jackal

FlyerTalker AlaskaCoho, one of Alaska's finest, recently expressed his willingness to answer questions we might have about the thing we FlyerTalkers love most: flying!

As someone who has followed the United Pilot Q&A Thread with great interest (I definitely recommend checking it--all 2,120 posts to date--out!), I thought it might be fun to have our own little homegrown area to ask questions, especially since flying for AS and in Alaska presents unique challenges. Therefore, with the blessing of the AS forum moderating team and the cooperation of AlaskaCoho, I present to you the Alaska Pilot Q&A Thread!

So a big thanks again to AlaskaCoho for his willingness to share his valuable time. If any other AS pilots would like to give their perspective, too, by all means, go for it!

jackal

I'll start with the first question:

I took some flying lessons up here at UAA, which was one of the original organizations involved with the Capstone program (others included the FAA and UPS Aviation Technologies). From what I remember them talking about and from a bit of reading I've done, Capstone basically took GPS and ADS-B and integrated them with a MFD displaying moving map/terrain information and in-cockpit weather information to give pilots additional situation awareness, helping to prevent traffic collisions and CFIT. That was Phase I, which was deployed (with much success) in the Lower Kuskokwim region of Alaska (Bethel).

Capstone Phase II took Phase I and added GPS-WAAS (for more accurate position information) and synthetic vision system, which took the 2D MFD and turned it into a 3D "flight simulator"-style display, in effect showing what the terrain ahead looks like regardless of the weather conditions.

After Phase II, news about the program died down--most of the available information about it was updated on UAA's and the FAA's Web sites in 2007.

Then I heard that Alaska was instituting "RNP" in the area that Capstone Phase II had been deployed in, and I began to wonder if there was a link between the two. I have yet to come up with a straight answer about what exactly RNP is, and this seems like the perfect place to ask such a question.

So, what is RNP?

Most definitions I find online seem to discuss it on a conceptual level in that it's basically a standard dictating the tolerance for non-ground-based navigation (i.e. GNSS). I'm interested in that, but I'm also interested in what it looks like in the cockpit. Are there new avionics (MFDs with moving maps and/or synthetic vision, like in Capstone Phase II, or HUDs that display tracks in the sky)? How are procedures different from non-RNP IFR flying?

Oh, and how does cat IIIC ILS figure in to all of this? Are AS's aircraft equipped with cat IIIC receivers? Does AS fly into any cat IIIC-equipped airports (with current procedures)? Have you ever landed in literally 0 visability? Does RNP replace or complement cat IIIC ? (I'm not sure it completely replaces it, since the minimums at JNU with RNP are still a 337-foot ceiling and one mile of visibility, from one article I read--but I'm not sure how to interpret this, hence why I'm asking here!)

OK, so that's one heck of a question to start off with. Hope it stimulates this thread, though!

Thanks again, AlaskaCoho, for your time!

dave1013

While we're waiting for AlaskaCoho's reply, here's some light reading on the US standard for RNP. It doesn't have MFD graphics but does contain some interesting technical info.

The ability to execute a Cat III (and Cat II, for that matter) procedure depends on several factors, including runway lighting and marking, approach lighting systems, standby power availability, etc. Some airports that may have the nav capability might lack these supporting features. You have to have the whole enchilada.

tony2x

Ok so my question is not so technical but does require first hand experience of flying up front.

Are there any appreciable differences in flying the different 737 variants that AS use? My dad was a bus driver and he had his favourite buses, even down to individual examples in a particular fleet. In fact I still have the front licence plate to one of his favourites that we rescued before it was taken off to scrap.

Are the NG 737s (7/8/900) preferred to the Classic 734s?

ANC

Ive noticed a big difference between minimum approach audios vary from aircraft to aircraft. Some start at 1000 then 500 300 ...200...100..50..40..30...20..10

While another might not start until 300 and skip 200 then go to 100...50...40...30....20..10

Others start the count at 500

My question is Does each airline establish their own minimum countdown? is it Airport specific? or does an A/C type come from the factory with specific hard wired minimums?

AlaskaCoho

To understand RNP we need to first talk about basic instrument flight. Since the 50s the standard instrument navigation, that is navigation by reference to instruments only has been conducted using ground based radio beacons called VOR, VORTAC, TACAN and NDB. Instrument approaches to airports were also conducted using these navaids and one additional navaid call the ILS. If you don't know what they are; well it’s not important for this discussion. Extended overwater navigation was conducted with LORAN and believe it or not up until the 70s with celestial navigation. In the 70s INS (Inertial Navigation System) navigation came into wide use. An INS is a navigation aid that uses a computer and motion sensors (accelerometers) to continuously calculate via dead reckoning the position, orientation, and velocity (direction and speed of movement) of a moving object without the need for external references. So for you pilots it’s a gyroscope or a combonation of 2 or 3 of them hooked to a computer commonly called a FMS or flight mangement system. INS navigation ushered in the age of RNAV or Area Navigation by use of onboard computer systems. Initially it was accomplished with INS. RNAV brought important capabilities to aviation navigation. RNAV aircraft can fly directly between waypoints rather than flying to/from ground-based radio beacons or relying on vectors from air traffic control. Maneuvering directly to distant waypoints rather than zigzagging over a scattered course of ground-based radio beacons significantly improves efficiency. So eventually this technology moved from oceanic navigation to navigation over the land as well.
RNP can be seen as the evolution of RNAV. It increases the precision of aircraft position using GPS. Now in addition to the INS feeding information to the FMS you have a GPS unit feeding position updates to the computer. It allows aircraft to stay on track using direct legs from even longer point to point legs and calculates turn radius from point to point for detailed flight navigation. Rather than having to monitor radio aids to see if they go off the air this combination of computer, gyro, and GPS monitors actual navigation performance and alerts the crew if tolerances are exceeded.

Now as I said RNP was originally developed for use by aircraft flying transoceanic routes where ground-based navigation aids are not available. Without radar or radio beacons, aircraft flying over oceans are required to meet specific navigation performance (ergo the name Required Navigation Performance, RNP) criteria to ensure that they do not conflict with one another. For example, operating RNP-10 requires that an aircraft establish with a high degree of certainty its location within 10 nautical miles.

Steve Fulton, a pilot at Alaska Airlines who used to work for Honeywell, realized that the airline could solve operational difficulties it was having in Juneau, Alaska using a more precise form of RNP. It was not uncommon for 10% of the airline's flights there to be diverted due to the mountainous terrain and poor weather. Fulton developed a procedure that began with Alaska aircraft using multiple GPS units in the same aircraft to establish their location with a high degree of accuracy. It also included the addition of enhanced GPWS (Ground Proximity Warning System) installation on all of our aircraft. EGPWS loaded a ground map of the entire globe into the aircraft’s computer. With certainty of location, the Alaska aircraft could follow narrow, pre-programmed paths between mountains in good weather or bad. In addition to guiding planes toward the runway, RNP procedures included terrain-avoiding directions away from the airport in case of a missed approach or for departures. Alaska's first landing using RNP occurred in 1996 at Juneau, Alaska. Alaska was the first airline to be certified to use RNP for approaches and departures, the first to train all there pilots to use the system and is using the system more widely than any other airline.

OK now I forgot the question. I’ll post this basic RNP 101 and use it to answer the rest of the questions.

AlaskaCoho

RNP and Capstone are two different animals. There is no connection at all. I have described RNP in my post RNP 101. Capstone is an avionics package added to aircraft that includes IFR capable global positioning system (GPS) receivers, a Universal Access Transceiver (UAT) data-link system that enables Automatic Dependent Surveillance-Broadcast (ADS-B) and Flight Information Services (FIS) including real-time weather, and a multifunction display (MFD) depicting terrain, other ADS-B aircraft, and weather graphics and text data. In phase I the FAA installed the package at no cost to 200 commercial light aircraft in and near Bethel as a test. In Phase 11 they will be installing the package in more aircraft, adding runway incursion warning software, adding the use of WAAS (ground based transmitters that increase GPS accuracy) and adding SE Alaska to the area of operation.

With Capstone the FAA hopes to reduce CFIT in remote areas of Alaska that do not have radar coverage. Since ATC can not see aircraft, Capstone aircraft send their position to ATC via the UAT datalink system using HF radio freq. ANC ARTCC then has equipment to receive the information and display it just like the aircraft were in radar contact. Using this system the aircraft can be afforded IFR service. In addition to this service, aircraft have the moving map displays and terrain depictions so they can operate with greater knowledge of the terrain.

The displays in these aircraft are a generation more advanced actually than the displays in Alaska's RNP equipped 737. The 737 displays a two dimensional magenta brick road. We can put waypoints, navaids and airports on the "Map". Terrain is depicted in shades of green, yellow and red similar to weather on radar. Capstone depictions resemble synthetic vision.

AlaskaCoho

Whew! OK lets talk ILS now. Again ILS and RNP have no connection to each other. See RNP 101. The ILS is back to the 1950s radio transmitter positioned in this case at the end of a runway to provide very precise nav info to receivers in the aircraft. ILS Cat IIIB is the lowest that Alaska is certified to do. The difference is with C its zero visibility and a blind landing. Aircraft need rollout guidance to perform this approach. Cat B takes us to 600 feet vis, the Captain clicks off the autopilot on landing and performs the rollout on the runway the old fashion way.

Don't quote me on this but I think the FAA TERPS for RNP is a min of 350 feet ceiling and enough vis to see the runway. Each approach may have different min's based on terrain. But the min the FAA will allow is 350 ceiling using the RNP. JNU RWY 26 runway touchdown altitude is around 26 feet so the RNP min of 376. I can’t remember the exact number and I don't have my Jepps at home.

ILS mins are based on visibility not ceiling. ILS Cat I is 1800 feet vis down the runway no ceiling req. Cat II is down to 1200. Cat III is below 1200 with B down to 600 feet and C zero zero.

I have flown about 10 or 12 actual 600 foot approaches, ahh with an airline... All Alaska pilots (I know from some reliable information) practice Zero Zero in the simulator each year during training. So in a pinch we…ahh they could do it.

The only time I flew zero zero was in the Air Force and I didn't want to, I was crying the whole way down. Very few airlines do IIIC since it costs so much to keep the aircraft certified.

jackal

Ah, interesting!

From my reading of your posts, it seems that Capstone seems to take some of the features of RNP (ground proximity warning, etc.) and build on them but without the strict reliability requirements RNP includes (I seem to recall reading something about RNP 0.3--which, as you inferred, would require a high degree of location certainty within 0.3 NM).

Does Capstone allow for precision approaches and reduced minimums? Or is it strictly an avionics package that assists with situational awareness and allows for IFR separation in an en-route environment where there is no radar coverage (i.e. below the MEAs, which, IIRC, are instituted to ensure adequate radar coverage), and approaches are still in effect GPS non-precision approaches?

If that's the case, then it appears they're perhaps targeted at different types of flying. Still, are there aspects of Capstone that would be useful for the kind of flying AS does? Does AS have any plans to outfit their aircraft with Capstone avionics or systems providing equivalent functionality?

AlaskaCoho

Well according to the FAA all the 737's fly the same so when a pilot is type rated on the 737 he/she is technically qualified to fly them all. However they do fly differently.

Most of us like to fly the NGs not so much because of the flying qualities but because of the layout of the controls and avionics in the cockpit. Hey and they have two cup holders two!!! Not too many of us like the 900 since it is so darn long it takes extra care in landing and takeoff to prevent a tail strike. I've never had one but they do occur. 900 performance is always an issue in the summer it seems.

The 400s have a different landing gear. They castor so you can land them with a bit more of a crosswind and the gear will actually spin to align with the runway. They have a softer gear too so the landing can be a bit harder without anyone noticing. The NGs gear is stiffer and won't castor so till guys got used to them we had a few harder landings.

The 200s before they left were really the sports car equivalent if you could image that. They rolled and pitched fast and had tighter control from the yoke. And man could they stop with clam shell reversers.

Without a doubt the 800s are the favorite now, they fly nice and they can go forever on a tank of gas.

Finally there are tail numbers we like and don't. Not really for anything important. The older ones are, well they take more MX to keep up.

AlaskaCoho

Humm well Alaska Jets the 737-400 and NGs only have two callouts. They all just call out "Minimums" at a pre-selected altitude we select prior to the approach. Some of the newer 800s also have a 500 foot call.

You may be talking about some of Horizons Dash 8s. I haven't flown them so I don't know which ones you may be talking about.

When an aircraft is certified by the FAA it has a preset call out list if you will. So each type of aircraft will have the same callout regardless of the airline. The only variable is what avionics package the airline bought. Some airlines flying aircraft will buy a lesser package to save money and they may not have the same callouts another has with the full blown CatIII aircraft. In other words All Dash 8s have the capability of calling out altitudes but some airlines disable them or don't buy them if they don't fly the aircraft in weather that requires it. If the callouts are activated they will be the same between all airlines flying that type aircraft.


OK Uncle for the night. I've got to go. Have a good one all and I'll try to get back here again tomorrow. Adieos

AlaskaCoho

No Capstone does not provide for reduced approach min or actually approaches at all. It is limited to one GPS so they can perform a public GPS approach but not RNP. Remember RNP also takes pilot certification as well as approach certification. So not just any pilot may perform an RNP approach like only certified pilots may do CatIII approaches. Capstone is designed really for enroute ops and enhanced situational awareness plus the ability for ATC to provide basic IFR service. Normally they would transition to the good old VOR or ILS approach if needed. RNP is much more accurate using multiple GPS and INS systems to very accurately determine position.

The only interface between the two for Alaska is that because they send their position via data link, Capstone aircraft will have TCAS so we will be able to see them. TCAS is a aircraft to aircraft collision avoidance system. Alaska jets have it but most aircraft flying in non radar areas of Alaska don't install a transponder. Without the transponder we can't see them on TCAS. Since Capstone equipped aircraft will now have this equipment even in non radar areas Alaska jets will be able to see the other aircraft now just like in the lower 48.

jackal

No worries--thanks again for your time! We do sincerely appreciate it!

(And in case it missed your eyes because I submitted it while you were typing another post, I did post a follow-up question about Capstone in post #9 up above... )

AlaskaCoho

Nothing misses the watchful eye of a trained professional. Answered it above. except maybe the spouse induced chore list around home!

beckoa

Wow... what a great thread, and awesome detail. Thanks AlaskaCoho^

Now for an easy question... and its lunchtime so somewhat appropriate...

I was watching a discovery channel show on how airline meals are made, and it was mentioned that the FO and Captain get different meals in case one has food poisoning. Is this SOP on AS? And, what do you guys eat? I've always wondered... and then of course, your favorite meal