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Northrop F-15A Reporter
The F-15 type was evaluated in the form of the single
XF-15 and XF-15A prototype conversions from XP-61E and P-61C standards with six cameras in a modified nose, and
the success of these two machines paved the way for the F-15A production model, of which 36 were completed and 139 more
were canceled. Number built: 36
F-15A Reporter in brief
The F-15 photo-Reconnaissance variant of the P-61 had
a new center pod with pilot and camera operator seated in tandem under a single bubble
canopy, and six cameras taking place of radar in the nose. Powered
by the same turbosupercharged R-2800-73 engines as the P-61C. The first prototype XF-15 was converted from the first
XP-61E prototype, the second XF-15A was converted from a P-61C (number 43-8335). The aircraft had a takeoff weight
of 32,145 pounds (14,580 kg) and a top speed of 382 knots (440 mph, 708 km/h). Only 36 of the 175
ordered F-15As were built before the end of the war. After formation of the United
States Air Force in 1947, F-15A was redesignated RF-61C. F-15As
were responsible for most of the aerial maps of North Korea used at the start of the Korean
War.
It was the last piston-powered photo-reconnaissance aircraft designed
and produced for the United States Air Force. Though produced in limited quantities, and with a relatively short service life,
the F-15's aerial photographs of the Korean Peninsula would prove vital in 1950, when North Korea invaded the south.
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Specifications
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General characteristics
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Crew: 2-3 (pilot, radar operator, optional
gunner)
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Length: 49 ft 7 in (15.11 m)
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Wingspan: 66 ft 0 in (20.12 m)
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Height: 14 ft 8 in (4.47 m)
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Wing area: 662.36 ft² (61.53 m²)
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Empty weight: 23,450 lb (10,637 kg)
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Loaded weight: 29,700 lb (13,471 kg)
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Max takeoff weight: 36,200 lb (16,420 kg)
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Powerplant: 2× Pratt & Whitney R-2800-65W
Double Wasp radial engines, 2,250 hp (1,680 kW) each
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Propellers: four-bladed Curtiss Electric
propeller, 1 per engine
Performance
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Maximum speed: 318 knots (440 mph at 33,000
ft)
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Combat range: 530 nm (610 mi, 982 km)
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Ferry range: 1,650 nm (1,900 mi, 3,060 km)
with four external fuel tanks
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Service ceiling: 33,100 ft (10,600 m)
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Rate of climb: 2,540 ft/min (12.9 m/s)
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Wing loading: 45 lb/ft² (219 kg/m²)
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Power/mass: 0.15 hp/lb (25 W/kg)
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Time to altitude: 12 min to 20,000 ft (6,100
m) (1,667fpm)
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Northrop F-15A Reporter prototype
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This was the unarmed photo-reconnaissance version of
the Black Widow. The type was evaluated in the form of the single XF-15 and XF-15A prototype conversions from XP-61E
and P-61C standards with six cameras in a modified nose, and the success of these two machines paved the way
for the F-15A production model, of which 36 were completed and 139 more were canceled. Number built: 36
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The F-15 Reporter was created when the guns were removed
from the experimental XP-61E, the last fighter variant of the P-61 Black Widow. With less than six months flying time, the
first XP-61E was taken back to the Northrop modification shop where it was converted into an unarmed photographic reconnaissance
aircraft. All the guns were removed, and a new nose was fitted, capable of holding an assortment of aerial cameras. The aircraft,
redesignated XF-15, flew for the first time on 3 July 1945, with Northrop
test pilot L. A. "Slim" Parrett at the controls. A P-61C-1-NO (serial number 42-8335) was also modified to XF-15 standards
as the XF-15A. Apart from the turbosupercharged R-2800-C engines, it was identical to the XF-15 and flew for the first time
on 17 October 1945. For unknown reasons Northrop subcontracted the nose
for the F-15A to the Hughes Tool Company of Culver City, California. The F-15A used the existing P-61C wings (without fighter
brakes), engines and tail sections but with an entirely new, more streamlined fuselage housing a crew of two under a continuous
bubble-canopy.
As a result of continuing development trouble with the Howard
Hughes' designed Hughes XF-11, the staff of the Army Air Force Headquarters determined an immediate need for 320 F-15 Reporters.
Even before the first flight of the XF-15 an initial contract for 175 aircraft was signed in June 1945. Following testing
it was determined that the F-15 Reporter possessed similar performance and flight characteristics to the troublesome XF-11,
despite the Reporter being powered by less powerful engines, and using mostly pre-existing parts. This spelled the end to
further development of the XF-11.
The first production F-15A was accepted in September 1946.
However, the contract was abruptly canceled in 1947, possibly because the performance of the aircraft was rapidly being overshadowed
by jets, with the last of only 36 examples being accepted by the United States Army Air Forces in April that year. The last
F-15 to be produced (serial number 45-59335) was produced as an F-15A-5-NO, which differed from the Block-1 version mainly
in having a new internal camera installation in the nose. It seems that this change had been contemplated for the last 20
F-15s as well, since some records indicate that these were all eventually re designated as F-15A-5-NO
Design
The F-15 had a revised center pod with pilot and camera
operator seated in tandem under a single bubble canopy. The first XP-61E, from which the first XF-15 was converted, had the
canopy hinged to the side, while all subsequent XF-15 and production F-15 employed a sliding canopy. The aircraft's six cameras
were placed in an elongated nose, replacing the XP-61Es four guns. Production F-15A were powered by the same turbosupercharged
R-2800-73 engines as the P-61C. The aircraft had a takeoff weight of 32,145 pounds (14,580 kg) and a top speed of
382 knots (440 mph, 708 km/h) at 33,000 ft. In the end, only 36 of the 175 ordered F-15As were built, and all
were constructed from aircraft originally contracted to be built as P-61C.
The pilot was seated in the front, with the reconnaissance
operator in the back. The back-seat occupant controlled the cameras and navigated the aircraft. However, the rear seat of
the F-15A was fitted with a set of rudimentary flying controls, which made it possible for the reconnaissance operator to
relieve the pilot if needed. Both crew members were rated pilots and both were trained in the reconnaissance task, so they
usually alternated position on each flight.
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Production
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F-15A Reporter As XF-15A, photo reconn. version, redesigned nose section for cameras, unarmed. Later
redesignated R-15A, then RF-61C in 1948. Produced 1946 - 1947 Northrop Hawthorne, California (NO)
45-59300 / 45-59335 |
3201 / 3236 |
Total: 036 |
139 additional airframes cancelled. |
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Of the 36 F-15As produced, nine were allocated to the Air
Material Command in the Continental U.S., and the remainder were issued to just one squadron, the 8th Photographic Reconnaissance
Squadron (PRS) attached to the 35th Fighter Group in Japan. The first four were sent over by ship, arriving in March 1947
at the Japan Air Material Area (JAMA), Kisarazu, Japan. Their voyage had not been smooth, and three of the four were in such
bad shape that they were used for spare parts.
The 8th PRS had been non-operational for about a year, and
was being brought up to strength to serve in the American occupation of Japan, participating in the Post-Hostilities Mapping
Program in which the beaches, villages, road networks, and cultural centers of Japan were to be extensively photographed,
work that was to be performed by the F-15 in association with the F-13 variant of the B-29 Superfortress. Under the command
of Maj. Benjamin H. Albertson, the 8th spent most of the summer of 1947 preparing for their missions to come, spending June
and July at JAMA helping to assemble the newly arriving F-15's. Capt. Jarvis and Lt. Heistand were the first two pilots selected
to fly back with the first pair of reporters in late June. The squadron spent most of July test flying their new machines.
Four additional aircraft arrived in July, giving the squadron seventy-three hours experience in the F-15. The unit's first
operational mission would also be flown in July, with Capt. Moore at the controls. The squadron lost its first F-15 in August
when a pilot made a very hard landing. The plane was a write-off, but the pilot walked away. In September Lt. Col. Ben K.
Armstrong became the commanding officer of the 8th. A unit strength of sixteen aircraft was finally reached in October, the
same month in which three aircraft and their crews were sent to Itazuke Air Force Base on the Japanese island of Kyūshū.
The detachment remained there until December 1947, flying four- to seven-hour aerial photography missions. In January 1948
a detachment of six F-15s were sent to Clark Field in the Philippines to assist the 5th Reconnaissance Group. Eventually other
detachments of F-15s from the 8th PRS were dispatched to Itzake and Chitose Air Base for various lengths of time. The detachment
to the 13th Air Force in the Philippines would remain until early September, with crews being rotated every thirty days.
Maintenance was a problem for F-15 operations from the beginning.
In January 1948 the entire fleet was grounded for ten days because of weather and a lack of spare parts, mostly heat exchangers
that were found to be cracking prematurely. Because of the lack of spare heat exchangers, replacements had to be obtained
from F-15s in storage at JAMA. By February 1948 the parts problem had become so critical that the 8th PRS had an average in
service rate of only two aircraft. Cannibalization of both damaged and flyable aircraft eventually brought this rate up, but
the unit would never reach a strength of sixteen operational aircraft again, reaching a high of fifteen only once, in December
1948.
In April 1948 Maj. Russell E. Cheever took over as squadron
commander. In August the unit was redesignated the 8th Tactical Reconnaissance Squadron (Night Photo). In addition, under
the new US Air Force designation system the name F-15A (F designating Photo under AAF classifications) became the RF-61A (R
for reconnaissance and F for fighter). This immediately caused confusion, both because the F-15A was unarmed and was never
considered a fighter, and because the F-15A was now reclassified as the P-61A both by the USAF and in squadron records (the
P-61A already existing as the earliest variant of the original "Black Widow"). The designation of RF-61C was applied later,
but by this point the unit had unofficially returned to calling the aircraft the F-15A, and would continue to do so for most
of their operational time with the machine.
The end of F-15 operations came on March 25 1949 when the
8th TRS (NP) was transferred to Yokota Air Base minus their equipment and personnel. There it became the 82d Tactical Reconnaissance
Squadron. On April 1 the 82nd, which consisted now of the former 8th's personnel and their F-15s, was deactivated and all
F-15s were assigned to the 35th Maintenance Squadron at Johnson Air Base for salvage or other disposition.
Of the nine F-15A allocated to Air Material Command, several
were operated for a short time by the Pennsylvania Air National Guard from their base in Harrisburg, Pennsylvania, before
they too were scrapped.
Mapping of Korea
During their operational lifetime F-15As, mostly operating
from bases in Japan, were responsible for most of the aerial maps of North Korea used at the start of the Korean War. These
photographs were to prove extremely valuable, as it was not until the arrival of Marine photo-reconnaissance F7F-3P in late
1950 that additional photographs of the peninsula could be made, and then only under constant threat from attacking North
Korean MiGs.
Civilian use
Some surviving F-15As were offered to civilian governmental
agencies, or declared surplus and offered for sale on the commercial market.
An F-15A (s/n 45-59300) was used by NACA at Moffett Field
in California to test some early swept-wing designs by dropping recoverable aerodynamic test bodies from high altitude. This
program was later joined by F-61C serial number 43-8330, borrowed from the Smithsonian Institution for the duration of the
tests. These drops were carried out over Edwards Air Force Base in the Mojave Desert in California.
Last flight
Surprisingly, the last flying example of the entire P-61
line was a rare F-15A Reporter (RF-61C) (s/n 45-59300), the first production model Reporter to be built. The aircraft was
completed on 15 May, 1946, and served with the Army Air Corps and later the U.S. Air Force until 6 February, 1948, when it
was reassigned to the Ames Aeronautical Laboratory at Moffett Field in California. There it was reconfigured to serve as a
launch vehicle for air dropped scale models of experimental aircraft. It served in this capacity until 1953, when it was replaced
by a mammoth wind tunnel used for the same testing. In April, 1955, the F-15 was declared surplus along with a "spare parts"
F-61C (s/n 43-8357). The F-15 was sold, along with the parts P-61, to Steward-Davis Incorporated of Gardena, California, and
given the civilian registration N5093V. Unable to sell it, the P-61C was scrapped in 1957. Steward-Davis made several modifications
to the Reporter to make it suitable for aerial survey work, including switching to a canopy taken from a T-33, and to propellers
taken from an older P-61. The plan was sold in September, 1956 to Compania Mexicana Aerofoto S. A. of Mexico City and assigned
the Mexican registration XB-FUJ. In Mexico the Reporter was used for aerial survey work, the very role for which it was originally
designed. It was bought by Aero Enterprises Inc. of Willets, California and returned to the USA in January 1964 carrying the
civilian registration number N9768Z. The fuselage tank and turbosupercharger intercoolers were removed; and the plane was
fitted with a 1,600-gallon chemical tank for fire-fighting. It was purchased by Cal-Nat of Fresno, California at the end of
1964, which operated it as a firefighting aircraft for the next 3 1/2 years. In March 1968 the F-15 was purchased by TBM,
Inc., an aerial firefighting company located in Tulare, California (the name of the company standing for the TBM Avenger,
the company's primary equipment), who performed additional modifications on the aircraft to improve its performance, including
experimenting with several types of propellers before deciding on Curtiss Electric type 34 propellers taken from a late model
Lockheed Constellation.
On 6 September, 1968, Ralph Ponte, one of three civilian
pilots to hold a rating for the F-15, was flying a series of routine Phoscheck drops on a fire raging near Hollister, California.
In an effort to reduce his return time Ponte opted to reload at a small airfield nearer the fire. The runway was shorter than
the one in Fresno, and despite reducing his load, hot air from the nearby fire reduced the surrounding air pressure and rendered
the aircraft overweight. Even at full power the Reporter had not rotated after clearing the 3500 foot marker, and Ponte quickly
decided to abort his takeoff. Every effort was made to control the hurtling craft, but the Reporter careened off the runway
and through a vegetable patch, before striking an embankment which tore off the landing gear. The aircraft then slid sideways,
broke up and caught fire. Ponte scrambled through the shattered canopy unhurt, while a firefighting TBM Avenger dropped its
load of Phoscheck on the plane's two engines, possibly saving Ponte's life. The F-15, though intact, was deemed too badly
damaged to rebuild, and was soon scrapped, bringing an end to the career of one of Northrop's most successful designs.
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Transonic techniques, testing recoverable models
from a high-flying airplane
The next step in developing transonic test methods came
in 1946, when Lockheed and NACA engineers simultaneously observed that the wing-flow method could be applied to wind-tunnel
testing by installing a bump, simulating the wing, on the floor of a high-subsonic-speed wind tunnel. At times the bump technique
was applied in the 16-foot tunnel while the wing-flow method was used in flight.
In 1946 the Flight Engineering Section at Ames foresaw the
end of the [148] deicing work and proposed a continuing program of research in the general field of aircraft operating
problems. This proposal was turned down by NACA management. Then along in 1947 Harry Goett, who was in general command of
the flight engineering activity, suggested to NACA Headquarters that Ames set up a pilotless-aircraft test operation similar
to the one being established by Langley at Wallops. Dr. Dryden was opposed to having Ames duplicate Langley's efforts in developing
rocket-launching and telemetry techniques, but he did not object when Harry proposed the dropping of recoverable models from
a high-flying airplane. Thus as the icing work began to phase out in 1947, Ames developed the technique for recovering intact,
by means of air brake and parachute, instrumented test models dropped at high altitudes from an airplane. In this way aerodynamically
clean models, if dropped from a sufficiently high altitude, would traverse the transonic range and, indeed, reach low supersonic
speeds before they had to be braked for a landing.
The airplanes chosen by Ames engineers for the drop
operation were a group of three Northrop P-61 "Black Widow" night fighters of which one, intended for photoreconnaissance
uses, had been equipped with a turbosupercharger. Another one, owing to the relative scarcity of P-61 airplanes, had been
borrowed, for cannibalization purposes, from the museum of the Smithsonian Institution. In the drop operation, the supercharged
P-61 was flown to altitudes up to 42,000 feet. As it did not have a pressure cabin, the physical stamina of the pilots was
sorely taxed. But useful data were obtained and the development of the recovery technique, a notable accomplishment in itself,
was helpful to other agencies later in attempts to recover expended missiles. The greatest contributors to the development
and use of the drop technique at Ames were Alun Jones, James Selna, Bonne Look and
Loren Bright. Among the pilots who flew the P-61 for the drop tests were George Cooper, Rudolph Van Dyke, and Robert Whempner
of Ames and Joseph Walker of the NACA High Speed Flight Station at Edwards, California.
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Variants
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F-15A
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XF-15 The
first prototype, converted from the first XP-61E.
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XF-15A The second prototype, converted from a P-61C (number 43-8335).
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F-15A Reporter Photoreconnaissance variant with a new center pod with pilot and camera operator seated in tandem under a single
bubble canopy, and six cameras taking place of radar in the nose. Powered by the same turbosupercharged R-2800-73 engines
as the P-61C. The aircraft had a takeoff weight of 32,145 pounds (14,580 kg) and a top speed of 382 knots (440 mph,
708 km/h). Only 36 of the 175 ordered F-15As were built before the end of the war. After formation of the United States
Air Force in 1947, F-15A was redesignated RF-61C. F-15As were responsible for most of the aerial maps of North Korea
used at the start of the Korean War
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RF-61C Reporter USAF designation for the F-15C from 1948 onwards.
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United States
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United States Air Force
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Alaskan Air Command
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449th Fighter Squadron (All Weather). Formed from
equipment and personnel of 415th Night Fighter Squadron at Adak Air Field, Aleutian Islands, Alaska on 1 Sep 1947. Later transitioned
to F-82 Twin Mustang in mid-1948.
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8th Photographic Reconnaissance Squadron. Flew F-15A
(RF-61C) Reporter (1947-1949) from Johnson AB, Japan. Aircraft reassigned to 82d Tactical Reconnaissance Squadron until inactivated
on 1 Apr 1949
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Continental Air Forces
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Propulsion
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XF-15 |
Reporter |
Northrop |
2 Pratt & Whitney R-2800-65 Double Wasp |
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XP-61E Black Widow |
XF-15A |
Reporter |
Northrop |
2 Pratt & Whitney R-2800-73 Double Wasp |
2 |
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F-15A |
Reporter |
Northrop |
2 Pratt & Whitney R-2800-73 Double Wasp |
3 |
RF-61C Black Widow |
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Note: Steward-Davis
Inc.
Steward-Davis Inc. was founded in 1946 by Herb Steward
and Stanley Davis at Compton Airport, California. They were one of many such innovative companies to come to life in the post-WW2
era specializing in aircraft conversions and aeronautical developments.
NORTHROP F-15 REPORTER Steward-Davis acquired this aircraft, a Northrop
F-15A-1-NO Reporter, for conversion to photographic duties possibly on behalf of one of their Mexican business
contacts.
In detail - the first production model Reporter to be built. The aircraft was completed
on 15 May, 1946, and served with the Army Air Corps and later the U. S. Air Force until 6 February 1948, when it was reassigned
to the Ames Aeronautical Laboratory at Moffett Field in California. There it was reconfigured to serve as a launch vehicle
for air dropped scale models of experimental aircraft.
It served in this capacity until 1953, when it was replaced
by a mammoth wind tunnel used for the same testing. In April 1955, the F-15 was declared surplus along with a "spare parts"
F-61C (s/n 43-8357). The F-15 was sold, along with the parts P-61, to Steward-Davis Incorporated of Gardena, California, and
given the civilian registration N5093V. Unable to sell it, the P-61C was scrapped in 1957. Steward-Davis made several modifications
to the Reporter to make it suitable for aerial survey work, including switching to a canopy taken from a T-33, and to propellers
taken from an older P-61. The aircraft was sold in September, 1956 to Compania Mexicana Aerofoto S. A. of Mexico City and
assigned the Mexican registration XB-FUJ. In Mexico, the Reporter was used for aerial survey work, the very role for which
it was originally designed. It was bought by Aero Enterprises Inc. of Willets, California and returned to the USA in January
1964 carrying the civilian registration number N9768Z. The fuselage tank and turbosupercharger intercoolers were removed;
and the aircraft was fitted with a 1,600 gal (6,056 l) chemical tank for fire-fighting. It was purchased by Cal-Nat of Fresno,
California at the end of 1964, which operated it as a firefighting aircraft for the next 3½ years. In March 1968, the F-15
was purchased by TBM, Inc. an aerial firefighting company located in Tulare, California (the name of the company standing
for the TBM Avenger, the company's primary equipment), who performed additional modifications on the aircraft to improve its
performance, including experimenting with several types of propellers before deciding on Curtiss Electric type 34 propellers
taken from a late model Lockheed Constellation. On 6 September 1968, Ralph Ponte, one of three civilian pilots to hold a rating
for the F-15, was flying a series of routine Phoscheck drops on a fire raging near Hollister, California. In an effort to
reduce his return time, Ponte opted to reload at a small airfield nearer the fire. The runway was shorter than the one in
Fresno, and despite reducing his load, hot air from the nearby fire reduced the surrounding air pressure and rendered the
aircraft overweight. Even at full power the Reporter had not rotated after clearing the 3,500 ft (1,067 m) marker, and Ponte
quickly decided to abort his takeoff. Every effort was made to control the hurtling craft, but the Reporter careened off the
runway and through a vegetable patch, before striking an embankment which tore off the landing gear. The aircraft then slid
sideways, broke up and caught fire.
Ponte scrambled through the shattered canopy unhurt, while a firefighting Avenger
dropped its load of Phoscheck on the aircraft's two engines, possibly saving Ponte's life. The F-15, though intact, was deemed
too badly damaged to rebuild, and was soon scrapped.
Note:
45-59300 was used by NACA at Moffett Field in California
to carry recoverable aerodynamic test bodies to high altitude, then drop them. This program was used to test some early swept-wing
designs. This program was later joined by F-61C serial number 43-8330 which was borrowed from the Smithsonian Institution.
These drops were carried out over Edwards Air Force Base in the Mojave Desert in California. F-61B-15-NO serial number 42-39754
was used by NACA's Lewis Flight Propulsion Laboratory in Cleveland, Ohio for tests of airfoil-type ramjets. F-61C 43-8357
was used at Ames as a source for spare parts for other F/RF-61 aircraft. After the tests were completed, the F-61C 43-8330
was returned to the Smithsonian Institution.
USAAF s/n |
Serial number |
Remarks |
45-59300 |
3210 |
1946 to USAAF, 1948 to NACA, April 1955 to
Steward-Davis Inc. N5093V, 1956
to Compania Mexicana Aerofoto XB-FUJ, 1964 to Aero Enterprises Inc. N9768Z for conversion to fire-bomber, 1968 to TBM Inc., w/o
California, 06 September, 1968. |
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Assorted photos
Drawings
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