Saturday, June 30, 2012

Mixtureless Travel

The ferry permit allows me to fly an aircraft without a valid certificate of airworthiness. As soon as I wrote in the logbook about the problem with the mixture, I voided the C of A. There's companies where you would not be well-regarded for doing that, and I always second guess myself if I over-reacted when I ground an airplane, but seeing as you're always supposed to be on the safe side of uncertain, and seeing the number of times something has been truly wrong when I have made the decision, this is my job. Every job has a not-as-fun part, and mine is every once in a while telling the boss that the airplane can't legally be flown.

A lot of people would have just said, "Hey, I can't really fly this properly, I'll just take it somewhere I can get it fixed," and a lot of companies would have expected that. There are probably plenty of people reading this thinking, "What a prig she is, putting her company to that trouble when she was willing to fly it the way it was, after talking to maintenance." Some are probably thinking, "Damn she's brave to snag something away from home like that." But I had given our maintenance unit plenty of opportunity to fix the problem when the plane was home and it had reached a point where it was my job to say no. And then to fly it while broken but legal.

I don't notice the power difference on takeoff. Perhaps all the fiddling has loosened it up and given it more travel. (Heh, I really wanted to put a silent t in "loosten" to make it match "fasten" even though I know perfectly well that fasten comes from fast, as in "make fast). Also I'm down the weight of a crewmember, his luggage, some fuel and that data unit. I can barely lift it. Maybe it's twenty kilograms. I don't have my detailed weight and balance with me to check. All the temps are in limits and the power is adequate to the job. I turn enroute and climb to a suitable altitude.

Hey pilots, remember set heading points? I haven't used one in years. All praise the thin pink line! (Non-pilots: when you're travelling visually from airport A to airport B, you can't take up a course directly from A to B, because you don't know while you're planning what runway you will take off from, exactly how the air traffic controllers will direct you, and what traffic you may have to avoid before you can turn on course. So you choose a point sufficiently far from the airport that you'll be out of the departure procedures by then, but sufficiently close that you won't get lost on the way there, and you calculate the exact heading from there to your destination. After takeoff you fly to your set heading point and turn on course. Except that thanks to the wonders of GPS, we don't have to do this anymore. Just take off, hit the direct-to button and follow the pink line on the display). That wasn't apropos of anything. I just remember turning on course without having to worry about where I was.

It's kind of scuddy--low clouds close to terrain--so I continue climb over them. There are a number of layers and eventually I want to go high enough that I have to call for clearance into class B airspace. It's like when you go out for a drink after work with a friend, and then you run into some more people you haven't seen in ages, so you have to have a drink with them, and then you might as well stay for dinner, and then you want dessert, but they know this place ... and before you know it you're out until three a.m. To tell the truth, that doesn't happen to me, but the other metaphor that came to mind was when you start to pick up something you dropped on the kitchen floor, but once you do that you see something else that needs cleaning and you end up having to move the refrigerator. I haven't ever cleaned behind my refrigerator. Who knows what's back there. If it gets too dirty, I'll just move. I hadn't really intended to go this high, but one thing led to another and here I am. It's cool. I have a clearance.

I level off. You piston pilots know that means that I close the cowl flaps, lower the nose to a cruise attitude, wait a bit for the airplane to speed up, slowly bring back the throttles to cruise power, adjust the propellers for the right "gear" for the power setting, and finally lean the mixture for efficient use of fuel. By habit I lean one at a time. That's because if I accidentally pulled both all the way back it would cut off fuel to both engines at once and that would be exciting. So I pull the left one, the good one back, seeing the fuel flow drop to the expected value as the EGT rises. And then I pull the right one, the bad one, back. I have to pull harder, so I have my hand kind of braced, so I can't pull it too far at once. It comes back. And so does the fuel flow. Nice.

The clouds are getting a little thicker beneath. It's still scattered. Or at least I'm calling it that, because in Canada the layers below need to be scattered or better for me to be VFR. But whatever the cloud coverage, they are too numerous for a smooth descent into destination, which is what ATC is offering me. I think they're already a little testy about my unfiled request for CVFR, and now they want to get rid of me. There's a big hole to my left, so I announce that I am descending in that direction to continue VFR below. And I do that, reducing power somewhat for the descent and then slowly enriching the mixture as the oxygen level in the air increases above what the turbochargers were providing when I first leaned the mixture.

Which is odd now that I stop to think about it, because I have great turbochargers. I can set a climb power manifold pressure with the throttles and it just sits there on the dot from 2000' up to FL190 without me having to touch anything. So why do I have to enrich the mixtures on the descent? I do. If I don't pay attention the EGT needles will creep up towards the red.

The turbochargers are compressing the ambient air such that the engine gets the same amount of oxygen it would at sea level. But on the way down I have to pull back the throttles to keep the manifold pressure the same, and I have to push the mixture up. The difference is that on the way up I have about ten inches more MP than on the way down. (Pilots have the weirdest units for power.)

I follow the valley under the clouds. The problem with being under the clouds is that its raining. Okay, this isn't a big big problem, but flying is more fun when you can see where you're going. It's really pouring. I fly to the VOR and then into the next valley where I can call ATC and announce inbound. They give me a VFR arrival to fly, and as I'm getting that sorted out they decide I don't have to fly that arrival after all, and should fly straight in, so I pull back the power more and dive into final, zooming to get gear and flaps sorted out, then land.

I taxi to the maintenance hangar and try to figure out where to park. It's kind of crowded outside and there are do-not-park-here lines in the places that don't have airplanes. I know they're going to work on it first thing, so I do the best I can and pull both mixture levers to idle. Both engines shut down. The cable is still in one piece.

And then it turns out that there's a guy there waiting for me at the AMO, even though it's after hours. He just wanted to make sure I got in safely. He says he'd offer me a ride, but he's on his bike. So I take a cab. That's right, I strung you along on a ferry in an unairworthy aircraft, with the mixture cable supposedly on the verge of breaking, and then nothing happened. But when I left I didn't know it wasn't going to break either, so it's only fair.

Tuesday, June 26, 2012

Mixture Equation

Company is scrambling to fix the problem, both the problem that the mixture cable is mostly stuck, and the problem that we and the intensely valuable data we collect are stranded here. The non-pilot member of the crew books a commercial passenger flight home. I share a taxi with him over to the terminal, where he checks his overnight bag and does a really good job of nonchalantly pretending that the fifteen-plus kilogram unit containing our hard drives is a featherweight carry-on. He doesn't want to be separated from it or his computer.

We share a meal in a restaurant at the terminal and then he heads to his gate. He says he's taken the units through airport security many times without difficulty, and this proves no exception. It does have official looking stickers on it designating it data storage unit eleven or something, but it's not as if terrorists aren't going to try and make their lead-lined doomsday devices look like harmless technology.

I walk back to the airplane. As I'm walking along the service road, I'm slowly overtaking another pedestrian. I say hi as I pass and he comments that they could at least have sidewalks. It's true. Despite the fact that last time I was here the rental car lots weren't even paved (they are now), it's an airport large enough to have commercial service, a restaurant in the terminal, and rental car lots, but they can't manage to provide sidewalks? I tell him my airplane situation. He sympathizes. We've all been there, and then he goes off to fly his and I go off to keep mine company while company decides what is to be done with it.

I actually have terrific field support. I need a flight plan sent in, a hotel room booked, anything that can be done long distance, and it happens. I tell the PRM, "Hey at least I broke an airplane on a Monday morning." I usually seem to break them on the Friday afternoon before a holiday weekend. Later I discover that it IS a holiday Monday in the United States, severely limiting our options for getting parts shipped. Nevertheless company manages to find a supplier for the cable. It's cheap, only $250 plus shipping so they order two and ship one here and one to a different city. That may sound strange, but I'll get to the strategy later. Oh and someone asked last time for more info on the cable. It's essentially a heavy duty bicycle cable. Instead of a single cable inside a plastic sheath it's a multi-strand cable running inside a metal sheath.

Right now they are looking at the best options to find or send someone who can repair the problem. Or to get the airplane to someone who can. They're thinking of getting a ferry permit, that's permission to operate an officially non-airworthy airplane for a limited purpose, usually to get it to somewhere that it will be repaired or scrapped. A company engineer texts me a picture of the innards of a throttle quadrant and asks me to take one like it on my phone. It is inconclusive at best. I don't know how he can assess the soundness to fly based on that. It's not fair to ask the no-moonlighting guy to sign off on that, because if something happens and the airplane doesn't arrive, he gets looked at, and he doesn't know, me, the company or the airplane. Company asks me if I'm willing to ferry the airplane if maintenance and Transport Canada okays it. The runway here is long enough to do a reduced power takeoff empty, and there's lots of room to climb. I ask what happens if the cable breaks in flight, does it go full rich or stick where it is, or will it roll back to idle cut-off? Maintenance has to get back to me on that. The conclusion is that it will fail in place. I won't be able to enrich the mixture, but seeing as the "mixture" cable controls available fuel and the throttle controls the air, I can control the actual ratio with the throttle. It just means that I'll be limited to a maximum power of whatever throttle setting is appropriate to the max fuel flow I'm stuck with. It would mean that I would have to slowly decrease the throttle setting in descent when I otherwise would slowly increase the mixture, until I was ready to slow down.

Company tells me the wording to write in the journey log, underneath where I have written that the mixture is stuck. It's something like, "Unable to rectify. Aircraft is operated in accordance with ferry permit number ____." Transport Canada accepts the maintenance sign off and issues a ferry permit. I scrutinize my faxed copy carefully for the restrictions. I'm okay to fly over built up areas, good. I'm cleared home with any necessary technical stops enroute. No passengers. I read it over several times but I can't find the ferry permit number. I call company. They agree there isn't one. I sign it off as "in accordance with ferry permit issued at _____ dated ____."

I think this will be my first cross-country solo in this airplane. All the other solo flights have been local test flights, or recurrency. I check carefully the items that my co-worker usually manages, and then I call for clearance and taxi out.

Wednesday, June 20, 2012

Lack of Mixture Travel

The right mixture lever has been stiff to move out of idle cut-off for weeks now. If I were writing in my old style of bombarding you with every trivial detail of my every day you would have heard it mentioned with every engine start. It seems to be better during the flight, and then worse again the next day. I complained about it to maintenance and they said there was nothing wrong with it. I complained about it to maintenance and they said they lubricated it.

It didn't really seem like the sort of issue that would be solved with lubrication, and it wasn't. Sure it was a lot better after they started, but so was it a lot better at the end of a flight. But at the beginning, wow. I wouldn't push an airplane part that hard for fear of breaking it, if you hadn't been led to do it, bit by bit, a little harder each day. My Person Responsible for Maintenance gets daily updates on this issue. (And every other issue. A contributing factor to my blogging hiatus was a PRM who actually appreciated daily reports that look kinda like an Aviatrix blog entry). One day it took three tried to start the right engine, not through any fault of the engine, but as I got a start I wasn't able to push the mixture lever far enough forward to sustain fuel flow before it died. It was STIFF. Third time lucky and we ran up and took off.

Barely off the runway and the right EGT needle flew right through the red bar into the territory beyond numbering, while the right engine fuel flow was about six gallons per hour lower than usual. I can see that split on both my analogue and digital fuel flow gauges. (Yeah, we use funky units like knots and gallons per hour: this is what my instruments read in. I guess I should be happy it's not furlongs and firkins per fortnight. You don't really have to know what a gallon is, just that less of them are going through the engine than usual). If gas is what's burning in the engines, why would less gas give more heat? Gas delivered to the cylinders in excess of the stoimetric necessity serves to cool them, so while not required for the chemical equation, those six millilitres more per second are definitely included in the manufacturer's equation for aircraft serviceability.

There are no obstacles ahead, so I lower the nose (which speeds us up and increases cooling) and start pulling power off the right engine until the temperature come down. It's a little below our normal cruise power. We've just come off a northern airport with no ATC and no one who would service our airplane. I call centre--or possibly they were calling me--to cancel the IFR, with no explanation, and turn south VFR. South to where people with parts and tools can make my airplane work right. South to where our cellphones work. Text messages fly. We have to choose between two likely airports. At one of them company hasn't been able to contact the purported maintenance outfit. At the other company has, but they have said they don't have the time to do it. Wherever we land, that's where we are until it's fixed, because it's not reasonable to do another takeoff if it's going to drive engine instruments through their limits like that.

We pick an airport and land. I finish the paperwork, including writing the snag in the logbook so I can't have an attack of stupidity and decide that it wasn't so bad after all. The other crew member goes to find someone to work on the airplane. He finds no one who can spare even the time to come and look at the problem. I say oh well, I'll just check that it's okay to park here, and wander into the nearest hangar doing the hello thing. Every time I do that I'm cognizant that I'm kind of trespassing, wandering around between someone else's expensive and secured aircraft, but usually the only way to find someone in a hangar is to wander in and follow the sound of the radio or the pneumatic tools until you see someone. I've never once had the reaction be fury or distrust. In this case the folks I find look and sound suspiciously like maintenance engineers.

"Hi, I came to ask you if it's okay to park outside against the fence, but you look like you could answer a more important question. Do you know anything about piston twins?"

The world of aviation maintenance is divided into camps based on the kind of engine (turbine vs. piston) and wing (fixed vs. rotary). This guy turns out to be qualified on just about everything, and has some time to spare. I bring him back to the plane. My co-worker (and boss) laments, "I go all over the airport looking for an engineer to look at our airplane and you find one in two minutes without trying?"

He pulls an engine cowling and pokes at the throttle quadrant a bit. We need the mixture cable replaced. I can't see what he sees, even with a flashlight, but I am unsurprised. He can't help us, though, because his contract forbids moonlighting. He's still been a help.

Thursday, June 14, 2012


I'm on a quick turn and after the mandatory break to pee, refill water bottles and file a new flight plan I'm back at the ramp to check on the airplane. My fuel caps are recessed into the top of the wings, with flaps that cover them, flush with the wing. The flaps are opened by giving a half-turn to a wingnut. One of the wingnuts is now missing. I track down the fueller. "Did the wingnut break off the fuel cap?" I ask.

He says it was like that when he found it. It seems very odd to me that a part that was affixed well enough for me to have opened and closed the cap to check it just five hours earlier became loose enough to bounce off in flight of its own accord. Sure there's airflow over it, but really? There's no point in arguing. Fortunately when the wingnut broke off it left a screwhead underneath and the cap is still perfectly usable to anyone with a tool. I have a tool.

Monday, June 11, 2012

Big Day

All evening last night my coworker was assuring me that today would be a big day. It became a joke, so that every five minutes one of us would ask the other, "Do you think tomorrow will be a big day?" so that the other can reply, "Yes, it's going to be a big day tomorrow."

The day starts with waiting for a cab. The cab is late. Late cabs steal my sleep, at either end of the day. When it finally arrives I walk around to put my bags in the trunk. I see the fish symbol and recoil from it like I fear it will burn my flesh. Fish Cab has come for us again. It has become more pungent overnight not less. The driver says, "Don't ask me to close the windows, because I won't." We make it to the airport, preflight quickly, and head out for our big day.

I've filed an IFR flight plan that includes the fix LETRM. Such five-letter fixes are ubiquitous, each unique in the world, easy to enter into a GPS receiver, but not always easy to say. If you're unfamiliar with an area and told to fly direct something that sounds like "wild" you can't guess if it's going to be WILED or WYLDE or WHYLD or WAILD or something else. You're supposed to know the fixes on your own flight plan or any approach you're given, and ATC is usually considerate enough to spell out fixes for pilots they don't recognize as locals. I'm not sure if this will sound like "LEH-trim" or "LEHterm" or "le trème". Probably not the last as it isn't a French-speaking area. The controller says it before I have to. It's the first one.

We're working in military airspace again, the one by LETRM, so those of you with the home version of this game can guess that's Cold Lake. This military airspace is a patchwork of different restricted areas, each restricted at different times and altitudes. I've called ahead to the base, and checked NOTAMs to ensure that I am allowed in the space I need. I'm on my way to the target and the controller calls me to check that I will remain ten miles outside CYR 204. Uhh, I planned to remain outside, but ten miles? That might not work. The controller is a hero for me and negotiates with Cold Lake terminal then comes back to me with a restriction to remain 65 DME from the Cold Lake VORTAC--that means a little less than sixty-five miles horizontally from a variable phase VHF transmitter located on the Cold Lake aerodrome. It's less than sixty-five, because DME measures slant range. Those of you who like trigonometry as much as I do can figure out exactly how far horizontally, when I tell you I was at FL180 and the Cold Lake aerodrome is at 1775' above sea level. Hmm, I might need to give you the air temperature, too. So don't worry about it. I just read the little numbers off the DME and keep them above sixty-five. I think I got down to sixty-seven.

Then we went north and did some more work, and then I started down for landing. I misjudged the descent, so ended up level in the lower bumpy altitudes fighting a strong headwind for a while. You can't win: you stay high too long with the tailwind and you can't get down to the airport or you descend and the tailwind switches around and you're too slow too far out. I'm so often directly above an airport I'm supposed to land at. I land, order fuel, fax (yeah, high tech, huh?) in a new flight plan, pee and then start engines to take off again.

More of the same, oxygen, water, granola bars, switch fuel tanks and descend for landing back where we started. Taxi to the pumps, fuel, taxi to parking, shut down again and ... you knew it as coming, didn't you? Back into Fish Cab for the ride to the hotel. It's now more like "overwhelming scent of Febreeze and more air fresheners than you thought you could cram in one car, but with a definite undertone of fish" cab.

We go out for dinner and the restaurant has a steak and lobster tail special, which we each gleefully order and consume. It was a big day.

Monday, June 04, 2012

Fish Cab

Centre releases me "for an approach" at an uncontrolled airport with no FSS on the field. I always feel like I'm playing around in Microsoft Flight Simulator when this happens. Ooh, what approach shall I fly? How shall I transition to it? Why does this feel like it shouldn't be legal? We're actually visual, but I don't do a lot of instrument approaches, so I need to fly them when I don't have to now and then to stay safe and legal for the rare times I need them.

There's an NDB approach to one end and a GNSS (Canadian for GPS) to the other. The wind is pretty much straight across the field, so I can pick either one. I'd pick the NDB, because NDB tracking is fun, especially on a windy day like this, but I got my NOTAMs like a good little pilot this morning and I recall that the NDB was NOTAMed unserviceable. The GNSS it is. I'm too high when I turn on, and remain too high and too fast for any kind of controlled approach until about two hundred feet and then do that thing I learned to do when I frequented an airport with a lot of military traffic where the controllers frequently asked me to maintain an approach speed higher than my gear speed: I plummet towards the runway until about two hundred feet agl, then pull up my nose to bleed speed. I climb, but when I lower my nose again I'm going 120 kts, with the gear and two notches of flaps deployed, ready to land. The boss says he's impressed. I feel guilty. It's a silly trick, and not a substitute for a well-planned descent, but for operational reasons were overhead the airport at 16,500' when we began our descent, and I really have to pee. The regs say I need six approaches to minima: doesn't say anything about them needing to be GOOD approaches. I promise to to better ones later.

The airplane is very easy to handle in a crosswind and crosswind landings are usually a non-event, with only the tiniest delay between contact for the into wind and out of wind wheels, even on those days where ATC volunteers two separate wind checks on final.

This airport is has a little chain hanging from posts near the parking lot to keep you from driving your car onto the apron, but no more significant airport security. That kind of town. We call a cab. It shows, eventually, according to the local definition of "right away." As the driver unlocks the trunk for us, I see a Christian fish symbol on the car. I don't have a problem with religious symbols on my cabs. In Vancouver they all seem to have Sikh symbols on them. But this fish turns out to have a greater significance. A strong fishy odour emanates from the back of the cab. I guess the last customers were up here fishing. The back seat has the same redolence. Apparently a passenger left behind a very small box of bait fish and it took a few days after the smell started for them to find it down the back of the trunk. Most of their fares don't use the trunk. The cab driver is telling this story as if the smell is in the past tense, but it's still very much present. Her nose must be just inured to it.

Friday, June 01, 2012

Greater on the Way Back

We're heading back across the mountains now, down at 9,500' because it's a beautiful smooth day and why suck bottled oxygen through my nose when I can breathe fresh, mountain air below ten thousand? It looks like this outside. Everywhere. The photo doesn't capture the shiny sparkles on the mountain peaks. I put on the autopilot and used both hands to take pictures as we went between these peaks. This isn't the Great Divide yet, still in British Columbia, but Vancouver Centre was trying to get a hold of us to transfer us to the next sector. They waited a little too long, or perhaps the altimeter setting was a little higher than usual, putting us a little closer to the rocks and further from line of sight to their antennae. They called me. I responded, but they couldn't hear me.

I so didn't care. I looked out the left side. I looked out the right side. I looked ahead (more spectacular peaks, but in all the pictures I took the morning sun highlighted the tiny scratches in the windshield so strongly that it stole the camera focus and that's all you see, with the peaks a mere background blur. Centre called another airplane (that company I went through groundschool for but ended up not working for) and asked them to relay a massage. It's not uncommon. The controller tells a pilot of an airplane at a higher altitude the callsign of and the message for the pilot they can't reach, and that pilot relays. You can also do it the other way around, as a pilot if you need to contact a controller but you are too low. When you hear another airplane making calls to that agency, you wait until their conversation is over and then ask them to pass your message. It's kind of fun. I accept the message, a frequency change from the relaying pilot, but don't take my eyes from the window to tune it until I'm through those peaks. It's not like Edmonton would have been able to receive my transmission at that altitude either.

Mountains: they are cold and cruel and can kill you quick, but oh so beautiful. In a few miles I called Edmonton Centre and then the knife-edged peaks gave way to the flat of the prairie. It happens startlingly quickly.