The T55L7C engine differs from the other T55L7 series
engines in the following ways: (1) an atomizing combustor is used as
opposed to the vaporizing type; (2) the 14 vaporizer "T" canes are
replaced by 28 dualorifice fuel spray nozzles for injecting fuel
into the combustor; (3) four ignitors and start fuel nozzles are
installed to ensure optimum ignition and flame propagation during
starting. However, only two of the four start fuel nozzles are used;
In addition, the T55L11A differs from the T55L7 series in
the following: (1)a twostage gas producer(GP) turbine is used; (2) a
more accurate electric torquemeter with an indicator reading in
percent of maximum torque; (3) five thermocouple probes, that measure
the gas temperature at the power turbine inlet; and (4) variable
inlet guide vanes to improve compressor efficiency.
Specifications for the T55L7, 7C and 11 engines used in
Army aircraft are summarized in the following chart.