I recently had the pleasure of helping a customer buy a Jetprop. We found a fabulous mid-90’s model with a -34 engine and they’ve been thrilled with the performance and reliability. The customer wanted to have a few other pilots trained in the Jetprop to ensure 100% of the missions could be handled. So, I received the call to provide initial training and headed out to West Texas to start 4 days of fun.
We based the training out of a smaller airport that had a “less than optimal” runway and ramp area, as it had older asphalt with lots of loose pebbles in the parking area. We had the Ice-Door “ON” as much as possible, but I was still concerned about the potential of sucking up a loose pebble and FODing out the engine.
On the cross-country portion of the training, we decided to fly to a 300NM trip to another West Texas town. On climb-out, we first noticed sluggish power as we climbed through about 15,000ft. As we continued to climb, the Jetprop had only a 300fpm climb through FL240, and…it was having trouble keeping the cabin pressurized. All of the engine gauges were, “in the green”, but the ITT was reaching the limit at a much lower torque setting. Basically, we were “temperature-limited” prior to being “torque-limited” at a much lower altitude than normal. Then, after leveling off we were cruising about 30kts slower than expected.
One of the worst feelings in the world is the, “something has gone wrong on my watch” feeling. It’s not a feeling of guilt, but the feeling that while I was PIC, things were developing as they should. I developed a bad case of that feeling as I pondered what could be wrong. The only conclusion I could imagine was one of those numerous tiny pebbles from the degrading asphalt airport had bounced up into the inlet and found its way into the engine while it was turning. That’s called a “FODded-out Engine”, the result of Foreign Object Damage (FOD). A FODded-out engine can be completely destroyed at worst, and at best cause ten’s of thousands of dollars in damage. With the engine turbine turning 35,000+RPM, the blades of the engine don’t stand a chance against anything but air entering the inlet…a pebble, tool, excessive dirt, or even ice can FOD an engine out quickly.
We landed without issue, but the next engine start was hotter than previous starts. I grew more and more nervous. I called a few of my aviation mentors (John Mariani and Travis Holland) to get their wisdom. Both listened to the story and thought of potential causes, but both agreed that FOD could have been the culprit. I then called Kevin Meade (as I’ve done many times before), and he thought of another possibility…the bleed air valve could be sticking. I prayed that he was right.
With this information, the owner ordered a new bleed-air valve and had it overnighted. This ended up being a super-good idea. The mechanic took off the cowling, and opened up the engine inlet so a mirror could be used to inspect the first stage of turbine blades. Fortunately, there was no FOD! I can’t tell you how relieved I was to hear those words!
The next morning the new bleed-air valve arrived, just as the old valve was coming off the engine. The old valve was sticking and leaking, which was sapping the power of the engine. Within an hour we were up in the air flying with a perfectly running PT6-34 up front.
Lessons learned/confirmed:
* Keep Kevin Meade’s phone # in your Rolodex. With minimal information through only a phone call, he’s diagnosed problems accurately many times over. There’s other good PA-46 mechanic shops out there (Chad Menne and Tony Beauchamp come to mind, and there’s probably some others too), but Kevin is the MMOPA-paid consultant for mechanic issues, and it is one of the best reasons to become an MMOPA member.
* Have good aviation mentors that you can call. Mine are John Mariani, Travis Holland, Chad Menne, and Kevin Meade. Every pilot should have someone they can call to get sound advice. I get lots of calls from people I train, and I hope I’m a help to them.
* Know your aircraft well enough to know when something’s not right. I train pilots to do the same thing every time they fly so that they recognize issues that may creep up. Although this problem was fairly hard to miss, small problems can creep up and are only evident to the pilot that is aware of normal performance numbers associated with the operation of the airplane. Bottom line…know your airplane!
* Be proactive. The owner of the Jetprop ordered the part we needed, paid extra to have it shipped quickly, and had it ready to install the next morning. Without this action, we’d have postponed training and everyone would have had their schedules shuffled.
* Pray for no locusts: Psalm 105:34-35 speaks of the Lord using locusts to devour the crops. It is a familiar illustration in the Old Testament used to describe the erosion of resources. My prayer while in the UGH-known of the situation was that the Lord keep away the locusts from the Jetprop owner, and simply allow the problem to be minor, and easily solvable. The Lord answered that prayer, and I must give the credit where credit is due. Oftentimes the Lord keeps away the locusts in our lives without us being fully aware, so when he clearly keeps the locusts at bay, I’m grateful for that blessing.
