Tuesday, March 30, 2010

Closing the Back Course?

When I saw a notice in the latest Aviation Information Circular about replacement of outdated localizers and glide path units with new state-of-the-art equipment, I wasn't too excited. Nav aids get shut down for maintenance all the time and you just use another approach if you happen to need to go there in bad weather. It's rare, in my experience, that the weather is in between the precision and non-precision minima, so I almost browsed right past it, but then I saw this line:

As well, new ILS systems do not generate a useable back-course signal; consequently, localizer back-course procedures will be replaced with area navigation (RNAV) approaches, where applicable.

I did not know that. ILS stands for Instrument Landing System, but that's a really useless abbreviation because there are half a dozen types of instrument landing systems, of which only one is called ILS, a.k.a. precision approach. An ILS provides both lateral and vertical guidance to a runway. It's not as simple as riding a single beam down to the runway threshold, but that's the image that works for me. The part of the transmission that the pilot follows to align with the runway is called the localizer and the part that lets the pilot know if she is too high or too low is called the glideslope. The signals are usable within ten degrees of the runway centreline, but the needle that indicates position on the localizer reaches full deflection 2.5 degrees from the centreline, so to make an acceptable approach, the airplane must remain within about one degree of the centre of the beam. Although the beam is associated with one runway (that is one end of a particular piece of pavement) the signals leak out in the other direction to the opposite runway. If there are no obstacles or terrain that interfere with a safe approach, it may be possible to design a backcourse approach using the same nav aid on the opposite runway. A pilot flying a backcourse approach follows the localizer signals in the opposite direction in every sense. If the front course approach is on a track of 090 to runway 09, then the back course approach will be on a track of 270 to runway 27, and when the instrument signals that the pilot is left of the localizer, the pilot should fly left and when the instruments show the pilot is too far to the right, the pilot should fly right! (There are ways to set some instruments up backwards so you don't always have to use reverse sensing, but that's the traditional way). The glideslope signals may be received on the back course, but they are not usable at all and the pilot should ignore fly up or fly down indications, not do the opposite. Also, you get to fly the airplane pointy end first and right side up.

So this AIC is telling me that all my long ago work learning how to fly with reverse sensing is going out the window because new technology localizers don't have a back course? Cool. I wish I could tell you more, but the link to more information in the bulletin 404s. Someday people will look at the LOC REV switch on old autopilots and wonder what the heck that was for. I wonder what else I'll see fall by the wayside during my aviation career. I hope a lot of those old autopilots get replaced, but I know some of them will never go away, even if they don't ever work again.

Sunday, March 28, 2010

Autopilot Disconnect

Sometimes I read so many manuals that the words scramble themselves and I can't tell what they mean any more. But sometimes it's not me, it's them. The truth is, my autopilot is so mad, that even the manual disconnects unexpectedly.

The Century Flight Systems, Inc. Lateral Guidance System contains. Track interception angles a completely automatic, analog computer that directs the autopilot in both VOR and ILS navigation. The system contains a five position mode selector switch which mounts in the instrument panel are 45° and an automatic 15° crosswind correction capabilities is provided. The complete capture, intercept and tracking sequence is accomplished automatically without monitoring or multiple switching.

What? It's some sort of scrambled puzzle. Here are the pieces:

  1. The Century Flight Systems, Inc. Lateral Guidance System contains
  2. .
  3. Track interception angles
  4. a completely automatic, analog computer that directs the autopilot in both VOR and ILS navigation.
  5. The system contains a five position mode selector switch which mounts in the instrument panel
  6. are 45° and an automatic 15° crosswind correction capabilities is provided.
  7. The complete capture, intercept and tracking sequence is accomplished automatically without monitoring or multiple switching.

Reordering 1-4-5-2-7-3-6 we get an almost coherent statement:

The Century Flight Systems, Inc. Lateral Guidance System contains a completely automatic, analog computer that directs the autopilot in both VOR and ILS navigation. The system contains a five position mode selector switch which mounts in the instrument panel. The complete capture, intercept and tracking sequence is accomplished automatically without monitoring or multiple switching. Track interception angles are 45° and an automatic 15° crosswind correction capabilities is provided.

The only problem is that "an automatic 15° crosswind correction" is a capability, not capabilities, plural. Can anyone solve the puzzle to make it an entirely readable paragraph in natural English? Perhaps the answer will result in the key to keep the actual product online for an entire flight.

Please, if you assemble or install autopilots or write equipment manuals, go easy on the liquor, and on the cut and paste options.

The autopilot seems like a skilled copilot in that it is usually very good at holding headings and altitudes, but it is actually a really poor copilot in that it it will not tell you if it is feeling unusual control forces and will never remind you of any other task. It is just a super fixated control manipulator, with no actual piloting skills. Narcolepsy is not the least of its problems.

Friday, March 26, 2010

Database Specification FAIL

I just booked a flight with a company that until today I considered a major Canadian airline. Their online booking system has changed slightly since they switched to SABRE and now they have input constraints that I hope would result in serious marks being docked in an elementary programming course. The company serves all regions of Canada and also offers international flights. But they come up with this:

Please spell your first and last names as they are on your government issued photo ID that you use for check-in. For example if your name is on your passport as Thomas Jones, please enter it as Thomas Jones, and not Tom Jones. Information entered into the name, address, password and cardholder name fields must be entered without special characters. Special characters such as apostrophes, hyphens, periods, symbols or accents (e.g. ^ à é # ) are not accepted in these fields by our system. (e.g. Enter Stéphanie Ducharme-L'Heureux as Stephanie Ducharme LHeureux, St. John's as St Johns, and Apt. # 123 as Apt 123).

I find that unprofessional to the point of insulting. If the purpose of the data is to collect the customer's name and home town, then collect that, not some garbled bastardization thereof. If the purpose is to compare the data with a straight ASCII database, then it is the duty of the programmer to strip or convert unwanted characters. I fly airplanes for a living and I think I could write a function that cleanly replaced accented characters with their unaccented equivalents and removed other special characters from a line of input, in not much more time than it would take me to write and format the dialogue telling the user to. But I'd be more likely to work a little harder to allow my database to spell my customers' names correctly. Asking a person to corrupt her own name for the purpose of buying an airline ticket is requiring a person to lie about her identity and herself. If an airline can't hire a programming staff that can deal with the concept of special characters, it makes me wonder if they can hack the complexities of time zones and confidential information. This would make me laugh if it didn't disgust me.

Update: I wrote them an e-mail to tell them that myself and I promptly received an autoreply beginning ...

Dear Guest,

If your issue is of an urgent nature (you’re traveling within the next 72 hours and/or needing a change or cancellation to an existing booking), please contact the Sales Super Center at 1 888 WestJet (937 8538).

That's right, travelling is misspelled and there are nine spurious characters replacing the apostrophe in you're. If you work at Westjet in Calgary, do me a favour. Find the person responsible for approving that garbage and slap them upside the head for me.

Wednesday, March 24, 2010

I Will Be Serving Rabbit

A while ago I was doing a Google Trends search comparing different countries, and noticed an annual pulse in some of the returns. For example, the annual double peak for France matches exactly to the dates of the Tour de France each year. Apparently the Google world searches for France pretty much exclusively to find out about bicycle racing (plus an unfortunate peak around the time of the Air France crash in the Atlantic). But there was a similar annual oddity for Turkey. What annual event in Ankara was causing all the interest? Was that Ramadan? I looked at it for a moment more and then realized that most people searching on Turkey are not interested in the country on the Bosphorus. The little triple blip at the end of the year is for people buying and cooking turkeys, the bird. There's a little rise in October for Thanksgiving as the holiday is celebrated in Canada, a big peak as the Americans have theirs in November, and another peak at the end of December, for Christmas.

To confirm this, limit the search to Canadian results and the shape of the graph changes significantly. Now there are two giant peaks, one for Thanksgiving and one for Christmas, with a little blip representing Canadians searching on their neighbours' holiday. Probably ex-pats and people wondering if that's why American businesses aren't answering their phones. And then I noticed that while in Canada the Christmas turkey peak is greater than the Thanksgiving one, in the US the Christmas peak is tiny compared to Thanksgiving. I'm curious about why.

It's probably not a reflection of the fact that almost all Americans celebrate Thanksgiving, but only Christians celebrate Christmas, because the proportion of the two peaks is much less than the proportion of Christians in the population. It could be that having just cooked a turkey for Thanksgiving, Americans either still remember how, thus don't need to google it, or don't want to cook another. So that leads to the question: what do Americans eat instead of turkey for Christmas dinner?

Additionally, a regular turkey peak shows clearly in the Canadian results matched with Easter, but there is none for the USA (discounting 2009, when the US president visited Turkey a few days before Easter). It suggests that Canadians are having turkey for Easter dinner. We get a four day weekend, so maybe we just make a bigger deal of it, but again, Americans have to eat, too. What then do Americans eat for Easter dinner?

I'm sure could google to find out, but it's more fun to ask you.

Tuesday, March 23, 2010

Peter Shewring

I was flying part time for two different companies, just starting out my aviation career and had a little over five hundred hours in my logbook. That was almost enough to take the SAMRA and SARON, two exams that make up part of the qualifications for the Canadian Airline Pilot Transport Licence. I told a mentor I was just going to study for it on my own because I had lots of study materials and was an experienced student. He laughed at me and said, "You don't take this course to learn the material. You take this course to make contacts." So I pulled out my credit card and signed up for the course he recommended.

I was never a very skilled schmoozer, so I can't say I have exchanged job tips with or remember any of my fellow students ever after, but the teacher was terrific. He kept everyone involved and motivated, made the material interesting and kept people learning whether they thought they were lost or thought they knew it all. During a break on the last day of the three-day course, I got a desperate call from one of my companies. I had taken the day off, which they had assured me was no problem, but the pilot rostered for that afternoon had forgotten to renew his medical certificate and the pilot who was supposed to be his back up said he was sick. So instead of going back to class after the break, I had to go to to work.

The instructor, Peter Shewring, was very understanding and promised me I could sit in on the next class, next time he was in my city, any time I wanted. I went to that course, and aced the exams. He wanted students to tell him about any tricky exam questions, and I tend to remember questions quite well so I sent him a list. And then I e-mailed him from time to time for no reason, just because something I had encountered that day was something his course had prepared me for. Funny thing is, it's regarded as a cram course, with the syllabus matched to the exam, but he taught useful material, little tips and tricks in a way that made the on-the-exam stuff easier to remember and the real life stuff easier to do. He encouraged me and said he wanted to do my next IFR ride (he was an examiner too). And I always meant to call him for one, but political reasons determined the next one and then I was in the wrong city, and then I was doing PPC rides instead. I went back to the same course again, years after the first one, for a refresher and Peter remembered me.

I'm not an easy student to have in a class. If the material is interesting and new I become engrossed and ask challenging questions or answer rhetorical ones, which may interfere with the flow of the class. I'm overly helpful and I have been known to unintentionally trample egos in pursuit of knowledge and correct information. Peter kept me interested and channelled my enthusiasm into actually helping others in the class. He even suggested that I might join his team of instructors. High praise indeed. The timing wasn't right then, but just the other day I was thinking I should call him back and see if I could help out anywhere.

And then today I learned that he has died. I don't know the specifics, but I know I'm not the only one who will miss him. There's a thread on AvCanada full of stories from people who feel the way I do.

Update: An obituary.

Sunday, March 21, 2010

Health & Safety

Interesting article here about a group of flight attendants who refused their flight assignment when the in-charge (lead flight attendant) told them that on an earlier flight the pilot had threatened to ditch the airplane into the Atlantic.

An inquiry couldn't find any evidence that the captain had ever threatened such a thing. It's not impossible that the captain threatened such a thing, but it requires less suspension of disbelief if the FA made up the story.

If the captain did threaten to ditch the airplane in the Atlantic during flight, it would either have to be while the first officer was present, or while the FA was alone in the cockpit with the captain while the FO was in the washroom. If the former, why would an FO collaborate with an insane captain to cover up a stated suicide plan? If the latter, what would be a reasonable response by the FA? Remember, he's believing that the person in charge of the aircraft intends to kill everyone on board. To say nothing to anyone who could corroborate the story either during the flight, on landing, or at all until it was time to meet for another flight with the same captain? Wouldn't you ring an emergency code on the call button, radio ATC with the threat, report to company as soon as you were able, enlist the help of your immediate co-workers to restrain the captain, or tell the FO what had transpired as you let him back into the cockpit?

It seems to me more likely that a conflict arose between the authority of the pilot and the authority of the in-charge. The captain is ultimately in charge in such a situation, but some flight attendants try to manage up, and some pilots take that worse than others. It's possible for someone to make a subordinate's life hell without actually transcending workplace regulations, and it's not uncommon for such subordinates to rebel. Maybe the in-charge asked the others to boycott the flight and provided the story. Maybe the in-charge made the others believe the captain really was that loopy. At any rate, I hope Air Canada has a better contingency plan than relying on employees to invoke workplace safety regulations in the event of flight attendants detecting mental instability in pilots.

I approve of workplace solidarity in the face of unacceptable demands. I disapprove of crashing airplanes into the Atlantic.

Saturday, March 20, 2010

Going for the Hat Trick

This news story relates a flight delay taken by Air Canada not for weather, not for mechanical, not for crew delays, but for hockey. It was the gold medal game between Canada and the US. The game was tied after three regulation periods (thanks to a literally last minute US goal) and had gone into sudden death overtime. The passengers simply refused to board the airplane until they had seen the winning goal.

Canadians, if everyone hasn't figured it out yet, love us some hockey. The streets across the country exploded with red and white clad fans as our men's and women's teams won Olympic gold last month. "Hockey" refers by default to ice hockey here. If we're talking about street hockey, roller hockey, or field hockey we'll specify. The last isn't very popular in Canada, especially not with me because I had to play it in elementary school phys ed in a skirt and without shin guards. The sticks were made of wood back then, some heavy dark shin-punishing wood. The latest kind of hockey for us to love is sledge hockey.

Sledge hockey is a winter hockey event for athletes with a permanent lower body disability. The players sit on little skate-runnered sledges and use sticks that have a regular blade on one end and a spike on the other, not for spearing, but to propel them around the ice. When these guys (I don't think there is women's sledge hockey) get checked into the boards, they're actually getting checked into the immobile boards, not the yielding plexiglass above the boards, and they always seem to cite this when interviewed about their sport, so I'm guessing any practice they got at pain tolerance while acquiring their disability comes into play here. It's a great game to watch, full of action and there's no professional league, so all the players are doing it just because they love to play. The bronze medal game is in a coupe of hours at 02Z and the gold medal game is tomorrow (March 20th) at 19Z. If it's not televised where you are, you can watch it on the net via Paralympic Sport TV.

A Hat Trick, for those from hockey-impoverished nations, is when the same player scores three goals in the same game. It is extended by metaphor to anyone doing anything three times.

Oh and more evidence that Canadians don't do anything else while the hockey is on.

Friday, March 19, 2010

No Surprise

Terse e-mail today informs me I should cancel my flight to the scheduled training I've been preparing for. Maybe the examiner remembers me after all, and fled the country in horror when he heard he might have to get back in an airplane with me. Or maybe the autopilot doesn't work; the boss got a contract and needs me flying not training/testing; we're selling the Weedwhackers and buying an all-jet fleet; Transport Canada didn't approve the RNAV training programme; or someone's horoscope said it was a bad month for PPC renewals.

I think it's a game the universe plays with me. I drifted off to sleep last night thinking of how well the flight test would go, and the e-mail arrived, now that I look at the header, pretty close to the same minute I probably fell asleep. Perhaps it will keep playing it until I don't even twitch at the prospect.

Bring it on, universe. Bring it on. I'll keep studying, as the training will be rescheduled sometime in the next couple of months.

Thursday, March 18, 2010

More G430 Notes

Studying new material triggered some student instinct deep within me and I made Kraft Dinner for lunch. I had forgotten how orange it is. Canadians eat more KD per capita than any other nation. It's the national food of poverty, like ramen noodles in the States. I think it's also how we dispose of the radioactive waste from CANDU reactors. But enough about what fuels my studying. Here are some leftovers from the rest of the manual.

  • We can put up to nine 30-item checklists in the unit, but I don't think I will be using it for checklists. Sometimes the checklist item involves checking something on the nav setup and I don't want to be swapping windows when I don't have to.
  • The INTEG flag means the unit is communicating with insufficient satellites to obtain a position. Even worse, "Searching the Sky" could take ten minutes. It means that the unit doesn't know where it is, probably from repositioning with the unit turned off or not flying for over a month. Both are possibilities for our operation, so note to self: turn on GPS at start up, even if it isn't needed, and when rejoining the airplane after it has taken a long break, turn on the GPS before the walkaround and make sure it has a position so clients aren't waiting for me.
  • The unit can be linked to traffic alerting hardware and XM [?] weather inputs for even more screens of data.
  • Standard abbreviations: WPT: destination waypoint, DIS: distance to waypoint, DTK: desired track.
  • The "nearest" function provides information on facilities within 200 nm. I guess it sucks to be in Animal Waterbody where the nearest published facility is 201 nm away. I think that feature should have some flexibility and show from one to five screens of "nearests." It's not like you're going to use the nearest key and page down through twenty screens when you want to find an airport two hundred miles from KJFK.
  • Airspace said to be "ahead" is within 10 nm.
  • Through a feature called crossfill, you can transfer direct-to data from another Garmin unit. I guess you can be flying on one while working what-if scenarios on the other. Unlikely.
  • "To use the vertical navigation features, ground speed must be greater than 35 knots." Heh. I picture some poor pilot in a tricked out Cessna Commuter struggling against a strong wind and losing VNAV capability.
  • A track given as a result of a direct-to input is by the great circle route, not a rhumb line.

Here's some communications radio-specific stuff that I hadn't guessed.

  • The comm can be operated with 8.33 kHz spacing for Europe, but is in American 25 kHz spacing by default.
  • Press the com volume button to disable/enable automatic squelch.
  • Under some circumstances if the COM system loses communication with the main system, the radio will automatically tune to 121.500 MHz for transmit and receive, regardless of the displayed frequency. That's probably a consequence of the insta-121.5 feature.
  • The unit has stuck mike protection If you transmit continuously for more than 35 seconds, the radio stops transmitting and the words "Push to talk key stuck" are displayed as a message. These guys really sat down and made a list of every annoying thing that can happen in an airplane and set out to fix them.

You can choose an absolute altitude or an altitude above a waypoint and have the unit guide your descent profile to put you on target. I doubt it's much better at it than a pilot with a grasp of basic arithmetic, and seeing as the pilot takes into account the reduction in airspeed from engine output due to stage cooling, the winds aloft and the reported winds at the airport, the pilot might do it more efficiently. Still, cool for the arithmetically challenged or the too busy to think.

Direct-to is probably the most used feature of aviation GPSes. It even has a standard symbol, a D with an arrow pointing right. (I guess that's not in Unicode, eh?) Instead of drawing up a flight plan you just press the button and tell it where you want to go, then it shows you the way. This unit unit knows pilots like that, so on any page that displays only one waypoint, you can fly direct to it by pressing the direct-to key, then enter and enter again. If the page shows more than one waypoint you have to first select it by activating the cursor and using the right scroll wheel to highlight the desired waypoint. You can cancel a direct-to and return to the flight plan you were on before with menu then cancel I like that. It's common if a pilot is tracking direct-to a waypoint and they have wandered off track a bit to just hit direct-to again and generate a new track, direct from the current location. The manual points out that if you are on the approach you are direct to the MAP, but if you recentre the CDI with this trick, you will cancel the approach. Obvious, really, because the approach is direct to the MAP along a specified track, so as soon as you specify another you aren't on the approach. But worth saying, I suppose.

And we're back after a Firefox restart. Apparently having tabs open for Blogger, three Garmin manuals, the CARs, a Google search for html footnotes, Kraft Dinner, Gmail, a video on the iPhone app for the GNS430, and CANDU is too much for Firefox to deal with you try to switch between tabs at the same time as Eudora polls for mail.

Also it irritates me that when I use the Blogger buttons to insert formatting, the window jumps back to the top so I have to scroll down to continue blogging.

Tuesday, March 16, 2010

Hold On

My mission, determined in the previous installment, is to learn how to program a hold into the GNS430 in no more than double the time it takes to calculate the hold and set it up manually. Or at least to figure out how to make the HSI behave like an HSI and allow me to fly the hold manually. I've tried wandering around the menus and scrolling down to the secret parts I can't see right away, but nowhere have I found a choice like "Select Hold" or "Hold at waypoint." I can visualize what the screen might look like, with an option to select my holding point, inbound track, turn direction (default right), desired time (default one minute) and an optional second point if it's a DME hold on an airway. But no such screen is in evidence.

Back to the pdf manual (damn being a pilot is so glamourous) to look for holds. There's nothing in the manual specifically about defining your own hold, but I found this advice online. There is also an iPod application on the GNS430; author Max Trescott generously offered me a promotional copy of the app, but sadly iTunes won't let Canadians do that. Thanks to everyone for your various suggestions. I need to go back to my friend the OBS key. They should have labelled that key HLD. It would make a lot more sense.

So I reposition the simulator to try out an enroute hold. And here's a problem I've never had in the real aircraft. I moved the simulator window slightly, and my HSI vanished. Just poof, gone. Blank spot in the simulated panel. The simulator, in other words, is not without bugs. I exit and restart.

This time, the hold was easy. Using the OBS key you can hold anywhere you have a waypoint.

  • fly direct the waypoint
  • before you reach it, hit the OBS button to disable waypoint sequencing
  • bug the outbound heading of the assigned hold
  • cross the fix, turn appropriately, and set the trackbar to the inbound course
  • fly the hold just like you would if it were a VOR hold and you didn't have a GPS

It's cool because you can fly a hold at any fix at all, without messing about trying to identify the fix using multiple nav aids, but if it's not a published hold (based on a comment, I'm guessing the American for that is "charted hold") the GPS doesn't do the timing for you.

That technique may sound kind of lame, as it's just pushing a button then flying a hold manually, but by comparison flying published holds on the GPS is not all that whiz bang either. The flight plan names the fix then has the word "hold" on the next line. About five seconds (yeah, real heads up there, Garmin) before crossing the fix it tells you the entry type (only "TEARDROP ENTRY" not any instructions on the outbound heading), or even reminding you if it's left or right turns. The timer is kind of a neat gimmick because it starts the clock at the correct moment, passing abeam the fix outbound and turning towards it inbound, but it's not like you push a button and then sit back and watch the airplane fly the hold. There are cockpit systems that do that, even calculating compensation for wind.

Also, the little kids doing the announcements for the Paralympic Winter Games opening ceremonies did a great job. I didn't realize how small they were until they introduced the Governor-General and they all walked along holding hands.

Monday, March 15, 2010

Confusion is Only Simulated

I knew that Garmin made simulator modules for their products, but I had to search to find it. The FAQ "expert assistant" search returned the answer "yes" to the question of whether there was a simulator available, but didn't actually return a link. It's easy to install though and the 150% view makes it nicely usable on the laptop. I selected the C/V volume knob to turn it on, and it started up fine, running through the same integrity checks as the real unit. I verified that all the flags were as they should be and then noticed a MSG light, so pressed the key to find the message. "Main processor error." I've no idea where that came from. Who would simulate a hardware flaw? It only came up the once and never again, so as long as the real units don't do it, it should be good.

It's well-designed as a simulator. The screen consists of a photographic representation of the physical knobs of the unit with superimposed arrows so you know where to click in order to turn the ones that need to be turned. For the aircraft interface they depict only an HSI and generic simplified autopilot controls. Really simple: NAV HDG ALT, an altitude increase/decrease rocker switch that instantly puts the airplane at the altitude you select, plus a SPEED slider that instantly puts the airplane at any speed from 0 to 600 knots. This takes aircraft performance and configuration completely out of the equation, you just set the speed you would have for the phase of flight, and it acts as both a pause key and a fast forward. The only non-intuitive part is using the OBS and heading bug knobs on the HSI. You need to click on the appropriate knob then hold and drag straight horizontally, maybe all the way across the screen for a large change. It's easy to do once you figure it out, though.

My first surprise was that the menu screens don't wrap all the way around. That is, if you're exploring the suboptions of the NAV menu by turning the inside right knob, when you get to the seventh screen you can't go back to the first one by turning the knob one more click. You have to go all the way back through the way you came. Weird.

I set up a flight plan from Saskatoon to Prince Albert, because aside from having a NSFW name (don't google for images) PA has at least one of every sort of approach. I dial the speed up to around mach one so that by the time I've followed the instructions for selecting a full procedure ILS runway 08 approach and admired all the pretty menus, I'm almost there. I slow down to a more realistic speed for my aircraft, activate the approach and start the descent. It counts down to the beacon, and I set the heading bug to the outbound intercept, but nothing happened. It starts counting up how far away from the beacon it is. I activated the approach again and it started turning right toward the airport, not left on the outbound PT. I let it, to see what it would do, and it turned all the way around. Ack, the logic must have told it to fly to the beacon and then outbound and with the beacon behind and just a hair to the right, that made it do the right 270.

It tracks outbound and I fly the procedure turn then toggle the CDI to VLOC while inbound on the reversal. I notice that the glideslope is flagged off and recheck the frequency. Everything looks okay, but no glideslope indication appears and the distance counts down to the FAF, then counts up again as the map depicts reaching the runway and overflying it. Back to the manual.

This time I program in a sample flight plan from the manual, it's KFDK-KLYH. I finally figure out what I've been doing wrong: I have to make sure that the OBS key is not selected. The OBS option suppresses automated sequencing of waypoints. Silly me, I thought it enabled the OBS.

The example in the manual tells me to select VOR 03 but the simulator database only has VOR04: the manual is from 2009 but the simulator database only goes up to 2006 and the approach has changed. I choose the VOR 04 -- and the transition as told. It's loaded but not activated. How do I tell if it's activated by looking at the GPS display? What happens if I activate it twice by accident? I'm not sure. The waypoints sequence and I try the simulated ILS approach, but the glideslope doesn't work for this, either. I guess its just not simulated.

I set my location back to PA and try to do a VOR/DME arc. It's a 14 DME arc that runs from XEXEX to XETUL (the latter is in line with the approach). I'm starting at the YPA VOR, not the way you'd do a real one, but I want to see how this works. I can see how to go direct XEXEX, but I aim manually for the arc, west of XEXEX, trying to set the obs to a radial perpendicular to the arc where I will intercept it, as I would without the GPS, but it doesn't work that way. I have to set it along the arc and it does the conversion itself. Even when I set the CDI to VLOC I can't use it the familiar way. The main nav screen doesn't tell me my DME from the VOR. I'd prefer that this do a better job or enhancing rather than completely replacing old habits. It directs me to turn left onto the approach before reaching the fly-by waypoint at XETUL. I turned as directed and then had to correct back to the right in order to get on the radial by PUVER. That was no good. I don't trust it so I'm doing things myself and we're fighting and making a mess. Try again, this time from the south.

I go way out so there's lots of room and select vectors so I won't be asked to go to XIBEV. I fly direct BETIM. It's irritating that it doesn't tell me the ONE piece of information I want setting up for a DME arc: my DME! I'm 16 nm from BETIM, which is 3.5 nm from YPA and it's a 14 DME arc, so I have a few miles. If BETIM to YPA were a straigt line I'd be expecting to intercept at 10.5, from BETIM but they are not, so it should be before then. Yet, crap! I'm 9.1 from YPA and there's no arc intercept depicted and no turn instruction. I guess "vectors" was vectors to the final approach for the VOR/DME 08 and not for the arc. Try again.

What you have to do, is what I did before, set up for the DME arc, choosing one of the endpoints XEXEX as the initial fix, then go into the flight plan where you see the sequenced waypoints XEXEX, dme arc, XETUL, PUVER, BETIM all one below the other. Activate the cursor, scroll down to dme arc, and select direct to. This is going to work. I pull up the NRST screen that shows me the GPS distance from the VOR and it's showing 15.0 as I follow the directions through the arc. If I'm on the arc, the GPS distance should actually be less than the DME because DME includes slant range, and the depiction on the NAV map shows the same: I'm tracking outside the arc. It's good enough, I suppose but not really clear guidance for flying the arc.

And then it's straight down the approach to the missed. I always have to go missed in this simulator, because there's no way to see the runway. The missed instructions are straight ahead to 3100 then left to YPA VOR. I climb instantaneously with the little rocker switch, check to make sure the CDI is in GPS and not VLOC mode (I'm going to do that as part of every missed approach so that I don't forget on the occasions that it's an ILS approach) and then cancel the SUSP by hitting the OBS button. The simulator turns left as the missed approach instructions specify, but that was chance, because I've since seen it turn right, so remember it is not flying the missed, just going to the holding point. It is entirely up to the pilot to fly the missed as published.

When I did this on the sample approach from the manual, approaching the holding point it gave directions to fly the TEARDROP hold entry. I didn't actually fly the hold there, just repositioned and went back to Canada.

Canadian plates don't usually depict a published hold after the MAP, you just know that you can hold there, on the inbound track, and ATC can direct you to hold anywhere. Back in simulated Canada (don't you wish the real GPS had a transporter function?) I intend to enter and fly the hold manually, because after the missed I'm right on top of it, and too close to scramble into menus. Left turns, my outbound course just right of my current track to the VOR, makes it a parallel entry. I watch a messy station passage on the map view and I make the first right, using the CDI button to pop the unit into VLOC mode, verifying that the YPA frequency is the active one, but the flag doesn't flip. Map view shows I'm clearly past the VOR. Weird. I start the timer anyway and fly a minute outbound. Right turn inbound, flying an intercept heading on the VOR, but map view shows me cross the selected radial with no change to the CDI. Obviously VLOC mode doesn't do what I thought it did. I'll take a vacuuming break and read up on this later.

Sunday, March 14, 2010

IFR Procedures with the G430

The GNS430 is installed and IFR certified, so it is approved to work with the autopilot. I program in what it's supposed to do, and then it will give the autopilot directions on how to proceed. My job then is to monitor that it is giving the right instructions and that the autopilot is carrying them out. It's like you could give your car's cruise control instructions from your dashboard GPS on where the speed limit changed and where your exit was, and it would automatically exit and slow down.

The IFR procedures are all stored on a data card, and yes the cards must be physically replaced every 28 days, which I just know is going to be a pain and a half someday soon when I need to escape IFR from somewhere where overnight delivery service takes three months. I hope it won't lock up and refuse to work at all just because the card has expired. [Update: Paul says the updates can be downloaded over the Internet.] Canadian procedures only change every 56 days, unless by NOTAM. Question: if a NOTAM has temporarily amended a procedure can I modify it in the device? I'm guessing no. I'd have to hand fly it.

To load a procedure into the flight plan, I must first have a flight plan (or it will settle for an active "direct-to" command to an airport). I press PROC and it pops up a menu of types of procedures. I use the large right knob to Select Approach (or Select Arrival?, Select Departure? as appropriate). Enter selects, and it presents a choice of procedures depending on the destination airport in the flight plan or direct-to. Assuming you're selecting an approach, it drills down to allow you to specify the initial approach fix (IAF) or that you will be receiving vectors to final. Once you have selected the procedure with the enter key you can choose to load or activate it. Typically you would load it but not activate it until cleared for it, but it looks like you can activate it any time without restrictions. To do that after loading, you press PROC and then choose Activate Approach.

About 30 nm from the runway the GPS switches to terminal mode, i.e. 1.0 nm CDI scaling each side. It's a gradual transition, so if you were sitting there one dot off centre on the 5 nm scaling it doesn't suddenly whip over to full scale deflection. If you want, you can press FPL and right knob scroll through the list of waypoints to review the approach procedures. Seeing as the autopilot is flying, you could do that the way you look at nav radios as you give the approach briefing.

Approaching the IAF it displays your next desired track (DTK) as the outbound from the nav aid. It's up to you to make sure the OBS is set correctly and to decide which procedure turn to fly. It doesn't direct you left or right but just depicts your position relative to the inbound track. About a minute after passing the final approach fix (FAF), the nav aid you'll fly toward on the way back in towards the runway, it directs Start procedure turn, but again it's up to you to choose and fly the reversal. This could be done presumably by hand flying or by directing the autopilot with the heading bug. Question: Is it always about a minute after the FAF? what about those facilities in tight valleys or over residential areas where you have to fly a longer outbound leg? Halfway through the reversal, the GPS sets your desired track to the inbound and leaves you to intercept it. I'm not entirely clear on how I should be using the heading bug here. The GPS-autopilot interface is quite mysterious, given that they are technologies invented close to fifty years apart in time.

The unit does not accept a barometric pressure setting, and does not display altitude on any of the screens I've looked at in the manual so far, so it would appear that the GPS provides directional guidance only, and that the pilot is responsible for instructing the autopilot in step down altitudes and rates of descent on a non-precision approach. (There is a mode to reach a target altitude at a specified location, but presumably that is GPS altitude and is intended for VFR use). The GPS directs the autopilot to hold a heading and the pilot directs the autopilot to descend to an altitude, while the pilot uses the throttles to instruct the engine regarding power input. It's like CRM between a human and two machines: you have to be very clear who is responsible for what.

On a precision approach, the GPS is not approved to maintain either lateral or vertical guidance: you must switch to the VHF navigation signal from the ground-based ILS. The CDI can be set to automatically switch from indicating deviation from the GPS track to the localizer track, so long as you are tracking within 1.2 nm of the localizer, starting 2.0 to 15 nm back from the FAF. If it isn't set to switch automatically, or if you have a less than 2 nm gate, you can activate it manually by pressing the CDI button. In either case, the correct ILS frequency must be set in the VLOC radio, for the switch to occur. The unit will put the ILS frequency up on standby for you, but you have to toggle it from standby to active yourself.

While you are on an approach, the missed approach point (MAP) is the current waypoint. As you reach the MAP, "SUSP" appears above the OBS key and the pilot is expected to either land or conduct the missed approach. To land I guess you just land: the autopilot is still on and presumably the last heading instruction the GPS issued to the autopilot is still valid, so the airplane continues to the runway and the pilot can disable the autopilot and land at whatever point they prefer. To initiate a missed approach, hit the OBS key (and switch the CDI back to GPS from VLOC if it was an ILS approach) then the unit should give directions into the hold. It is not entirely clear from the documentation whether it will take you step by step through an elaborate missed, but at any rate if the missed called for an immediate hundred degree turn away from the mountain, I would be doing that before messing with the GPS for guidance. It looks like the GPS is a fair weather helper that is not willing to help you with the highest workload portion of the flight. It will tell you the correct entry procedure for a hold, but I'm thinking that unless it is a published hold that the database knows about, it would be quicker to work out the entry myself than to input the hold instructions.

Question: does the approach I fly have to be the LAST WPT, such that I can't pre-include the alternate as part of the flight plan? It appears that that is the case.

It looks like the easiest things to forget are: taking care of the vertical profile; activating the approach; and ensuring the correct CDI source for the phase of flight. Anyone who has any IFR experience with autopilot-linked Garmins is very much encouraged to give me pointers here. I am, for example, stymied as to how I define a hold that is not depicted on the plate as part of an approach, if say there's someone ahead of me on the approach and I just need to hold at the NDB and wait for them, or if ATC suddenly assigns a hold while they sort themselves out.

Tomorrow's post (not skipping a day this time) will be me trying it all out in the Garmin-supplied simulator.

Friday, March 12, 2010

Garmin 430 Overview

I'm training on a new GPS NAVCOM next week. (That is a GPS receiver that has an integrated communications radio and simulates traditional navigation instruments). This one talks to the radio navigation instruments and can combine their knowledge with its. The GPS can drive my HSI CDI so that I'm looking at the traditional instruments, but navigating by GPS information. This is good, because the traditional instruments have a better display and are right in front of me, so more comfortable to use. The system is complicated, but fortunately it's a Garmin, and I've used a lot of Garmin GPS receivers, so the logic isn't completely foreign; I'm working my way through the first online manual now.

Equipment like this has a lot of context sensitive keys. For example if you push the middle of the bottom right knob, you activate or deactivate the GPS cursor. If the cursor is deactivated, turning that knob changes screens, but if the cursor is active, turning that knob moves the cursor from field to field. But not to all fields. There's a separate cursor for changing VHS standby frequencies1, and two separate frequency swapping buttons. I like that, as I have been caught out on units that had one cursor, messing up my standby frequency just before I needed it, because I was hunting for the approach page. The section of the screen that acts as what would be labelled NAV on the analog radios is designated VLOC here. That represents VOR plus LOCalizer2, i.e. this radio is used to tune VOR or ILS frequencies. They needed a more specific term than NAV, because the whole thing is for navigation.

The 29 possible display pages are in logical groups, so you first use the bottom right knob, cursor deactivated, to select a group, i.e. NAV, WPT, AUX or NRST, then you turn the inside right knob to select an individual page within that group. I need to familiarize myself with which information is available on which pages. Setup is under AUX. Airport information is under WPT. If I get lost3, I can press and hold the CLR key to get back to the default NAV page.

Hmm, on page 17 it says that to stop navigating a flight plan I select Delete Flight Plan. Single use flight plans? That seems a little drastic. That option is usually Stop Navigation. It isn't until page seventy-five in the full Pilot's Guide that it confirms "Deleting a flight plan does not delete the waypoints contained in the flight plan from the database or user waypoint memory." You're really just deleting it from RAM and it's still stored, ready to be selected again.

Some of the pages can be accessed without going through the menu system. The approaches and all their associated pages are accessed with one touch, the PROC key. This is good. All those other pages are just pretty information screens. The approaches are going to actually tell me--or the autopilot4--where to go. The unit will tell me if I select an approach that has not been approved as standalone GPS. For such approaches I have to navigate primarily by the traditional nav aids, and monitor the GPS only for situational awareness. If traditional nav aids are available, I'll be monitoring them anyway, but it's a matter of what is driving my CDI5. I press the CDI button to select that, or "An ‘Auto ILS CDI’ setting provides automatic switching to ‘VLOC’ once established inbound on the final course segment of an approach." Nice, but dangerous, in the way that autothrottles are: more than one pilot accustomed to the airplane doing things for him has forgotten to do them himself when the occasion called for it. I'll have to make verifying that that AUTO CDI switch occurred a part of my routine.

Ever memorized something because you were told to, without being given enough context to use it or even understand it? I hate doing that, but I did so years ago in order to know the answers to questions I was told would be on the exam. I guess they were. I had to know the CDI scaling for different phases of flight. I don't remember them now, so I don't know if they are the same as on this 430, but the numbers here are:

PhaseScalingLocation
ENR5.0 nmenroute
TERM1.0 nm<30 nm from destination or 1-5 nm from departure
APR0.3 nm<2 nm from destination when on a GPS approach

I think those are full scale deflection each side. I'll have to confirm that with the next manual. I'll make the procedures for flying an approach on this unit a post unto itself, for another day, because despite all the bells and whistles, that's what I'm really here to learn. This whole week will be Garmin 430 posts.


Notes

Anyone know if there is an html tag that will automatically number footnotes, and superscript the index, like in LaTeX? Ideally it would provide internal page links to the footnote and back to the text, too.

1. If you press and hold the com swapping button for about two seconds, you get the emergency frequency of 121.5. I wonder how long it takes before the unit malfunctions and you risk getting 121.5 any time you swap frequencies. It's very common for older radios to double-flip when you try to swap them, leaving you talking to the same controller who just told you to switch frequencies. Embarrassing, but having that happen on 121.5 would be more so.

2. This makes VLOC a deeply recursive acronym, as VLOC is short of VOR/LOCalizer, and VOR is short for VHF Omnidirectional Range, and VHF is short for Very High Frequency, but no one ever thinks about what VOR stands for as they are saying it. It's usually pronounced Vee-Oh-Are, but there are a few people who say "vore." I suspect they are all students of the same eccentric flight instructor.

3. Lost in the menu screens, not lost flying the plane, nor can I get Lost the TV series on the little screen. It is in colour, though.

4. I'll believe that the autopilot works in this plane when I experience it myself.

5. The CDI is the little needle that tells me which way I need to correct to be on course.

Wednesday, March 10, 2010

406 MHz

When you get in my airplane, part of your safety briefing includes me telling you where in aircraft the Emergency Locator Transmitter is installed. (It's in the vertical stabilizer, marked on the outside with a sticker, and can be reached by tearing off a panel. You don't need tools to get it off if you're willing to destroy it in the process, and if you need it it's an emergency, so you should be). You shouldn't need to physically reach it anyway, as it's supposed to start transmitting automatically in the case of a crash, advising the world of the need for rescue and the location of the accident. ELTs are required by law to be in almost all aircraft operating in Canada. (There are a few exceptions for things like balloons, skydiving operators, and delays in repairs). The problem is, the law no longer requires the ELT to transmit on the most useful frequency. It's not that the law changed, it's that the useful frequency changed and the law didn't. Satellite monitoring of 121.5 was turned off over a year ago, leaving only the new 406 MHz frequency.

Below is an informative Transport Canada video on the advantages of the 406 MHz units, made somewhat entertaining by its "historical" character. Watch for the old-style green CFS in the tower. I love that the "typical Canadian pilot" is a while male in a Skyhawk. About right, really. The point of the video is to encourage Canadians to embrace the new 406 MHz ELT technology, because they are monitored by satellite and send information on the registered owner of the ELT. Without satellite monitoring, the old ELTs that transmit only on 121.5 MHz are useful only for informing people monitoring that frequency that there may be an airplane crashed in their approximate vicinity. Or maybe just a faulty microwave oven.

Embedding this video seems to crash some people's browsers, so click the check mark in the two-line table on this page.

The unchanged law wasn't an oversight. It was supposed to change years ago, calling for the minimum legal ELTs to transmit on 406. There were handbills and videos and stickers and probably mousepads and t-shirts too, all promoting the new standard. But there affordable general aviation ELTs didn't exist. Canadian advocacy groups said, "Hey, wait, these exceed 20% of the cost of some of our members' airplanes!" Transport Canada funded a 2008 study into reducing the cost of 406 MHz ELTs. Aviation supplies are expensive enough to start with, but usually Canadians can rely on getting the best possible prices as a result of the competitive American market. There are so many GA pilots in the US, that anything they want to buy is available from multiple competing suppliers and innovation plus economies of scale bring the price down. But in this case Canada was mandating equipment that was not required by and was not particularly useful to most US pilots. Alaska is like most of Canada, but flying in the rest of the US being out of radar contact while enroute is so rare that the controllers point it out to you with some concern. Not only were the Americans not going to sell us cheap ELTs, but they were opposed to the regulation.

This US pilot group discussion typifies their concerns, back when Feb 2009 was the deadline. US pilots have three understandable objections.

  • They don't want to buy 406 MHz ELTs just to legally cross the border, but the regulation effectively imposes a three thousand dollar per aircraft fee for operating in Canada.
  • The discussion demonstrates a national difference in philosophy with "If I waive Search and Rescue service, I shouldn't have to pay for an ELT." I think this is likely the same difference that makes people on opposite sides of the border feel differently about government-funded healthcare. Canadian SAR looks for everyone who is known to be missing, no matter how poorly prepared they are, so we don't consider it out of line to require a level of preparation that will save all taxpayers a lot of money on UNSAR. And of course Americans can't be expected to care about Canadian taxes.
  • The pilots believe that having flown in the US, which is itself huge and has some areas of low population density, that they understand the barrenness of Canada. The latter has less than a tenth of the average population density of the former, and the population we do have is more asymmetrically distributed.

Government kept pushing the effective date of the new regulation forward into the future. A requirement to carry a 406 MHz ELT is still not in the current rules. They haven't forgotten about it, but it's dropped off the front page. The only FAQ question about ELTs on the TC site is about the angle you can put the antenna on, on a helicopter. It's still pending.

Meanwhile there's nothing to prevent Canadians from replacing the old ELTs with modern units that broadcast on 121.5 and 406 MHz. Relying on the 121.5 broadcast means hoping that someone hears it and can home in on it by reports of where the signal is audible at what strength.

ELT signal from inside cat

Monday, March 08, 2010

Tie-Downs

When you put cargo in an airplane, it needs to be tied down. Not so much so it doesn't fall over and break, but so that it doesn't move around and kill you, either by falling on you or by shifting the centre of gravity such that the airplane becomes unflyable. And kill you. Securing the load in an airplane is important.

When the load is people, the tiedowns are called seatbelts. Often the tiedowns are seatbelts when the load is not people, too, because seatbelts are easy to fasten, easy to adjust and certified for holding objects upwards of 200lbs in place. Humans don't usually have 90 degree edges on them, and objects don't usually have waists, so using seatbelts is discouraged for non-human objects. If your load consists entirely of non-human objects, then the seats and attached seatbelts can be removed from the equation (and airplane) entirely and dumped in the back of the hangar before the cargo is loaded and secured to tie-down rings.

A removable cargo tie-down ring consists of a square of metal with a ring attached to the top. It's about the size of a stack of seven saltine crackers, with a ritz cracker balanced edgewise on top. There's a channel in the bottom of the metal square so that it can slide onto the same rail that an aircraft seat attaches to, and a thumbscrew on the side to secure it in position once it has been slid to the desired location. Each tie-down ring, of course, costs over $200, about ten times more than a piece of metal with a ring and a thumbscrew on it ought to.

The law of tie-down rings is that there are never enough. One reason that there are never enough stems from the fact that there are often not enough, so captains learn to hoard them in their flight bags, exacerbating the shortage, and thus the hoarding. But even if you have a whole flight bag full of tie-down rings, you still can't secure your cargo properly because you can't put them in the right places.

You can only put the removable ones where there are seat rails. In other places you have to rely on the ones the manufacturer provided. You're lucky if there are any tie-down rings installed in the cargo compartment. I have worked with people who have resorted to the "pack it so tightly it can't shift" method. I suppose if you have literally packed the aircraft floor to ceiling with similar density cargo, and there is protection to prevent them from entering the cockpit, and you have forward emergency exits, you're covered, but just packing things in the rear cargo tightly enough that they are hard to remove won't cut it. Normal vibration or abnormal deceleration could still bring them down on top of you.

You have to plan the packing so you get the tie-down straps hooked into the tie-down rings before you bury them in cargo, and then just tighten everything down. The ratcheting cargo straps are nice, but I hate it when they get all jammed up in the reel.

Once I worked at a place that had truly awesome cargo nets that secured into custom recessed ports all around the inside of the cargo space. One airplane still had mismatched parts on the empennage from repairs following a years-ago towing accident, but the customers were safe from their cargo and the pilots could work efficiently. Rare that a company gets that priority right.

Saturday, March 06, 2010

Kicking It

I started this post when I ran into this quotation.

"I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times."
— Bruce Lee

Commenter Frank Van Haste added this one.

"...there's them that's flown a thousand hours, and there's them that's flown the same hour a thousand times."

It's two different points. The first is that you have to focus, perfect one thing, gain complete mastery over your muscles, mind and reflexes. Continue consistent practice until you get it right. It refers to practice, training, which is what I'm doing when I hack at my flight simulator game.

The second is about breadth of experience. Different conditions, different aircraft, different crews, different places, different mindset, always adding what you learned last time to the new experience. And there's something I've found in aviation, that every thousand hours or so, something happens. Inadvertent IMC, engine failure, smoke monster*, icing, or something you thought you had mastered long ago that suddenly rears its head and becomes an issue again.

I don't think I've practiced ten thousand approaches yet, either different or the same, but I keep practicing.

*My affectionate thanks to everyone who has been with me long enough to know I'm not talking about Lost.

Thursday, March 04, 2010

Ominous Signs

I probably blogged about this the first time I installed iTunes, but it makes me laugh every single time I see it.

THE APPLE SOFTWARE IS NOT INTENDED FOR USE IN THE OPERATION OF NUCLEAR FACILITIES, AIRCRAFT NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL SYSTEMS, LIFE SUPPORT MACHINES OR OTHER EQUIPMENT IN WHICH THE FAILURE OF THE APPLE SOFTWARE COULD LEAD TO DEATH, PERSONAL INJURY, OR SEVERE PHYSICAL OR ENVIRONMENTAL DAMAGE.

Is there some way you can use Abba tunes to calculate an air position? Is there a way to stay on glideslope using country western lyrics? Is there some method of cross-connecting my iPod to the autopilot that will steer me clear of the Danger Zone? Should I turn off the iPod before making a course correction? I was given a POH to study once and the very first page of the manual, before the title page and the table of contents, the very first page warned me in all capital letters that I was never to put the propellers into reverse while in the air. The position and strictness of the warning told me immediately that (a) this has already had disasterous consequences, (b) quite a lot of people did it, so it must be pretty cool.

I'm clearly missing some vital function of the iPod shuffle, considering that I merely use it to listen to music during quiet moments. I hope it's okay with Apple that I sometimes listen to my music while navigating?

Also, message to iTunes: contrary to what you think, it's not all about you. You can stop putting up a "what should I do about this?" box every time I insert a CD ROM or add a peripheral. Your purpose on my computer is to manage songs on my iPod. You are not the operating system.

And I think it's lame that the iPod Touch has a whole app for managing YouTube videos, but all it does is bookmark them and play them back. What's the point if I can't save them to watch when I don't have an Internet connection? The Kindle is pretty cool, but I'm disturbed by the whole shift in the way published content is meted out to the consumer. Whole cultures have survived attempts at extermination because they preserved and hid their literature, in tangible printed form. Centralized control over access and content of publications is too 1984 for me. I don't want a corporation to decide for me that something is no longer worth reading or listening to; I don't want a seriously compromised server to wipe out a decade of literature; and I don't want governments to have a means of determining who is reading what. Whether or not they are using it for navigational purposes.

Tuesday, March 02, 2010

Runway 88

Recently I learned an air traffic control code that hadn't known before. I saw some movement statistics for an airport that included the column "Runway 88." This looks as odd to a pilot as a reference to the 21st hole would to a golfer. (Cue eleven readers telling me that some golf courses go past eighteen holes). Runway numbers correspond to the hundreds and tens digits of the bearing you are on while on or lined up for that runway. There is no compass bearing of 880 degrees, so what was this runway?

I knew they weren't keeping statistics on bar attendance, a la the 19th hole of a golf course, so I checked and found that Runway 88 is the designation for an aircraft just passing through a control zone, but not landing at the airport there. You might pass through if the weather is too poor to go above, or if you've just taken off from another nearby airport and haven't had a chance to climb above this control zone through yet.

Does anyone know how universal that code is, or if there are any more like that? Perhaps air traffic controllers have a black humour that includes a runway designation for runway excursions, or a speculative destination for pilots who don't appear to have it sufficiently together to make it to their filed destination. Probably not, but it amuses me to think of a controller tagging someone up as "runway 73" as a message to her colleague.