In the G model, we could and did run it out to 800KIAS. Not for very long,
however!!
"WaltBJ" wrote in message
m...
There are three redlines for the F104A with either the -3b or the -19
engine.
710 KIAS, 121C or M 2.0. I believe most Zipper pilots honored these
limits in the breach, as the Limeys say. They are all artificial
limits as even the -3b engined proverbial 'squadron dog' would exceed
all 3 limits. The hard concrete limit is the aluminum airframe. M 2.4
at STP will anneal the aluminum alloy and now the design strength is
gone never to return. (The F106 on display at the USAFA is a case in
int - 2.46 Mach and she was grounded forever.)
FWIW the 2.0 limit is because of reduction in lateral stability beow
USAF criteria; Cnbeta limit is .03; think of this as a stability
restitution coefficient. Of course if you don't do anything really
dumb like stomping on teh rudder - hey,let 'er rip.
The KIAS limit is because of internal pressure limits at the rear of
the compressor. There is a limit built into the fuel control and it's
quite noticeable when it cuts in - but you're over 710 when it does.
the airplane is accelerating like mad because those little scoops are
really taking in the ram air and all of a sudden the 'governor' cuts
in and she stops accelerating. I remember seeing at that point about
750 and 1.2 on the clock at about 100 ASL just before I went right
over the top of a shrimp trawler on a test hop early one Florida
morning - and that was with an old tired -3b engine.
The 121C limit is from a temp sensor in the generator cooling air
duct. It turns on the Slow light. The 100 CIT is from the T2 probe at
the front of the compressor.
I know a couple fearless single Zipper pilots who have been out all
the way up at altitude; neither would own up to what their Mach was.
One of them returned with scorched paint on his warhead-loaded AIM9s.
The other was turned ;ate on a supersonic target on a night exercise -
the conroller called 'skip it - we're too far behind.' Howie replied
'keep talking' and put teh throttle in teh far left corner. He heard
the controller over an open mike call otu to his buddies - 'Hey! Come
look at this!' Howie caught and passed an f4 cruisng supersonic in
(probably) minimum AB. Howie, back then, wasn't about to let a little
thing like a book limit bother him. He also let teh F4 know he was
there. We wondered what the F4 crew thought as something blitzed past
them close aboard at least 500 knots faster than they were cruising.
One thing I noticed was the fuel flow increase as the IAS increased. A
static 8500PPH at the end of the runway (those little intakes!) during
the pre-takeoff runup rose to about 12500 at 600KIAS, still on the
deck. Since the fuel-air ratio is fixed that indicates the thrust
developed increased proportionately. Once took a Dash19 Zipper right
off the line, usual war load of 20mm ammo plus 2 AIM9Bs, from brake
release to 45000 in 90 seconds flat. Takeoff acceleration was from
brake release to .97 - 43 seconds. Rotated to hold .97 and at 40000
stood her on her tail. Exhilirating ride! Mommy, I want a Zipper for
Christmas!
Walt BJ