Monday, July 28, 2014

Dead Reckoning

As usual I have flight-planned for one task and the onboard satellite communications link to base brings us instructions to do something else. We're to fly direct to a particular airport, and get a maintenance extension from an approved maintenance organization there. We can do that. I punch it in on the GPS, O Mighty Box that guides us safely from place to place.

The GPS in this particular airplane is not that mighty. It's a nice colour moving map, WAAS capable IFR installation, but it has a habit of losing GPS position for exactly two minutes at a time, about twice a day.  We don't fly GPS approaches in this airplane. The database isn't up-to-date and it has a great ADF and VOR.

It's almost nice to have the one or twice a day reminder to keep my navigation skills honed.  DEAD RECKONING says the screen, continuing to show the little airplane symbol, assuming that we're continuing on the same track and speed.  People say that it used to be deduced reckoning, reduced to ded. reckoning, and then converted to dead. I don't know if that's a reverse etymology or not, but some people get quite stuffy about spelling it DED. Garmin does not agree. And two minutes later, almost to the second, it knows where it is again. It isn't a satellite configuration issue. It hasn't lost power. I haven't banked excessively, blocking the GPS antenna. it just does it. We track the issue for a while, trying to troubleshoot but never find its periodic outages corresponding to time of day, time in operation, position, anything.

Eventually when the plane was down for maintenance long enough for this to happen, we pulled the entire unit and sent it in for repair. Like all electronic devices these days "repair" consisted of us receiving a reconditioned model of the same type. It hasn't lost GPS position since, and we bought a database subscription for it, so now I trust it with my life. Or at least with my acute embarrassment.

Thursday, July 24, 2014

Summer One-Liners

I always scribble notes on my OFPs, but I don't always get time to transform them into blog entries. Here are a few.

This is an oldie that has come back.  Many types of flight require a flight plan, a notification to air traffic control of where and when you want to fly your airplane. You "file" the plan either electronically, or still the old fashioned way by telephone. It's often easier to make a phone call than to get an internet connection. When you call to file a flight plan you start by specifying the call sign, the registration of the aircraft. The specialist can sometimes look up the aircraft in his or her database, removing the need for the pilot to specify the aircraft type, onboard navigational equipment, aircraft colours, and other details that don't change from flight to flight. It's common for the controller to double check that they have the right database entry by saying the type after they find it. There's a flight service joke that I first heard as a student, still stumbling over the required information for the flight plan. The specialist takes the callsign, and then says, "Ah yes, here it is, Boeing 747 on floats."

The correct answer to this is obviously, "Nah we put it on skis over the winter, haven't swapped them back yet." Or perhaps, "Nah that's GOLF Mike Tango Foxtrot. People get us mixed up all the time."

One the flight plan is filed, you need a taxi clearance, permission to drive the airplane on the ground to the runway, or maybe from the parking space to the place you pick up your passengers or buy fuel. Much of the ground may be uncontrolled, not requiring a clearance, but at an unfamiliar airport it is not always clear exactly where the controlled portions of the apron are. One always errs on the side of caution and asks for taxi clearance. Or even if I know it's uncontrolled, I'll usually call and tell the controller, so he or she isn't wondering where this airplane is off to. The controllers are usually happy to give directions on the uncontrolled portion of the airport, to help pilots find a particular hangar. So it's wasn't completely bizarre to hear a ground controller say this to another pilot, just funny.

Ground controller, "If you know where you are going, continue."

Then you take off, and the controllers help you stay clear of other traffic.  You know you're pretty far north on a clear day when you hear the words, "you'll be following a VFR 737" and you're not in the approach phase of the flight. One usually expects aircraft as large as a B737 to fly IFR for most of their trip.

But by the end of the flight on a good day everyone is cancelling IFR to make it easier for others to get descent clearance. Descent for us means a chance to take off our oxygen masks, the context for my final quote, from my co-worker. "Taking off an oxygen mask is like taking off ski boots."


Saturday, July 19, 2014

Human Factors

My Human Factors training is not yet up for renewal, but I'm looking at notes on the training materials we used last time. They were aimed at the maintainer, not the pilot.

The main benefit of this is realizing how many shortcuts and errors maintenance personnel make. If I take a shorcut, it works or doesn't that day. If they do, their not-quite-right repair or incompletely inspected part might be in there, waiting to kill me for another 500 hours.

Some of the "good practice" and "bad practice" sample conversations from the videos sound just like ones I hear in the hangar, especially the one on the "Lack of Awareness" item. It could be a recording from folks I know. It's a personality trait of maintainers to be proud of their knowledge and to enjoy catching each other out. 

"I thought the tag was good enough."
"Nope, you have to test an aircraft component."

I'm still not sure whether it was an error that I received the maintenance-specific training, or it was just intended as general training with all the examples coming from another specialty. Helicopter pilots must have to suffer that indignity all the time, attending general courses where the examples are all from fixed wing experience. A person should see his or herself reflected in instructional materials, to make it feel relevant and applicable. That goes for gender, race, job, type of operation, and type of aircraft. Even though we know we're all people, working with equipment, there's something about "that's someone like me doing what I do" that makes us sit up and take note.

 That said, lot of advice is applicable across disciplines and the though required to transpose it forces one to think about it a little more. For example the course recommends the maintainer think, "I am a qualified technician, not an idiot. I know what information I need to have to assess and repair this damage." At least I assume she's meant to think that and not say it out loud to her supervisor. Likewise I am a qualified pilot, not an idiot. I know what information I need to plan and conduct a flight."  But that's not something I ever really need to say. People don't hurry me or demand I fly with inadequate weather information or poor equipment.

Maybe this one is more useful: "Safety nets" for stress are being aware of how stress can impact your work, stepping back and rationally analyzing the problem, rationally determining what to do and then doing it, talking to others, asking others to check your work, taking time off or at least taking short breaks, keeping fit and healthy, and using assertive communication."

Stress can definitely affect my work. It can affect the thoroughness of my preflight, the amount of sleep I get, the way I treat my coworkers and my concentration on the job. I ask others to check my logic and my arithmetic. I have a day off today and I just came back from a 7.5 km run. The badder ass you know you are, the more confidence you have to step up and stand up for what you need for safety.

The best one is the advice to look for negative norms, then openly talk about them and work at changing them. It's also very difficult. Fish don't see the water, and it's hard to persuade people that the thing they do all the time, might even take pride in as a source of efficiency, may be a safety risk.

I'll make it my mission to find a negative norm at work this week.

Tuesday, July 15, 2014

Day Trip

I and a fairly new coworker are assigned to go to a site about an hour away and do some work. It's expected to be a single flight: zip up there, do the work and come back to base without landing. I say, "Just in case the work takes longer and we have to land for fuel, do you have a company credit card?" He doesn't yet, so I grab mine, just in case.

We fly to the location, but don't succeed in completing the work. The conditions aren't appropriate. We've just turned for home when my coworker receives a message on the satellite link. "Do you guys have overnight gear?"

The true answer is, "No," but we understand that it means, "Don't come home until the work is done." Never leave home in an airplane without a toothbrush and a change of underwear. I turn the airplane around and land at an airport nearby where we both know people. We get a ride into town in a veterinary van (no not driven by a Terminatrix), check into a hotel, call our friends, and go visiting.

Next morning we are preparing to do the work they sent us up here to do, but we are sent instead to another province. And then up north. Where we got snowed in. The new coworker goes home on the airlines. I eventually spend almost a week in the field, including the day I spent digging the airplane out of a snowbank. I think it was May. At least it was May by the time I got home.

When I finally get home, the vice president sees me carrying my gear into the office: my flight bag, a Wal Mart bag of emergency clothing and toiletry purchases, ten thousand dollars of credit card receipts, and a straw broom I bought to whisk the snow off the airplane. "What's that for?" he asks, indicating the broom. "Is that how you got back?"

So you see, management considers me to be a mighty and powerful sorceress. Or something.

Saturday, July 12, 2014

It Did Not, However, Contain a Live Bobcat

I'm picking an airplane up from a routine maintenance inspection and service. It's early in the morning, before anyone from the maintenance unit is in. This is not unusual. It's a little unusual for us to have scheduled maintenance performed away from home base, but sometimes the person responsible for maintenance makes arrangements with other companies.

I pick up the journey log. If that paperwork is not done, the maintenance is considered incomplete, so I always check it first. The signed maintenance release shows the work that has been performed on the airplane, so I know what to pay particular attention to on my inspection. The entry matches the purchase order, and is unremarkable.

I start the walkaround. Numerous cowling screws are loose. These are things that work themselves loose over time. I find loose ones in the field and just snug them up.  If a particular one is consistently loose, I report it and maintenance repairs the anchor. There's probably a reading of the regulations that requires me to leave my Swiss army knife in my pocket and call a licensed AME to tighten my cowling screws, but who would do that? It's permissible for a few to be missing, but I'd rather they stay in. While I'm not impressed that these folks didn't check that all the screws were tight after replacing the cowling, I'm more concerned about what they didn't tighten that I can't check. I verify through the front opening in the cowlings that the front few spark plugs are tight.  I had a coworker once (different job, different maintenance unit) who came back from a flight reporting a rough running engine.  While waiting with him for the AME to arrive, I poked about in the cowling, not expecting to find anything, just the equivalent of opening the hood and staring at a non-functioning car engine. But in this case my hand came back with a spark plug that had only been finger tight. Someone was distracted between setting it in place and putting a wrench on it. It turned out that day that all the bottom spark plugs were loose.

The spark plugs I can reach are tight here,but the little door in the cowling that can be opened to access the oil quick drain is still open. The oil quick drain itself is closed and there is oil in the engines.  A quart difference between the levels in the two crankcases, but they're both in the acceptable range.

There's a tire gauge in the baggage compartment, a screwdriver in the cabin, and the piece de resistance: there's an electronic multi-tester inside one of the engine cowlings, barely visible through the little door through which I access the oil dipstick.

We do not depart until I have spoken with the PRM and a maintenance supervisor here, and we find ourselves a new maintenance unit in this area. I did return the tools, even though I always figure that anything left in my airplane after maintenance should be mine to keep.

Oh, and if you're confused about the bobcat reference .

Wednesday, July 09, 2014

Hazards on the Taxi

I'm taxiing into the ramp of a familiar FBO. There's a local airline/charter outfit that flies out of here and I have to run the gauntlet between their ranks of parked airplanes to get to where I'm going. Today there's an additional obstacle. Someone is washing one of their airplanes and a hose stretches from the hangar across my path.

I weigh the possibilities. Probably I can taxi over it with no harm to anything, save a momentary interruption in water pressure for the guy washing the plane.  But there's a possibility, as when taxiing in the vicinity of any rope, that it could be picked up by one of my propellers and turned into a flail of destruction. I've never seen this, and I haven't spoken to anyone it happened to. In fact I can't even remember when I first learned it, but deep in my memories is a flight instructor telling me not to taxi over ropes because they could get caught in the propeller. Before passing on this wisdom I did a little googling to find a student whose instructor learned this the hard way. That's one student who will remember the time and place of the instruction as well as the knowledge.  I can envision the knowledge spreading out around them in ripples as they recount the tale.

So a hose is like a rope. It is however secured to a tap at one end and in someone's hand at the other, so not quite as threatening. But I can shut down and haul the airplane the rest of the way by hand. I put on the brakes. The guy with the hose also knows that airplanes shouldn't taxi over such things. He picks up the hose and crosses back towards the tap with it, leaving the aisle clear for me to taxi through.

Hoses aside, this ramp has more FOD on it than it used to. The pavement is not in great shape and after shutdown I find metal objects--screws and washers--on the ramp. Not impressed. I shut down and do all the piloty post flight things and then after I walk away can't remember turning off the master and mags. I turn around go back and check. Everything is off.

The problem is that now the chief pilot knows not only my every screw up, but even my every almost could have been, thought I screwed up but didn't. And chews me out for it. Oh well, I get to keep my job.

Sunday, July 06, 2014

Premature Ditching & Last Minute Go Around

A train carrying Boeing fuselages to assembly plants in Washington state derailed in Montana, dumping the aircraft parts into a river. No one was injured, but I'm guessing someone's airplane deliveries might be late.

The video is taken by river rafters coming up on the scene.

And here's a go around at Barcelona: Russian crew forced to put in the power and abort their landing at the last moment because an Argentinian aircraft was taxiing across the runway. I don't know whether this was the result of an ATC error, or the Argentinians failed to hold short of the runway.

Thursday, July 03, 2014

Photo Finish

I checked with maintenance regarding my recent post about the fire protection system. Our fire detector is photocell activated. The photocell is sensitive to a particular wavelength of light, supposedly characteristic of fire.

I didn't get to ask the obvious questions about why fire detection systems aren't overwhelmed with false positives from the sun, an awesome source of almost every electromagnetic wavelength, and able at some time of the day or some practical bank angle, to shine through every chink and opening in an engine cowling. An apprentice had a more pressing question about reinstallation of an exhaust manifold, and I was wearing silly girl shoes for a social event, so I teetered back out of the hangar to the office and left the maintenance to the maintainers.

Along with the answer to my question, and before the apprentice needed direction, I received the following story. A certain air carrier's night maintenance crew (they know who they are) conducted an inspection on at least one of the carrier's fleet. Their fire detection system used visible light, and the crew followed the manufacturer's instructions to test it by shining a flashlight on the detectors. The system failed the test. The crew was preparing to replace several thousand dollars worth of aviation grade electronic gear, when someone realized that that instructions were as old as the system, twenty years or so, and predated the invention of the LED flashlights the crew were using. The diodes were not emitting the necessary wavelength to trigger the detector, because when the instructions said "flashlight" an incandescent flashlight was assumed.

 The Wikipedia article on Fire Detection suggests that our photocell might be tuned to multiple wavelengths, possibly including UV and/or IR to compare the ratios. This still doesn't explain how an ordinary incandescent flashlight would trigger it, but the sun wouldn't, but does make the concept of photometric flame detection clearer. While looking for more information on flame detectors I discovered that there is a whole new generation of fire detection that uses machine intelligence to recognize the appearance of actual flames, something that is pretty fricking clear to humans. Combined with smoke detectors, something a commenter suggested on the previous post, there are enough different kinds of combustion detectors on aircraft to warrant a survey post on the topic, some time when my working day is shorter.

I was also entertained by the Wikipedia article on the Flashlight, which explains why Americans call them flashlights. The earliest zinc–carbon batteries could not provide a steady electric current so when combined with the inefficient carbon-filament bulbs, the result was a light that frequently blinked off so the battery could recover.