Grumman F9F-6/7/8 Cougar Pt.1

93 Pages·2001·57.882 MB·English

by  Corky Meyer

PUBLISHER'S NOTE:
The Grumman Cougar, like the
Panther se ries before it, will be pub
lished in several volumes. This, the
first volume, covers the Cougar's
development as experienced by
Corwin "Corky" Meyer, its structures,
equipment and the Blue Angels. It just
touches on the F9F-6P/8P photo
Cougars and the F9F-8T two-seat air
craft as each will have its own volume
in the Naval Fighters series. In addi
tion, a large volume will concentrate
on the Navy and Marine single-seat
Cougars in squadron and operational
service in the Fleet, Reserves, and at
shore-based Naval Air Stations.
ABOUT THE AUTHOR:
Corwin "Corky" Meyer joined
Grumman in 1942 as an experimental
test pilot. He became project pilot for
the following fighters: Hellcat,
Tigercat, Bearcat, Panther, Jaguar,
Tiger and the Mach two Super Tiger.
In 1954 , he became the first civilian
pilot to qualify aboard an aircraft car
rier in jets. This was accomplished
while flying with VF-61 in Cougars
aboard the USS Lake Champlain
(CV A-39). In 1965, he became
Director of Aircraft Delivery opera
tions, and in 1969 he became Senior
Vi ce President of all Manufacturing
Operations and Quality Contro!. In
1974 he became President and CEO
of Grumman American, a commercial
aircraft subsidery. Steve Ginter, 1754 Warfield Cir., Simi Museum, Larry Smalley, Bob Stolloff,
Valley, California, 93063 William Swisher, Tailhook Association,
Warren Thompson, Norm Taylor,
After retiring in 1978, he became
Kirsten Tedesco, Gary Verver (China
President and CEO of Enstrom All rights reserved. No part of this
Lake web site), and Nick Williams.
Helicopter Corporation, Falcon Jet publication may be reproduced,
Corporation, and OMAC. Mr. Meyer is stored in a retrieval system, or trans
a Fellow of the Society of mitted in any form by any means elec
Experimental Test Pilots and an tronic, mechanical, or otherwise with Above, Corwin "Corky" Meyer prior to
Associate Fellow of the American out the written permission of the pub an F9F-8T test flight. (Grumman)
Institute of Astronautics and Aero lisher.
FRONT COVER: F9F-8B BuNo 141140
nautics. He also served as a consul- .
tant to the European research organi CONTRIBUTORS: configured for the long-range carrier
Combat Air Patrol (CAP) mission with
zation AGAARD (a NATO Committee
two Aero 150-gallon drop tanks and
for Research and Development) and Scot Bloom, Peter Bowers, Fred
four inert AIM-9B Sidewinder air-to-air
Freeman, Harry Gann, Hili Goodspeed
NASA. Mr. Meyer has a daughter, missiles. (Grumman)
(National Museum of Naval Aviation,
Sandra Louise, and two sons, John BACK COVER: Top, factory fresh F9F-
Gene "Mule" Holmberg, Lloyd Jones,
Fyfield and Peter Corwin. 8 BuNo 144378. (Grumman) Middle, the
Craig Kaston, Clay Jansson, William T.
National Museum of Naval Aviation's
© 2005 by Steve Ginter Larkins, Bob Lawson, T. Matsuzaki, F9F-6 BuNo 128109 in the markings of
David Menard, Barry Miller, John VF-142 in 1999. (Ginter) Bottom, a row
Moore, Wayne Morris, Stan Piet, Mick of eight F9F-6K drones at China Lake.
ISBN 0-942612-66-3
Roth, Fred Roos, San Diego Aerospace (0. Olson via Nick Williams)
DEVELOPING THE GRUMMAN F9F COUGAR BV CORWIN "CORKV" MEVER
THE PANTHER METAMORPHOSIS equipped with leading edge slats to Above, the first XF9F-6, BuNo 126670,
see if handling characteristics and just before its first flight on 20
When Grumman and the Navy stall speeds could be made amenable September 1951. The three prototypes
first discussed the Panther, both par to carrier operations. They put out a were modified F9F-5 airframes 126670-
ti es had been privy to the Navy bid request to both Grumman and 672. (Grumman) Below, Bell L-39 (mod
ified P-63) was a Navy-sponsored 35°
Technical Team's findings in German Bell Aircraft to get one flying in the
swept-winged research aircraft with
WW-II research immediately after the shortest possible time. Bell judicious
leading edge slats for carrier suitabili
war and the fact that many of the top Iy proposed sweeping the wings of
ty. The yarn-tufted wings demonstrat
German fighter designers had two P-63 King Cobras, one with lead
ed visual wing flow to the pilot and the
"migrated" to our new enemy, Russia. ing edge slats and one without. wing cameras mounted on the canopy
This information put firm emphasis on Grumman proposed Design 77, a just behind the pilot. The four-foot
the greater critical Mach number pos swept-wing version of the Wildcat, extension of the fuselage can be seen
sibilities with swept wings over a con and an all-new aircraft. Both of just aft of the wing fairing, needed to
ventional straight-wing fighter for both Grumman's proposals were far more compensate for the large aft move
ment of the center-of-lift due to the
the United States and the USSR. expensive-thus Bell received the con
sweep angle. (via Corwin Meyer)
Therefore, the F9F-2 Panther tract.
straight-wing jet fighter contract
awarded Grumman in October 1946
had provisions in it for developing a
swept-wing version.
Because the unknowns of higher
stall speeds inherent in swept-wing
jet aircraft and concerns about cata
pults and arresting gear capabilities
of World War II Essex class carriers,
the Grumman design crew naturally
gave maximum priority to the straight
wing version wh ich was by now under
firm contract. Grumman also went
under competitive pressure from
McDonnell, whose twin-engine,
straight-wing FH-1 Phantom I had
been carrier qualified on 26 July
1946, and the more powerlul F2H-1
Phantom was not far behind.
The Navy Bureau of Aeronautics,
however, decided that the proof of the
pudding would be in flying a swept
wing experimental research aircraft
1
On 19 June 1946, I flew a
Tigercat to the Bell plant in Niagara
Falls, NY and evaluated both of the
Bell prototypes. My flight in the L-39,
a swept wing P-63 with no leading
edge device, was short. It cavorted
like a cat on catnip during the stalls
and required excessive altitude for
recovery. The L-39 prototype with
leading edge slats was docile during
stalls and accelerated stalls. Both
Above, not only did Rolls Royce seil their Nene engine license to the U.S. tor use maneuvers could be performed with
in the Grumman Panther but they sold it to the Russians who used it in the swept little wing-dropping and normal alti
wing MiG-15. The Navy's straight-wing F2H Banshee and F9F Panther (below)
tude loss. These two prototypes
became instantly obsolete. The XF1 OF program was cancelled and the swept-wing
made it clear that slatted, swept
Cougar became a priority. (Gordan Williams) Below, VMF-224 F2H-2 BuNo 123259.
wings would provide carrier-suitable
(via Harry Gann) Below middle, F9F-2 BuNo 122567 with tour bombs over Long
flight characteristics and stall speed
Island in 1950. (Jim Hawkins via Norm Taylor) Bottom, the author Corky Meyer was
the XF1 OF's test pilot. (Grumman) performance for fighters. I was soon
to find out that the L-39 flights were
only Swept-Wing Course 101.
Efforts on Grumman's swept
wing Panther (Design 83) languished
because of the much higher priority
given by the Navy to produce the
straight-wing Panther in large num
bers. Design 83, therefore, slowly
evolved into a completely new aircraft
with a variable-sweep wing moving
from 13 degrees sweep for the land
ing condition to 45 degrees for com
bat, the much larger Westinghouse J-
40 engine with afterburner and
unorthodox longitudinal and lateral
controls. Grumman engineering
believed this design to be the only
solution that would guarantee swept
wing carrier suitability. It later evolved
into the aborted XF10F-1 Jaguar.
It was unknown at Grumman but
the Navy Bureau of Aeronautics
found out after the fact that Rolls
Royce had sold the Russians the
same Nene engine rights Pratt and
Whitney had purchased for Panther
manufacture. When Naval Intell
igence determined in late 1950 that it
was being installed in swept-wing
MiG-15 fighters, the Grumman
Panther and the McDonnel1 F2H-1
Banshee straight-wing fighters just
coming into Navy inventory became
instantly obsolete. Needless to say,
the revised swept-wing Panther
(Design 93) was now given top priori
ty and Design 83, the XF1 OF-1, was
temporarily shelved. A priority study
contract was awarded to Grumman in
December 1950 to re-energize
2
Grumman engineering and expedite
the design of a swept-wing Panther.
To make the Cougar a more
straight-forward and produceable
design, the Panther's fuselage,
engine installation, wing center sec
tion, fin, rudder and landing gear were
retained. The upper rudder was con
verted to a yaw damper that was
required for the inherent increase in
yawing and rolling caused by swept
wing aerodynamics in rough air. The
wings were swept to 35 degrees and
hydraulic-powered leading edge slats
similar to the Bell L-39 slats were
installed. The Cougar's wing area
was increased from the Panther's 250
square feet to 300 square feet to
retain the same carrier approach
speed as the Panther. The stabilizer
was swept 35 degrees and was made
Above, an abortive attempt to eure stall pitchup on the prototype Cougar, XF9F-6
fully trimmable for high Mach number
BuNo 126670. These fences, installed just outboard of the engine air duct
flight. Normal elevators were in entrances, and vortex generators installed at the 30% chord position at the wing
stalled. The first aircraft flew with a outboard section, demonstrated no corrective air flow by the yarn tufts installed on
power operated spoiler flaperon and the right wing outboard surface. (Grumman via Corky Meyer) Below, the second
an aerodynamic aileron (in case of XF6F-6, BuNo 126672, with Grumman logo and AN/ARA-25 fairing under the nose.
power failure of the flaperon) as a (Grumman via Peter M. Bowers) B6ttoin, belly view of F8F-8 BuNo 141143 showing
the three long, slim black marks in a line which were the vent holes to prevent buf
safety combination lateral contro!.
feting of the rear speed brakes when they were extended. The left aft flap speed
Tip tanks could not be installed on the
brake has been outlined in black on this photo. The flap speed brakes worked
Cougar because of the far aft location
simultaneously with the front speed brakes which can be identified by all the round
of the swept wing tips. The resulting
holes located just below the engine intakes and behind the closed nose wheel
reduction of fuel capacity was some doors. (Grumman via Corky Meyer)
what made up by increasing the
length of the forward fuselage fuel
tank by two feet and installing bladder
tanks in the leading edge of the wings
behind the slat mechanisms. The
total fuel relative to the F9F-5 Was
decreased fram 1003 to 919 US gal
Ions, giving the Cougar a range of
1150 nautical miles at 430 knots
cruising speed. Because of its swept
wings, the Cougar had much lower
aeradynamic drag than the Panther,
thus an additional speed brake was
installed as part of the inboard land
ing flaps and was synchranized with
the front speed brake. The flap speed
brakes, however, were immobilized
when the landing flaps were extend
ed.
A contract was finally signed 2
March 1951. Only six-and-a-half
months later, on September 20, test
pilot Fred Rowley flew the XF9F-6
Cougar on its maiden flight. The first
Cougars were delivered to VF-32 in
November 1951, just one year after
3
-
the MiG-15 debut in Korea. It was
interesting for me to watch the vast
increase in interest and effort rapidly
applied to the Cougar design after top
Navy and Grumman priority was
demanded by the Mig-15 introduc
tion. Combat necessity was the
speedy mother of Cougar invention.
EARL Y PRODUCTION VARIANTS:
F9F-6. Two flying prototypes
Above, F9F-6 BuNo 128256 with wing fixes and nose fairing with AN/ARA-25. (via
(Buno 126670 and 126672) and a
SDAM) Below, prototype F9F-6P photo Cougar BuNo 127473 in flight. Blow-in
static test airframe (Buno 126671)
doors on the upper rear fuselage are open. The F9F-6P Cougar conversion was lit
tle different from that of the F9F-5P Panther. (Grumman) Below middle, all-red F9F- were ordered with Pratt and Whitney
6K drone BuNo 130828 at an open house. This aircraft started out life as an F9F-7, J48P-6 engines of 7000 pounds stat
but was re-engined as was all -7s, thus both F9F-6 and F9F-7 Cougars were desig ic thrust with water injection and 6250
nated F9F-6D/Ks after conversion. (via Norm Taylor) Bottom, F9F-7 BuNo 130912 pounds dry. This engine was only
in flight in 1954. (Harold G. Martin via W. T. Larkins) installed in the first 30 production
Cougars. They were later fitted with
J48-P-8 engines rated at 7250
pounds of static thrust without water
injection. All were armed similar to the
Panther with four 20 mm cannon with
190 rounds per gun and the Mark 6
fire control system with the APG-30
radar range system. They also had
two bomb racks capable of carrying
Aero-1 C 150 gallon tanks or 1,000
pound bombs. Later aircraft were fit
ted with two racks for the AIM-9D
Sidewinder air-to air missiles. In ser
vice F9F-6s were fitted with in-flight
refueling probes and the UHF homing
antenna in fairings beneath the nose
cone. 877 F9F-6/7 Cougars were
constructed with production ending in
April of 1954.
F9F-6P. Sixty F9F-6 airframes
were fitted at Grumman with vertical,
lateral and oblique Fairchild cameras
and delivered as F9F-6Ps between
June 1954 and March 1955. They
were similar to the camera installation
in production F9F-5P Panthers.
F9F-6D and K models. Many
F9F-6 and re-engined F9F-7 aircraft
were modified as pilotless drone
directors with various navy research
and development programs.
F9F-7. Grumman's conservatism
was also reflected in a dual engine
availability for the Cougar. The Pratt
and Whitney J48-P-6 was going
through some growing pains with
thrust increases and manufacturing
changes so Grumman Engineering
4
suggested and the Navy agreed that
the AIIison J33-A-16 with its lesser
6350 pounds of thrust be installed in
early production aircraft. These 168
aircraft were labeled F9F-7s.
Grumman and Navy pilots aptly
named these Allison engines "The
Poopless Wonders". As soon as Pratt
geared-up production with their 7250
pound thrust J48-P-8 engines, they
were immediately installed in all the
F9F-7 aircraft. During my carrier
indoctrination with squadron VF-61 in
1954, the squadron only had Allison
powered Cougars for all of our Field
Carrier Landing Practice sessions, in
July heat at NAS Oceana. During
those practice sessions we were car
rying 97% engine rpm, which left pre
cious little thrust for necessary climb
out during missed approaches. We from the grip. I immediately closed Above, VF-61 F9F-8s in 1956. Corwin
were all pleased when the squadron the throttle, extended the speed "Corky" Meyer carrier qualified with
was outfitted with Pratt and Whitney brakes, and while decelerating VF-61 F9F-7 aircraft re-engined with
Pratt & Whitney J48-P-8 in 1954. (USN)
J48-P-8 engines with 1,000 pounds of through 500 mph, the buzz stopped. I
Below, the Cougar prototype XF9F-6
additional thrust just before we went landed immediately for a complete
BuNo 126670 early in the wing modifi
to sea for actual carrier operations. aircraft inspection wh ich showed no
cation program. The area just outboard
damage. I was then told that no previ
of the duct had the two-foot sharp
COUGAR GROWING PAINS: ous flight had exceeded 475 mph! On upper wing leading edge reworked to a
my next flight at 525 mph my chase more curved wing airfoil shape. This
As the Senior Engineering Test pilot noted that the spring tab on the change was constructed of balsa wood
Pilot, I relinquished the program of elevator, designed to reduce stick covered with fabric and thus could be
demonstrating additional external forces, was a one-inch blur when the test flown the next day. It was the first
fix in reducing spanwise flow and its
stores for the F9F-5 Panther to anoth vibration was in progress. Upon land
ensuing violent pitchup at the stall.
er pilot and was brought into the ing, engineering soon determined
(Grumman)
Cougar program to assist Fred that non-static balanced tabs, which
Rowley shortly after its first flight. had been used on all previous
Grumman fighters, were required to
Checkout in the Cougar from the be 100% static balanced when locat
Panther was simple because the only ed on a 35° control surface. The bal increasing the tab's flutter speed weil
change in the cockpit from the anced tab cured the problem by above the Cougar's design maximum
Panther was the flaperon/aileron lat
eral control system, wh ich had an
automatic changeover to the normal
ailerons if the hydraulic power to the
flaperons failed. A temporary paper
placard listing airspeed limitations
was past.ed to the instrument panel
stating that the maximum air speed
was 575 mph, slightly lower than the
Panther's maximum speed at sea
level and estimated to be the
Cougar's best climb speed. I stupidly
assumed that the Cougar had already
been to its cockpit placard limits.
Wrong!
As I was accelerating through
525 mph on my first flight, I feit a
strong buzz in the stick wh ich was
quite visible when I removed my hand
5
limit speed of 650 mph. We had now
matriculated to 35° sweep "U".
The next problem that we found
was that the small wing-tip ailerons
floated at different angles during tran
sonic dives without pilot input, so
much so that the airplane was use
less for gunnery tracking. We first
tried installing small vortex generator
vanes on the upper surface of the
wing tip to smooth out the supersonic
flow ahead of the ailerons, but they
proved useless. It was then decided
that the ailerons must be eliminated
and the powered flaperons be
extended another six feet to the wing
tips.
Above, leading edge slats extended on the second F9F-7 BuNo 130753. The slats A SEEMINGL Y SIMPLE
were hydraulically actuated with wing flap extension. (National Archives) Below, TEST FLIGHT:
130753 with wing flaps extended. What looks like a short wing-tip aileron was actu
ally a trim tab found only on the port wing. (National Archives) Bottom, the wing
was again taxiing down the
tip trim tab is seen deflected upwards and the outlines of the flaperon and the
main runway at Grumman Bethpage
flaperette above the trim tab and below the national insignia can be clearly seen.
for an easy flight test of spoiler-type
(National Archives)
flaperon extensions to replace the
ailerons. The shop had bonded a
twelve-foot sheet of 1/2" inch alu
minum to each of the six-foot flaper
ons, hopefully to double the roiling
capability of our new swept-wing
Cougar jet fighter. I had attempted to
fly this configuration the day before
when I had a very eerie experience.
I had been sitting in the cockpit
after finishing my pre-takeoff check
list, when I had a feeling that some
thing was drasticaily wrong, but didn't
have a clue as to the problem. I
looked down into the left cockpit con
sole to go over my check list again
when I noticed something off-beat
outside the canopy in my far left
peripheral vision. Now focusing on
the left wing spoiler flaperon, I was
shocked to note that the left wing
spoiler flaperon was 45 degrees fuil
deflection up with the stick centered!!
I moved the stick right to bring it down
flush with the top of the wing but it
remained full up. I then checked the
right flaperon and it was also fuil up
and not obeying stick motions either.
As I taxied back to the line, I was
pleased that I had found the discrep
ancy. Had I started the take-off roll,
the very high drag of the extended
spoiler flaperons would have never
permitted the airplane to leave the
6
ground. I was relieved not to have
discovered the cause at 150 mph,
tearing thru the village of Bethpage at
the end of the runway!
The inspection subsequently
revealed that some basic and impor
ta nt ground tests had been omitted by
engineering in the rush to get this
change into the air! I was told that my
full deflection stick motions to check
freedom of the controls had pushed
the flaperon linkage over center and
jammed them in the up position. As
the flaperon system linkage was now
corrected, tested and inspected to my
Above, f1aperon fully extended on F9F-6 BuNo 127325. The flaperon was hydrauli
satisfaction, I taxied into the takeoff
cally actuated for lateral control from the pilot's stick. (National Archives) Below,
position and fervently thanked the
127325 with flaperette extended. With hydraulic power out, flaperettes were "air
Lord for coming to my assistance the
bottle" actuated with only ten actuations for use in final approach or touchdown
previous day in the nick of time. only. (National Archives) Bottom, the effect of tip stall on longitudinal trim shows
the chordwise wing air flow after the three fixes for the initial pitchup and spin
My check list now completed, problems were installed on the Cougar prototype XF9F-6 BuNo 126670. During
took off uneventfully to make a full stalls prior to these fixes, the wing airflow would flow spanwise to the wing tip
stalling the entire outer half of the wing wh ich moved the wing center of lift sever
evaluation this new flaperon addition.
al feet further forward than this picture demonstrates. (via Corwin Meyers)
About thirty seconds after takeoff the
radio started a very high-pitched
squealing and the cabin pressuriza
ti on system cycled from minus two
thousand to plus four thousand feet
cabin altitude. I thought my eardrums
were going to come out of my head.
At the same time the aircraft started
vibrating so strongly that the instru
ment panel was ablur. My mind was
completely overloaded by this
screaming, pulsating and vibrating
monster in aircraft's clothes. The
shaking was similar to a complete
AIIison J33-A-16 engine failure I had
experienced two weeks before when
a large number of turbine blades
departed the tailpipe, unbalancing the
engine.
Instinctively I slammed the throt
tle aft and pulled up to a steep climb
CG OF
in case of my need to eject. I immedi AIRPLANE
ately turned the radio and the cabin
pressure system off to rid myself of
their part of the cockpit cacophony. A
few very long seconds later the vibra
tions stopped and I found myself at
150 mph and 8,000 feet so I leveled
off to inspect the engine instruments
I
to see if I was in a Grumman engine , CENTER
less glider again. When I hopefully OF
~.,....,.",--LIFT
and gingerly pushed the throttle for
ward, the engine spooled up and the
tail pipe temperature started climbing.
After performing this simple motion
l
7