Subject: Number 102 in the Series--Convair F-102A Delta Dagger (1 of 5)

From: [email-masked]
Date: 6 Dec 93 15:13:09 GMT

>From [email-masked]

The Convair F-102A Delta Dagger single-seat all-weather interceptor was 
the first delta-winged combat aircraft in the world to enter 
operational service.  It was also the world's first all-weather 
interceptor capable of supersonic performance in level flight.  It was 
the first fighter to have an all-missile armament provided as standard 
from the very start of the initial design stage.  It was also the 
first manned interceptor designed from the outset as the principal 
component of a weapons system.  

The F-102 had its origin in an early-1949 request by the USAF for an 
advanced interceptor capable of supersonic performance that would be 
able to deal with the advanced Soviet intercontinental jet-powered 
bombers that intelligence services warned would soon be available in 
quantity.  The North American F-86D Sabre, the Northrop F-89 Scorpion, 
and the Lockheed F-94 Starfire were all subsonic aircraft, and were 
deemed to have insufficient growth potential to be able to meet this 
threat.  This project came to be known as the "1954 interceptor", 
after the year that new interceptor would supposedly be entering 
service.  

At that time, the Air Force recognized that the increasing complexity 
of modern weapons made it no longer practical to attempt to develop 
equipment, airframes, electronics, engines, and other components in 
isolation and expect them to work properly when they were put together 
in the final product.  To address this problem, the Air Force decided 
to use the so-called "weapons system" concept for the new interceptor, 
in which components would be integrated with each other from the very 
beginning, making sure that the various systems would be compatible 
with each other when they were incorporated into the final aircraft.  
The project was given the designation WS-201A, where WS stood for 
"Weapons System".  As originally conceived, WS-201A was a weapons 
system consisting of a primary armament of air-to-air guided missiles 
to be guided and directed by an all-weather search and fire control 
radar, all housed in an airframe capable of supersonic flight.  

The electronics package for the new WS-201A system came first.  
Project MX-1179 was the designation given to that portion of the 
project which was dedicated to the armament and electronic 
fire-control system of the 1954 Interceptor.  In October of 1950, the 
Hughes Aircraft Company was named the winner of the MX-1179 contract.  
The Hughes proposal consisted of a MA-1 fire control system acting in 
conjunction with GAR-1 Falcon air-to-air guided missiles.  For a brief 
time, the Falcon missile was known as the F-98, a fighter designation.  

The airframe part of the project was designated MX-1554.  Proposals 
for the airframe were requested by the Air Force on June 18, 1950.  
When the bidding closed in January of 1951, nine proposals had been 
submitted by six different manufacturers.  Republic submitted three 
separate proposals, North American two, and single proposals were made 
by Chance-Vought, Douglas, Lockheed, and Convair.  

On July 2, 1951, the Air Force announced that designs by Convair, 
Lockheed, and Republic had been selected to proceed with preliminary 
development.  All three companies were to proceed with their designs 
all the way to the mockup stage, with the design being deemed most 
promising at that time being awarded a production contract.  Later, 
the USAF deemed it too costly to carry through with three concurrent 
development programs, and it cancelled the Lockheed project in its 
entirety.  The Convair and Republic entries were given the go-ahead to 
proceed.  

The Republic entry bore the company designation of AP-57.  It called 
for an extremely advanced aircraft capable of achieving a Mach 3 
performance at altitudes of up to 80,000 feet.  This was clearly a 
quantum leap in the state of the art for the early 1950s.  

The Convair entry in the MX-1554 project was closely related to the 
experimental XF-92A which Convair had built in 1948 to provide data 
for the proposed F-92 Mach 1.5 fighter designed in consulation with 
Dr. Alexander Lippisch.  Dr. Lippisch had done pioneering work on 
delta-winged aircraft in Germany during the war, and Convair had 
become convinced that the delta configuration provided a viable 
solution to the problems of supersonic flight.  The XF-92A had been 
the first powered delta-wined aircraft to fly, but the F-92 project 
had itself been cancelled before any prototype could be built.  

On September 11, 1951, Convair received a contract for its delta 
winged design which was designated F-102.  Work on the competing 
Republic design was also authorized, and that aircraft was assigned 
the designation XF-103.  However, the XF-103 was so far ahead of the 
state of the art that it was deemed too risky to be a serious 
contender for the 1954 Interceptor project, which made the F-102 for 
all practical purposes the winner of the contest.  

The Air Force authorized the fitting of a Westinghouse J40 turbojet in 
the first few examples of the F-102, but later production aircraft 
were to have the appreciably more-powerful Wright J67 (a license-built 
version of the Bristol Olympus).  The J40-powered F-102 was to be 
capable of a speed of Mach 1.88 at 56,500 feet, with the J67 
production version capable of Mach 1.93 at 62,000 feet.  

In order to expedite the development of its 1954 Interceptor program, 
the Air Force adopted the so-called "Cook-Craigie" program, named for 
its originators, Generals Laurence C. Craigie and Orval R. Cook.  
During the late 1940s, these two officers had developed a concept of 
an aircraft development program in which the usual prototype stage 
would be skipped.  Instead of waiting to start full-scale production 
until the prototypes had passed flight testing and the bugs had been 
ironed out, the Cook-Craigie plan called for the delivery of a small 
number of production aircraft during the flight testing phase.  Any 
major changes deemed to be necessary could be incorporated into 
permanent factory tooling in order for combat-ready aircraft to be 
delivered when mass production started.  This program is inherently 
risky-- it can produce a new combat aircraft in a hurry if everything 
goes according to plan during flight testing, but can result in a lot 
of costly and time-consuming fixes in the field if unexpected problems 
turn up.  

The Cook-Cragie plan is really viable only if there is a high degree 
of confidence that the aircraft is really going to go into production.  
Since the F-102 was basically a scaled-up XF-92A, the risk was deemed 
work taking.  

By December of 1951, it was apparent that the J67 engine and the MA-1 
fire-control system would not be ready in time.  This forced the USAF 
to change its plans.  At that time, the Air Force decided to proceed 
with an interim version of its 1954 Interceptor, one which could be 
introduced into service at an early date, pending the availability of 
the fully-developed version at a later time.  The interim version was 
to be designated F-102A, with the fully-developed advanced version 
being designated F-102B.  

The F-102A was to be equipped with an interim fire-control system, the 
Hughes E-9, which was a modified E-4.  The E-9 was later renamed MG-3 
after a number of changes had substantially improved its capability.  
The MG-3 was in turn supplanted by the MG-10 which incorporated the 
AN/ARR-44 data link, the MG-1 automatic flight control system, and the 
AN/ARC-34 miniaturized communication set.  

The F-102B ultimately turned out to be so different from the F-102A 
that it was assigned the new designation of F-106 in 1956.  It will be 
discussed in a later post.  

The mockup of the F-102A was inspected in November of 1952.  At that 
time, the Air Force decided that the F-102A should be capable of 
carrying external stores, and they recommended some rearrangement of 
the cockpit components.  

All throughout the development cycle, the weight of the F-102A had 
been spiraling ever upwards, an all-too-familiar pattern.  In 1951, 
the Westinghouse J40 engine was the most powerful turbojet in 
production, but it now lacked the thrust to give the F-102A its 
required performance.  Consequently, the Air Force decided to switch 
to the Pratt & Whitney J57 turbojet, which was in the 10,000 lb.st 
class and was scheduled to enter production in early 1953.  

Manufacture of a preliminary order for ten YF-102s (two Model 8-80s, 
52-7994/7995) and eight Model 8-82s (53-1779/1786) began in April of 
1952.  

The first 32 F-102A production aircraft were ordered on December 17, 
1952, under a contract approved on June 12, 1953.  First service was 
planned for December of 1955, almost two years later than originally 
planned.  

The YF-102 was basically a scaled-up XF-92A with a slim nose and 
lateral air intakes replacing the nose intake.  A strong skeleton of 
milled aluminum spars and longerons covered with aluminum skins 
carried the fuel in wing spaces.  The electronics was carried in the 
fuselage.  The armament was to consist of six Hughes GAR-1 Falcon 
air-to-air missiles carried internally in a ventral bay.  In addition, 
twenty-four 2-inch FFAR rockets were to be carried in channels 
contained inside the missile-bay doors.  A maximum speed of 870 mph at 
35,000 feet was promised.  

A severe problem cropped up early in 1953, one which was potentially 
fatal for the entire program.  At that time, wind tunnel testing 
discovered that the initial drag estimates of the YF-102 had been way 
off, and that the F-102 would be unable to exceed Mach 1.  

In the meantime, work on the first YF-102s was proceeding at a rapid 
pace.  The first YF-102 was finally completed in the autumn of 1953.  
It was powered by a J57-P-11, rated at 10,900 lb.s.t. dry and 14,500 
lb.s.t. with afterburning.  It was trucked from San Diego out to 
Edwards AFB.  It took off at Edwards on its maiden flight on October 
24, 1953, with Richard L. Johnson at the controls.  In initial tests, 
severe buffeting was encountered at Mach 0.9.  Even more serious, the 
aircraft proved to be incapable of exceeding the speed of sound in 
level flight, fully confirming the results of the wind tunnel testing.  

The first YF-102 was written off on November 2 in a forced landing 
following an engine failure.  The second YF-102 flew on January 11, 
1954.  This aircraft was limited to Mach 0.99 in level flight.  Dives 
at higher speeds resulted in severe yaw oscillations.  

The F-102 program was in BIG trouble.  In fact, the performance of the 
YF-102 was not all that much better than the F-86D Sabre, which was 
already in production.  If no cure could be found, the program would 
undoubtedly be cancelled.  

While eight more YF-102s (Model 8-82, serials 53-1779/1786) were being 
built to the same standards as the first two, Convair embarked on a 
major investigation and redesign program in an attempt to save the 
F-102.  The salvation of the project turned out to be in the "area 
rule" devised by NACA scientist Richard Whitcomb.  According to the 
area rule, the total cross sectional area along the direction of 
flight should be a constant in order to achieve minimum transonic 
drag.  In order to achieve this, it was required that the fuselage be 
narrowed down in the region where the wing roots were attached, then 
broadened back out again when the wing trailing edge was reached.  
This gave the aircraft fuselage a characteristic "wasp-waist" or 
"Coke-bottle" shape.  The length of the fuselage was increased by 11 
feet, and a pair of aerodynamic tail fairings were added aft of the 
trailing edge, these fairings extending beyond the end of the 
afterburner tailpipe in a pair of characteristic protrusions.  These 
tail fairings were purely for aerodynamic purposes and had no other 
function.  A new cockpit canopy with a sharper leading edge was 
fitted, although it had an adverse effect on overall visibility.  
Cambered leading edges were fitted to the thin delta wings to improve 
the behavior of the thin airfoil at high angles of attack, and the 
wingtips were given wash-in.  

A J57-P-23 engine was fitted, which was considerably lighter and more 
powerful than the previous J57-P-11.  The J57-P-23 engine rated at 
11,700 lb.s.t. dry and 17,200 lb.s.t. with afterburning.  The aircraft 
was lightened by reducing excess structures no longer required by the 
lighter engine.  The new aircraft was given the designation YF-102A.  

Designated Model 8-90, the first of four YF-102As (53-1787/1790) was 
rolled out at San Diego just 117 days after redesign had started.  It 
was trucked out to Edwards AFB and took off on its maiden flight on 
December 20, 1954.  On the next day, Mach 1 was easily exceeded.  
fully confirming the predictions of the area rule.  

A milestone was reached on July 8, 1955, when a YF-102A fired six 
Falcon missiles and 24 unguided rockets in less than 10 seconds.  

The retooling required by the changes in the YF-102A played havoc with 
the Cook-Craigie plan for early production.  Fully two-thirds of the 
30,000 tools that had been purchased had to be thrown out and new ones 
acquired.  Following the costly re-tooling procedure, full production 
of the F-102A began at the Convair plant in San Diego.  The first 
production Model 8-10 or F-102A (53-1791) flew on June 24, 1955.  and 
was delivered to the Air Force five days later.  It had a J57-P-23 
engine.  

The initial production run of 40 aircraft (production blocks -5 
through -25) were all employed in research and development work, and 
none entered operational service with the USAF.  As a result of the 
tests, some significant airframe changes were made, including a 
three-foot addition to the height of the tail fin.  This new tail fin 
was devised as a cure for some high-speed instability problems that 
had turned up during flight testing and was first tested in December 
of 1955.  It was introduced as standard on all F-102As built after the 
25th example, and earlier F-102As were retrofitted with this new 
taller fin.  

The first delivery to an operational Air Defense Command unit (the 
327th Fighter Interceptor Squadron based at George AFB in California) 
took place on May 1, 1956, three years later than originally expected.  

In mid-1956, it was decided that only the 2.75-inch FFARs would be 
used as backups to the Falcon missiles.  Earlier F-102s were 
retrofitted in the field and exchanged their T-214 2-inch FFARs for 
the 2.75-inch FFARS.  Some 170 F-102s were modified according to this 
standard.  

In May of 1956, a Douglas MB-1 Genie nuclear-capable unguided rocket 
was fired from a YF-102A.  For a while, the Air Force considered 
equipping the F-102A with the Genie rockets, but this project was 
abandoned in early 1957.  

Early F-102As had been been plagued by landing gear failures.  By 
November of 1957, all F-102As had been fitted with serviceable struts 
and a new oleo strut metering pin and the side brace boss bearing of 
the landing gear was modified.  In addition, a fix had been found for 
the in-flight failures of the speed brakes mounted behind the vertical 
fin.  

The popular name *Delta Dagger* for the F-102A was chosen in 1957.  
Between 1952 and 1957, five production contracts were awarded for a 
total of 875 F-102As.  

The MG-3 fire-control system was replaced in the field by the improved 
MG-10 in most F-102As.  More sophisticated and less troublesome 
versions of the Falcon air-to-air missile were fitted as they became 
available.  Conversions were later performed which made the F-102A 
capable of launching the GAR-11 (later redesignated AIM-26A) 
nuclear-tipped Falcon.  Ensuing modifications eventually made it 
possible to interchangeably carry AIM-26 and AIM-4 (GAR-1 through 
GAR-4 in pre-1962 designation schemes) Falcons in the central weapons 
bay.  

In October of 1957, a new wing was introduced on the production line 
beginning with approximately the 550th F-102A.  This innovation raised 
combat ceiling to 55,000 feet (a 5000-foot increase) and raised 
maximum speed at 50,000 feet to Mach 1.  In addition, maneuverability 
was substantially improved and low-speed stability was markedly 
enhanced.  

in 1957, Convair began a modernization program for early F-102As to 
bring them up to the latest standards.  These changes included a 
larger tail, an MG-10 fire control system in place of the MG-3, 
attachment points for a pair of 230 US gallon underwing drop tanks, 
and provision for 2.75-inch unguided rockets in place of the 2-inch 
rockets originally carried.  When the underwing tanks were carried, 
however, the F-102A was limited to subsonic performance.  

By the end of 1958, 26 ADC squadrons were flying F-102As, and the 
F-102A had replaced the North American F-86D Sabre as the most 
numerous interceptor with the ADC.  F-102As in service numbered 627, 
or about half of the total number of interceptors operated by the Air 
Defense Command.  At the height of its service, 32 ADC units flew the 
F-102A.  The last of 873 F-102As produced (serial number 57-909) was 
delivered in September of 1958.  

A subsequent in-service modification program added an infrared 
sighting system for target acquisition, lock-on and completion of run.  
The infrared scanner was mounted in a transparent dome immediately in 
front of the pilot's windshield.  The internal unguided rocket 
armament was deleted, and provisions were made for the carrying of 
later marks of the Falcon AAM such as the AIM-4E radar homer and the 
AIM-4F infrared homer.  

Most of the F-102As were stationed stateside as interceptors for the 
Air Defense Command.  However, a few were sent overseas.  The first 
overseas deployment of the F-102A took place in June of 1958 when the 
327th Fighter Interceptor Squadron moved to Thule, Greenland.  The 
first squadron in Europe to receive the F-102 was the 525th FIS based 
at Bitburg in West Germany, which received 25 aircraft in early 1959.  
Five other squadrons based in Germany, Spain, and the Netherlands 
eventually got Delta Daggers.  

A few Pacific-based squadrons got F-102s, the first being the 16th FIS 
based at Naha AFB on Okinawa which re-equipped in March of 1959.  It 
was in the Pacific theatre that the F-102 was to achieve its only 
taste of combat.  Aircraft from the 590th Fighter Interceptor Squadron 
were transferred to Tan Son Nhut AFB near Saigon in South Vietnam in 
March of 1962 to provide air defense against the unlikely event that 
North Vietnamese aircraft would attack the South.  F-102As continued 
to be based there and in Thailand throughout much of the Vietnam war.  
F-102As stood alert at Bien Hoa and Da Nang in Sout Vietnam and at 
Udorn and Don Muang in Thailand.  The F-102A was finally withdrawn 
from Southeast Asia in December of 1969.  The F-102A established an 
excellent safety record in Vietnam.  In almost ten years of flying air 
defense and a few combat air patrols for SAC B-52s, only 15 F-102As 
were lost.  Although a few missions were flown over North Vietnam, the 
Southeast Asia- stationed F-102As are not thought to have actually 
engaged in air-to-air combat.  However, one of my references has one 
being lost to a MiG-21 in action.  

During the early 1960s, the F-102A was gradually replaced in the ADC 
by the McDonnell F-101B Voodoo and the Convair F-106 Delta Dart.  By 
mid-1961, the number of F-102As in service with the ADC was down to 
221.  However, by the end of 1969, with the exception of a squadron 
maintained in Iceland, all ADC F-102As had been transferred to the Air 
National Guard.  The F-102As stationed in the Pacific had been 
withdrawn in December of 1969.  

The only F-102As still in service with the USAF at the beginning of 
1970 were all stationed overseas.  At that time, the USAF still 
retained a few F-102A squadrons in Germany and the Netherlands.  In 
the early 1970s, European-based F-102As were replaced by F-4 Phantoms.  
By the end of June 1973, the number of active F-102As had been reduced 
to ten.  

The last ADC unit to operate the F-102A, the 57th FIS based at 
Keflavik in Iceland finally traded in its F-102As for McDonnell F-4C 
Phantoms in mid-1973.  

As they left USAF service, most F-102As were transferred to the Air 
National Guard.  First to receive the F-102A was the 182nd FIS of the 
Texas ANG, receiving the plane in mid-1960.  By 1966, ANG inventories 
amounted to 339 F-102As.  Twenty-two ANG units ultimately got F-102As, 
including ANG squadrons of Louisiana, Florida, Texas, North Dakota, 
Hawaii, Pennsylvania, New York, Washington, Connecticut, Oregion, 
Maine Vermont, Tennessee, Arizona, South Carolina, South Dakota, 
Wisconsin, Minnesota, Montana, Idaho, and California.  

A 1967 proposal to modify F-102As into RF-102As as the standard ANG 
reconnaissance aircraft was deemed infeasible and was not proceeded 
with.  

The F-102A was not equipped for midair refuelling.  In the late 1960s, 
some consideration was given to retrofitting existing F-102As with 
inflight-refuelling probes mounted immediately aft of the cockpit.  
This idea was rejected since the fitting of the probe would have 
adversely affected performance.  

In the late 1960s, Convair proposed a close air support version of the 
F-102 equipped with an internally-mounted cannon.  The USAF was not 
particularly interested and this idea got no further than the 
preliminary planning stage.  

Large-scale retirement of the F-102A from the ANG began in late 1969 
and continued throughout the 1970s.  The last F-102A finally left ANG 
service in 1978.  Most of the retired F-102As ended up in the 
boneyards at the Davis-Monthan AFB storage facility.  Many were 
subsequently converted into remote-controlled drone aircraft.  

F-102A-75-CO serial number 56-1416A is on display at the 
Wright-Patterson AFB in Dayton, Ohio.  

Specification of F-102A: 

One Pratt & Whitney J57-P-23 turbojet, 10,200 lb.s.t. dry and 16,000 
lb.s.t. with afterburning, or a J57-P-25, 11,700 lb.s.t. dry and 
17,200 lb.s.t. with afterburning.  Maximum speed: 825 mph at 35,000 
feet (Mach 1.25).  Initial climb rate: 13,000 feet per minute.  An 
altitude of 51,800 feet could be attained in 9.9 minutes.  Combat 
ceiling was 51,800 feet and service ceiling was 53,400 feet.  Maximum 
range was 1350 miles.  Weights were 19,350 pounds empty, 24,494 pounds 
combat weight, 28,150 pounds gross, and 31,500 pounds maximum takeoff.  
Dimensions: wingspan 38 feet 1 1/2 inches, length 68 feet 4 1/2 
inches, height 21 feet 2 1/2 inches, wing area 695 square feet.  
Maximum internal fuel load was 1085 US gallons.  In later versions, 
two underwing tanks could be carried, bringing total fuel capacity to 
1510 US gallons.  Armament consisted of six air-to-air guided missiles 
housed internally in a ventral weapons bay--usually a mixture of three 
Hughes AIM-4A or -4E Falcon semiactive radar-homing missiles and three 
Hughes AIM-4C or -4F Falcon infrared homing missiles.  Later 
installations included three Falcons plus one AIM-26A or B In 
addition, twenty-four 2.75-inch unguided FFARs could be carried in 
launching tubes mounted inside the weapons bay doors.  In later 
versions, the unguided rockets were often omitted.  

F-102A serial numbers:

52-7994/7995		Convair YF-102 Delta Dagger
53-1779/1786		Convair YF-102 Delta Dagger
53-1787/1790		Convair YF-102A Delta Dagger
53-1791/1794		Convair F-102A-5-CO Delta Dagger
53-1795/1797		Convair F-102A-10-CO Delta Dagger
53-1798/1802		Convair F-102A-15-CO Delta Dagger
53-1803/1811		Convair F-102A-20-CO Delta Dagger
53-1812/1818		Convair F-102A-25-CO Delta Dagger
54-1371/1383		Convair F-102A-30-CO Delta Dagger
54-1384/1400		Convair F-102A-35-CO Delta Dagger
54-1401/1407		Convair F-102A-40-CO Delta Dagger
55-3357/3379		Convair F-102A-41-CO Delta Dagger
55-3380/3426		Convair F-102A-45-CO Delta Dagger
55-3427/3464		Convair F-102A-50-CO Delta Dagger
56-957/972		Convair F-102A-51-CO Delta Dagger
56-973/1044		Convair F-102A-55-CO Delta Dagger
56-1045/1136		Convair F-102A-60-CO Delta Dagger
56-1137/1233		Convair F-102A-65-CO Delta Dagger
56-1234/1274		Convair F-102A-70-CO Delta Dagger
56-1275/1281		Convair F-102A-75-CO Delta Dagger
56-1282/1285		Convair F-102A-65-CO Delta Dagger
56-1286/1296		Convair F-102A-70-CO Delta Dagger
56-1297/1429		Convair F-102A-75-CO Delta Dagger
56-1430/1518		Convair F-102A-80-CO Delta Dagger
57-770/855		Convair F-102A-90-CO Delta Dagger
57-856/909		Convair F-102A-95-CO Delta Dagger

Sources:

  General Dynamics Aircraft and their Predecessors, John Wegg,
  Naval Institute Press, 1990.

  The Illustrated Encyclopedia of Aircraft Armament, Bill Gunston,   
  Orion, 1988.

  United States Military Aircraft Since 1909, Gordon Swanborough and
  Peter M. Bowers, Smithsonian, 1989.

  The American Fighter, Enzo Angelucci and Peter Bowers, Orion, 1987.

  Fighters of the United States Air Force, Robert F. Dorr and
  David Donald, Temple Press Aerospace, 1990.

  American Combat Planes, Third Enlarged Edition, Ray Wagner, Doubleday,
  1982.

  Post-World War II Fighters, 1945-1973, Marcelle Size Knaack,
  Office of Air Force History, 1986. 

  The World Guide to Combat Planes, William Green, MacDonald, London, 1966

  The World's Fighting Planes, William Green, Doubleday, 1964.

  The Aircraft of the World, William Green and Gerald Pollinger, Doubleday,
  1965.

Joe Baugher		AT&T Bell Laboratories   	
2000 North Naperville Road      Naperville, Illinois 60566-7033