Sixty-three years ago today, the No. 1 USAF/Bell X-2 rocket-powered flight research aircraft reached a record speed of 2,094 mph with USAF Captain Milburn G. “Mel” Apt at the controls. However, triumph quickly turned to tragedy when the aircraft departed controlled flight, crashed to destruction, and Apt perished.
Mel Apt’s historic achievement came about because of the Air Force’s desire to have the X-2 reach Mach 3 before turning it over to the National Advisory Committee For Aeronautics (NACA) for further flight research testing. Just 20 days prior to Apt’s flight in the X-2, USAF Captain Iven C. Kincheloe, Jr. had flown the aircraft to a record altitude of 126,200 feet.
On Thursday, 27 September 1956, Apt and the X-2 (Ship No. 1, S/N 46-674) dropped away from the USAF B-50 mothership at 30,000 feet and 225 mph. Despite the fact that Mel Apt had never flown an X-aircraft, he executed the flight profile exactly as briefed. In addition, the X-2′s twin-chamber XLR-25 rocket motor burned propellant 12.5 seconds longer than planned. Both of these factors contributed to the aircraft attaining a speed in excess of 2,000 mph.
Apt and his aerial steed hit a peak Mach number of 3.2 at an altitude of 65,000 feet. Based on previous flight tests as well as flight simulator sessions, Apt knew that the X-2 had to slow to roughly Mach 2.4 before turning the aircraft back to Edwards. This was due to degraded directional stability, control reversal, and aerodynamic coupling issues that adversely affected the X-2 at higher Mach numbers.
However, Mel Apt was now faced with a difficult decision. If he waited for the X-2 to slow to Mach 2.4 before initiating a turn back to Edwards Air Force Base, he quite likely would not have enough energy and therefore range to reach Rogers Dry Lake. On the other hand, if he decided to initiate the turn back to Edwards at high Mach number, he risked having the X-2 depart controlled flight. Flying in a coffin corner of the X-2’s flight envelope, Apt opted for the latter.
As Apt increased the aircraft’s angle-of-attack, the X-2 departed controlled flight and subjected him to a brutal pounding. Aircraft lateral acceleration varied between +6 and -6 g’s. The battered pilot ultimately found himself in a subsonic, inverted spin at 40,000 feet. At this point, Apt effected pyrotechnic separation of the X-2′s forebody which contained the cockpit and a drogue parachute.
X-2 forebody separation was clean and the drogue parachute deployed properly. However, Apt still needed to bail out of the descending unit and deploy his personal parachute to complete the emergency egress process. However, such was not to be. Mel Apt ran out of time, altitude, and luck. The young pilot lost his life when the X-2 forebody from which he was trying to escape impacted the ground at a speed of one hundred and twenty miles an hour.
Mel Apt’s flight to Mach 3.2 established a record that stood until the X-15 exceeded that mark in August 1960. However, the price for doing so was very high. The USAF lost a brave test pilot and the lone remaining X-2 on that fateful day in September 1956. The mishap also ended the USAF X-2 Program. NACA never did conduct flight research with the X-2.
However, for a few terrifying moments, Mel Apt was the fastest man alive.
Thirty-six years ago this month, the valiant crew of a USAF KC-135 Stratotanker performed multiple aerial refuelings of a stricken USAF F-4E Phantom II over the North Atlantic Ocean. Conducted under extremely perilous flight conditions, the remarkable actions of the aerial tanker’s crew allowed the F-4E to remain aloft long enough to safely divert to an alternate landing field.
On Monday, 05 September 1983, a pair of USAF F-4E Phantom II fighter-bombers departed the United States for a routine flight to Germany. To negotiate the trans-atlantic distance, the F-4E’s would require aerial refueling. As they approached the refueling rendezvous point, one of the aircraft developed trouble with its No. 2 engine. Though still operative, the engine experienced a significant loss of thrust.
The problem with the Phantom’s engine caused it to lose speed and altitude. Further, its No. 1 engine began to overheat as it tried to keep the aircraft airborne. As if this were not enough, the aircraft’s starboard hydraulic system became inoperative. Coupled with the fact that the fuel gauge was edging toward empty, the specter of an ejection and parachute landing in the cold Atlantic looked all but certain for the F-4E crew.
Enter the venerable KC-135 Stratotanker and her crew of Captain Robert J. Goodman, Captain Michael R. Clover, 1st Lt Karol R. Wojcikowski and SSgt Douglas D. Simmons. Based with the 42nd Aerial Refueling Squadron, their immediate problem was two-fold. First, locate and navigate to the pair of F-4E aircraft flying somewhere over the open ocean. Second, get enough fuel to both aircraft so the latter could complete their trans-atlantic hop. Time was of the essence.
Following execution of the rendezvous, the KC-135 crew needed to get their steed out in front of the fuel-hungry Phantoms. The properly operating Phantom quickly took on a load of fuel. However, the stricken aircraft continued to lose altitude as its pilot struggled just to keep the aircraft in the air. By the time the first hook-up occurred, both the F-4E and KC-135 were flying below an altitude of 7,000 feet.
Whereas normal refueling airspeed is 315 knots, the refueling operation between the KC-135 and F-4E occurred below 200 knots. Both aircraft had to fly at high angle-of-attack to generate sufficient lift at this low airspeed. Boom Operator Simmons was faced with a particularly difficult challenge in that the failed starboard hydraulics of the F-4E caused it to yaw to the right. Nonetheless, he was able to make the hook-up with the F-4E refueling recepticle and transfer a bit of fuel to the ailing aircraft.
The transfer of fuel ceased during the first aerial refueling when the mechanical limits of the aircraft-to-aircraft connection were exceeded. The F-4E started to dive as it came off the refueling boom. At this critical juncture, Captain Goodman made the decision to follow the Phantom and get down in front of it for another go at aerial refueling. As the second fuel transfer operation began, the airspeed indicator registered 190 knots; barely above the KC-135’s landing speed.
While additional fuel was transferred to the F-4E, it was still not enough for it to make the divert airfield at Gander, New Foundland. The KC-135 performed two more risky aerial refuelings of the struggling Phantom. The last of which occurred at an altitude of only 1,600 feet above the ocean. At times during these harrowing operations, the KC-135 actually towed the F-4E on its refueling boom to help the latter gain altitude.
At length, the F-4E manged to climb to 6,000 feet and maintain 220 knots as its No. 1 engine began to cool. Able to fend for itself once again, the Phantom punched-off the KC-135 refueling boom. Goodman and crew continued to escort the F-4E to the now-close landing field at Gander, New Foundland. The Phantom pilot greased the landing much to the relief and joy of all.
For their heroic efforts on that eventful September day over the North Atlantic, the crew of the KC-135 received the USAF’s Mackay Trophy for the most meritorious flight of 1983.
Thirty-four years ago today, the USAF/LTV ASM-135 anti-satellite missile successfully intercepted a target satellite orbiting 300 nautical miles above surface of the Earth. The historic test was the first and only time that an aircraft-launched missile successfully engaged and destroyed an orbiting spacecraft.
The United States began testing anti-satellite missiles in the late 1950′s. These and subsequent vehicles used nuclear warheads to destroy orbiting satellites. A serious disadvantage of this approach was that a nuclear detonation intended to destroy an adversary satellite will likely damage nearby friendly satellites as well.
By the mid 1970′s, the favored anti-satellite (ASAT) approach had changed from nuclear detonation to kinetic kill. This latter approach required the interceptor to directly hit the target. The 15,000-mph closing velocity provided enough kinetic energy to totally destroy the target. Thus, no warhead was required.
The decision to proceed with development and deployment of an American kinetic kill weapon was made by President Jimmy Carter in 1978. Carter’s decision came in the aftermath of the Soviet Union’s successful demonstration of an orbital anti-satellite system.
LTV Aerospace was awarded a contract in 1979 to develop the Air-Launched Miniature Vehicle (ALMV) for the USAF. The resulting anti-satellite missile (ASM) system was designated the ASM-135. The two-stage missile was to be air-launched by a USAF F-15A Eagle executing a zoom climb. In essence, the aircraft acted as the first stage of what was effectively a 3-stage vehicle.
The ASM-135 was 18-feet in length and 20-inches diameter. The 2,600-lb vehicle was launched from the centerline station of the host aircraft. The ASM consisted of a Boeing SRAM first stage and an LTV Altair 3 second stage. The vehicle’s payload was a 30-lb kinetic kill weapon known as the Miniature Homing Vehicle (MHV).
The ASM-135 was first tested in flight on Saturday, 21 January 1984. While successful, the missile did not carry a MHV. On Tuesday, 13 November 1984, a second ASM-135 test took place. Unfortunately, the missile failed when the MHV that it was carrying was aimed at a star that served as a virtual target. Engineers went to work to make the needed fixes.
In August of 1985, a decision was made by President Ronald Reagan to launch the next ASM-135 missile against an orbiting US satellite. The Solwind P78-1 satellite would serve as the target. Congress was subsequently notified by the Executive Branch regarding the intended mission.
The historic satellite takedown mission occurred on Friday, 13 September 1985. USAF F-15A (S/N 77-0084), stationed at Edwards Air Force Base, California and code-named Celestial Eagle, departed nearby Vandenberg Air Force Base carrying the ASM-135 test package. Major Wilbert D. Pearson was at the controls of the Celestial Eagle.
Flying over the Pacific Ocean at Mach 1.22, Pearson executed a 3.8-g pull to achieve a 65-degree inertial pitch angle in a zoom climb. As the aircraft passed through 38,000-feet at Mach 0.93, the ASM-135 was launched at a position 200 miles west of Vandenberg. Both stages fired properly and the MHV intercepted the Solwind P78-1 satellite within 6-inches of the aim point. The 2,000-lb satellite was completely obliterated.
In the aftermath of the stunningly successful takedown of the Solwind P78-1 satellite, USAF was primed to continue testing the ASM-135 and then introduce it into the inventory. Plans called for upwards of 112 ASM-135 rounds to be flown on F-15A aircraft stationed at McChord AFB in Washington state and Langley AFB in Virginia. However, such was not to be.
Even before the vehicle flew, the United States Congress acted to increasingly restrict the ASM-135 effort. A ban on using the ASM-135 against a space target was put into effect in December 1985. Although USAF actually conducted successful additional ASM-135 flight tests against celestial virtual targets in 1986, the death knell for the program had been sounded.
In the final analysis, a combination of US-Soviet treaty concerns, tepid USAF support, and escalating costs killed the ASM-135 anti-satellite effort. The Reagan Administration formally cancelled the program in 1988.
While the ASM-135 effort was relatively short-lived, the technology that it spawned has propagated to similar applications. Indeed, today’s premier exoatmospheric hit-to-kill interceptor, the United States Navy SM-3 Block IA anti-ballistic missile, is a beneficiary of ASM-135 homing guidance, intercept trajectory and kinetic kill weapon technologies.
Sixty-five years ago this month, USAF Major Arthur W. “Kit” Murray set a new world altitude record of 90,440 feet in the rocket-powered Bell X-1A. In doing so, Murray reported that he could detect the curvature of the Earth from the apex of his trajectory.
The USAF/Bell X-1A was designed to explore flight beyond Mach 2. The craft measured 35.5 feet in length and had a wing span of 28 feet. Gross take-off weight was 16,500 pounds. Power was provided by an XLR-11 rocket motor which produced a maximum sea level thrust of 6,000 lbs. This power plant burned 9,200 pounds of propellants (alcohol and liquid oxygen) in about 270 seconds of operation.
Similar to other early rocket-powered X-aircraft such as the Bell XS-1, Douglas D-558-II, Bell X-2 and North American X-15, the X-1A flew two basic types of high performance missions. That is, the bulk of the vehicle’s propulsive energy was directed either in the horizontal or in the vertical. The former was known as the speed mission while the latter was called the altitude mission.
On Saturday, 12 December 1953, USAF Major Charles E. “Chuck” Yeager flew the X-1A (S/N 48-1384) to an unofficial speed record of 1,650 mph (Mach 2.44). Moments after doing so, the X-1A went divergent in all three axes. The aircraft tumbled and gyrated through the sky. Control inputs had no effect. Yeager was in serious trouble. He could not control his aircraft and punching-out was not an option. The X-1A had no ejection seat.
Chuck Yeager took a tremendous physical and emotional beating for more than 70 seconds as the X-1A wildly tumbled. His helmet hit the canopy and cracked it. He struck the control column so hard that it was physically bent. His frantic air-to-ground communications were distinctly those of a man who was convinced that he was about to die.
As the X-1A tumbled, it decelerated and lost altitude. At 33,000 feet, a battered and groggy Yeager found himself in an inverted spin. The aircraft suddenly fell into a normal spin from which Yeager recovered at 25,000 feet over the Tehachapi Mountains situated northwest of Edwards. Somehow, Yeager managed to get himself and the X-1A back home intact.
The culprit in Yeager’s wide ride was the then little-known phenomenon identified as roll inertial coupling. That is, inertial moments produced by gyroscopic and centripetal accelerations overwhelmed aerodynamic control moments and thus caused the aircraft to depart controlled flight. Roll rate was the critical mechanism since it coupled pitch and yaw motion.
In the aftermath of Yeager’s near-death experience in the X-1A, the Air Force ceased flying speed missions with the aircraft. Instead, a series of flights followed in which the goal was to extract maximum altitude performance from the aircraft. USAF Major Arthur W. “Kit” Murray was assigned as the Project Pilot for these missions.
On Thursday, 26 August 1954, Kit Murray took the X-1A (S/N 48-1384) to a maximum altitude of 90,440 feet. This was new FAI record. Murray also ran into the same roll inertial coupling phenomena as Yeager. However, his experience was less traumatic than was Yeager’s. This was partly due to the fact that Murray had the benefit of learning from Yeager’s flight. This allowed him to both anticipate and know how to correct for this flight disturbance.
Murray’s achievement in the X-1A meant that the X-1A held the records for both maximum speed and altitude for manned aircraft. It did so until both records were eclipsed by the Bell X-2 in September of 1956.
Kit Murray was a highly accomplished test pilot who never received the public adulation and notoreity that Chuck Yeager did. He retired from the Air Force in 1960 after serving for 20 years in the military. Murray went on to a very successful career in engineering following his military service. Kit Murray lived to the age of 92 and passed from this earthly scene on Monday, 25 July 2011.
Fifty-five years ago this month, the fabled North American X-15 hit a speed of 3,590 mph (Mach 5.23) in a flight that reached an altitude of 103,300 feet. While decelerating through Mach 4.2, the nose gear of the aircraft unexpectedly deployed in flight.
The 114th powered flight of the legendary X-15 Program took place on Friday, 14 August 1964. USAF Major Robert A. Rushworth was at the controls of X-15 Ship No. 2 (S/N 56-6671). The mission would be Rushworth’s 22nd flight in the famed hypersonic aircraft.
X-15 drop from the NB-52A (S/N 52-0003) launch aircraft took place over Delamar Dry Lake, Nevada. Seconds later, Rushworth called for 100% power from the X-15’s XLR-99 liquid-fueled rocket engine as he pulled into a steep climb. He subsequently pushed-over and then leveled-off at 103,300 feet.
XLR-99 burnout occurred 80.3 seconds after ignition. At this juncture, the X-15 was traveling at 3,590 mph; better than 5 times the speed of sound. Following rocket motor burnout, the aircraft slowed and began to lose altitude under the influence of weight and aerodynamic drag.
As the Mach meter needle passed through Mach 4.2, Rushworth heard a loud bang from the airframe. The aircraft became hard to control as it gyrated in pitch, yaw and roll. Rushworth was equal to the moment and brought his troubled steed under control. However, the aircraft had an uncommanded sideslip and Rushworth had to use left aileron to hold the wings level.
Gathering his wits, Rushworth realized that the loud bang he heard was very similar to that which occurred when the nose gear was deployed in the landing pattern. Unaccountably, the X-15 nose gear had deployed in supersonic flight. An unsettling confirmation of Rushworth’s hypothesis came when the pilot spotted smoke, quite a bit of it, in the X-15 cockpit.
As Rushworth neared Edwards Air Force Base, chase aircraft caught up with him and confirmed that the nose gear was indeed down and locked. Further, the tires were so scorched from aerodynamic heating that they probably would disintegrate during touchdown on Rogers Dry Lake. They verily did.
Despite his tireless nose gear, Rushworth was able to control the rollout of his aircraft fairly well on the playa silt. He brought the X-15 to a stop and deplaned. Man and machine had survived to fly another day.
Post-flight analysis revealed that expansion of the X-15 fuselage due to aerodynamic heating was greater than expected. The nose gear door bowed or deformed outward more than anticipated as well. Together, these two anomalies caused the gear uplock hook to bend and release the nose gear. Fixes were subsequently made to Ship No. 2 to prevent a recurrence of the nose gear door deployment anomaly.
Rushworth next flew X-15 Ship No. 2 on Tuesday, 29 September 1964. He reached a maximum speed of 3,542 mph (Mach 5.2) at 97,800 feet. The nose gear door remained locked. However, while decelerating through Mach 4.5, Rushworth heard a bang that was less intense than the previous flight. This time, thermal stresses caused the nose gear door air scoop to deploy in flight. While the aircraft handled poorly, Rushworth managed to get it and himself back on the ground in one piece.
Following another redesign effort, Rushworth took to the air in X-15 Ship No. 2 on Thursday, 17 February 1965. He hit 3,539 mph (Mach 5.27) at 95,100 feet. On this occasion, both the nose gear door and nose gear door scoop remained in place. Unfortunately, the right main landing skid deployed at Mach 4.3 and 85,000 feet.
Thermal stresses were once again the culprit. Despite degraded handling qualities with the landing skid deployed, the valiant Rushworth safely landed the X-15. Upon deplaning, he is reported to have kicked the aircraft in a show of disgust and frustration. Unprofessional maybe, but certainly understandable.
Yet another redesign effort followed in the aftermath of the unexpected main landing skid deployment. This was the third consecutive mission for X-15 Ship No. 2 and Rushworth to experience a thermally-induced landing gear or landing skid deployment anomaly. Happily, subsequent flights of the subject aircraft were free of such vexing problems.
Fifty-six years ago today, NASA chief research pilot Joseph A. Walker flew X-15 Ship No. 3 (S/N 56-6672) to an altitude of 354,200 feet. This flight would mark the highest altitude ever achieved by the famed hypersonic research vehicle.
Carried aloft by NASA’s NB-52A (S/N 52-0003) mothership, Walker’s X-15 was launched over Smith Ranch Dry Lake, Nevada at 17:05:42 UTC. Following drop at around 45,000 feet and Mach 0.82, Walker ignited the X-15’s small, but mighty XLR-99 rocket engine and pulled his ship into a steep vertical climb.
The XLR-99 was run at 100 percent power for 85.8 seconds with burnout occurring around 176,000 feet on the way uphill. Maximum velocity achieved was 3,794 miles per hour which translates to Mach 5.58 at the burnout altitude. Following burnout of the XLR-99, Walker’s X-15 gained an additional 178,200 feet in altitude as it coasted to apogee.
Joe Walker went over the top at 354,200 feet (67 miles). Although he did not have much time for sight-seeing, the Earth’s curvature was strikingly obvious to the pilot as he started downhill from his lofty perch. Walker subsequently endured a hefty 5-g’s of eyeballs-in normal acceleration during the backside dive pull-out. The aircraft was brought to a wings-level attitude at 70,000 feet. Shortly after, Walker greased the landing on Rogers Dry Lake at Edwards Air Force Base, California.
The X-15 maximum altitude flight, in which the aircraft’s design altitude was exceeded by more than 100,000 feet, lasted 11 minutes and 8 seconds from drop to nose wheel stop. In that time, Walker and X-15 Ship 3 covered 305 miles in ground range. This mission was Ship No. 3’s 22nd flight and the 91st of the legendary X-15 Flight Research Program.
For Joseph Albert Walker, the 22nd of August 1963 marked his 25th and last flight in an X-15 cockpit. The mission qualified him for Astronaut Wings since he had exceeded the 328,000 foot (100 km) FAI/NASA standard set for such a distinction. However, it would be more than four decades after his historic mission that Walker would be officially be recognized as an astronaut. In a special ceremony conducted at NASA’s Dryden Flight Research Center on Tuesday, 23 August 2005, Joe Walker was posthumously awarded his Astronaut Wings.
Fifty-four years ago this month, NASA astronauts Leroy Gordon “Gordo” Cooper and Charles M. “Pete” Conrad set a new spaceflight endurance record during the flight of Gemini 5. It was the third of ten (10) missions in the historic Gemini spaceflight series. The motto for the mission was “Eight Days or Bust”.
The purpose of Project Gemini was to develop and flight-prove a myriad of technologies required to get to the Moon. Those technologies included spacecraft power systems, rendezvous and docking, orbital maneuvering, long duration spaceflight and extravehicular activity.
The Gemini spacecraft weighed 8,500 pounds at lift-off and measured 18.6 feet in length. Gemini consisted of a reentry module (RM), an adapter module (AM) and an equipment module (EM).
The crew occupied the RM which also contained navigation, communication, telemetry, electrical and reentry reaction control systems. The AM contained maneuver thrusters and the deboost rocket system. The EM included the spacecraft orbit attitude control thrusters and the fuel cell system. Both the AM and EM were used in orbit only and discarded prior to entry.
Gemini-Titan V (GT-5) lifted-off at 13:59:59 UTC from LC-19 at Cape Canaveral, Florida on Saturday, 21 August 1965. The two-stage Titan II launch vehicle placed Gemini 5 into a 189 nautical mile x 87 nautical mile elliptical orbit.
A primary purpose of the Gemini 5 mission was to stay in orbit at least eight (8) days. This was the minimum time it would take to fly to the Moon, land and return to the Earth. Other goals of the Gemini 5 mission were to test the first fuel cells, deploy and rendezvous with a special rendezvous pod and conduct a variety of medical experiments.
Despite fuel cell problems, electrical system anomalies, reaction control system issues and the cancellation of various experiments, Gemini 5 was able to meet the goal of an 8-day flight. But it wasn’t easy. The last days of the mission were especially demanding since the crew didn’t have much to do. Pete Conrad called his Gemini 5 experience “8 days in a garbage can.”
On Sunday, 29 August 1965, Gemini 5 splashed-down in the Atlantic Ocean at 12:55:13 UTC. Mission elapsed time was 7 days, 22 hours, 55 minutes and 13 seconds. A new spaceflight endurance record.
Gemini 5 was Gordon Cooper’s last spaceflight. Cooper left NASA due to a deteriorating relationship with management. Pete Conrad flew three (3) more times in space. In particular, he commanded the Gemini 11, Apollo 12 and Skylab I missions. Indeed, Conrad’s Apollo 12 experience made him the third man to walk on surface of the Moon.
Fifty-nine years ago this month, USAF Captain Joseph W. Kittinger, Jr. successfully completed a daring parachute jump from 102,800 feet (19.5 miles). The historic bailout took place over the Tularosa Basin of New Mexico.
Kittinger’s jump was the final mission of the three-jump Project Excelsior flight research effort which focused on manned testing of the Beaupre Multi-Stage Parachute Parachute (BMSP). The system was being developed to provide USAF pilots with a means of survival from an extreme altitude ejection.
Transport to jump altitude was via a 3-million cubic foot helium balloon. Kittinger rode in an open gondola. He was protected from the harsh environment by an MC-3 partial pressure suit as well as an assortment of heavy cold-weather clothing. Kittinger and his jump wardrobe and flight gear weighed a total of 313 pounds
The Excelsior III mission was launched just north of Alamogordo, New Mexico at 11:29 UTC on Tuesday, 16 August 1960. Ninety-three minutes later, Kittinger’s fragile balloon reached float altitude. At 13:12 UTC, Kittinger stepped out of the gondola and into space. As he did so, he said: “Lord, take care of me now!”
The historic record shows that Joe Kittinger experienced a free-fall that lasted 4 minutes and 36 seconds. During this time, he fell 85,300 feet (16.2 miles). Incredibly, Kittinger reached a maximum free-fall velocity of 614 miles per hour (Mach 0.92) passing through 90,000 feet.
The BMSP worked as advertised. Kittinger entered the cloud deck obscuring his Tularosa Basin landing point at 21,000 feet. Main parachute deployment occurred at 17,500 feet. Total elapsed time from bailout to touchdown was 13 minutes and 45 seconds.
While Joe Kittinger and the Excelsior team focused on flight testing technology critical to the survival of fellow aviators, a byproduct of their efforts were aviation records that stood for over 50 years. Those achievements include: highest parachute jump (102,800 feet), longest free-fall duration (4 minutes 36 seconds – this record still stands), and longest free-fall distance (85,300 feet).
Sixty-four years ago this month, the USAF/Republic XF-84H experimental turboprop fighter took to the air on its maiden flight. The test sortie was flown at Edwards Air Force Base with Republic test pilot Henry G. “Hank” Beaird, Jr. at the controls.
The XF-84H was an experimental variant of Republic Aviation’s turbojet-powered F-84 Thunderstreak. An Allison XT40-A-1 turboprop engine, rated at 5,850 hp, served as the power source for this novel aircraft. The XT40 drove a variable-pitch, 3-blade, 12-foot diameter propeller at 3,000 rpm. Thrust level was changed by varying blade pitch.
Owing to its high rotational speed and large diameter, the outer 2 feet of the XF-84H propeller saw supersonic velocities. The shock waves that emanated from the prop produced a deafening wall of sound. The extreme sound level produced intense nausea and raging headaches in ground crewmen. As a result, the XF-84H was dubbed the Thunderscreech.
The prop wash from the aircraft’s powerful turboprop necessitated the use of a T-tail to keep the horizontal tail and elevator in clean air flow. The engine’s extreme torque was partially countered by differential deflection on the left and right wing flaps and by placement of the aircraft’s left wing root air intake a foot ahead of the its right intake.
A pair of XF-84H prototype aircraft (S/N 51-17059 and S/N 51-17060) was built by Republic Aviation. The inaugural flight of an XF-84H took place on Friday, 22 July 1955 at Edwards Air Force. This test hop, performed in Ship No. 1 (S/N 51-17059), was cut short by a forced landing.
A total of twelve (12) test flights were made in the two Thunderscreech prototypes; eleven (11) in Ship No. 1 and one (1) in Ship No. 2. Total flight time accumulated by these experimental airframes was 6 hours and 40 minutes. The majority of flights experienced forced landings for one reason or another.
The XF-84H suffered from reduced longitudinal stability and poor handling qualities. The aircraft was also plagued by frequent engine, hydraulic system, nose gear and vibration problems. Faced with the type’s obvious non-viability, USAF opted to cancel the XF-84H Program in September of 1956.
Historical records indicate that the XF-84H reached a top speed of 520 mph during its brief flight test life. This figure was a full 120 mph short of the aircraft’s design speed. Nonetheless, the XF-84H held the speed record for single-engine prop-driven aircraft until Monday, 21 August 1989. On that date, a specially modified Grumman F8F Bearcat established the existing record of 528.33 mph.
Fifty years ago today, Apollo 11 astronauts Neil Alden Armstrong, Edwin Eugene Aldrin, Jr., and Michael Collins returned safely to the Earth to bring to a close the first space mission to land men on the lunar surface. With their safe return, President John F. Kennedy’s inspired national goal of landing men on the Moon and bringing them safely home before the end of the 1960’s was successfully accomplished.
The crew of Apollo 11 and their celestial chariot, Columbia, splashed-down in the Pacific Ocean at a point 812 nautical southwest of Hawaii. The epic journey to the Moon and back covered 952,700 nautical miles. Mission total elapsed time was 195 hours, 18 minutes, and 35 seconds.
Following splashdown, the Apollo 11 astronauts and their Command Module Columbia were brought aboard the USS Hornet (CV-12). Concerned that they would infect Earthlings with lunar pathogens, NASA quarantined the astronauts in the Mobile Quarantine Facility (MQF), which was a converted vacation trailer.
The Hornet steamed for Hawaii and transferred the MQF for airlift to Ellington Air Force Base, Texas. Following landing, the MQF and its heroic occupants were transported to the Johnson Spacecraft Center (MSC) in Houston, Texas. Once there, the astronauts and several medical staff were transferred from the MQF to more substantial accommodations known as the Lunar Receiving Laboratory (LRL).
Combined stay time in the MQF and LRL was 21 days. During their forced confinement, Armstrong, Aldrin, and Collins debriefed the Apollo 11 mission, rested, and mused about their unforgettable experiences at the Moon.
The Apollo 11 astronauts were released from the LRL on Thursday, 13 August 1969, having never contracted nor transmitted a lunar disease.
Parenthetically, Apollo 11 brought the first geologic samples from the Moon back to Earth. Roughly 48 pounds of lunar rock samples were collected. Two primary types of rocks, basalts and breccias, were found at the Sea of Tranquility landing site. Subsequent analyses indicated that these samples neither contained water nor provided evidence for living organisms at any time in the history of the Moon.
