Subject: Number One Hundred in the Series--North American F-100 Super Sabre (2 of 12)

From: [email-masked]
Date: 21 Oct 93 13:05:41 GMT

>From [email-masked]

The F-100A (company designation NA-192) was the first production 
version of the Super Sabre.  The first F-100A (52-5756) was completed 
on September 25, 1953, and made its first flight on October 29, George 
Welch again being at the controls.  This was only two weeks after the 
maiden flight of the second YF-100A prototype, indicative of the speed 
with which the Super Sabre program was being rushed along.  

The F-100A was similar in most respects to the YF-100A, but had a 
shorter and more stubby vertical tail with increased chord.  There was 
a fuel vent tube mounted on the fin's trailing edge at the midpoint.  
There was a small rudder fitted to the trailing edge of the fin below 
the vent tube.  

The mission of the F-100A was seen as that of daylight air 
superiority, and the aircraft was pictured as the natural replacement 
of the F-86A/E/F Sabre of Korean War fame.  The armament of the F-100A 
consisted of four 20-mm Pontiac M-39 cannon installed in the lower 
fuselage below the cockpit and carrying 200 rounds per gun.  The M-39 
had been tested in Korea on modified F-86Fs as the T-160, and fired 
1500 rounds per minute at a muzzle velocity of 3300 feet per second.  

At the end of November of 1953, the first three F-100As were delivered 
to George AFB to re-equip the 436th Fighter Day Squadron of the 479th 
Fighter Day Group of the TAC.  This Group became operational with the 
F-100A on September 29, 1954.  

During late 1953, slippages in the Republic F-84F Thunderstreak 
program caused the Tactical Air Command (TAC) to recommend that a 
version of the Super Sabre be developed with a secondary 
fighter-bomber capability.  On December 31, 1953 the USAF directed 
that the last 70 F-100As on the order be modified as fighter-bombers 
and redesignated F-100C.  The fourth production F-100A (52-5759) was 
chosen for modification as the prototype for the F-100C.  The wingtips 
were extended twelve inches on either side, improving the roll 
characteristics and decreasing stalling speed.  These wingtip 
extensions were considered sufficiently advantageous that they were 
incorporated into the F-100A production line beginning with the 101st 
example.  

The first F-100As had been delivered with a short vertical tail.  In 
service, USAF pilots reported stability and control problems with 
their F-100As, and their suspicion was that the vertical tail was not 
large enough to maintain adequate directional stability.  This problem 
was especially severe when the underwing drop tanks were being 
carried.  Consequently, most of these early F-100As were never flown 
to the limits of their performance envelopes.  

The 11th F-100A introduced a retractable tail skid to prevent 
accidental damage to the rear fuselage underbelly during landings at 
high angles of attack.  

The 24th F-100A introduced a yaw damper system.  Provisions for a 
pitch damper were installed in the 154th aircraft and subsequent.  

The F-100A had been rushed into service with unseeming haste, often 
over the objections of Air Force flight crews who found that the Super 
Sabre had some serious problems that were not being adequately 
addressed.  Disaster struck on October 12, 1954.  On that day, veteran 
test pilot George Welch was carrying out a maximum performance test 
dive followed by a high-G pullout with the ninth production F-100A 
(52-5764) when his aircraft disintegrated in midair.  Welch was able 
to eject, but his injuries proved to be fatal since his airplane had 
broken at the cockpit area and had sent chunks of metal tearing into 
his body.  On November 8, visiting RAF officer Geoffrey D. Stephenson 
was killed at Elgin AFB when his F-100A went out of control and 
crashed.  On November 9, Major Frank N. Emory's F-100A (52-5771) went 
out of control and crashed during a practice gunnery mission over 
Nevada.  Fortunately, Major Emory was able to eject safely.  On 
November 10, the USAF grounded the entire F-100A fleet, which by this 
time numbered about seventy aircraft.  A further 108 Super Sabres had 
been completed and were awaiting delivery at the factory.  

After an exhaustive investigation, the source of the F-100A's 
stability problems was traced to its new shorter tail, which USAF test 
pilots had suspected all along.  A decision was made to switch back to 
the original taller tail of the YF-100A.  27 percent more vertical 
tail area was added, which served to delay the onset of instability to 
speeds above Mach 1.4, which were outside the F-100A's performance 
envelope.  The aspect ratio of the vertical tail was also increased.  
With these changes, the height of the modified F-100A increased to 
15.34 feet.  The wingtip extensions planned for the F-100C were 
adopted as standard for the F-100A, increasing the wingspan from 36.78 
feet to 38.78 feet and the wing area from 376 square feet to 385.21 
square feet.  The artificial feel systems for the aileron and 
stabilizer powered controls were modified.  

These changes seemed to do the job, and the existing F-100As were 
retrofitted with the changes.  The first aircraft to complete the 
modification program was the 34th Super Sabre, and the first batch of 
11 modified aircraft was delivered to NAA Engineering Flight Test.  
Because of the rapid rate at which production had been built up, it 
was not until the 184th airframe that these modifications could be 
introduced on the assembly line.  Earlier aircraft (68 accepted and 
112 completed) were retrofitted in hangar areas.  Deliveries of the 
modified F-100A began from the Los Angeles factory in the spring of 
1954.  The grounding order on the F-100A was finally lifted early in 
February of 1955.  

Initial operational capability with the new and improved F-100A was 
achieved in September of 1955 by the 479th Fighter Day Wing at George 
AFB.  Late in 1955, pilots from the USAF Air Proving Ground Command at 
Elgin AFB in Florida participated in *Project Hot Rod* to evaluate the 
suitability of the F-100A for operational service.  Their conclusions 
were similar to those of earlier evaluations--the performance was good 
but there were still some major operational deficiencies which 
prevented the F-100A from being a really good day fighter.  
Consequently, the F-100A was never very popular with its flight crews.  

F-100As from number 167 onward had the J57-P-39 engine, which had the 
same thrust as the P-7.  

The ejector seat of the F-100A received a rather spectacular test of 
its effectiveness on February 26, 1955.  On that day, company test 
pilot George F. Smith was doing a low-altitude speed run in F-100A 
serial number 53-1659 when his plane suffered a hydraulic lock which 
resulted in an uncontrollable dive.  He was forced to eject at Mach 
1.05 and was severely injured, but recovered to fly again.  I think 
that Smith was the first pilot to eject at supersonic speed and 
survive.  

The last F-100A was delivered to the USAF in July of 1955.  A total of 
203 F-100As were built.  

Since the F-100A was not considered as a truly effective air 
superiority fighter, the service life of the type with the USAF was 
rather brief, most aircraft being phased out of the active USAF 
inventory beginning in 1958.  They were then transferred to the Air 
National Guard or placed in storage at Nellis AFB.  

In mid-1959, fifteen of these stored F-100As were transferred to the 
Chinese Nationalist Air Force on Taiwan.  In 1960, 65 more F-100As 
were sent to China.  

The first Air National Guard unit to receive the F-100A was the 188th 
TFS of the New Mexico ANG, which received these planes in April of 
1958.  In 1960, the ANG reached its peak inventory of 70 F-100As.  
During the Berlin crisis of 1961, numerous Air National Guard and Air 
Force Reserve units were mobilized and called to active duty.  This 
had the effect of returning some of these ex-USAF F-100As to active 
service.  

In spite of their deficiencies, some F-100As which had been operated 
by these activated ANG units were retained by the USAF even after the 
ANG personnel were released from active duty in early 1962 following 
the end of the Berlin crisis.  Most of the F-100As retained by the 
USAF were used for aircrew training and were not considered as being 
combat-capable aircraft.  

Thirty-eight of these reactivated F-100As were transferred to 
Nationalist China.  A total of 118 F-100As were ultimately transferred 
to the Chinese Nationalist Air Force, which was more than 58 percent 
of the total F-100A production.  Many of these F-100As were upgraded 
with the vertical tail of the later F-100D before being sent to China.  

The F-100A had an abominable safety record, even after the 
modifications which had corrected the stability problems with the 
original short vertical tail.  About 50 F-100A were lost in accidents 
while in service, which was about 25 percent of the total F-100A 
production.  The last F-100A finally left USAF service in early 1970.  
The ANG had lost its last F-100A to attrition in 1967.  

The NACA received an early F-100A (52-5778) which it used to perform 
stability and control tests.  NACA test pilot Scott Crossfield flew 
the F-100A during the late fall of 1954 to determine the flight 
boundaries where inertial coupling could occur.  

Serials of the F-100A: 

52-5754/5755 	North American F-100A-1-NA Super Sabre 
52-5766/5778 	North American F-100A-5-NA Super Sabre 
53-1529/1568 	North American F-100A-10-NA Super Sabre 
53-1569/1608 	North American F-100A-15-NA Super Sabre 
53-1609/1708 	North American F-100A-20-NA Super Sabre 

Specificiations of the F-100A: 

One Pratt & Whitney J57-P-7/39 turbojet, 9700 lb.st.  dry and 14,800 
lb.st.  with afterburning.  Wingspan 38 feet 9 inches, length 47 feet 
1 1/4 inches, height 15 feet 8 inches, wing area 385 square feet.  
Maximum speed 760 mph at sea level, 852 mph at 35,000 feet.  Initial 
climb rate 23,800 feet/minute.  Service ceiling 44,900 feet, combat 
ceiling 51,000 feet.  Normal range 358 miles, maximum range 1294 
miles.  Fuel capacity 1294 US gallons.  Weights were 18,185 pounds 
empty, 24,996 pounds gross.  Armament of four 20-mm Pontaic M-39 
cannon with 200 rpg.  In addition, two underwing stations were 
provided which could accommodate bombs as large as 1000 pounds in 
weight.  

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