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and economy are good arguments for hav- ing “cold” seats, but hot seats offer an extra added layer of safety; in the case of a low altitude emergency, there may not be time for a manual bail-out. Worldwide, there have been more than 7,560 documented fighter jet ejections with a pilot survival rate of 89 percent. One in three pilots sustained spinal compression injury.
Drop down steps and spring-loaded panels provide ladder-like entry to the front and rear cockpits. After removing the six safety pins, the ejection seats are “armed” and ready to go. Maneuvering into the seats requires careful placement of feet through loops of white lanyard. These lines will tighten during ejection, pulling the pilot’s legs in for protection during egress. The integral seat belt/ejec- tion harness is secured with a 4-point chest buckle. Twin ejection seat handles with integral triggers rise between the pilot’s thighs.
The start sequence begins by engag- ing the parking brake, which will not grab until hydraulic pressure builds dur- ing engine rotation. Master and engine control switches on the right bulkhead
panel are toggled, and a minimum of 24 volts is confirmed. An APU port on the port side can be used if needed. When the annunciator panel “Do Not Start” and “Canopy Not Secure” lights are ex- tinguished, the Saphir Starter button on the left side panel is depressed. A “Ready” light illuminates on the annunciator panel when the Saphir engine is up to speed and stabilized. This is the signal to engage the “Start Engine” button and position the throttle up to the idle/start position. An immediate whine fills the cockpit as the N1 RPM begins to climb. At 26 RPM, the engine lights and settles to an idle speed of about 56 percent. Electrical systems are engaged, the cabin pressurization lever on the right side is advanced, bleed air is switched on, and cabin temperature controls are set.
Taxiing the L-39 takes a bit of prac- tice. The nose wheel casters passively and directional control is provided by differential braking. The brake lever is on the stick and look and feels like a bi- cycle hand brake or motorcycle clutch lever. Pulling the handle routes hydraulic pressure to the brakes, with differential
braking provided by rudder pedal posi- tion. The desired rudder pedal is fully depressed to initiate a turn. This keeps your legs moving during taxi, especially with a crosswind. Before takeoff, the flaps are tested for full deflection using push buttons on the left side panel and then set to Take Off position. Speed brakes are cycled by activating a switch on the throttle handle. Engine run-up is to full MIL power, taking note of bleed air surge valve closings at 76 percent and 84 per- cent power, and measuring the speed of acceleration and deceleration of the engine. The AI-25TL engine is known for its slow spooling time: it takes anywhere from 8-11 seconds to go from idle to max power. This takes some getting used to, especially for pilots transitioning from piston or turboprop aircraft who are used to more ready power on demand. The relatively low bypass ratio of the turbofan contributes to power lag. A few L-39s sport the Garret TFE-731 motor. This conver- sion offers simpler operation, better fuel efficiency, much faster spooling times (less than three seconds) and obviates the need for the Saphir unit.
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