Interesting as the military test pilots out of the Patuxset flight test office favored the F4. The
F-104 had the same problem with the windshield above about Mach 2. Quite a surprise when at Mach 2+ a
big red light came on the panel that said "SLOW DOWN" --I did. :-) Another item about the F8U3.
Above Mach 2 the thrust required and the thrust available diverged, and therefore the faster you
went the faster you went.!!!!
Hal Vincent
I've heard of, but have never seen the F8U-3. I did fly the F-104G (German
model) for two years at Luke AFB while on exchange duty with the USAF from
the USMC. Hal Vincent is right about the thrust divergence above Mach 2 -
the faster it went, the faster it would go. However, in the G model the
light was red and flashing and said "Slow". It may have related to the
canopy, but the major problem in this model was the temperature of the front
frame of the engine. The factory reps said that the reason for this is that
the air through the intakes remained supersonic all the way to the engine
instead of being slowed by the shock wave that was caused by the spikes on
the fuselage in front of the intakes. --Merv Burns
This originated with Joe Angelone, and reached us via a few fwds. I hope I am not stepping on any
toes by passing it along. The -3 is a bird whose storied performance I have always drooled over.
His description of the compressor stalls is particularly intriguing.
The –3 was a mixture of joy and frustration. It had superb handling qualities. It was a 40,000 pound
airplane with around 25,000 pounds of thrust, making it less agile than the F8U-1 at lower speeds.
However, it was amazing at high mach number, as we would typically throttle back at Mach 2 on our
early test flights. We were limited by windshield and lower wing skin temperatures as higher mach
numbers were explored.
A typical flight would involve taking off from Edwards AFB and climbing to 40,000 feet to the East
boundary of California. Here we would turn West and enter the supersonic corridor with a USAF F-104
chase airplane. We would accelerate out to Mach 2, throttle back at this speed, and run through our
test plan. As we passed over Edwards we would drop subsonic and say goodbye to the 104, as he was
about out of fuel. We would then pick up an F-100 chase for the remaining tests. As a former USAF
fighter pilot, I got a perverse chuckle out of running their star fighter out of fuel half way
through our test plan.
I have read an article that was very critical of our retractable ventrals. We had two incidents with
them. I had one where the right ventral actuation system broke locked in the down position. I was
able to successfully break it off during a landing on the dry lake bed. Later on Jack Walton had a
hydraulic system failure and successfully broke both ventrals off during landing. Obviously we
needed to provide a means to retract them with a hydraulic system failure. The concept was great, as
was the performance.
One item was very frustrating. Afterburner shutdown at high mach number always resulted in engine
high energy compressor stalls. These stalls consisted of brief air flow interruption, continued fuel
flow, then brief recovery of air flow followed by explosive ignition of accumulated fuel, brief air
flow recovery and repetition of the cycle. The automatic fuel control was unresponsive to pilot or
system inputs in these cycles. The explosive blasts would travel up the intake duct and violently
whip the nose of the airplane up and down, knocking the pilot’s feet off the rudder pedals. In one
event I saw a 1” gap between the top of the canopy bow and the windshield as the nose whipped. I
compared these blasts to that experienced dropping a couple of 500 pound bombs low enough to get in
one’s own bomb shrapnel on a dive bombing attack – which I’ve done. The number of shut down
repetitive high energy stalls would vary from a few to as many as 11, depending upon what corrective
design changes were being tried. The engine would eventually go into a steady state stall, a nice
low volume whirring sound. The pilot would get throttle control back when the speed dropped to 1.4
Mach, where the engine would recover from the stall. Unfortunately we were not able to correct this
problem before contract cancellation, as the F4 won the competition.
Why did we lose the competition? We had outstanding performance and handling qualities! We had a
very serious engine problem, and no correction in hand. The single engine single pilot controversy
was real, particularly for the all weather mission of this bird. We had a fixed base simulator of
our design that I flew extensively, and I felt Navy Ensigns could handle the mission with our
design. Unfortunately, I believe the engine problem and the single engine – single pilot issue made
the F4 the safest way for the Navy to go.
...The test F8-3 regularly hammered everything including the F4 so badly in the
test ranges on the east coast that it was a joke....
...[it] just left the F-104 chase in the dust and routinely out ran it.
Dudley Moore: Regarding the F8U-3:
The J-58 was indeed a Navy sponsored engine for the -3. It was under
development when the -3 went into testing so they used a 'tweaked J-75 AF
engine' for initial testing. It did outrun four (4) count 'em again four
F-104 chase planes in its supersonic runs.
Even with the J-75 it started melting going past M2.6. It was still
accelerating and would have hit M3 easily even with the J-75.
It would have been interesting to see what it would do with the J-58. It
also packed 'a little something extra' like an 8000# solid fuel rocket motor
buried in the aft fuselage. It achieved the speed by having a by-pass door
on each side of fuselage vs. only one on the -1 & -2 F8s coupled with a
computer controlled translating spike intake. The SR - 71 achieved the same
thing in its engine nacelles with a series of blow in doors and spike. At
about M3.5 or so the doors closed fully and the spike was fully retracted
resulting in ram jet performance - 100% by pass.
The test F8-3 regularly hammered everything including the F4 so badly in the
test ranges on the east coast that it was a joke. The NASA pilots were told
to knock it off. Well the Navy bought the joke and look what happened.
All this from ace NASA test pilot Ed 'Fast Eddie' Schneider at Edwards circa
1988.
Interestingly enough he gave me the history of the two F8s on poles in front
of the Ops bldg at Edwards. They just left the F-104 chase in the dust and
routinely out ran it. I expressed disbelief at that until he told me why.
They put the J57 P420 in them, a combo the Navy never had. Well I said 'Ed
those engines have to be here somewhere, I want them for our bird'. It was
to take 4 years to locate a P420 at Yuma...after a 3 week engine swap, we
had a 21.5 drive in a 16.5 frame...lordy it was a screamer...1/1
thrust/weight ratio at 'fighting speed'.
We briefly toyed with the idea of putting a second cooling door in the right
side of our F8 but stuff costs and this was expensive. Besides with the big
drive and the dinky ventral fins, I would not want to be in it going past M2
as it would decouple easily ala F-104.
[in a followup, Dudley confirmed that he was referring to the Thunderbird Aviation F8's,
which were bought by Paul Allen the MS guy and are in his museum in Seattle.]
...on my first flight, the air traffic controller from Norfolk Center ask me, "NASA, what in the world are you flying?" He was impressed with the aircraft's rapid acceleration and climb---so was I.
Don Mallick, who flew the -3 for NASA, sends this:
I flew on the NASA Langley Sonic Boom program in June 1959. Another NASA Langley pilot, the late
Bill Alford and I shared the flying of the F8U-3, BN 146340. We had a second F8U-3, but it was kept
in the hangar as a parts source for 340.
Chance Vaught pilot, John Conrad had delivered the aircraft to NASA Langley, after they lost the
competition with the F4H. NASA Langley had procured the aircraft for sonic boom generators with a
large performance envelope. The program was accelerated and my log book indicated it ended in
October 1959. We flew at altitudes of 60,000 feet and Mach 2.2 Our actual aim mach number that we
repeated at various altitudes up to 60,000 feet was Mach 2.0 This allowed for determining altitude
affects on the pressure or shock wave that reached the ground.
John Conrad stayed with us, until Bill Alford and I had two flights each. There were no handbooks,
just written notes that John brought along. John Conrad was on the radio and served as our
reference, if anything developed that we did not understand during the check out flights. The
flights went well. I recall on my debriefing on my first flight, I commented to John that I had an
unusual side slip develop right after I became airborne--over 1/2 ball out of center. John laughed
and said it was the tailpipe on the big J-75 engine. It distorted some in full afterburner and
caused the sideslip. It was not noticeable at higher speeds.
Out flight test track lay just off the coast and went from abeam of Virginia Beach to Chincoteague
Virginia. The sound test range was laid out East and West across Chincoteague and out to sea on
several boats. We started our acceleration abeam Virginia Beach and climbed and accelerated to our
planned altitude and Mach. We were stabilized on speed and altitude several minutes prior to passing
the sound range---where the sensitive ground microphones measured the pressure wave, or sonic boom.
I recall on my first flight, the air traffic controller from Norfolk Center ask me, "NASA, what in
the world are you flying?" He was impressed with the aircraft's rapid acceleration and climb---so
was I.
I saw an earlier comment on the engines, the J-75s. I recall it provided about thrust of 26,500 lbs
in full afterburner. Not bad for those days. One problem was, the pilot could not modulate the
afterburner; it was either on full, or off. That was a problem for maintaining speed and I actually
used the speed brake (not limited) to hold Mach 2.0 for the test point. Otherwise, the airplane
would keep accelerating. We did have to live with a 5 minute limit at Mach 2.0. The reason was the
F8U-3 did not have a heavy armor windshield. It was Plexiglas and the heating at Mach 2.0 would
cause it to soften and perhaps blow in. The estimate was 10 minutes to failure, we used 5 minutes
for a safety factor. The ground controller set his clock, when we called Mach 2.0 to back us up; on
coming out of burner.
I loved flying the airplane. Prior to the F8U-3, I had flown a F-100C and the Grumman Tiger F11F.
The F8U-3 "smoked" these airplanes as far as performance. It also "smoked" the F-100C as far as
handling qualities. I don't think I ever flew an airplane with better handling qualities than the
F11F Tiger.
I noted an earlier comment on the J-58 used in the SR 71's, as being planned for the F8U-3. I do
not believe that to be the case. The F8U-3 was not designed for sustained mach number in the range
of the SR 71's. The J-58 was designed for full time afterburner operation up to Mach 3.2. The
cruise EGT on the J-58's was 804 degrees centigrade. The turbine blades on the J-58 had cooling
holes to allow bleed air (cooler than the exhaust gases) to pass through the turbine blades to cool
them and then go out with the exhaust gases---i.e. thus the ability to run at 800 degrees exhaust
gas temperature.
It was quite an airplane and the hottest thing I had flown at that time. The only thing I forgot to
mention was, the crosswind landing characteristics were not so nice. With the large side area,
fuselage height and narrow gear, it loved to heal and lean on the roll out. Also, typical Navy
Bird, no antiskid brakes in those days, so you had to be easy on the brakes until the airplane
slowed and settled some weight on the runway. I would touch down close to the approach end and roll
all the way to the end of the east-west runway at Langley, when I had a strong crosswind.
I think flying the F8U-3 "wet my appetite" for high speed and I transferred to Edwards in 1963 to
continue on that line.
I was fortunate enough to fly the SR-71s at NASA Edwards from 1970 to 1979. As much as I enjoyed the
F8U-3 experience at Langley in 1959, I have to say nothing could compare to the Blackbird.
I also flew a modified F8U-2; it was modified with a super critical wing. I just had one qualitative
flight in that one.
I had a book published about my flying career, Navy and NASA in 2004. It is titled: "The Smell of
Kerosene, A Test Pilot's Odyssey" It is available on the NASA Dryden Web site-to read or download.
It is also available through an Internet book broker.
www.nasa.gov/centers/dryden/history/Publications/index.html
www.alibris.com
It is a government publication and I receive no royalties.
[Ed. note -- I believe the Supercritical wing is one of two F8's on poles at Edwards, the other
being the DFBW machine]
Created on ... October 16, 2008
