Page 22 - March 2015 Volume 9, Number 3

that we may overheat and ruin a starter? This most likely may happen when faced with the aftermath of an unsuccessful starting attempt.
As we know, three ingredients are needed for the fire to begin in the combustion chamber: air, fuel, and ignition. In the early days of King Airs, the only one of these three that the pilot could truly verify was happening was air, as shown by the compressor spinning up to a typical stabilized speed well above the minimum 12 percent required. As for fuel? In those days, the fuel flow gauges were AC-powered and did not operate during the start since no inverter was yet on. Ignition? For all King Airs, the ignition annunciator does not verify actual ignitor operation but instead just shows that the appropriate relay has activated to send power to the system. Well, the glow plug-type of ignitors that early King Airs used made no sound, unlike the rather loud snapping that can be heard from the newer spark-type of ignitor. Thus, if a start was unsuccessful with no light-off in an earlier King Air, the pilot really could not tell whether the problem was ignition or fuel related.
This has not been the case for over three decades. Now in most cases, except on a very noisy ramp, the sparking sound of the ignitors may be heard to support the ignition annunciator. The fuel flow gauges are now DC-powered, meaning they are working during the start and the pilot can observe the expected fuel flow when the condition lever is advanced forward from Cut-Off.
What I am saying is that there is less-than-stellar airmanship being demonstrated if the pilot of a more modern King Air does not recognize that something is amiss with ignition or fuel quite early in the starting attempt and does not immediately terminate the attempt to analyze and remedy the cause. For the pilot to actually run the condition lever forward and then wait the full ten seconds before deciding to terminate the attempt should not be nearly as likely now as it was back in the ‘60s and ‘70s, during the days of AC-powered fuel flow gauges and glow-plug ignitors.
Nevertheless, let’s say we have attempted a start, it was unsuccessful with no light off, and we’re going to try it again. Perhaps we found the ignitor circuit breakers still pulled, an action mechanics have been known to take to prevent accidental engine starts in the shop. So we have reset them and suspect that the next attempt will be successful. (Drat! We should have done a more thorough cockpit prestart check and caught this before the starting attempt, eh?!)
Wait! We cannot do another start attempt yet. What about the unburned fuel that has likely accumulated in the engine during that first attempt? We need to conduct an engine clearing procedure first, to avoid dramatic torching of fire out the exhaust stacks on the next start. This involves using the “Starter Only,” bottom, position of the “Ignition and Engine Start” switch. We keep the condition lever in Cut- Off and then depress and keep holding the Starter Only switch position for a time as long as the starter time limit, although
20 • KING AIR MAGAZINE
MARCH 2015