Tag Archives: HP cock

Two strange incidents

By Shyam Hattangadi

These, among many others, occurred while I was on Gnats.

The first was where an aircraft was started and the engine went to full power, the aircraft jumped the chocks and crashed through the wall of the Flight Commander’s office – Jit Dhawan – whose utter shock of suddenly finding a Gnat nose next to his chair, can only be imagined. Apparently, a techie on an earlier shift had disconnected the throttle connection next to the engine, which, being spring loaded to full open position, stayed there. In the next shift, without knowing the situation the aircraft was started up for a ground run leading to the consequences. I only heard about this incident and someone who was present there may be able to elaborate on it.

In the second incident, I was involved. I started an aircraft for an air test when suddenly the RPM began to increase rapidly. Throttling back had no effect nor was putting the HP cock off. The RPM kept rising and I fully expected the aircraft to jump the chocks when after a few hair-raising moments, it began to reduce and finally the engine shut itself off. In the meantime there were frantic gestures from outside to switch off the aircraft little knowing my predicament.

What had happened was that when the engine was started, the fuel cap on the spine not having been closed properly had popped open and fuel had begun to gush out. This fuel flowed down on to the upper surface of the wing and began to get sucked into the intake, setting up a perpetual cycle with no way of interrupting it even with the HP cock off. Fortunately, a little later, the wind shifted enough to cut the supply to the intake off and the incident did not result in a catastrophe as in the earlier case.