Page 20 - Nov 2015 Volume 9, Number 11

both been carefully sealed to prevent the ingress of new water. However, it is not uncommon for the gauges to be inaccurate for a while after a wash job, until things dry out. Those operators who are based in moist, humid climates fight a lot more problems in this area and it is sad, but true, that the gauge accuracy is not generally a King Air strong point. I surely wish the 200s, like the 300s, had an independent low-fuel-warning system – an optical sensor in the nacelle tank – but they do not, not even as an option.
As for the fuel migrating from the mains back into the aux – no, that should not happen. There are three vent connections at the top of the nacelle tank – under that oval plate – and if one or more of them leaks, it allows the backwards flow to take place. (There is also a return path back through the jet pump, but seepage here is not as common as from the nacelle top.) This is most likely to happen when the plane lands while still transferring aux fuel, before the auxes are empty, if one follows the Beech procedure precisely. I recently wrote an article for this magazine about the problems associated with “over-stuffing” the mains with aux fuel, and this takes place all the time unless you use our “trick.” The trick is to keep the left and right Aux Transfer circuit breakers pulled as standard practice, only pushing them in at Top-of-Climb, when you have aux fuel, then pulling them again when the auxes go empty. This eliminates the pressurizing of the mains and
goes a long way towards alleviating the type of situation you are observing.
The final question comes from Aircraft Maintenance Manager Fixed Wing Fleet, Carolinas HealthCare System /MedCenter Air, Ken Blevins, who writes, “The first question is: In the King Air B200, if the brake de-ice is left on, the landing gear is retracted after the 10-minute time delay that turns off the brake de-ice system, does the “Brake De-ice” annunciator remain illuminated or does that annunciator turn off? We have looked at the wiring diagrams for this system and we do not see a clear cut circuit that would turn the “Brake De-ice” annunciator off if the system is turned off by the time delay printed circuit card.
The second question: In the King Air B200, what prevents the propellers from going into the Beta range or even into Reverse if the power levers are selected to the Ground Fine or Reverse positions in flight?
Apparently our pilots are being told by CAE / SimuFlite that it is ‘not possible’ for the propellers to enter Beta range or Reverse in flight even if someone was brave enough (stupid enough?) to try it.
I have been working on all series of King Air aircraft for over 20 years now, and I do not believe that there is anything installed on the King Air airframe or on the PT6 engines that would actually prevent or make it impossible for the propellers to enter Beta or Reverse in flight.”
Hi Ken,
First, yes, the Brake Deice annunciator should extinguish if the timer times out. Go ahead and try it on a flight or two; it won’t hurt anything, especially if you turn it on at altitude where it’s cold. Did you read my recent article on this system? A couple of comments from there: First, even if the gear is up for only a few minutes – say, three – and then the switch is turned off, the timer keeps running, so after the total 10 minutes elapse, it won’t be able to be activated for the “rest” of the time. Second, it can be reactivated by, of course, extending the gear, but also by cycling the circuit breaker.
As for the second question, it looks like CAE/SimuFlite is putting out some bad information. We can only enter Beta and Reverse when the propellers are in an underspeed condition, turning at less than the selected propeller governing speed. Depending on the exact model of propeller installed, even with the propeller governor set at its maximum speed (2,000 RPM) and with the power levers at Idle, the indicated airspeed must still get below 110 knots or so before the propellers will finally encounter their Low Pitch Stop and hence start to slow down, or underspeed. So in most flight conditions, it is true that selecting Beta or Reverse will merely tend to stretch the Reverse cable and not achieve anything except mis-rigging; the same as trying to Reverse in the
18 • KING AIR MAGAZINE
DECEMBER 2015