The monsoon season in Vietnam made flying tough. Every day there
was rain, overcast and low visibility, which made it nearly impossible
from airport to airport using Visual
. So we used other means.
The FAA has very sophisticated enroute radar control that allows
airliners to fly all over the U.S. with Instrument
. But in Vietnam the civil enroute air traffic
have radar. Instead, IFR was done the pre-radar way based on
aircraft reporting over
navigation aids. This meant that very few aircraft could fly IFR
in the same airspace
at the same time, so IFR departure delays of up to four hours were
But the Air Force didn't wait for civil aviation rules in
Vietnam. Instead, we used "Tactical" Visual Flight Rules.
TAC VFR meant using visual flight rules in instrument
meteorological conditions. If this sounds like an oxymoron, it
The civil air traffic controllers didn't have radar, but the Air Force
GCI (Ground Control Interception) guys did. In good weather
used radar to direct air attacks on specific locations. In bad
they did advisory radar flight following for guys like us flying TAC
VFR. There were GCI sites in Saigon (call sign Paris), Ban Me
(call sign Pyramid), Nha Trang (call sign Port Call), Danang (call sign
Panama), Binh Thuy (call sign Paddy), and others.
The good news was that the GCI controllers' radar could see aircraft
quite effectively in the weather. The bad news was that the
have information about all flights. And their radar had no
about what altitude the traffic was using. Panama might call us
advise, "Fast mover northbound at your 12 o'clock, 2 miles,
non-beacon." This meant that there was an unknown jet directly
of us with no transponder information. It may have been thousands
of feet above or below us, but
couldn't tell, so we had to take immediate evasive action.
Theoretically, IFR-assigned altitudes provided vertical separation
between IFR and VFR
(and TAC VFR) traffic so long as you were in level flight.
Aircraft flying IFR were assigned altitudes at thousands of
e.g. 4,000' (flight level 40). VFR and TAC VFR rules said to fly
thousands of feet plus 500, e.g. 4,500'. (In the weather Army
helicopters made up their own convention, flying at altitudes of
thousands of feet plus
250', e.g. 4,250',
which they called flight level 42.5.) When flying TAC VFR, I
to find a cruise altitude above 10,000', which was above most
helicopters, unpressurized aircraft, and piston-engine aircraft.
All in all, TAC VFR was an
but risky method of getting from place to place in the weather.
Approach and landing at the destination was a whole different ball
game. Most airports had published instrument approaches that gave
us a path
to descend safely in the clouds to a specified minimum altitude.
minimums we had the runway in sight, we could land. If we
land safely, we followed the published missed approach procedure and
climbed out again. Large airfields had precision approaches that
to fly down to 200' or even 100' in the clouds. At medium-sized
airfields we could use radio
navigation aids to descend to about
500' above the ground.
had no navigation aids.
Arrivals, November 6, 1970
The weather was lousy that day and as soon as we departed Tan Son Nhut
departure control told us that the field was now closed because the
was below landing minimums (100'). At nearby Bien Hoa we picked
up 80 Marines who had arrived
in Vietnam just the day before. They were replacement troops for
one organization, so this was considered a "unit move". That
meant that they didn't get to enjoy our luxurious bucket
. Instead they were "combat-loaded" onto pallets with
for seat belts. I believe this was to welcome them to the combat
zone and help them make their
brand-new jungle fatigues look less brand new.
We flew TAC VFR to Chu Lai
approach control eventually picked us up on
radar. They gave us a GCA (radar ground-controlled approach) so
we had precision radar guidance all the way down. We broke out of
the cloud layer at about 250', but unfortunately they hadn't aligned us
with the runway and
we couldn't make a safe landing from that position. So we
followed the missed approach procedure and climbed back into the
clouds. This down-and-back-up stuff was probably pretty
disconcerting to our green-bean passengers, who had probably never done
a go-around or missed approach before. But we'd done it hundreds
of times and it was pretty routine.
We told approach control how they had aligned us so they could adjust
on the next try. The weather had apparently gotten worse, because
this time we descended in the overcast all the way to minimums--200'
above the ground
. We couldn't see anything but clouds, so
missed approach again. We
gave up on landing at Chu Lai so we called up our Airlift Control
Center and asked
where we they wanted us to take our passengers. They told us to
go to Cam Ranh Bay. So that day our passengers flew with us 300
to Chu Lai, endured
two missed approaches, then flew 200 miles back down
to Cam Ranh Bay. Maybe
you could call that 100 miles of progress--welcome
And this brings me to a related issue: optimistic weather
observations. We could not make an instrument approach if
the weather was below minimums for that approach. For example, if
the cloud ceiling was at 200', it wouldn't make sense to start an
approach that had a minimum descent altitude of 300'. But when
the weather was really bad and approach controllers were really busy,
they had a temptation to fudge the numbers a little. For
That day we returned from Cam Ranh Bay to Tan Son Nhut
and the weather was still bad there.
Approach control called it a 300'
so they gave us a non-precision
allowed us to descend to 300' above the ground and didn't require a
radar controller. At 300' we were still in the clouds so we had
approach. Obviously the ceiling was well below 300'
they revised the weather observation down to 200' overcast
and gave us a precision GCA down to
. At 100' above the ground we still
didn't see any
we went missed approach again. Obviously the ceiling was well below 200'
. On the third try
we broke out of
weather at 100' above the ground
and landed OK. Whew! Can you imagine