Monday, December 26, 2005

PFM

I like to talk to the people who maintain our airplanes to learn more about the aircraft and to see their side of the story. And I'm trying, chip-by-chip, to break down the wall that exists between the two sides of the operation.

Some maintenance people seem to think all pilots are ignoramuses who have no idea how their aircraft work, and simply spend their day breaking airplanes. And I can understand that viewpoint. The people who disassemble and reassemble a system are going to know it better than the people who just pull the levers. And no matter how thoroughly they fix the airplanes, whenever they let the pilots fly them, the airplanes eventually come back broken.

When I do a test flight with an AME on board watching, sometimes I feel like they're going to say, "well no wonder it keeps breaking, if you're going to fly it like that." So far they haven't, though. And for some repairs, the airplane can't be officially released from maintenance without my signature under a rubber stamp confirming that I have flown it and that the aircraft conforms to the standard of the type. Meaning that no significant parts came off in my hands during the test flight.

This is where the pilots who think maintenance are stupid get their side of the story. Pilots tell maintenance that the gear won't stay up, or that the ammeter spikes for no apparent reason and then the mechanics sign it off and send it back online. The problem recurs, and the pilots think the mechanics are incompetent. Sometimes it takes a few iterations to identify the root cause.

And some things are hard to understand. An apprentice was telling me how the steering works on an Airbus. He described a linkage and then said, "Everything inside is PFM."

Aviation is rife with acronyms and terms, and Airbus has been keen on reinventing existing terminology, so I wasn't too surprised not to recognize the term. "PFM?" I asked.

He explained. "Everything inside is pure magic." I so walked in to that one.

And I know a pilot that got back at an arrogant AME by asking him about the flux capacitor. The AME was happy to tell the pilot it was located in the wing. He was, of course, thinking of the flux gate compass, but the pilot got a good laugh out of hearing the mechanic bluff on about the crucial component of a fictitious time machine.

8 comments:

Anonymous said...

Flux capacitor? Even MY car has one of those, and it's only a beemer.

Anonymous said...

Don't touch that! You'll let the magic smoke out of the flux capacitor. We can't fly without it.

... works equally well when describing electronics.

-iF.

Anonymous said...

I find it interesting how the everyday experiences of people in their jobs can significantly impact their work.

Working in the computer security industry, I can certainly understand why police officer folk, and others who are constantly exposed to the less than ideal side of humanity can become pretty cynical and some go off the deep-end or over to the dark side. In their experience, everyone is a cheat, a liar, and a murderer.

Aircraft mechanics think that pilots spend all day breaking planes because all they ever see are broken planes.

I wonder what other jobs are so profoundly influenced by a very narrow experience of one aspect of life.

D

Anonymous said...

that first paragraph should state that "I find it interesting how the everyday experiences of people in their jobs can significantly impact their outlook on life."

Perhaps editors think that everyone is an illiterate moron, in my case I sometimes wonder about my brain's ability to fully form thoughts before putting them down on paper.

Anonymous said...

ministers think everyone will eventually find the truth. eventually. given enough patience and persistence.

psychiatrists think everyone is out to get their patients.

facilities workers think everyones bathrooms at home are disgusting and how can they leave the clog like that?

tech support think nobody knows where the START BUTTON is. or what it does. or why their computer's built-in cup holder breaks so easily with their mug on it.

Dave Starr said...

Years ago I worked as a technical instructor of folks maintaining complex communication equipment in Cheyenne Mountain, home of the Joint US/Canadian Aerospace Defense Command. There was more than one dog-eared complex logic diagram that had a little hand-drawn flip-flop or other logic device added to the drawing to make the eventual signal output come right labeled 'PFM'.

I maintained inertial nav systems on Air Force C-141s (yes, they went out of service last year, I _am_ old).

Our aircrews were super, in most cases they knew their systems as well or better than most maintainers. But one day there was a certain transient crew with a navigator who obviously wanted to RON at McGuire AFB where I worked. The Aircraft Commander and the rest of the crew just as obviously wanted to press on with the next leg of the mission, across the pond to Ramstein. The navigator found 6 or 8 supposed faults during preflight causing the attendance of several other techs as well as myself. Everyone else convinced the crew that their systems were good but my navigator 'friend' fixated on the INS, claiming a 'fault' that I knew was caused by him skipping a step in the checklist. Using the "I'm stupid, help me walk through this" technique I worked through the entire checklist with him and the system proudly proclaimed itself good to go.

"I still think it's bad," the nav stated, irrationally.

Turning around in his seat and giving me a frustrated and pleading look the Aircraft Commander, younger and junior to the recalcitrant nav, was obviously looking for a little help.

Since I was a civilian employee and immune to rank and politics I looked the nav straight in the eye and said, "Major, Lindbergh flew the Atlantic with just a compass and a clock, do you mean you can't find your way with all these extra dials"?

Over the howls of laughter of the rest of the crew the nav mumbled, bitterly, 'Well I guess I'll accept it, because you're all out to get me."

Anonymous said...

that was a great experience

bam said...

I'm in the slow process of getting a typerating right now and have lots of time at hand so I started reading your blog.
Couldn't stop laughing after I read this post: Just today a flight engineer accused us of always trying to break his engines.
He even had some monkeys depicted in a cockpit on one of his powerpoint slides while teaching us...

Now back to reading - interesting/funny stories!