barrier, and the first in a line of X- aircraft leading to the space shuttle. German swept-wing research being unknown, the configuration developed was a thin, straight-winged aircraft with a bullet-shaped fuselage.

• 1944 January 1 - Congress appropriated funds to carry out a rocket aircraft research program. -
  The National Advisory Committee for Aeronautics, the Air Force, and the Navy were designated participating members.

• 1944 March 16 - NACA proposes a jet-propelled transonic research airplane. -
  At a National Advisory Committee for Aeronautics (NACA) seminar, in Washington, D.C., with Air Force and Navy personnel attending, NACA personnel proposed a jet-propelled transonic research airplane be developed. This proposal ultimately led to the 'X' series research airplane projects.

• 1944 December 13 - X-1 manned supersonic rocket aircraft begun. -
  In an AAF-NACA conference, Air Force representatives indicated strong preference for use of rocket engines instead of jets in X-1 research airplane project.

• 1946 January 19 - XS-1 Flight 1 - Crew: Woolams.
  Bell flight 1. First glide flight of AAF-NACA XS-1 rocket research airplane (No.1 of the original three X-1's built), by Jack Woolams, Bell Aircraft test pilot, at Pinecastle Army Air Base, Fla.

• 1946 February 5 - XS-1 Flight 2 - Crew: Woolams.
  Bell flight 2. At Pinecastle AAF, Florida.

• 1946 February 5 - XS-1 Flight 3 - Crew: Woolams.
  Bell flight 3. At Pinecastle AAF, Florida.

• 1946 February 11 - XS-1 Flight 4 - Crew: Woolams.
  Bell flight 4. Gear retracted, left wing damaged. At Pinecastle AAF, Florida.

• 1946 February 19 - XS-1 Flight 5 - Crew: Woolams.
  Bell flight 5. Nosewheel retracted on landing runout. Landing-gear door damaged. At Pinecastle AAF, Florida.

• 1946 February 25 - XS-1 Flight 7 - Crew: Woolams.
  Bell flight 7. Longitudinal and directional stability investigation. At Pinecastle AAF, Florida.

• 1946 February 25 - XS-1 Flight 6 - Crew: Woolams.
  Bell flight 6. Static directional stability investigation. At Pinecastle AAF, Florida.

• 1946 February 26 - XS-1 Flight 9 - Crew: Woolams.
  Bell flight 9. Rate of roll investigation. At Pinecastle AAF, Florida.

• 1946 February 26 - XS-1 Flight 8 - Crew: Woolams.
  Bell flight 8. Dynamic stability check. At Pinecastle AAF, Florida.

• 1946 March 6 - XS-1 Flight 10 - Crew: Woolams.
  Bell flight 10. Static longitudinal stability investigation. At Pinecastle AAF, Florida.

• 1946 October 7 - X-1 moved to Edwards. -
  First of three XS-1 (later X-1) rocket research airplanes moved from Bell Aircraft's Niagara Falls plant to Muroc, Calif.

• 1946 October 11 - XS-1 Flight 11 - Crew: Goodlin.
  Bell flight 1. Glide flight, pilot familiarization.

• 1946 October 14 - XS-1 Flight 12 - Crew: Goodlin.
  Bell flight 2. Glide flight.

• 1946 October 17 - XS-1 Flight 13 - Crew: Goodlin.
  Bell flight 3. Glide flight, small check.

• 1946 December 2 - XS-1 Flight 14 - Crew: Goodlin.
  Bell flight 4. Glide flight, check of fuel-jettison system.

• 1946 December 9 - XS-1 Flight 15 - Crew: Goodlin.
  Bell flight 5. First XS-1 powered flight. Mach 0.79 at 10675 m. Minor engine fire. At Edwards AFB, California.

• 1946 December 20 - XS-1 Flight 16 - Crew: Goodlin.
  Bell flight 6. Familiarization powered flight.

• 1947 January 8 - XS-1 Flight 17 - Crew: Goodlin.
  Bell flight 7. Buffet boundary investigation. Mach 0.80 at 10675 m.

• 1947 January 17 - XS-1 Flight 18 - Crew: Goodlin.
  Bell flight 8. Buffet boundary investigation. Full-power climb. Plane reached mach 0.82.

• 1947 January 22 - XS-1 Flight 19 - Crew: Goodlin.
  Bell flight 9. Buffet boundary investigation. Full-power climb. Telemetry failure.

• 1947 January 23 - XS-1 Flight 20 - Crew: Goodlin.
  Bell flight 10. Buffet boundary investigation. Full-power climb.

• 1947 January 30 - XS-1 Flight 21 - Crew: Goodlin.
  Bell flight 11. Accelerated stalls. Partial power due to engine igniters. Mach 0.75.

• 1947 January 31 - XS-1 Flight 22 - Crew: Goodlin.
  Bell flight 12. Buffet boundary investigation. Mach 0.7.

• 1947 February 5 - XS-1 Flight 23 - Crew: Goodlin.
  Bell flight 13. Machmeter calibration.

• 1947 February 7 - XS-1 Flight 24 - Crew: Goodlin.
  Bell flight 14. Buffet boundary investigation.

• 1947 February 19 - XS-1 Flight 25 - Crew: Goodlin.
  Bell flight 15. Accelerated stalls.

• 1947 February 21 - XS-1 Flight 26 - Crew: Goodlin.
  Bell flight 16. Flight aborted after drop because of low engine-chamber pressure.

• 1947 April 10 - XS-1 Flight 27 - Crew: Goodlin.
  Bell flight 11. Glide flight and stall check. At Muroc Dry Lake, California.

• 1947 April 11 - XS-1 Flight 28 - Crew: Goodlin.
  Bell flight 12. Nosewheel damaged. First powered flight of XS-1 # 1 aircraft. At Muroc Dry Lake, California.

• 1947 April 29 - XS-1 Flight 29 - Crew: Goodlin.
  Bell flight 13. Handling qualities check. At Muroc Dry Lake, California.

• 1947 April 30 - XS-1 Flight 30 - Crew: Goodlin.
  Bell flight 14. Handling qualities check. At Muroc Dry Lake, California.

• 1947 May 5 - XS-1 Flight 31 - Crew: Goodlin.
  Bell flight 15. Handling qualities check. At Muroc Dry Lake, California.

• 1947 May 15 - XS-1 Flight 32 - Crew: Goodlin.
  Bell flight 16. Buffet-boundary investigation. Aileron-damper malfunction.

• 1947 May 19 - XS-1 Flight 33 - Crew: Goodlin.
  Bell flight 17. Buffet-boundary investigation. At Muroc Dry Lake, California.

• 1947 May 21 - XS-1 Flight 34 - Crew: Goodlin.
  Bell flight 18. Buffet-boundary investigation. At Muroc Dry Lake, California.

• 1947 May 22 - XS-1 Flight 35 - Crew: Johnston Alvin.
  Bell flight 17. Pilot familiarization flight. Mach 0.72, 8 g pullout.

• 1947 May 29 - XS-1 Flight 36 - Crew: Goodlin.
  Bell flight 18. Airspeed calibration flight to mach 0.72. End of Bell contractor program.

• 1947 June 5 - XS-1 Flight 37 - Crew: Goodlin.
  Bell flight 19. Demonstration flight for Aviation Writers Association. At Muroc Dry Lake, California.

• 1947 August 6 - XS-1 Flight 38 - Crew: Yeager.
  AF glide flight 1. Pilot familiarization.

• 1947 August 7 - XS-1 Flight 39 - Crew: Yeager.
  AF glide flight 2.

• 1947 August 8 - XS-1 Flight 40 - Crew: Yeager.
  AF glide flight 3.

• 1947 August 29 - XS-1 Flight 41 - Crew: Yeager.
  AF powered flight 1. Mach 0.85.

• 1947 September 4 - XS-1 Flight 42 - Crew: Yeager.
  AF flight 2. About mach 0.89. Telemeter failure required repeat of this flight.

• 1947 September 8 - XS-1 Flight 43 - Crew: Yeager.
  AF flight 3.

• 1947 September 10 - XS-1 Flight 44 - Crew: Yeager.
  AF flight 4. Mach 0.91. Stability and control investigation.

• 1947 September 12 - XS-1 Flight 45 - Crew: Yeager.
  AF flight 5. Mach 0.92. Check of elevator and stabilizer effectiveness. Also buffet investigation.

• 1947 September 25 - XS-1 Flight 46 - Crew: Yeager.
  NACA acceptance flight. Number 4 cylinder burned out.

• 1947 October 3 - XS-1 Flight 47 - Crew: Yeager.
  AF flight 6. Check of elevator and stabilizer effectiveness. Also buffet investigation.

• 1947 October 8 - XS-1 Flight 48 - Crew: Yeager.
  AF flight 7. Airspeed calibration flight. Plane attained mach 0.925.

• 1947 October 10 - XS-1 Flight 49 - Crew: Yeager.
  AF flight 8. Stability and control investigation. Plane attained mach 0.997.

• 1947 October 14 - XS-1 Flight 50 - first supersonic manned flight - Crew: Yeager.
  AF flight 9. World's first supersonic flight in level or climbing flight was made by Capt. Charles E. Yeager (USAF) at Muroc, Calif., in a rocket-powered NACA-USAF research plane, Bell XS-1XS-1 # 1 attained mach 1.06 at 13,115 m, approximately 1126 kph.

• 1947 October 21 - XS-1 Flight 51 - Crew: Hoover.
  NACA glide-familiarization flight for NACA pilot. Stall check. Nosewheel collapsed on landing.

• 1947 October 27 - XS-1 Flight 52 - Crew: Yeager.
  AF flight 10. Electric power failure. No rocket ignition.

• 1947 October 28 - XS-1 Flight 53 - Crew: Yeager.
  AF flight 11. Telemetry failure.

• 1947 October 29 - XS-1 Flight 54 - Crew: Yeager.
  AF flight 12. Telemetry failure.

• 1947 October 31 - XS-1 Flight 55 - Crew: Yeager.
  AF flight 13.

• 1947 November 3 - XS-1 Flight 56 - Crew: Yeager.
  AF flight 14.

• 1947 November 4 - XS-1 Flight 57 - Crew: Yeager.
  AF flight 15.

• 1947 November 6 - XS-1 Flight 58 - Crew: Yeager.
  AF flight 16. Mach 1.35 at 14823 m.

• 1947 December 16 - XS-1 Flight 59 - Crew: Hoover.
  NACA powered flight 1. Familiarization. Mach 0.84. No telemetry record.

• 1947 December 17 - XS-1 Flight 60 - Crew: Hoover.
  NACA flight 2. Familiarization. Mach 0.8.

• 1948 January 6 - XS-1 Flight 61 - Crew: Hoover.
  NACA flight 3. Turns and pull-ups to buffet. Mach 0.74.

• 1948 January 8 - XS-1 Flight 62 - Crew: Hoover.
  NACA flight 4. Turns and pull-ups to buffet. Mach 0.83.

• 1948 January 9 - XS-1 Flight 63 - Crew: Lilly.
  NACA flight 5. Pilot familiarization.

• 1948 January 15 - XS-1 Flight 64 - Crew: Lilly.
  NACA flight 6. Turns and pull-ups to buffet. Sideslips. Mach 0.76.

• 1948 January 16 - XS-1 Flight 65 - Crew: Yeager.
  AF flight 17. Airspeed calibration. Mach 0.9.

• 1948 January 21 - XS-1 Flight 66 - Crew: Hoover.
  NACA flight 7. Stabilizer effectiveness investigation. Mach 0.82 at 8845 m.

• 1948 January 22 - XS-1 Flight 67 - Crew: Yeager.
  AF flight 18. Pressure distribution survey. Mach 1.2.

• 1948 January 23 - XS-1 Flight 68 - Crew: Hoover.
  NACA flight 8. Attempted high-speed run aborted at mach 0.83, drop in chamber pressure.

• 1948 January 27 - XS-1 Flight 69 - Crew: Hoover.
  NACA flight 9. High-speed run to mach 0.925 at 11590 m. Cylinders 2 and 3 failed to fire.

• 1948 January 30 - XS-1 Flight 70 - Crew: Yeager.
  AF flight 19. Pressure distribution survey. Mach 1.1.

• 1948 February 24 - XS-1 Flight 71 - Crew: Fitzgerald.
  AF flight 20. Engine fire after launch forced jettisoning of propellants, completed as a glide flight. However Fitz-Gerald reached 12.1 km and reached Mach 1.10 before the engine was shut off, in the process becoming the second person to break the sound barrier.

• 1948 March 4 - XS-1 Flight 72 - Crew: Hoover.
  NACA flight 10. High-speed run to mach 0.943 at 12200 m.

• 1948 March 10 - XS-1 Flight 73 - Crew: Hoover.
  NACA flight 11. First NACA supersonic flight. First civilian supersonic flight. Mach 1.065. Nosewheel failed to extend for landing. Minor damage.

• 1948 March 11 - XS-1 Flight 74 - Crew: Yeager.
  AF flight 21. Attained mach 1.25 in dive.

• 1948 March 22 - XS-1 Flight 75 - Crew: Hoover.
  NACA flight 12. Stability and loads investigation. Mach 1.12.

• 1948 March 26 - XS-1 Flight 76 - Crew: Yeager.
  AF flight 22. Attained mach 1.45 at 12239 m during dive. Fastest flight ever made in original XS-1 aircraft.

• 1948 March 30 - XS-1 Flight 77 - Crew: Hoover.
  NACA flight 13. Stability and loads investigation. Mach 0.90.

• 1948 March 31 - XS-1 Flight 78 - Crew: Lilly.
  NACA flight 14. Stability and loads investigation. Plane attained mach 1.1.

• 1948 March 31 - XS-1 Flight 79 - Crew: Yeager.
  AF flight 23. Engine shutdown after launch. Propellants jettisoned, completed as glide flight.

• 1948 April 5 - XS-1 Flight 80 - Crew: Lilly.
  NACA flight 15. Engine failed to ignite. Propellants jettisoned, completed as glide flight.

• 1948 April 6 - XS-1 Flight 81 - Crew: Fitzgerald.
  AF flight 24. Pilot-check flight. Mach 1.1, during 4-cylinder run at 12505 m.

• 1948 April 7 - XS-1 Flight 82 - Crew: Lundquist.
  AF flight 25. Glide flight only.

• 1948 April 8 - XS-1 Flight 83 - Crew: Fitzgerald.
  AF flight 26. Familiarization flight.

• 1948 April 9 - XS-1 Flight 84 - Crew: Lilly.
  NACA flight 16. Stability and loads investigation. Mach 0.89.

• 1948 April 9 - XS-1 Flight 85 - Crew: Lundquist.
  AF flight 27. Powered pilot-check flight.

• 1948 April 16 - XS-1 Flight 86 - Crew: Lilly.
  NACA flight 17. Stability and loads investigation. Plane's nosewheel collapsed on landing. Moderate damage.

• 1948 April 16 - XS-1 Flight 87 - Crew: Lundquist.
  AF flight 28. Pressure distribution survey. Only cylinders 2 and 4 ignited.

• 1948 April 26 - XS-1 Flight 88 - Crew: Fitzgerald.
  AF flight 29. Aborted because of inconsistent rocket operation. Reached mach 0.9.

• 1948 April 29 - XS-1 Flight 89 - Crew: Lundquist.
  AF flight 30. Pressure distribution survey. Attained mach 1.18.

• 1948 May 4 - XS-1 Flight 90 - Crew: Fitzgerald.
  AF flight 31. Pressure distribution survey. Mach 1.15.

• 1948 May 21 - XS-1 Flight 91 - Crew: Lundquist.
  AF flight 32. Stability and control and buffeting investigation. Mach 0.92.

• 1948 May 25 - XS-1 Flight 92 - Crew: Fitzgerald.
  AF flight 33. Buffet investigation, wing and tail loads. Mach 1.08.

• 1948 May 26 - XS-1 Flight 93 - Crew: Yeager.
  AF flight 34. Buffet investigation, wing and tail loads. Mach 1.05.

• 1948 June 3 - XS-1 Flight 94 - Crew: Lundquist.
  AF flight 35. Left main gear door opened in flight. Nosewheel collapsed on landing.

• 1948 November 1 - XS-1 Flight 95 - Crew: Hoover.
  NACA flight 18. Stability and control. Mach 0.9. Number 4 cylinder failed to fire.

• 1948 November 15 - XS-1 Flight 96 - Crew: Hoover.
  NACA flight 19. Stability and control. Also pressure-distribution survey. Mach 0.98.

• 1948 November 23 - XS-1 Flight 97 - Crew: Champine.
  NACA flight 20. Pilot familiarization. Check on handling qualities and pressure distribution.

• 1948 November 29 - XS-1 Flight 98 - Crew: Champine.
  NACA flight 21. Check on handling qualities and pressure distribution. Mach 0.88.

• 1948 November 30 - XS-1 Flight 99 - Crew: Champine.
  NACA flight 22. Check on handling qualities and pressure distribution.

• 1948 December 1 - XS-1 Flight 100 - Crew: Yeager.
  AF flight 36. Handling qualities and wing and tail loads at mach 1.

• 1948 December 2 - XS-1 Flight 101 - Crew: Champine.
  NACA flight 23. Check on handling qualities and pressure distribution. Plane exceeded mach 1 briefly.

• 1948 December 13 - XS-1 Flight 102 - Crew: Yeager.
  AF flight 37. Handling qualities and wing and tail loads at mach 1.

• 1948 December 23 - XS-1 Flight 103 - Crew: Yeager.
  AF flight 38. Wing and tail loads during supersonic flight at high altitudes. Mach 1.09.

• 1949 January 5 - XS-1 Flight 104 - Crew: Yeager.
  AF flight 39. Rocket takeoff from the ground.

• 1949 March 11 - XS-1 Flight 105 - Crew: Ridley.
  AF flight 40. Familiarization flight. Mach 1.23 at 10675 m. Small engine fire due to loose igniter.

• 1949 March 16 - XS-1 Flight 106 - Crew: Boyd.
  AF flight 41. Familiarization flight. Inflight engine fire and shutdown.

• 1949 March 21 - XS-1 Flight 107 - Crew: Everest.
  AF flight 42. Familiarization flight. Mach 1.22 at 12200 m.

• 1949 March 25 - XS-1 Flight 108 - Crew: Everest.
  AF flight 43. Check of pressure suit for altitude operation. Mach 1.24 at 14640 m. Rocket fire and automatic engine shutdown.

• 1949 April 14 - XS-1 Flight 109 - Crew: Ridley.
  AF flight 44. Accelerated stall check at transonic speeds. Mach 1.1 at 12200 m.

• 1949 April 19 - XS-1 Flight 110 - Crew: Everest.
  AF flight 45. Altitude attempt. Only 2 cylinders fired.

• 1949 May 2 - XS-1 Flight 111 - Crew: Yeager.
  AF flight 46. Partial engine malfunction, faulty engine ignition plug.

• 1949 May 5 - XS-1 Flight 112 - Crew: Everest.
  AF flight. Engine chamber exploded, jamming rudder. Everest landed safely.

• 1949 May 6 - XS-1 Flight 113 - Crew: Champine.
  NACA flight 24. Check on airplane instrumentation. Mach 0.88 at 12200 m.

• 1949 May 13 - XS-1 Flight 114 - Crew: Champine.
  NACA flight 25. Spanwise pressure distribution, stability and control. Mach 0.91.

• 1949 May 27 - XS-1 Flight 115 - Crew: Champine.
  NACA flight 26. Spanwise pressure distribution, stability and control. Mach 0.91. Stabilizer found more effective than the elevator during pull-ups at mach 0.91.

• 1949 June 16 - XS-1 Flight 116 - Crew: Champine.
  NACA flight 27. Spanwise pressure distribution, stability and control. Rolls and pull-ups around mach 0.91.

• 1949 June 23 - XS-1 Flight 117 - Crew: Champine.
  NACA flight 28. Spanwise pressure distribution, stability and control. Rolls, pull-ups, check of stabilizer effectiveness.

• 1949 July 11 - XS-1 Flight 118 - Crew: Champine.
  NACA flight 29. Spanwise pressure distribution, stability and control. Rolls, pull-ups, check of stabilizer effectiveness. Mach 0.91. Number 2 cylinder failed to fire.

• 1949 July 19 - XS-1 Flight 119 - Crew: Champine.
  NACA flight 30. Spanwise pressure distribution, stability and control. Rolls, pull-ups, check of stabilizer effectiveness. Mach 0.91. Number 2 cylinder failed to fire.

• 1949 July 25 - XS-1 Flight 120 - Crew: Everest.
  AF flight 48. Altitude attempt. Attained 20388 m altitude.

• 1949 July 27 - XS-1 Flight 121 - Crew: Champine.
  NACA flight 31. Spanwise pressure distribution, stability and control. Rolls, pull-ups, check of stabilizer effectiveness.

• 1949 August 4 - XS-1 Flight 122 - Crew: Champine.
  NACA flight 32. Spanwise pressure distribution, stability and control. Rolls, pull-ups, check of stabilizer effectiveness.

• 1949 August 8 - XS-1 Flight 123 - Crew: Everest.
  AF flight 49. Altitude attempt. Attained 21930 m altitude.

• 1949 August 25 - XS-1 Flight 124 - Crew: Everest.
  AF flight 50. First use of partial pressure suit to save life of pilot during flight at high altitude. X-1 # 1 lost cockpit pressurization about 21000 m. Everest made safe emergency descent.

• 1949 September 23 - XS-1 Flight 125 - Crew: Griffith.
  NACA flight 33. Pilot familiarization. Mach 0.9.

• 1949 October 6 - XS-1 Flight 126 - Crew: Fleming.
  AF flight 51. Pilot familiarization.

• 1949 October 26 - XS-1 Flight 127 - Crew: Johnson.
  AF flight 52. Pilot familiarization.

• 1949 November 29 - XS-1 Flight 128 - Crew: Everest.
  AF flight 53. High-altitude wing-tail loads investigation.

• 1949 November 30 - XS-1 Flight 129 - Crew: Griffith.
  NACA flight 33. Mach 0.91.

• 1949 December 2 - XS-1 Flight 130 - Crew: Everest.
  AF flight 54. High-altitude wing-tail loads investigation.

• 1950 February 21 - XS-1 Flight 131 - Crew: Everest.
  AF flight 55. Wing-and-tail-loads investigation.

• 1950 April 26 - XS-1 Flight 132 - Crew: Yeager.
  AF flight 56. Lateral stability and control investigation.

• 1950 May 5 - XS-1 Flight 133 - Crew: Ridley.
  AF flight 57. Buffeting, wing and tail loads.

• 1950 May 8 - XS-1 Flight 134 - Crew: Ridley.
  AF flight 58. Buffeting, wing and tail loads.

• 1950 May 12 - XS-1 Flight 135 - Crew: Griffith.
  NACA flight 34. Spanwise pressure distribution, stability and control. Pull-ups and rolls.

• 1950 May 12 - XS-1 Flight 136 - Crew: Yeager.
  AF flight 59. Last flight of XS-1 No. 1 rocket research airplane, for RKO motion picture "Test Pilot," which was turned over to the National Air Museum at the Smithsonian on August 28th.

• 1950 May 17 - XS-1 Flight 137 - Crew: Griffith.
  NACA flight 35. Spanwise pressure distribution, stability and control. Pull-ups and rolls. Mach 1.13 at 12810 m.

• 1950 May 26 - XS-1 Flight 138 - Crew: Griffith.
  NACA flight 36. Spanwise pressure distribution, stability and control. Pull-ups and rolls. Mach 1.20. Nosewheel collapsed on landing.

• 1950 August 9 - XS-1 Flight 139 - Crew: Griffith.
  NACA flight 38. For pressure distribution and stability and control data. Check of stabilizer effectiveness. Mach 0.98.

• 1950 August 11 - XS-1 Flight 140 - Crew: Griffith.
  NACA flight 39. For pressure distribution and stability and control data. Check of stabilizer effectiveness.

• 1950 September 21 - XS-1 Flight 141 - Crew: Griffith.
  NACA flight 40. For pressure distribution and stability and control data. Check of stabilizer effectiveness. Also drag investigation. Pull-ups. Mach 0.90.

• 1950 October 4 - XS-1 Flight 142 - Crew: Griffith.
  NACA flight 41. For pressure distribution and stability and control data. Check of stabilizer effectiveness. Also drag investigation. Pull-ups.

• 1951 April 6 - XS-1 Flight 143 - Crew: Yeager.
  NACA flight 42. Flight for RKO film Jet Pilot. Slight engine fire but no damage.

• 1951 April 20 - XS-1 Flight 144 - Crew: Crossfield.
  NACA flight 43. Pilot familiarization. Reached mach 1.07.

• 1951 April 27 - XS-1 Flight 145 - Crew: Crossfield.
  NACA flight 44. Plane and instrument check.

• 1951 May 15 - XS-1 Flight 146 - Crew: Crossfield.
  NACA flight 45. Wing loads and aileron effectiveness. Aileron rolls at mach 0.90.

• 1951 July 12 - XS-1 Flight 147 - Crew: Crossfield.
  NACA flight 46. Wing loads and aileron effectiveness. Aileron rolls at mach 1.07.

• 1951 July 20 - XS-1 Flight 148 - Crew: Crossfield.
  NACA flight 47. Wing loads and aileron effectiveness. Abrupt rudder fixed aileron rolls left and right, from mach 0.70 to mach 0.88.

• 1951 July 31 - XS-1 Flight 149 - Crew: Crossfield.
  NACA flight 48. Wing loads and aileron effectiveness.

• 1951 August 3 - XS-1 Flight 150 - Crew: Crossfield.
  NACA flight 49. Wing loads and aileron effectiveness.

• 1951 August 8 - XS-1 Flight 151 - Crew: Crossfield.
  NACA flight 50. Wing loads and aileron effectiveness. Elevator and stabilizer pull-ups.

• 1951 August 10 - XS-1 Flight 152 - Crew: Crossfield.
  NACA flight 51. Wing loads and aileron effectiveness. Elevator and stabilizer pull-ups, clean stalls.

• 1951 August 27 - XS-1 Flight 153 - Crew: Walker Joseph.
  NACA flight 52. Pilot familiarization. Reached mach 1.16 at 13420 m during four-cylinder run.

• 1951 September 5 - XS-1 Flight 154 - Crew: Crossfield.
  NACA flight 53. Fuselage pressure distribution survey. Number 1 cylinder failed to fire. Stabilizer pull-ups at mach 1.07.

• 1951 October 23 - XS-1 Flight 155 - Crew: Walker Joseph.
  NACA flight 54. Engine cut out after two ignition attempts; propellants jettisoned and flight completed as glide flight. Plane subsequently grounded because of possibility of fatigue failure of nitrogen spheres.

• 1951 November 9 - XS-1 No. 3 destroyed in ground explosion. - Crew: Cannon. Launch Site: Edwards. Launch Complex: -.
  Planned captive flight with B-50 for propellant jettison test. XS-1 (No. 3) rocket research airplane and its B-29 "mother" airplane were destroyed on the ground by postflight explosion and fire. Pilot Cannon was injured.