November 2012 - Indian Airforce

airborne six minutes later as planned, to execute
a planned rendezvous (RV) as a part of the sortie
profile. They too contacted the SU, seeking to
maintain 7000’ and 8000’ respectively to maintain
safe height separation for the RV. Having levelled
out at the allotted heights, the formation
was permitted to change over to the training
frequency by the Recovery Director (RD), who is
the FC controlling local flying in the sectors, with
an instruction to give ‘Ops normal’ call every ten
minutes. It was only after about 7-8 min that the
RD started getting perturbed when the formation
started deviating from the track passed by the
Base Ops Room. The RD could not check with the
formation as they were on a different frequency
and so asked the Recovery Assistant (air warrior
detailed to assist the RD) to call up Base Ops
Room and check the route.
The fighter formation meanwhile had
completed three legs of the route but had not
effected the RV. The trail pair was together,
trailing the lead pair by about 15 Km. As per
the sortie profile, a bogie was simulated by the
supervisor and the trail pair took tactical action.
In the process, the Air Interception Radar of one
of the ac picked up a track approaching from the
right and after resuming course, the left member
reported the civil airliner, after making visual
contact. The right member ‘ducked down’ to
create separation and the left member ‘pulled up’.
The Gulfstream civil aircraft passed between the
two ac with RA cutting in, asking the pilot to first
pull up and then push down. Neither the civil ac
nor the fighter formation was informed of each
other’s presence.
The RA is an audio warning, notifying
imminent danger of collision, given by Traffic
Collision Avoidance System on transponder
equipped ac. When an RA is issued, the pilot is
expected to respond immediately. He is allowed
(at that time) to violate the ATS instructions given
to him till the danger is over.
The Mistakes Made / Questions to be Asked.
In retrospect it is clear that mistakes were
committed by many operators/functionaries in
the chain for the situation to reach such unsafe
levels. There are also some questions that arise.
Some of them are listed below.
Should the formation have stuck to its profile,
now that it had got airborne during red period,
given that at the newly decided heights, they
were going to transgress into the airspace of ac
operating in the sectors? It should also have been
expected that the traffic in sectors would have
been heavier as everyone had launched nearly
together with the weather suddenly clearing up.
While planning, ATS route crossing should
have been as close to perpendicular as possible.
Positive RT contact / clearance should have been
taken from SU before crossing/approaching
ATS route. Should the formation have been
Continued on page 17
INDIAN AIR FORCE 2 0 1 2 N o v e m b e r Aerospace Safety 13