My Next Project

I'm dusting things off here and starting work on a new manuscript for a book on the development of high-speed flight. 

Most attention has been paid to experimental test planes, but I am much more interested in how these innovations were translated into production aircraft that reached operational service.  My emphasis will be to explore aerodynamic, airframe, structural, and turbojet innovations that were needed to achieve first supersonic flight, then the even greater challenge of achieving Mach 2.  I will cover the X-1, D-558, X-2, etc., in due course, but will essentially start the story with the YP-38 Lightning, look at early transonic designs such as what would become the XF3H-1 Demon, and follow things forward from there through at least the development of the F-104A.  

Look for some little draft snippets to start showing up here soon.  I might put up some new F-101 stuff as well based on continuing research.  Stay tuned, fighter fans!

The Fighter Writer is back on the air!

Good evening, fighter fans!

Having moved a little over a year ago, unpacking, embarking on a new career and basically settling in, I've neglected my blog and after much trouble have regained access to it--after establishing that the malfunction was caused by an operator headspace error.

I've continued expanding the original manuscript for my F-101 book and have been assisting a couple of other authors with their own research projects.  As time allows, I am continuing to research USAF and Communist night fighter operations in the Korean War.  The manuscript on a new book on the F3H Demon is on the back burner but continuing to simmer away.  I've also been delving deep into ECM development for SAC bombers from the Korean War to the early years over Vietnam.

Things have been a little crazy and for those who may be following me in this dusty little corner of the Internet, my apologies for the absence.  But in any case, look for more Voodoo and fighter goodness to come your way soon!

Taiwan and the RF-101A Voodoo

After the conclusion of the Korean War, the Communist Chinese began construction of at least ten new airfields across the Taiwan Straits from the island of Formosa, or Taiwan, which since 1948 had been the refuge of Kuomintang or “Nationalist Chinese” forces after their expulsion from the mainland.  Having evacuated to Formosa, they remained as a government-in-exile as the Republic of China.  The late 1950s saw a continuing pattern of improvements to Red Chinese capabilities that could threaten Taiwan and its key strategic outposts on the islands of Quemoy, covering the approaches to the port city of Amoy, and Matsu, overlooking the port city of Fuzhou.  Also, a rail line had been built from the city of Yingtan to Amoy, along with a major POL (Petroleum, Oil, and Lubricants) facility of 1,500,000 gallons capacity located at about the halfway point.  The rail line, completed in early 1957, offered a vastly increased capability to sustain logistical support of an invasion of Nationalist-held territories.  Soon after the Quemoy crisis of 1958 came advanced Soviet-supplied weapons such as the MiG-19 and SA-2 “Guideline” surface-to-air missile.

With the need to monitor Red Chinese activity in the aftermath of the latest crisis over the Taiwan Strait, an agreement between the USAF and Republic of China Air Force (ROCAF) was signed in November 1959 to provide reconnaissance aircraft.  By this point, the ROCAF had already received several now-obsolescent RF-86F aircraft, and operated about 20 Republic RF-84F Thunderstreaks, four North American RF-100A “Slick Chicks”, and a single Martin RB-57D for high-altitude reconnaissance.  The ROCAF was dissatisfied with the RF-100A as it entered service in 1959 and by the time it was retired at the beginning of 1961, it never flew an operational mission.  To augment high-speed, low-altitude reconnaissance assets and replace the RF-100As, four RF-101A Voodoos would be supplied to Taiwan under Project Boom Town.

ROCAF RF-101As at Taoyuan AB, Taiwan.  From front to rear: “5652” (ex-54-1503), “5656” (ex-54-1519), “5650” (ex-54-1500), and “5654” (ex-54-1499).  “5656” would be shot down over the Taiwan Straits by a MiG-19 on 18 March 1965, while “5650” would become the last operational RF-101A, serving with the ROCAF until August 1973. Jim Sullivan Collection.

 

The four RF-101As transferred were 54-1500 as “650”, 54-1503 as “652”, 54-1499 as “654”, and 54-1519 as “656”.  USAF records show two aircraft delivered to the ROCAF on 28 October 1959 under provisions of the Military Assistance Program (MAP).  These aircraft were assigned to the 4^th Tactical Reconnaissance Squadron at Taoyuan AB, west of the capital city of Taipei.  At least in December 1959, these aircraft appear to have been on PACAF’s books as it had a total of 40 RF-101A/C aircraft assigned, four more than authorized, based at Kadena AB, Okinawa with the 15^th TRS and the 45^th TRS at Misawa AB, Japan.  Conversion training for the ROCAF pilots took place at Kadena AB.  Once the ROCAF pilots of the 4^th TRS completed their training on the Voodoo, missions over the coastal areas of the Chinese mainland began on 8 December 1960 under Project Sentry Dog, covering all of the Communist air bases opposite of Quemoy.  The ROCAF was very pleased with the low-level reconnaissance ability of the RF-101A, despite the fact that their aircraft used standard A-9B film magazines without image motion control, which limited their minimum mission altitude.  Ingress routes to the objective were flown at literally rooftop level, avoiding trees and power lines along the way, followed by a “pop-up” to a suitable altitude over the objective to ensure good image quality and then maximum power egress back toward the Taiwan Strait at supersonic speed.  In addition to Red Chinese airfields, the Voodoos also soon collected detailed photographs of radar sites and Communist monitoring stations and signals intelligence (SIGINT) facilities directed toward the heavily-populated northern half of Taiwan.  A mission by Major Yeh Chang-ti in June 1961 brought back photos of five new MiG airfields along the coast, for which both Major Yeh and the 4^th TRS were personally recognized by Generalissimo Chiang Kai-shek.  Major Yeh soon went on to become one of the first ROCAF pilots assigned to fly the U-2 as one of the famed “Black Cats.”

Photographed prior to its transfer to the ROCAF in mid-1961, RF-101A 54-1498, as “5649,” became the first Voodoo lost to hostile fire when Maj. Wu Pao-tze was hit by AAA and captured near Fuzhou, Red China on 2 August 1961. Mark Nankivil Collection.

Attrition losses soon began to take their toll on the small Nationalist RF-101A fleet.  On 23 July 1961, an RF-101A, 54-1503 as “5652”, was badly damaged in an accident and unavailable until the end of 1961.  An attrition replacement was soon provided, 54-1498 as “5649”.  This aircraft became the first-ever combat loss of an RF-101 on 2 August 1961, when “5649” was shot down by anti-aircraft fire over the port of Fuzhou in mainland China.  The pilot, Major Wu Pao-tze, was captured and became a POW.   Subjected to brainwashing by his captors, Wu later collaborated by a broadcast calling upon ROCAF Voodoo pilots by name to defect to the mainland with their aircraft.  The damaged aircraft, “5652”, was repaired during the fall of 1961 and returned to service, bringing the total strength back to four aircraft.  As Chiang Kai-shek continued his plans to overthrow the Communist government on the mainland and the Red Chinese continued work toward building an atomic bomb, ROCAF reconnaissance aircraft continued to remain quite busy conducting missions over the coastal areas of the mainland.

Nationalist Chinese operations with the RF-101A continued after the conclusion of the 1962 Taiwan Strait crisis in August of that year.  In early 1963, the first of three new RF-101As were transferred to Taiwan under MAP to take the place of three of the original aircraft that were scheduled for depot-level maintenance at Hill AFB.  These aircraft, “5650” (54-1500), “5652” (54-1503) and “5654” (54-1499) departed for the United States via Kadena AB.  The replacement aircraft appear to have been 54-1501 (as “5651”), 54-1505 (as “5660”) and 54-1506 (as “5658”).  At least the last two aircraft had been modified with the small afterburner cooling inlet on the leading edge of the vertical fin, as present on the RF-101C.   This appears to have been a one-off modification to allow the ROCAF RF-101A aircraft extended time in afterburner.

RF-101A-25-MC 54-1505 shortly after recovering at Ontario Airport, CA during Desert Strike in May 1964.  Soon afterward, this aircraft would be transferred to Taiwan as an attrition replacement for the ROCAF  as “5660.” NARA via Mark Nankivil.

Tensions across the Taiwan Strait increased sharply with the detonation of an atomic bomb by the Communist Chinese on 16 October 1964.   Reconnaissance sorties by ROCAF RF-101A aircraft had begun to increase during the summer of 1964.  Meanwhile, Taiwan was in the midst of transitioning from the RF-84F to the new RF-104G, which would become operational with the 12^th TRS in November 1964.  The ROCAF suffered its second combat loss of an RF-101A when “5651” (54-1501) was severely damaged by a J-6 (MiG-19) “Farmer” interceptor over Wenzhou, Zhejiang Province in late December 1964.  Major Hsieh Hsiang-ho was captured by local fishermen after bailing out of his stricken Voodoo just offshore and became a POW.  Up to that point, ROCAF RF-101As had completed 139 successful reconnaissance missions over the Chinese mainland without being intercepted by Communist MiGs.  A second loss to the speedy and powerful J-6 occurred on 18 March 1965 with the loss of “5656” (54-1519) and the pilot, Lt. Col. Chang Yu-pao, who was killed in action.  His aircraft was shot down over the Taiwan Strait just offshore of Guangdong, near Shantou.  This would be the last operational loss of a Nationalist RF-101A.  Left with two operational RF-101A Voodoos that suddenly appeared vulnerable to the MiG-19, on 22 April 1965 the Air Staff at Headquarters USAF reportedly ordered that they be replaced in their role by RF-104G aircraft with the speed and acceleration to evade the newer interceptors.  However, this account is disputed by Taiwanese sources.  Analysis of MAP records shows a sharp reduction in flying hours per aircraft for the RF-101A after the losses, but by the late summer of 1965 this decision had either been rescinded or ignored by the ROCAF as RF-101A utilization returned to early 1965 levels.  Both the RF-101A and RF-104G maintained a similar number flying hours per aircraft through mid 1970, averaging roughly 60 hours per quarter, strongly implying that the RF-101A was not superseded but rather complemented by the RF-104G.

Shenyang J-6 Farmer of the PLAAF, an unlicensed copy of the Soviet MiG-19.  The agility, rate of climb, lethal 30-millimeter cannon armament, and excellent low-level speed of the Farmer made it a formidable defensive weapon against even the speedy Voodoo.  Wikipedia.

Although faster, the RF-104G carried only three 70-millimeter format KS-67A cameras in a trimetrogon configuration in the forward fuselage in front of the engine.  The negatives were much smaller than the 9-inch by 9-inch negatives of the KA-2 cameras carried by the RF-101A in the same arrangement.  The RF-104G did not have any provision for a forward oblique camera and could not conduct “dicing” missions as the RF-101A could.  The newer aircraft also had nothing even approaching the capabilities of the split vertical KA-1 arrangement of the RF-101A.  While the 70-millimeter cameras did offer good resolution given their size, the area covered by the trimetrogon fan was also deemed insufficient.  However, the retention of the KA-2 cameras in the ROCAF Voodoos restricted their minimum mission altitude as had been the case for USAF aircraft during the Cuban Missile Crisis.  Using the A-9B film magazines with no IMC capability, the RF-101A would have had a V/H ratio of about 0.26, limiting their aircraft to a minimum altitude of about 1,700 feet at 400 knots and 2,600 feet at its maximum speed of 637 knots.  Overall, although the low-altitude performance of the RF-104G was impressive, the opinion within the ROCAF was that it was hampered by its camera system and seldom produced quality results.  The ROCAF RF-101A contingent was brought back up to four aircraft by the end of 1965 with the return from Hill AFB of two of the aircraft sent to the United States for maintenance.  The third aircraft, 54-1503, was apparently too far gone for economical repair and was not returned.  This left the surviving ROCAF force as consisting of 54-1499 (“5654”), 54-1500 (“5650”), 54-1505 (“5660”) and 54-1506 (“5658”), still serving with the 4^th Tactical Reconnaissance Squadron.

Chiang Kai-shek’s continued obsession with “liberating” mainland China against clearly insurmountable Communist forces had long ago become a source of friction with the United States, which had committed to defend Taiwan against attack but would never approve of overt military action to overthrow the regime of Mao Tse-tung.  From an aerial reconnaissance standpoint, the issue came to a head over the course of 1967.  On 13 January 1967, an RF-104G mission over the mainland led to an air battle over the Taiwan Strait in which a pair of Red Chinese MiG-19s were downed by F-104Gs covering the escape of the ROCAF reconnaissance aircraft.  The day previously, another RF-104G conducting a high-altitude mission over a coastal objective was pursued over the Taiwan Strait for the first time by a pair of  MiG-21 interceptors.  This was followed in the late summer of 1967 by the downing of a ROCAF U-2 over Quzhou in Jiaxing Province.  These events soon led to the termination of all CIA and US military-sponsored overflights of mainland China by ROCAF reconnaissance aircraft.  From this point on, only peripheral missions using oblique photography would be approved.  The last overflight of mainland China by a ROCAF U-2 occurred on 16 March 1968.

Coincident with the planned retirement of the RF-101 from the regular USAF, the Nationalist Chinese RF-101A force was reduced in the fall of 1970 from four aircraft to one operational aircraft.  It would appear that the three retired ROCAF aircraft were retired to provide equipment spares for the last remaining aircraft, 54-1500 (“5650”).  Despite its age, the last remaining RF-101A offered unique imaging capabilities that could not be equaled by the RF-104G.  This last aircraft remained operational with the 4^th TRS until the unit was deactivated in February 1973, when it was transferred to the 12^th TRS for its last six months of active service into the summer of 1973, when it was retired from service on 1 August and later returned to the United States.  RF-101A 54-1500 does not show up in AMARC records and was apparently scrapped at Hill AFB.  The other three aircraft remained in Taiwan to become display aircraft, where they remain at this writing.

Voodoos vs. MiGs: 1965-1968

Selected North Vietnamese pilots had begun training in China to operate MiG-15s and MiG-17s in 1960.   By the end of 1962 this contingent received 36 MiG-17F “Fresco-C” fighters to form the first fighter squadron of the Vietnam People’s Air Force (VPAF), the 921^st Fighter Regiment, but both the unit and its aircraft remained in China.  In the aftermath of the Gulf of Tonkin incident, the 921^st Fighter Regiment was recalled from China and arrived at Noi Bai airport (known to the Americans as Phuc Yen) near Hanoi on 6 August 1964.  In April 1965, North Vietnamese MiG-17s made their first kills of the war when two MiG-17Fs of the 921^st Fighter Regiment shot down two F-105Ds of the 355^th TFW near Thanh Hoa.  Maj. F. E. Bennett and Capt. J. A. Magnuson were killed in action.  The threat of MiGs had appeared, but then seemed to fade afterwards.  Of greater concern to mission planners was new imagery of two SA-2 “Guideline” surface-to-air missile sites under construction.  Concerned about the MiG threat, in June 1965 CINCPAC in Hawai’i ordered daily photo coverage of all jet-capable airfields in North Vietnam above 20-degrees North latitude.  Green Python RF-101Cs from Udorn RTAFB covered the requirement on odd days, Navy RF-8As on even days.  Effective 7 September 1965, the VPAF formed a second fighter squadron, the 923^rd Regiment, equipped with MiG-17s.  By this time, the 921^st had begun conversion to the MiG-21F-13 “Fishbed-C” and operated both types.  On 18 September 1965, the Americans discovered eight MiG fighters photographed at a new base at Kep Airfield, 35 nautical miles northeast of Hanoi, along with 24 shipping crates at Phuc Yen.  Soon, US intelligence analysts noted that the North Vietnamese were demonstrating proficiency in GCI control of MiGs.  By early November, CINCPAC expressed concern that MiGs might present a greater threat to recon aircraft.  2nd Air Division assured CINCPAC that the speed and maneuverability of the RF-101C would be sufficient defense against MiG-15 and MiG-17 interceptors.

VPAF pilots of the 923^rd Fighter Regiment on the flight line with their new MiG-17F “Fresco-C” interceptors. USAF.

The MiGs were the newest threat, but others remained more concerning. While anti-aircraft guns remained the deadliest component of North Vietnamese air defenses, planners continued to cast a wary eye on the increasing numbers of SA-2 sites being discovered in North Vietnam, especially after the brief and unsuccessful introduction of the QRC-160 ECM pod in the spring of 1965.  Throughout the course of May 1965, U-2 aircraft monitored the emplacement of more sites surrounding Hanoi.  RF-101Cs could not provide detailed photography of the sites due to the 40 nautical mile range restriction around Haiphong and the MiG base at Phuc Yen.  It had been noticed that MiGs would not be scrambled against targets outside of the 40-mile radius.

Engagement envelopes of guns and surface to air missiles encountered during the conflict in Indochina. USAF.

The North Vietnamese MiGs tangled with the Voodoo for the first time on 12 October 1965.  A pair of RF-101s conducting a mission near Yen Bai, 30 miles northwest of Hanoi, reported taking cannon fire from a pair of MiG-17s, but received no damage.  A month later, on 15 November 1965, two 15^th TRS RF-101Cs were flying at 9,000 feet photographing an objective at Yen Bai when they encountered a pair of MiGs passing behind them at 15,000 feet, setting up in a high left perch, and then diving right to open fire on the wingman.  After completing his photo run, the lead RF-101Cs egressed at maximum speed toward friendly territory.  Meanwhile, the wingman descended to 500 feet AGL and maximum speed, transiting Yen Bai at 100 feet.  The MiG-17s, flying into the face of ferocious anti-aircraft fire directed toward the Voodoos from a significant portion of the 200 AAA pieces at Yen Bai, broke off their attack and the second RF-101s successfully returned to Udorn after the pilot flew into a fog-filled valley and used the tremendous power of his Voodoo to execute a rapid climb to 44,000 feet.  On 26 November, two more Voodoos conducting a mission north of Yen Bai were engaged by four MiG-17s diving at them and opening fire with their cannons from a range of 4,000 feet.  The RF-101s broke left and dived down to 200 feet, losing sight of the MiGs and returning home.  Within a month, the new MiG-21s of the 921^st regiment were known to be active.  At about the same time, the VPAF received the first of ten radar-equipped MiG-17PF “Fresco-D” interceptors.  In late January 1966 the 921^st Fighter Regiment began introduction of the MiG-21F-13 “Fishbed-C”, taking part in combat missions the following month alongside the more numerous MiG-17.  A number of MiG sightings occurred in February and March 1966, the most notable of which concerned a mission near the Chinese border on 12 February 1966.  A pair of RF-101s had completed a reconnaissance run over an objective in North Vietnam at 40,000 feet when they had apparently strayed inside of Chinese airspace to a point about 5 miles west of where the Tengtiao River crosses the border with North Vietnam.  Two incoming bogeys were sighted on a southerly heading toward them, but abruptly turned west at the time of the sighting.  No positive identification could be made but they were apparently inbound Chinese MiGs.  The Voodoo experienced another reported encounter with MiGs over North Vietnam on 17 March 1966. Two RF-101Cs piloted by Major Hallet P. Marston and Captain Richard M. Cooper were near their objective in the vicinity of Dien Bien Phu when they were engaged by MiG-17s, which made four firing passes.  Dense haze allowed RF-101s to evade further visual contact, engage afterburner and escape, easily outdistancing the pursuing MiGs.

Commander of the VPAF 921^st Fighter Regiment, Major Tran Hanh, in the cockpit of a MiG-21PFM “Fishbed-F” ca. 1970.  The 921^st was the first North Vietnamese unit to field the MiG-21 beginning in April 1966. USAF.

MiG-21PF “Fishbed-D” interceptor of VPAF.  Lacking the cannons and maneuverability of the MiG-17, the MiG-21 had Mach 2 speed and carried either 57-mm rocket pods or AA-2 “Atoll” IR-guided missiles. USAF.

On 23 April 1966, MiG-21s engaged American fighters for the first time with no success. By this time the VPAF received its first MiG-21PF “Fishbed-D” interceptors.  Over the course of the spring of 1966, numerous problems with the R-3S (NATO: AA-2 “Atoll”) missiles and inexperience with the relatively complex fire control system of the MiG-21 resulted in very limited combat effectiveness.  While the initial MiG-21F-13 aircraft were each armed with a single 30-millimeter cannon, the newer MiG-21PF with its much more capable RP-21 radar had no internal cannon and relied solely upon either “Atoll” missiles or 57-millimeter rocket pods.  The North Vietnamese pilots were also required to work within overly strict and inflexible tactical guidelines.  In the case of the MiG-21 pilots, the tactical maneuvers that worked well for the agile MiG-17 proved far less suited to the MiG-21.  With the introduction of the MiG-21, both MiG types underwent a division of labor in which the MiG-21s would engage targets above 8,000 feet, and the MiG-17s anything below 5,000 feet.  Any aircraft in the intermediate zone could be engaged by either type.  However, the SA-2 surface-to-air missile remained the primary defensive weapon.

The reintroduction of ECM pods and changes in tactics to avoid gunfire in the latter half of 1966 caused a change in MiG activity.  To avoid the far more numerous small-caliber AAA weapons, USAF strike aircraft started flying their missions above a minimum altitude of 6,500 feet.  Beginning in the early fall, F-105 units reintroduced improved ECM pods that proved highly effective against both missiles and the fire control radars of the larger-caliber AAA guns.  However, the pods had the disadvantage of highlighting the positions of strike packages on the scopes of North Vietnamese GCI operators, who could triangulate on the American strike aircraft and vector MiGs to those positions.  As a result, VPAF MiG pilots became distinctly more active and aggressive toward the end of 1966.

RF-101C-65-MC 56-0083 of the 45^th TRS departing in afterburner, ca. 1966.  The first aircraft in Southeast Asia to carry camouflage, the original all-black tail markings have been modified with the serial number now in white.  This aircraft carries both nose and tail antennas for the AN/APR-25 RWR system.  NARA via Mark Nankivil.

On New Year’s Day 1967, two RF-101Cs photographing objectives southwest of Hanoi received an electronic indication of approaching MiGs.  Along with much of the fleet, the Voodoos had recently been modified with AN/APR-25 radar warning receivers, which showed an X-Band strobe at their 10 o’clock, moving toward their 9 o’clock position.  The contact then settled into their 6 o’clock at one ring, uncomfortably close.  Taking advantage of dense cloud cover and accelerating to Mach 1.05, the recon aircraft turned for home and noted the high speed of the pursuing aircraft, which were able to remain close enough to remain at two rings on the indicator before the contact broke off pursuit at the Laos border.  The Voodoo pilots could not get a visual identification on the interceptors but due to their speed believed that they were MiG-21s.  However, the next day the North Vietnamese MiG-21 force was dealt a very severe blow on 2 January 1967, courtesy of Operation Bolo, conceived by the staff of the legendary former commander of the 81^st Tactical Fighter Wing at RAF Bentwaters and new boss of the 8^th TFW “Wolfpack”, Colonel Robin Olds, claiming seven VPAF MiGs.  While the MiG-17s were directed to remain below the cloud deck over the area, the MiG-21s climbed through to engage what they thought was another strike force of F-105 Thunderchiefs to meet a buzz saw composed of waves of hungry F-4C Phantoms that were loaded for bear with air-to-air missiles.   North Vietnamese MiG-21s would remain out of action for several months as they reformed their depleted ranks while MiG-17 operations continued at a lower level than had been the case previously.

Colonel Robin Olds, former commander of the 81^st TFW ca. October 1967 as commander of the 8^th TFW in Thailand. USAF.

With the North Vietnamese MiG force at least temporarily out of commission, the focus of American defensive efforts shifted back to electronic countermeasures. Much of the effectiveness of the ECM was contingent upon a properly-spaced tactical formation.  The protection afforded by QRC-160A-1 pods was additive, single aircraft were judged to remain somewhat vulnerable.   Although the pods produced extra drag, the effect was offset by a net increase in fuel efficiency due to the reduced need for evasive maneuvering.  With the successful test of the improved QRC-160 equipment after its troublesome introduction in 1965, medium altitude was opened up once again for USAF tactical aircraft.  After the spectacular success of the evaluation, the QRC-160A-1 pod was soon given an official designation as the AN/ALQ-71.  However, although its overall reliability was greatly improved, the ram-air turbine providing power to the electronics proved prone to failure, disabling the pod.  Also, at ranges closer than 8 to 10 nautical miles from the target emitter, the jammed radar would begin to “burn through” and render the pod ineffective.  Due to its radiation pattern, maneuvering flight could negate the pod’s effectiveness.

Rear quarter view of the QRC-160A-1 self-protection ECM pod, accepted into service as the AN/ALQ-71. USAF.

By January 1967, 7^th Air Force now had enough ALQ-71 pods available to begin equipping F-4s and F-105s.  For the time being, the RF-101C was not selected to carry the new ECM pod.  The stated reasons were that RF-101s usually flew alone and would refuse to jam until being tracked by hostile radar.  Therefore, the Navy’s AN/ALQ-51 deception jammer seemed ideal for the Voodoo as it activated automatically after being triggered by signals from a targeting radar.  The ALQ-51 also had the advantage of being internally mounted and therefore avoiding the previous drag and wing twisting problems experienced with the RF-101 when carrying the QRC-160-1 pod in the spring of 1965.  The equipment was initially very effective at countering SA-2 missiles, but during the summer of 1967 RF-101 losses began to mount as North Vietnamese defenses began to rapidly adjust. 7^th Air Force therefore directed withdrawing ALQ-51 units from use after less than a year.  A new directive was issued to resume two-ship RF-101C flights, with each aircraft carrying a pair of ALQ-71 pods under wings.   Due to the detrimental effect on the best defensive qualities of the RF-101, maneuverability and above all speed, it was directed that the Voodoo aircraft remain away from MiG operating areas, leaving these target sets to the faster and more capable RF-4C.  An alternate tactic allowing some more flexibility for the RF-101C was to provide fighter escorts carrying the ALQ-71 pods to provide protection.

Although MiG activity had decreased after Operation Bolo, RF-101s continued to occasionally encounter MiGs in the early months of 1967.  Two weeks after Operation Bolo, on 16 January 1967, an RF-101C inbound at 22,000 feet to photograph a secondary target in Laos about 45 nautical miles southwest of Dien Bien Phu received an X-Band contact on his APR-25 receiver at 1 o’clock, which persisted for three minutes.  He then sighted a silver, swept wing aircraft at 25,000 feet, setting up for an apparent quartering head-on attack.  The pilot broke his Voodoo hard left 180 degrees and descended through a thin cloud deck at 12,000 feet at military power and made his way back to Udorn RTAFB.  Barely two weeks later, 65 nautical miles northwest of Hanoi, a pair of RF-101s climbing through 10,000 feet tallied a pair of MiG-17s orbiting directly overhead.  The Voodoos quickly ducked back down to 100 feet AGL to avoid being noticed and continued their mission.  On 10 February 1967, another pair of RF-101s at 21,000 feet operating over northeastern Laos, about 30 miles from the border with North Vietnam, sighted a MiG on a reciprocal heading at about 35,000 feet and 10 miles.  Heading northwest and crossing into North Vietnamese airspace to a point east of Dien Bien Phu, the Voodoos about 15 minutes later sighted an IL-14 “Crate” transport at 4,000 feet, flying out of Dien Bien Phu.  While the RF-101s were photographing the transport, they noticed an Mi-6 “Hook” heavy transport helicopter in the same vicinity.    

Finally recovered from its mauling at the hands of the Phantoms of Robin Olds’ 8^th TFW “Wolfpack” to open 1967, the MiG-21s of the 921^st Fighter Regiment re-entered the fight during the spring of that year.  Shortly after Operation Bolo, the VPAF high command evaluated what had happened and made changes to ensure that such an event would never happen again.  One of the first adjustments was to change to “hit-and-run” tactics that played to the strengths of the MiG-21, namely speed, acceleration, and presentation of a small, fleeting target.  These qualities were tactically integrated with the positive qualities of the MiG-17, which still formed the backbone of the VPAF.  Attacking MiGs would work primarily in small groups of two to four aircraft approaching at varying altitudes.  The MiG-21s would be positioned to attack American aircraft from above with “Atoll” missiles while the MiG-17s would approach from the sides of approaching strike formations to make the best use of their maneuverability and heavy cannon armament.  The VPAF MiG-21s resumed combat operations on 23 April 1967 with the engagement of USAF F-4Cs.  On 29 April, a MiG-21 was sighted by a Voodoo during a mission over Hoa Loc airfield.  Flying at 15,000 feet, the RF-101 was fired on by an SA-2 when at the same time the pilot noticed the MiG at 4 o’clock and 6 miles, climbing.  There was no further contact and the Voodoo returned to base.  Several days later, on 3 May 1967, the pilots of a pair of Voodoos conducting a mission in North Vietnam 16 miles ENE of Thai Nguyen noticed black puffs 25-50 feet from their aircraft, then observed a single MiG tracking them from their right at 2 miles.  There was no further contact with the MiG.  On 22 May, a pair of RF-101s photographing the Xac Mai motor pool south of Hanoi at 12-14,000 feet observed the launch of two SA-2 missiles.  At the same time the second missile passed them, the Voodoos began to take fire from 85-mm AAA.  A MiG alert soon followed, after which the American pilots noticed what appeared to be two MiG-17s at their 8 o’clock position.  After two more SA-2s were fired at them, they received a MiG call on the Guard frequency just before it cut out due to enemy jamming.  The RF-101s chose to select afterburner for 3 minutes and egress southwest toward Laos to clear the mountains, then dropped to low level to ensure that they shook off any pursuing MiGs.    

Due to the improved tactics and increased familiarity with the MiG-21 and its somewhat cumbersome weapon system, the MiG-21 saw increased activity through the spring and well into the summer of 1967.  On 11 June 1967, an RF-101C on a Blue Tree mission 17 miles southeast of Son La, just north of the border with Laos, was at 25,000 feet when the pilot noticed a MiG-21 with contrails at 30,000 feet and 5 miles.  When the MiG broke right to dive toward the Voodoo, the pilot dropped his external tanks and executed a left diving turn to level off at 100 feet AGL, selected afterburner, and egressed at 620 knots on the deck, picking up an X-Band strobe on his APR-25 display.  The Voodoo pilot noticed that the MiG appeared to parallel his aircraft during his descent but was not observed again after crossing a short distance into Laos.  Numerous MiG warnings were being received that day for 60 miles west to 80 miles northwest of Hanoi.  The luck for the intrepid Voodoo crews was about to run out.  On 16 September 1967, a 20^th TRS RF-101C, 56-0180, was shot down by a MiG-21about 5 miles north of Son La.  The Voodoo was flown by Maj. Bob Bagley as part of two-ship formation photographing the Northwest Railroad.  Bagley was captured and became a POW.   The following day, another 20^th TRS Voodoo, 56-0181, flown by Capt. Bob Patterson, who had been downed by an SA-2 less than three months previously, was also downed by a MiG-21 but fortunately was once again rescued by American forces.  Both aircraft were downed by MiG-21F-13 “Fishbed-C” fighters assigned to the 921^st “Sao Do” Fighter regiment, using AA-2 Atoll missiles in both cases.  Nguyen Ngoc Do claimed Bagley’s aircraft while flying “4420”, while Pham Thanh Ngan claimed Patterson’s Voodoo in “4520.”  The standard configuration for the RF-101C during such a mission would have called for the carriage of ALQ-71 pods, but these incidents made it clear that they reduced the speed of the Voodoo to such a degree that the RF-101C could be overtaken by the MiG-21 before the interceptors would have to break off due to low fuel.  These two incidents led 7^th Air Force to prohibit further RF-101C missions over the heavily-defended northern areas of North Vietnam, but missions over Laos and the North Vietnam panhandle continued.  The 20^th TRS experienced its last RF-101C loss when Nick Pishvanov was hit by gunfire over Laos, leading to the loss of 56-0212.  Pishvanov ejected and was soon rescued by a CH-3 “Jolly Green Giant” rescue helicopter.  Now vulnerable to the MiG-21 with the ALQ-71 pods and to the SA-2 without them, there was no recourse left but to withdraw the RF-101C from major combat operations over North Vietnam. 

Closest in this row of 20^th TRS Voodoos is the first one lost to the MiG-21, 56-0180.  Maj. Bob Bagley was shot down near Son La, North Vietnam by an AA-2 “Atoll” missile fired by Nguyen Ngoc Do on 16 September 1967.  Nguyen was flying MiG-21F-13 “4420” during the mission, an early “Fishbed-C” aircraft. NARA via Mark Nankivil.

MiG-21PF “Fishbed-D” interceptor with underwing AA-2 “Atoll” missile. USAF.

As a postscript, the RF-101 would soon be evaluated against the same aircraft that had recently demonstrated success against the Voodoo, a captured MiG-21F-13 in Nevada, given the code name “Have Doughnut.”  Provided to the USAF by the Israeli government after their intelligence services had arranged with an Iraqi pilot to defect with his aircraft, the Fishbed-C was evaluated against a variety of USAF and U.S. Navy aircraft beginning in February 1968 within the restricted airspace of the Nevada Test Site.  The sole evaluation of the MiG-21 against a “clean” 363^rd TRW RF-101 at 15,000 feet took place during a 40 minute flight on 15 March 1968.   Acceleration was compared between the two aircraft at both military and maximum power, yielding basically equal results.  During the two simulated engagements that followed, the MiG-21 was able to keep up with and track the Voodoo through its break turn and maneuvers during diving flight.  The MiG-21 experienced significant buffet at 530 knots indicated airspeed and was unable to accelerate further while the RF-101 continued to accelerate away to reach a speed of 650 knots.  The results of the test flight indicated that the best defensive maneuver for the RF-101 when engaged by a MiG-21 was a straight unloaded acceleration with minimum maneuvering to defeat an “Atoll” missile launch and separate at minimum altitude.  A steep descent of 45-degree dive angle would not only take advantage of ground clutter against the infrared seeker head of the “Atoll,” but due to the high stick forces and poor pitch rate of the MiG-21 at speeds above 500 KIAS at these relatively low altitudes, the MiG pilot would have to be worried about ground impact.  An earlier evaluation flight against an F-105D equipped with the same APR-25 RWR carried by the RF-101C showed that it was vulnerable to the X-band SRD-5MK “High Fix” radar of the MiG-21F-13 and would not detect the radar until the MiG was within launch range of the “Atoll” missile at an average distance of 1.9 nautical miles and could not detect it at all past 2.7 nautical miles. 

Soon afterwards, an RF-4C was evaluated against the MiG-21.  Unlike the Voodoo, the reconnaissance Phantom enjoyed a significant acceleration advantage over the Fishbed-C at altitudes below 30,000 feet, particularly at military power, giving the Phantom a wider set of escape options from pursuing MiGs.  The Phantom could carry its ECM equipment with a reduced drag penalty and, unlike the Voodoo, could also carry a QRC-353A chaff dispenser which proved effective in breaking radar lock of the MiG-21’s “High Fix” ranging radar.  Also, having two sets of eyes in the Phantom was beneficial in picking up the very small visual profile of the MiG-21 given the inability of the APR-25 RWR to give effective warning.  While the results proved that the Voodoo could survive against the MiG-21 under favorable conditions, flight evaluation had shown that the RF-4C was significantly more survivable in the threat environment over North Vietnam.  The decision to withdraw the Voodoo from combat operations over most of North Vietnam had been clearly justified, and would not be reversed.  However, events would prove that no matter how old and worn the proud warhorse was becoming, the Voodoo was anything but “being put out to pasture.”

Bitter disappointment: The F-101 in SAC war plans

Yesterday's news reports of the publication of a declassified 1956 Strategic Air Command study of proposed targets has for many reasons already garnered worldwide notoriety.  The report may be viewed here at the National Security Archive: http://nsarchive.gwu.edu/nukevault/ebb538-Cold-War-Nuclear-Target-List-Declassified-First-Ever/

What has not been mentioned is that along with the B-47s, B-52s, and missile systems was SAC's strategic fighter of the future, the F-101A Voodoo.  By the time the study was commissioned in February 1956, the entire F-101 program was suffering multiple problems that would nearly lead to its cancellation.  While the pitch-up problem was garnering most of the headlines, its still-secret armament concept, the McDonnell Model 96 weapon-fuel pod, was causing tremendous problems of its own.  To this day, it remains virtually unknown even among those who otherwise know the Voodoo pretty well.  But this study illustrates what the F-101A weapon system was intended to accomplish in the event of a general nuclear war, a supersonic intruder using unimaginably powerful weapons to blow gaping breaches in Soviet defenses in front of streams of B-47 and B-52 bombers with the intent of utterly destroying the Soviet Union.  The scale of these SAC war plans for the late 1950s is mind-boggling, and it should give pause to both historians as well as those who today would propose the same mode of warfare against a different enemy.  This history serves as both a lesson and a warning.  It must never be revisited.  The following is a re-edited section from my recent book on the F-101, incorporating new information based on SAC Report SM 129-56: Atomic Weapons Requirements Study for 1959: 


Bitter disappointment: The F-101 in SAC war plans and the end of the Model 96

Still far above the fray as all hell began to break loose with the Voodoo and the strategic fighter concept in general, the Joint Chiefs of Staff commissioned a study of atomic weapons requirements for 1959 as SM 129-56 on 15 February 1956, published four months later on 15 June 1956.  Anticipating both new bomber and missile capabilities available to Strategic Air Command by that time, the study assessed and prioritized a burgeoning list of strategic targets within the Soviet Union and allied states.  Target categories for Strategic Air Command were: 1.) Soviet nuclear bomber, air defense, and tactical aircraft; 2.) air bases, launch sites and depots; 3.) atomic stockpile sites; 4.) military and government control centers; air industry and resources directly supporting enemy air capability.  Further strikes would be directed against Soviet population centers.  SAC medium and heavy bomber forces  in 1959 were projected to consist of 1,267 B-47, 225 RB-47, 495 B-52 aircraft, along with strategic missile forces consisting of 64 Snark ICCMs, 60 Rascal air-launched cruise missiles, 72 Crossbow missiles, and 180 IRBMs.  Aircraft payloads would consist of MK 6 B and MK 6 C fission weapons, MK 15 boosted fission and MK 27 thermonuclear weapons, forming the primary armament for the B-47 force.  High-yield MK 36 weapons would primarily be reserved for the B-52 force.  RB-47s were programmed for the MK 28 as primary armament, with the MK 27 as alternate.  

Also among the SAC assets directed against 3,400 projected targets, or Designated Ground Zeroes (DGZs) were a projected 150 F-101A Voodoo strategic fighters by 1959, enough to equip two combat wings.  Given the relatively short range and earliest arrival of forward-based F-101A strategic fighters, their primary targets would have consisted of Soviet fighter and interceptor bases and air defense sites, although a handful of forward bomber bases would also be within range.  As listed in SM 129-56, the primary weapon for the F-101A was to be the MK 28 bomb, with the MK 27 as an alternate weapon.  Unlike the lower-yield MK 28-Y2 versions slated for other nuclear-capable fighters like the F-100D and F-105, as a SAC aircraft the F-101A would carry the more powerful MK 28-Y1 producing 1.1 megatons yield, ten times the destructive power of the W-5 weapon that the Voodoo had been redesigned to carry a few short years previously.  The MK 27, slated as a primary weapon for both the B-47 and the Rascal air-launched cruise missile, had a yield of 2 megatons.  Against airfield targets, ground burst was specified to maximize blast radius, ensure the collapse and destruction of any underground facilities, crater runways, and produce enough heavy local fallout to prohibit repair or use of the target.  Under visual delivery conditions, the expected accuracy for the F-101A was a Circular Error Probable (CEP) of 600 feet.  The unparalleled combination of fighter speed and megaton-level punch of the F-101A constituted an extremely formidable weapon in the hands of SAC planners.  But as the report was being written, it was all becoming for naught.

Model 96 LABS and “Over-the-shoulder” delivery flight paths.  When this study was published on 22 June 1954, the 100-kiloton W-5 fission weapon was the planned payload for the Model 96 store, along with 849 gallons of fuel.  With the rapid development of lightweight, small-diameter hydrogen bombs, by early 1956 the 1.1 megaton MK 28 was slated as the primary weapon for the F-101A by 1959, with the larger and more powerful W-27 warhead earmarked for carriage in a modified Model 96 pod.  This would have made the Voodoo by far the most heavily armed fighter aircraft ever conceived.   Department of Energy.

By the beginning of 1956, McDonnell had more pod concepts on the drawing boards, but flight test of the F-101/Model 96 combination was continuing to reveal serious problems.  By this time, F-101As had arrived at Kirtland AFB, NM and were undergoing flight testing with the 4925^th Test Group (Atomic), including 53-2441.   McDonnell had developed two new electronic warfare versions of the Model 102 store, with formal design work beginning in November 1955, both retaining the original shape of the Model 96 store.  The Model 102H contained both fuel and electronic countermeasures equipment.  Interchangeable nose and tail assemblies were available, containing AN/ALT-6, AN/ALT-7, and/or AN/ALT-8 “noise” jammers, and an 11-carton capacity AN/ALE-1 chaff dispenser.  The Model 102J store was not provided with jamming equipment, instead carrying 943 gallons of fuel along with an ALE-1 chaff dispenser with 20 cartons capacity.  These were followed in March of 1956 when work began on a new design, the Model 117A store.  Intended for both the F-101 and RF-101, the newer pod could contain various combinations of ALT-6B and ALT-8B dispensers along with an ALE-1 unit with a 20-carton capacity.  Unlike the previous designs, the Model 117A apparently did not contain fuel.  The equipment in these pods were standard for SAC B-47B-II and B-47E-II Stratojet aircraft that were upgraded with Phase III ECM equipment beginning in late 1954.  By the beginning of 1956, SAC had made the decision to get out of the fighter business and would begin to deactivate its existing strategic fighter units.  Given the change in mission and the forthcoming “Blue Cradle” EB-47E aircraft with Phase IV ECM to provide escort jamming support for the bombers, and the fact that the equipment was not standard for TAC (which in any case considered electronic countermeasures of little importance) work on these new ECM stores for the F-101 would eventually be cancelled.

JF-101A 53-2427 with the Model 96.  The final warhead considered was the XW-27 hydrogen weapon, much improved over the earlier and heavier TX-15 boosted-fission design.  With a yield of two megatons, the XW-27 / Model 96 would have made the F-101A by far the most heavily-armed fighter ever to enter service.  Instead, the development of this vital component of the WS-105A strategic weapon system stalled and it was never deployed.  Gerald Balzer Collection, Greater St. Louis Air & Space Museum.

Unfortunately, it was becoming clear that the problems of the Model 96 store on the F-101 were nowhere near being solved.  In addition to the continuing deficiencies in both directional and lateral stability, another serious problem cropped up during testing.  The Model 96 shape added a great deal of cross-sectional area to the forward and middle of the aircraft, with a sharp drop-off in cross sectional area aft of the wing.  Under the recently discovered “Area Rule”, this sharp discontinuity in the area distribution would have led to higher than anticipated transonic drag.  Given that the F-101 cruised and fought in the transonic region, this increased drag resulted in a reduction in mission radius and increased buffeting and associated control problems at altitude. 

JF-101A 53-2428, the second “special weapon” test aircraft, at Lambert Field with a T-63 training “shape” for the MK 7 fission weapon.  Both the T-63 shape and lower and aft fuselage of the Voodoo are tufted for flow studies. Gerald Balzer Collection, Greater St. Louis Air & Space Museum.

In January 1955, the Air Force Special Weapons Center (AFSWC) stated that application of the thermonuclear XW-27 warhead to the Model 96 appeared feasible. With regard to the payload of the Model 96 store, word came down that major structural changes would be necessary for the Model 96 to accommodate the XW-27 warhead.  Meanwhile, the W-5 warhead that the Model 96 was built to carry was already obsolete as smaller, lighter, and higher-yield weapons such as the MK 28 were on the horizon.  These smaller weapons would offer at least as much yield as the Model 96 with negligible aerodynamic effects on the F-101 and, due to decreased weight and drag penalty, a similar combat radius when carrying one centerline weapon with two 450-gallon fuel tanks.  Seeing rapidly diminishing returns ahead for continued development of the F-101/Model 96 combination, the XW-5/F-101 and XW-27/F-101 programs were canceled in March 1956 in favor of future integration with the MK 28.  In the interim, the F-101 would make do with the relatively puny MK 7 weapons used by the F-84 once the Voodoo became operational with SAC strategic fighter wings.  The upshot was that, while the F-101A remained useful for the nuclear delivery mission, it lacked the needed range and strategic-level “punch” that had been expected of the high-yield warheads to be accommodated in the Model 96 store.  As with the air superiority mission, the F-101 was now unable to fulfill the anticipated vision of the “strategic fighter”.  This meant that even before SM 129-56 was published in June 1956, the targeteers of Strategic Air Command had to go back to the drawing board to account for a strategic fighter that now appeared completely useless for its apocalyptic mission.

"Zip" Fuels: the F-101 and Research on Borane Fuels

Last week saw the celebration of the 61st anniversary of the first flight of the F-101 Voodoo, on 29 September 1954.  Ship No.1, 53-2418, had a very interesting career after initial flight testing.  She was soon "bailed" to General Electric for tests with their new J79 engine, then under final stages of development for the Convair B-58A Hustler and Lockheed F-104A Starfighter.  Due in part to the persistent compressor stalls encountered with the Pratt & Whitney J57-P-13 engines, the J79 garnered considerable interest from McDonnell for developed versions of the Voodoo.  While it did not offer the fuel efficiency of the standard Pratt & Whitney engine, the J79 produced more thrust from a lighter engine and, most importantly, was free of compressor stalls, even with the initial Type I inlets that had caused so much grief for both the Air Force and McDonnell from its first flight.  But as the J79 began to mature into an established engine, General Electric was already at work on a very advanced derivative, the much larger J93 engine intended for the North American B-70 Valkyrie bomber.  Initial flight testing would take place with the J93-GE-3 engine, using hydrocarbon fuel.  Six of these engines would propel the massive stainless steel bomber to speeds of over Mach 3.  But design work proceeded on another version, the J93-GE-5, using a completely new, synthetic type of fuel that was so volatile it did not exist in nature.  Rather than using petroleum-based hydrocarbon fuel, the new fuel was composed of a class of chemicals called boranes.  Ground testing, in cooperation with the NACA, began in the mid-1950s using a modified J47 engine as a testbed.  But by 1957, the time had come to begin planning for flight testing of modified engines with the new fuel.  Given that the J93 was essentially a scaled-up J79 engine, the twin-engine General Electric Voodoo was selected for those historic tests.  Below is the rest of the story:

Ship No. 1,  bailed to General Electric and carrying modified YJ79 engines, conducting the first-ever powered flight using high-energy borane “zip” fuel on 28 September 1958. Gerald Balzer Collection, Greater St. Louis Air & Space Museum.

Pursuant to the 21 June 1955 request for a study of the J79 engine for the Voodoo, Ship No. 1, 53-2418, was bailed to General Electric in 1956 and modified with a pair of YJ79 engines in place of its Pratt & Whitney J57s.  The keel area was reworked to accommodate the new engines and the intakes were modified with longer ramps.  53-2418 first flew with theYJ79 installation on 3 November 1956 with an initial fit of two YJ79 Phase 0 engines.  Later that year, the NF-101A was modified with improved YJ79 Phase I engines modified with the Basket Burner Test Package and the Parker afterburner selector valve.  During its service with G.E., the aircraft also flew with YJ79-GE-3 and YJ79-GE-7 engines.  In 1958, 53-2418 became the first aircraft to flight test exotic borane-based high-energy “zip” fuel (HEF). This was done as an adjunct to the General Electric J93-GE-5 program.  The J93 was an enlarged derivative of the J79 intended for use with the B-70 Valkyrie and F-108 Rapier.  The kerosene-fueled J93-GE-3 made it to the hardware stage and was extensively flight-tested on the XB-70.  Waiting on the drawing boards was the J93-GE-5 engine, substituting borane compounds for traditional hydrocarbon compounds as fuel.

Instrument panel of 53-2418 on 2 October 1958.  The master switch for the borane fuel supply can be seen on the upper right, marked "HEF". Gerald Balzer Collection, Greater St. Louis Air & Space Museum.

Borane fuels were the focus of a great deal of research in the 1950s, with hundreds of millions of dollars quietly spent on their development.  These materials reacted with oxygen like traditional hydrocarbon fuels, but offered nearly twice the energy for the same weight of fuel.  In theory, an airplane using these fuels would need to expend less fuel to produce a given amount of thrust, resulting in greatly increased range.  This made borane fuel an extremely attractive option for the B-70, a six-engine, Mach 3-capable aircraft that required intercontinental range without refueling.  However, there were very serious drawbacks to the use of boranes as a practical fuel.  Besides being extremely toxic, boranes are also extremely reactive.  The same qualities that make them an excellent fuel also explain why they do not exist in nature—chemically, they are very unstable.  Boranes have to be synthesized, a very expensive process.  Diborane, the basic building block of all other borane compounds, is a gas that combusts simply on exposure to air at normal temperatures and pressures.  Pentaborane, a liquid, spontaneously combusts at temperatures above 78°F and was itself too unsafe to use as a practical fuel.  Decaborane, which is stable at normal operating temperatures, received serious attention from researchers as both a jet and rocket fuel, but is a solid at room temperature.  Decaborane could be added to the air mixture of a turbine engine as a fine dust or mixed with a hydrocarbon liquid such as benzene.  Unfortunately, the combustion products of borane fuels form a highly corrosive mixture of boric anhydride and water as well as extremely refractory deposits of boron carbide. (Slightly less hard than diamond, boron carbide is presently used as an industrial abrasive and has been used for cockpit armor on the Ling-Temco-Vought A-7D Corsair II).  Injecting borane fuel into the combustion chambers of a turbojet would soon result in a wrecked engine.

In order to be usable, boranes had to be injected into the afterburner section, well behind the more delicate engine components.  This was the arrangement planned for the J93-GE-5.  Borane fuels were flight-tested with this configuration for the first time on 28 September 1958, using the NF-101A with modified J79 engines as the test bed.  The flight tests themselves were successful, but the borate deposits left in the nozzle and afterburner section seriously degraded the usable life of the engines.  Also, the borane fuel produced a great deal of smoke, enough for some to judge it as being impractical and to be potentially unsafe during takeoff.  Despite the promise of borane fuels, their benefits were greatly outweighed by safety concerns and by production and maintenance costs.  Although not an important consideration in the late 1950s, widespread use of these fuels with their acidic combustion products could have also posed significant environmental problems.  One borane compound, triethylborane (TEB) found use as a catalyst for the ignition of the high-flashpoint JP-7 fuel of the SR-71.  The Department of Defense abandoned work on the J93-GE-5 in 1959, in large part due to the results of the flight test work performed by the NF-101A.  However, general research on borane fuels continued for some time afterwards.

By May of 1959, the NF-101A had had its J79 engines removed before the open house at Edwards AFB that year.  Thus, the unwanted and little-heralded Voodoo played an integral part in what had once been thought one of the most important and promising research programs of the Cold War.  Fortunately, this historic aircraft has been preserved.  After the J79 installation was removed, 53-2418 was moved in 1960 to Amarillo AFB Technical Training Center and used as a hydraulics trainer until placed on stands outside of the base as a “gate guard”.  With the closure of the base in 1970, the aircraft was later sold as excess property and purchased by Mr. Dennis E. Kelsey in February 1975.  After residing on the grounds of Bell Helicopter Co., 53-2418 was issued FAA Number N9250Z on 7 April 1976 and moved to Pueblo, Colorado on 11 January 1977.   At this writing, 53-2418 has been moved from Pueblo and after extensive restoration work has been on display at the Evergreen Aviation and Space Museum in McMinniville, Oregon since 2013.