On Sun, 08 Aug 2004 10:03:33 GMT, Guy Alcala
wrote:


Most tactical jets have some armor protecting at least the pilot, although
nothing like the titanium bathtub the A-10 pilot sits in. For the BUFF and
similar nuclear-tasked a/c of its era, armor was considered irrelevant and
counterproductive to the mission. If it's only going to be used once 'for
real', and even extremely high attrition rates still allow the mission to be
accomplished (75% losses? Moscow's still a smoking hole in the ground), then
armor just decreases the a/c's performance and takes up weight that can far
more usefully be dedicated to defensive electronics or other features that
provide greater protection.

I don't recall any armor in the F-105 or F-4.

Of course, when we found ourselves fighting a drawn-out conventional war in
Vietnam where the majority of losses were to AW, AAA and SAM warhead
fragments (as opposed to nuclear blast and radiation), where it wasn't one
strike and we hold the victory celebration (in the local deep mine where
we've ensconced ourselves to while away the years repopulating the human
race and listening to Vera Lynn, waiting for the radiation levels to die
down), the balance changed. Many of the a/c used in Vietnam were modified to
decrease their vulnerability to combat damage. Sometimes armor and
self-sealing and/or flame-retardant foam lined fuel tanks were retrofitted;
in many cases redundant, separated hydraulic systems were retrofitted to a/c
like the F-105s (designed as nuclear strike a/c) that Ed flew.

The F-105 was "dry wing" so no threat there, but the tanks were not
foamed. The F-4 initially was not foamed, but after leading-edge slats
were installed and during later production runs of E-models, the tanks
were foam-filled. The F-4 was "wet wing".

The F-105 had redundant hydraulic systems, but they weren't designed with
combat damage in mind. The two lines ran side by side inside the dorsal
fairing, so a hit that took out one usually took out the other, and once all
the fluid had run out of the system the horizpntal stabilizer went to the
max. nose up positions and it was time punch out.

All the aircraft of the period (Century Series) had three hydraulic
systems--two for flight controls and one for utility. They were
usually inter-mingled so that one side of a control actuator was
powered by one FC system and the other by utility. Gear, flaps,
refueling door, gun drive, etc. were utility.

As you state, the 105 piping was adjacent and often two hydraulic
systems could be taken out by one hit.

Understandably, pilots took a dim view of ejecting over North Vietnam
because they had no control of their a/c, so Fairchild instituted a quick
fix which, when the hydraulic system had taken a hit, allowed the pilot to
lock the stabilizer in the position appropriate for 350KIAS (IIRR. Ed will
probably remember) before the fluid ran out. They could control their
height by increasing or decreasing the throttle. That at least gave them a
shot at getting out of North Vietnam and over the Gulf of Tonkin or Laos,
Cambodia or Thailand before ejecting, where the odds of being rescued were
far higher, but there was no way they had enough control to attempt a
landing.

I never flew with that mod. But you essentially describe it correctly.
When it was apparent you would lose hydraulics, you flipped switch
which sealed the system at several points and locked the slab at 350
KIAS trim position. Nose control was through throttle maneuver--more
gas, nose rises, pull power off, nose falls.

TE flaps on the 105 were electric and with the slab-lock engaged a
toggle switch was activated that let you control differential flaps
for roll.

Strictly a "get out of Indian country" system. Bailout was mandatory
after engagement.

First guy that I know of that tried it was a friend, Wayne Fullam who
rode the airplane in. His last radio call was "how do you get the
&^%$$ nose up?"



Ed Rasimus
Fighter Pilot (USAF-Ret)
"When Thunder Rolled"
"Phantom Flights, Bangkok Nights"
Both from Smithsonian Books
***www.thunderchief.org