# List of X-1 flights

The Bell X-1 was the first crewed airplane to exceed the speed of sound in level flight and was the first of the X-planes.

## XS-1 pilots

| Pilot | Agency | Flights | Aircraft |
| Joseph Cannon | Bell Aircraft | 1 | 46-064 |
| Chalmers "Slick" Goodlin | Bell Aircraft | 26 | 46-062 (9), 46-063 (17) |
| Alvin "Tex" Johnston | Bell Aircraft | 1 | 46-063 |
| Jack Woolams | Bell Aircraft | 10 | 46-062 |
| Robert Champine | NACA | 13 | 46-063 |
| Scott Crossfield | NACA | 10 | 46-063 |
| John H. Griffith | NACA | 9 | 46-063 |
| Herb Hoover | NACA | 14 | 46-063 |
| Howard Lilly | NACA | 6 | 46-063 |
| Joseph A. Walker | NACA | 2 | 46-063 |
| Fred Ascani | USAF | 1 | 46-063 |
| Albert Boyd | USAF | 1 | 46-062 |
| Frank Everest | USAF | 10 | 46-062 |
| James Fitzgerald | USAF | 7 | 46-062 |
| Patrick Fleming | USAF | 1 | 46-062 |
| Richard Johnson | USAF | 1 | 46-062 |
| Gustav Lundquist | USAF | 6 | 46-062 |
| Jack Ridley | USAF | 5 | 46-062 |
| Chuck Yeager | USAF | 34 | 46-062 (33), 46-063 (1) |

## XS-1 flights

| Vehicle Flight # | Date | Pilot | Aircraft | Agency | Velocity -Mach- | Altitude - m - | Comments |
| XS-1 #1 | January 19, 1946 | Jack Woolams | 46-062 | Bell 1 #1 | ? | ? | Pinecastle AAF Base, FL. Glide flight. |
| XS-1 #2 | February 5, 1946 | Jack Woolams | 46-062 | Bell 2 #1 | ? | ? | Pinecastle AAF Base, FL. Glide flight. |
| XS-1 #3 | February 5, 1946 | Jack Woolams | 46-062 | Bell 3 #1 | ? | ? | Pinecastle AAF Base, FL. 2nd flight on this date. Glide flight. |
| XS-1 #4 | February 11, 1946 | Jack Woolams | 46-062 | Bell 4 #1 | ? | ? | Pinecastle AAF Base, FL. Gear retracts after landing, left wing damage. Glide flight. |
| XS-1 #5 | February 19, 1946 | Jack Woolams | 46-062 | Bell 5 #1 | ? | ? | Pinecastle AAF Base, FL. Nose Gear retracted on landing. Landing gear door damage. Glide flight. |
| XS-1 #6 | February 25, 1946 | Jack Woolams | 46-062 | Bell 6 #1 | ? | ? | Pinecastle AAF Base, FL Directional stability tests. Glide flight. |
| XS-1 #7 | February 25, 1946 | Jack Woolams | 46-062 | Bell 7 #1 | ? | ? | Pinecastle AAF Base, FL. Longitudinal stability tests. 2nd flight on this date. Glide flight. |
| XS-1 #8 | February 26, 1946 | Jack Woolams | 46-062 | Bell 8 #1 | ? | ? | Pinecastle AAF Base, FL. Dynamic stability tests. Glide flight. |
| XS-1 #9 | February 26, 1946 | Jack Woolams | 46-062 | Bell 9 #1 | ? | ? | Pinecastle AAF Base, FL. Roll rate tests. 2nd flight on this date. Glide flight. |
| XS-1 #10 | March 6, 1946 | Jack Woolams | 46-062 | Bell 10 #1 | ? | ? | Pinecastle AAF Base, FL. Longitudinal stability tests. Glide flight. |
| XS-1 #11 | October 11, 1946 | Chalmers Goodlin | 46-063 | Bell 1 #2 | ? | ? | All XS-1 flights now from Muroc AAF Base, CA. Glide flight, familiarization. |
| XS-1 #12 | October 14, 1946 | Chalmers Goodlin | 46-063 | Bell 2 #2 | ? | ? | Glide flight. |
| XS-1 #13 | October 17, 1946 | Chalmers Goodlin | 46-063 | Bell 3 #2 | ? | ? | Glide flight. |
| XS-1 #14 | December 2, 1946 | Chalmers Goodlin | 46-063 | Bell 4 #2 | ? | ? | Glide flight. Check fuel jettison system. |
| XS-1 #15 | December 9, 1946 | Chalmers Goodlin | 46-063 | Bell 5 #2 | 0.79 | 10,675 | First powered flight. Minor engine fire. |
| XS-1 #16 | December 20, 1946 | Chalmers Goodlin | 46-063 | Bell 6 #2 | ? | ? | Familiarization flight. Powered. |
| XS-1 #17 | January 8, 1947 | Chalmers Goodlin | 46-063 | Bell 7 #2 | 0.80 | 10,675 | Buffet boundary investigation. |
| XS-1 #18 | January 17, 1947 | Chalmers Goodlin | 46-063 | Bell 8 #2 | 0.80 | ? | Buffet boundary investigation. Full power climb. |
| XS-1 #19 | January 22, 1947 | Chalmers Goodlin | 46-063 | Bell 9 #2 | ? | ? | Buffet boundary investigation. Full power climb. Telemetry failed. |
| XS-1 #20 | January 23, 1947 | Chalmers Goodlin | 46-063 | Bell 10 #2 | ? | ? | Buffet boundary investigation. Full power climb. |
| XS-1 #21 | January 30, 1947 | Chalmers Goodlin | 46-063 | Bell 11 #2 | 0.75 | ? | Accelerated stalls. Partial power. |
| XS-1 #22 | January 31, 1947 | Chalmers Goodlin | 46-063 | Bell 12 #2 | 0.70 | ? | Buffet boundary investigation. |
| XS-1 #23 | February 5, 1947 | Chalmers Goodlin | 46-063 | Bell 13 #2 | ? | ? | Machmeter calibration. |
| XS-1 #24 | February 7, 1947 | Chalmers Goodlin | 46-063 | Bell 14 #2 | ? | ? | Buffet boundary investigation. |
| XS-1 #25 | February 19, 1947 | Chalmers Goodlin | 46-063 | Bell 15 #2 | ? | ? | Accelerated stalls. |
| XS-1 #26 | February 21, 1947 | Chalmers Goodlin | 46-063 | Bell 16 #2 | ? | ? | Aborted after launch. Low engine-chamber pressure. |
| XS-1 #27 | April 10, 1947 | Chalmers Goodlin | 46-062 | Bell 11 #1 | ? | ? | Glide flight, stall check. |
| XS-1 #28 | April 11, 1947 | Chalmers Goodlin | 46-062 | Bell 12 #1 | ? | ? | First powered flight of aircraft #1. Nosewheel damaged. |
| XS-1 #29 | April 29, 1947 | Chalmers Goodlin | 46-062 | Bell 13 #1 | ? | ? | Handling qualities check. |
| XS-1 #30 | April 30, 1947 | Chalmers Goodlin | 46-062 | Bell 14 #1 | ? | ? | Handling qualities check. |
| XS-1 #31 | May 5, 1947 | Chalmers Goodlin | 46-062 | Bell 15 #1 | ? | ? | Handling qualities check. |
| XS-1 #32 | May 15, 1947 | Chalmers Goodlin | 46-062 | Bell 16 #1 | ? | ? | Buffet boundary test. Aileron damper malfunction. |
| XS-1 #33 | May 19, 1947 | Chalmers Goodlin | 46-062 | Bell 17 #1 | ? | ? | Buffet boundary test. |
| XS-1 #34 | May 21, 1947 | Chalmers Goodlin | 46-062 | Bell 18 #1 | ? | ? | Buffet boundary test. |
| XS-1 #35 | May 22, 1947 | Alvin "Tex" Johnston | 46-063 | Bell 17 #2 | 0.72 | ? | Pilot familiarization. 8 g (78 m/s²) pullout. |
| XS-1 #36 | May 29, 1947 | Chalmers Goodlin | 46-063 | Bell 18 #2 | 0.72 | ? | Airspeed calibration. End of Bell contractor program. |
| XS-1 #37 | June 5, 1947 | Chalmers Goodlin | 46-062 | Bell 19 #1 | ? | ? | Demonstration for Aviation Writers Association. |
| XS-1 #38 | August 6, 1947 | Chuck Yeager | 46-062 | USAF glide 1 | ? | ? | Pilot familiarization. |
| XS-1 #39 | August 7, 1947 | Chuck Yeager | 46-062 | USAF glide 2 | ? | ? | Glide flight. |
| XS-1 #40 | August 8, 1947 | Chuck Yeager | 46-062 | USAF glide 3 | ? | ? | Glide flight. |
| XS-1 #41 | August 29, 1947 | Chuck Yeager | 46-062 | USAF powered 1 | 0.85 | ? | First USAF powered flight. |
| XS-1 #42 | September 4, 1947 | Chuck Yeager | 46-062 | USAF 2 | 0.89 | ? | Telemetry failure. Flight had to be repeated. |
| XS-1 #43 | September 8, 1947 | Chuck Yeager | 46-062 | USAF 3 | ? | ? | - |
| XS-1 #44 | September 10, 1947 | Chuck Yeager | 46-062 | USAF 4 | 0.91 | ? | Stability and control test. |
| XS-1 #45 | September 12, 1947 | Chuck Yeager | 46-062 | USAF 5 | 0.92 | ? | Check elevator, stabilizer and buffet. |
| XS-1 #46 | September 25, 1947 | Chuck Yeager | 46-063 | NACA acceptance | ? | ? | Number 4 engine tube burned out. |
| XS-1 #47 | October 3, 1947 | Chuck Yeager | 46-062 | USAF 6 | ? | ? | Check elevator, stabilizer and buffet. |
| XS-1 #48 | October 8, 1947 | Chuck Yeager | 46-062 | USAF 7 | 0.925 | ? | Airspeed calibration flight. |
| XS-1 #49 | October 10, 1947 | Chuck Yeager | 46-062 | USAF 8 | 0.997 | ? | Stability and control test. |
| XS-1 #50 | October 14, 1947 | Chuck Yeager | 46-062 | USAF 9 | 1.06 | 13,115 | First supersonic flight. 1,126 km/h. |
| XS-1 #51 | October 21, 1947 | Herb Hoover | 46-063 | NACA glide 1 | ? | ? | Familiarization flight. Stall check. Nose wheel collapsed at landing. |
| XS-1 #52 | October 27, 1947 | Chuck Yeager | 46-062 | USAF 10 | ? | ? | Power failure. Rocket didn't fire. |
| XS-1 #53 | October 28, 1947 | Chuck Yeager | 46-062 | USAF 11 | ? | ? | Telemetry failure. |
| XS-1 #54 | October 29, 1947 | Chuck Yeager | 46-062 | USAF 12 | ? | ? | Telemetry failure. |
| XS-1 #55 | October 31, 1947 | Chuck Yeager | 46-062 | USAF 13 | ? | ? | - |
| XS-1 #56 | November 3, 1947 | Chuck Yeager | 46-062 | USAF 14 | ? | ? | - |
| XS-1 #57 | November 4, 1947 | Chuck Yeager | 46-062 | USAF 15 | ? | ? | - |
| XS-1 #58 | November 6, 1947 | Chuck Yeager | 46-062 | USAF 16 | 1.35 | 14,823 | First-ever aircraft flight to exceed July 6, 1944, flight speed record (702 mph/1,130 km/h) of Heinz Dittmar in Me 163B V18 prototype |
| XS-1 #59 | December 16, 1947 | Herb Hoover | 46-063 | NACA powered 1 | 0.84 | ? | No record of telemetry. |
| XS-1 #60 | December 17, 1947 | Herb Hoover | 46-063 | NACA 2 | 0.80 | ? | Familiarization. |
| XS-1 #61 | January 6, 1948 | Herb Hoover | 46-063 | NACA 3 | 0.74 | ? | Turns, pull-ups to buffet. |
| XS-1 #62 | January 8, 1948 | Herb Hoover | 46-063 | NACA 4 | 0.83 | ? | Turns, pull-ups to buffet. |
| XS-1 #63 | January 9, 1948 | Howard Lilly | 46-063 | NACA 5 | ? | ? | Pilot familiarization. |
| XS-1 #64 | January 15, 1948 | Howard Lilly | 46-063 | NACA 6 | 0.76 | ? | Turns, pull-ups to buffet. Sideslips. |
| XS-1 #65 | January 16, 1948 | Chuck Yeager | 46-062 | USAF 17 | 0.9 | ? | Airspeed calibration. |
| XS-1 #66 | January 21, 1948 | Herb Hoover | 46-063 | NACA 7 | 0.82 | 8,845 | Stabilizer effectiveness test. |
| XS-1 #67 | January 22, 1948 | Chuck Yeager | 46-062 | USAF 18 | 1.2 | ? | Pressure distribution survey. |
| XS-1 #68 | January 23, 1948 | Herb Hoover | 46-063 | NACA 8 | 0.83 | ? | Attempted high speed flight. Aborted due to drop in chamber pressure. |
| XS-1 #69 | January 27, 1948 | Herb Hoover | 46-063 | NACA 9 | 0.925 | 11,590 | High speed flight. Cylinders 2 and 3 didn't fire. |
| XS-1 #70 | January 30, 1948 | Chuck Yeager | 46-062 | USAF 19 | 1.1 | ? | Pressure distribution survey. |
| XS-1 #71 | February 28, 1948 | James Fitzgerald | 46-062 | USAF 20 | ? | ? | Engine fire at launch. Propellants jettisoned. Glide flight. |
| XS-1 #72 | March 4, 1948 | Herb Hoover | 46-063 | NACA 10 | 0.943 | 12,200 | High speed flight. |
| XS-1 #73 | March 10, 1948 | Herb Hoover | 46-063 | NACA 11 | 1.065 | ? | First NACA supersonic flight. Nose wheel didn't extend at landing. Minor damage. |
| XS-1 #74 | March 11, 1948 | Chuck Yeager | 46-062 | USAF 21 | 1.25 | ? | Reached Mach 1.25 in a dive. |
| XS-1 #75 | March 22, 1948 | Herb Hoover | 46-063 | NACA 12 | 1.12 | ? | Stability and loads test. |
| XS-1 #76 | March 26, 1948 | Chuck Yeager | 46-062 | USAF 22 | 1.45 | 12,239 | Reached Mach 1.45 in a dive. Highest speed achieved in original XS-1. |
| XS-1 #77 | March 30, 1948 | Herb Hoover | 46-063 | NACA 13 | 0.90 | ? | Stability and loads test. |
| XS-1 #78 | March 31, 1948 | Howard Lilly | 46-063 | NACA 14 | 1.10 | ? | Stability and loads test. |
| XS-1 #79 | March 31, 1948 | Chuck Yeager | 46-062 | USAF 23 | ? | ? | Engine shutdown after launch. Propellants jettisoned. Glide flight. |
| XS-1 #80 | April 5, 1948 | Howard Lilly | 46-063 | NACA 15 | ? | ? | Engine didn't ignite. Propellants jettisoned. Glide flight. |
| XS-1 #81 | April 6, 1948 | James Fitzgerald | 46-062 | USAF 24 | 1.1 | 12,505 | Pilot check flight. All 4 cylinders fired. |
| XS-1 #82 | April 7, 1948 | Gustav Lundquist | 46-062 | USAF 25 | ? | ? | Glide flight. |
| XS-1 #83 | April 8, 1948 | James Fitzgerald | 46-062 | USAF 26 | ? | ? | Familiarization flight. |
| XS-1 #84 | April 9, 1948 | Howard Lilly | 46-063 | NACA 16 | 0.89 | ? | Stability and loads test. |
| XS-1 #85 | April 9, 1948 | Gustav Lundquist | 46-062 | USAF 27 | ? | ? | Powered pilot-check flight. |
| XS-1 #86 | April 16, 1948 | Howard Lilly | 46-063 | NACA 17 | ? | ? | Stability and loads test. Nose wheel collapsed on landing causing moderate damage. |
| XS-1 #87 | April 16, 1948 | Gustav Lundquist | 46-062 | USAF 28 | ? | ? | Pressure distribution test. Only cylinders 2 and 4 fired. |
| XS-1 #88 | April 26, 1948 | James Fitzgerald | 46-062 | USAF 29 | 0.9 | ? | Aborted due to rocket malfunction. |
| XS-1 #89 | April 29, 1948 | Gustav Lundquist | 46-062 | USAF 30 | 1.18 | ? | Pressure distribution test. |
| XS-1 #90 | May 4, 1948 | James Fitzgerald | 46-062 | USAF 31 | 1.15 | ? | Pressure distribution test. |
| XS-1 #91 | May 21, 1948 | Gustav Lundquist | 46-062 | USAF 32 | 0.92 | ? | Stability, control and buffeting test. |
| XS-1 #92 | May 25, 1948 | James Fitzgerald | 46-062 | USAF 33 | 1.08 | ? | Wing, tail loads, buffet test. |
| XS-1 #93 | May 26, 1948 | Chuck Yeager | 46-062 | USAF 34 | 1.05 | ? | Wing, tail loads, buffet test. |
| XS-1 #94 | June 3, 1948 | Gustav Lundquist | 46-062 | USAF 35 | ? | ? | Left main landing gear door opened in flight. Nose wheel collapsed on landing. |
| XS-1 #95 | November 1, 1948 | Herb Hoover | 46-063 | NACA 18 | 0.9 | ? | Stability and control test. Number 4 cylinder did not fire. |
| XS-1 #96 | November 15, 1948 | Herb Hoover | 46-063 | NACA 19 | 0.98 | ? | Stability, control and pressure distribution test. |
| XS-1 #97 | November 23, 1948 | Robert Champine | 46-063 | NACA 20 | ? | ? | Pilot familiarization. Handling qualities and pressure distribution test. |
| XS-1 #98 | November 29, 1948 | Robert Champine | 46-063 | NACA 21 | 0.88 | ? | Handling qualities and pressure distribution test. |
| XS-1 #99 | November 30, 1948 | Robert Champine | 46-063 | NACA 22 | ? | ? | Handling qualities and pressure distribution test. |
| XS-1 #100 | December 1, 1948 | Chuck Yeager | 46-062 | USAF 36 | 1.0 | ? | Wing, tail loads and handling qualities at mach 1. |
| XS-1 #101 | December 2, 1948 | Robert Champine | 46-063 | NACA 23 | 1.0 | ? | Handling qualities and pressure distribution test. |
| XS-1 #102 | December 13, 1948 | Chuck Yeager | 46-062 | USAF 37 | 1.0 | ? | Wing, tail loads and handling qualities at mach 1. |
| XS-1 #103 | December 23, 1948 | Chuck Yeager | 46-062 | USAF 38 | 1.09 | ? | Wing, tail loads during supersonic flight at high altitude. |
| XS-1 #104 | January 5, 1949 | Chuck Yeager | 46-062 | USAF 39 | 1.03 | 23,000 | Ground takeoff with 50% fuel load. |
| XS-1 #105 | March 11, 1949 | Jack Ridley | 46-062 | USAF 40 | 1.23 | 10,675 | Familiarization flight. Minor engine fire caused by loose igniter. |
| XS-1 #106 | March 16, 1949 | Albert Boyd | 46-062 | USAF 41 | ? | ? | Familiarization flight. Inflight engine fire and shutdown. |
| XS-1 #107 | March 21, 1949 | Frank Everest | 46-062 | USAF 42 | 1.22 | 12,200 | Familiarization flight. |
| XS-1 #108 | March 25, 1949 | Frank Everest | 46-062 | USAF 43 | 1.24 | 14,640 | Pressure suit altitude test. Engine fire and automatic shutdown. |
| XS-1 #109 | April 14, 1949 | Jack Ridley | 46-062 | USAF 44 | 1.1 | 12,200 | Accelerated stall check at transonic speeds. |
| XS-1 #110 | April 19, 1949 | Frank Everest | 46-062 | USAF 45 | ? | ? | High altitude flight attempt. Only 2 cylinders fired. |
| XS-1 #111 | May 2, 1949 | Chuck Yeager | 46-062 | USAF 46 | ? | ? | Engine malfunction, faulty ignition plug. |
| XS-1 #112 | May 5, 1949 | Frank Everest | 46-062 | USAF 47 | ? | ? | Engine chamber exploded. Rudder jammed. Safe landing. |
| XS-1 #113 | May 6, 1949 | Robert Champine | 46-063 | NACA 24 | 0.88 | 12,200 | Instrumentation check. |
| XS-1 #114 | May 13, 1949 | Robert Champine | 46-063 | NACA 25 | 0.91 | ? | Spanwise pressure distribution. Stability and control. |
| XS-1 #115 | May 27, 1949 | Robert Champine | 46-063 | NACA 26 | 0.91 | ? | Spanwise pressure distribution. Stability and control. Stabilizer more effective than elevator in mach 0.91 pull-ups. |
| XS-1 #116 | June 16, 1949 | Robert Champine | 46-063 | NACA 27 | 0.91 | ? | Spanwise pressure distribution. Stability and control. Rolls, pull-ups at mach 0.91 |
| XS-1 #117 | June 23, 1949 | Robert Champine | 46-063 | NACA 28 | ? | ? | Spanwise pressure distribution. Stability and control. Rolls, pull-ups, stabilizer effectiveness. |
| XS-1 #118 | July 11, 1949 | Robert Champine | 46-063 | NACA 29 | 0.91 | ? | Spanwise pressure distribution. Stability and control. Cylinder 2 didn't fire. |
| XS-1 #119 | July 19, 1949 | Robert Champine | 46-063 | NACA 30 | 0.91 | ? | Spanwise pressure distribution. Stability and control. Cylinder 2 didn't fire. |
| XS-1 #120 | July 25, 1949 | Frank Everest | 46-062 | USAF 48 | ? | 20,388 | High altitude flight. |
| XS-1 #121 | July 27, 1949 | Robert Champine | 46-063 | NACA 31 | ? | ? | Spanwise pressure distribution. Stability and control. Rolls, pull-ups, stabilizer effectiveness. |
| XS-1 #122 | August 4, 1949 | Robert Champine | 46-063 | NACA 32 | ? | ? | Spanwise pressure distribution. Stability and control. Rolls, pull-ups, stabilizer effectiveness. |
| XS-1 #123 | August 8, 1949 | Frank Everest | 46-062 | USAF 49 | ? | 21,930 | High altitude flight. |
| XS-1 #124 | August 25, 1949 | Frank Everest | 46-062 | USAF 50 | ? | 21,000 | First use of partial pressure suit. Cabin lost pressure at 21,000 m. Pilot made safe emergency descent. |
| XS-1 #125 | September 23, 1949 | John Griffith | 46-063 | NACA 33 | 0.9 | ? | Pilot familiarization. |
| XS-1 #126 | October 6, 1949 | Patrick Fleming | 46-062 | USAF 51 | ? | ? | Pilot familiarization. |
| XS-1 #127 | October 26, 1949 | Richard Johnson | 46-062 | USAF 52 | ? | ? | Pilot familiarization. |
| XS-1 #128 | November 29, 1949 | Frank Everest | 46-062 | USAF 53 | ? | ? | High-altitude wing, tail loads test. |
| XS-1 #129 | November 30, 1949 | John Griffith | 46-063 | NACA 34 | 0.91 | ? | - |
| XS-1 #130 | December 2, 1949 | Frank Everest | 46-062 | USAF 54 | ? | ? | High-altitude wing, tail loads test. |
| XS-1 #131 | February 21, 1950 | Frank Everest | 46-062 | USAF 55 | ? | ? | Wing, tail loads test. |
| XS-1 #132 | April 26, 1950 | Chuck Yeager | 46-062 | USAF 56 | ? | ? | Lateral stability, control test. |
| XS-1 #133 | May 5, 1950 | Jack Ridley | 46-062 | USAF 57 | ? | ? | Buffeting, wing, tail loads test. |
| XS-1 #134 | May 8, 1950 | Jack Ridley | 46-062 | USAF 58 | ? | ? | Buffeting, wing, tail loads test. |
| XS-1 #135 | May 12, 1950 | John Griffith | 46-063 | NACA 35 | ? | ? | Spanwise pressure distribution. Stability and control. Rolls, pull-ups. |
| XS-1 #136 | May 12, 1950 | Chuck Yeager | 46-062 | USAF 59 | ? | ? | Last XS-1 #1 flight. Flown for movie, "Test Pilot". |
| XS-1 #137 | May 17, 1950 | John Griffith | 46-063 | NACA 36 | 1.13 | 12,810 | Spanwise pressure distribution. Stability and control. Rolls, pull-ups. |
| XS-1 #138 | May 26, 1950 | John Griffith | 46-063 | NACA 37 | 1.2 | ? | Spanwise pressure distribution. Stability and control. Rolls, pull-ups. Nose wheel collapsed on landing. |
| XS-1 #139 | August 9, 1950 | John Griffith | 46-063 | NACA 38 | 0.98 | ? | Pressure distribution. Stability and control. Stabilizer check. |
| XS-1 #140 | August 11, 1950 | John Griffith | 46-063 | NACA 39 | ? | ? | Pressure distribution. Stability and control. Stabilizer check. |
| XS-1 #141 | September 21, 1950 | John Griffith | 46-063 | NACA 40 | 0.90 | ? | Pressure distribution, stability, control, stabilizer check. Drag test. Pull-ups. |
| XS-1 #142 | October 4, 1950 | John Griffith | 46-063 | NACA 41 | ? | ? | Pressure distribution, stability, control, stabilizer check. Drag test. Pull-ups. |
| XS-1 #143 | April 6, 1951 | Chuck Yeager | 46-063 | NACA 42 | ? | ? | Flown for movie, "Jet Pilot". Minor engine fire. No damage. |
| XS-1 #144 | April 20, 1951 | Scott Crossfield | 46-063 | NACA 43 | 1.07 | ? | Pilot familiarization. |
| XS-1 #145 | April 27, 1951 | Scott Crossfield | 46-063 | NACA 44 | ? | ? | Plane and instrument check. |
| XS-1 #146 | May 15, 1951 | Scott Crossfield | 46-063 | NACA 45 | 0.90 | ? | Wing loads, aileron effectiveness. Aileron rolls at mach .9. |
| XS-1 #147 | July 12, 1951 | Scott Crossfield | 46-063 | NACA 46 | 1.07 | ? | Wing loads, aileron effectiveness. Aileron rolls at mach 1.07. |
| XS-1 #148 | July 20, 1951 | Scott Crossfield | 46-063 | NACA 47 | 0.88 | ? | Wing loads, aileron effectiveness. Rudder fixed aileron rolls left and right, from mach 0.70 to mach 0.88. |
| XS-1 #149 | July 20, 1951 | Joseph Cannon | 46-064 | Bell 1 #3 | ? | ? | Glide flight. First and only free flight for XS-1 #3. Known as "Queenie". |
| XS-1 #150 | July 31, 1951 | Scott Crossfield | 46-063 | NACA 48 | ? | ? | Wing loads, aileron effectiveness. |
| XS-1 #151 | August 3, 1951 | Scott Crossfield | 46-063 | NACA 49 | ? | ? | Wing loads, aileron effectiveness. |
| XS-1 #152 | August 8, 1951 | Scott Crossfield | 46-063 | NACA 50 | ? | ? | Wing loads, aileron effectiveness. Elevator and stabilizer pull-ups. |
| XS-1 #153 | August 10, 1951 | Scott Crossfield | 46-063 | NACA 51 | ? | ? | Wing loads, aileron effectiveness. Elevator and stabilizer pull-ups, clean stall. |
| XS-1 #154 | August 27, 1951 | Joseph Walker | 46-063 | NACA 52 | 1.16 | 13,420 | Pilot familiarization. |
| XS-1 #155 | September 5, 1951 | Scott Crossfield | 46-063 | NACA 53 | 1.07 | ? | Fuselage pressure survey. Stabilizer pull-ups. Cylinder 1 didn't fire. |
| XS-1 #156 | May 10, 1950 | Fred Ascani | 46-063 | NACA/USAF | ? | ? | Pilot familiarization. Gen. Ascani says he flew the X-1 in the "Fall of 1951". Most sources do not have a record of this flight. General Ascani's Form 5 was located a few years prior to his passing and the entry for his flight in the X-1 was 10 May 1950. |
| XS-1 #157 | October 23, 1951 | Joseph Walker | 46-063 | NACA 54 | ? | ? | Two ignition attempts. Engine cutout. Propellants jettisoned. Glide flight. Aircraft grounded due to possible nitrogen sphere fatigue. |