Pumping the brakes: we were a couple of hours into our KC-130J logistics run when we heard, "whoop, whoop.".
Pull engine FIRE handle.
Place ENGINE START switch to STOP.
Do not attempt a restart.
However, rather than prepare for an engine shutdown, my copilot casually pressed the annunciator switch light to silence the warning, as the crew chief nonchalantly noted that the ACAWS was erroneous. I nodded in agreement. Why were we so sure? For as long as anyone in our crew could remember, there has been a "read and initial" referring to an interim flight clearance addressing this very situation. The R&I states that if the crew performed a successful overspeed governor check on the propeller in question, and the power lever for that engine has remained in flight idle since the successful check (which it had in our case), then it is mechanically impossible for the low pitch stop to be in a failed state. In this situation you can disregard the ACAWS, and the NATOPS-directed crew action is unnecessary.
At this point, my crew had completed our in-range and approach checklists, and we were on radar vectors for the visual. Our mission was to drop off the 20 passengers, then make the three-hour flight back to home plate.
"Whoop, whoop," the same ACAWS sounded again. It was met with the same casual suppression. Again, the crew consensus was an erroneous indication. The ACAWS sounded again shortly thereafter, then again and again. The seeds of doubt began to grow and eventually blossomed.
The propeller is fine as long as the engine remains in flight idle, but what happens once we bring it into the ground range for landing? Will the aircraft be down for the count until a part gets flown or shipped out to us? My crew and I had more questions than answers, and in a text-book, normalization-of-deviance situation, we made a judgment-call that put our aircraft, ourselves, and most importantly our passengers, in jeopardy.
Here's some background.
Aircraft commander (AC): 814 hours in type, model, series (TMS), less than 30 hours as an aircraft commander.
Copilot: 852 hours in TMS, recently had progression to aircraft commander suspended for performance-related issues.
Crew chief: 786 hours in TMS, recently upgraded to CC2.
Loadmaster: 368 hours in TMS, extremely confident in his fellow crew members.
Two days before the event in question, the same AC, copilot, and crew chief were stranded 15 minutes from home base with a recurring propeller-overspeed, governor-test failure, which required a limp from the active runway to troubleshoot. NATOPS tells us that these tests are only required on the first flight of each day. However, as a community, we always make sure of a good test before each takeoff. We do this because pitch-control-unit (PCU) sensor faults are a common issue that routinely result in a "LO PITCH STOP FAIL" ACAWS. If we always ensure a good overspeed test before each takeoff, then we never have to shut down an engine for this ACAWS according to the interim flight clearance.
After calling maintenance control, we were told to try completely shutting down the aircraft, then attempting a fresh test--a reboot if you will. Rather than clobber the runway yet again for what may likely be another test failure, our crew decided to perform the test on the apron. While an overspeed-governor test requires the throttles to be in the flight range, doing engine runs near ramp space are not uncommon. The crew agreed that our prop wash would not pose a hazard to anyone or anything nearby. If the test failed, we would simply shut down in place. If it passed, we would leave the symmetrical power levers in flight idle and use reverse on the opposite engines, braking as necessary to control taxi speed.
We executed the plan, passed the test, and taxied from parking for takeoff. This procedure is patently nonstandard, yet, at the time, we felt it was a reasonable solution that allowed us to RTB without additional inconvenience to the airfield and ATC controllers. In hindsight, we were fortunate that an aborted takeoff was not required, considering the amount of brake energy required to control our taxi speed.
Now, back to our incident. The same AC, copilot, and crew chief were on final descent with a repetitive "PROP 1 LO PITCH STOP FAIL" warning. We didn't know if the aircraft would be hard down after we pulled the power lever into the ground range, but, we did know that having previously passed an overspeed governor test, it was good to go so long as it stayed in the flight range. We then made an extremely poor decision. Rather than follow standard NATOPS procedures, we decided that leaving the No. 1 and No. 4 engines in flight idle for the landing, taxi, passenger offload, and subsequent takeoff was a valid solution to our perceived problem. Just as before, we executed our plan.
The braking required during the landing rollout in conjunction with the braking during taxi to control taxi speed with two power levers in the flight range exceeded the braking capability of the aircraft. As we pulled to a stop, the loadmaster noted smoke from the brakes, which was confirmed by the lineman. After stopping the aircraft a brake fire was confirmed, and the crew did an emergency evacuation of the aircraft. No one was harmed, but all four brakes were destroyed.
Rather than accept that we didn't have all of the answers we needed in the few minutes before touchdown, we had charged forward with a decision that we believed would enable us to complete the mission and return home without having to inconvenience anyone. Well, it turns out that four seized brakes on a KC-130 three hours from home is quite inconvenient.
AFTER READING THIs sCENARIO, you might say this has get-home-itis written all over it. While that may have been a factor for some of my crew members, I felt differently. It was the drive to say "yes" when I should have said "no."
Marines are part of an organizational culture that pushes to do more with less. As our budgets and personnel are cut, our workload remains or grows. We search for a way to make things happen when others would assume impossibility. At its worst, the recurring theme is that requesting relief is a sign of weakness, incompetence or incapability. These conditions can result in exceeding the capability of the personnel and the aircraft. We seek to squeeze efficiencies everywhere we can. In this case, we squeezed too hard by rationalizing that a non-standard procedure which worked previously would work again, despite a different phase of flight. Our intention to be efficient resulted in damage and was ultimately inefficient.
Although the costs were below the mishap threshold, we walked away with lessons learned. I learned that we as leaders must have the will to say "no" even when those around us are happy to charge forward. I also learned that in the future I'll choose to pump the brakes when it's called for, but only if the throttles are in the ground range.
CART. BROOKS FLIES WITH VMGR-252.
|Printer friendly Cite/link Email Feedback|
|Date:||Jan 1, 2013|
|Previous Article:||Remember that approach article you were going to write?|
|Next Article:||Talk about it later.|