Showing posts with label ICAO. Show all posts
Showing posts with label ICAO. Show all posts

Tuesday, March 31, 2015

The AOPA Is On Board! (finally)

The FAA wants to move forward. On October 1, the FAA wants to move forward with the flight plan form change for everyone. The airlines have mostly moved forward to use only the ICAO format since about 2008, for all flights.



Today the AOPA agreed that maybe it is time to retire that old friend 7233-1. Yes, that is the old flight plan form that we all grew up with (unless you are in another country, or went straight to a major Airline from a good flight school). You may even send AOPA your comments: airtrafficservices@aopa.org

The Association has a quick video about the changes.

http://www.aopa.org/News-and-Video/All-News/2015/March/26/Changes-to-Flight-Services-planned


It is no secret that I have been trying to get rid of the 7233 form. The ICAO for, looks intimidating, but is really simple once you look at it. Everything before the "FPL" is not needed and everything after field 18 is optional. The stuff translates pretty well, starting in field 7, aircraft ID is either the N number or the flight number that the ATC will know the aircraft as. Field 8 is the flight rules and type, IFR or VFR, just put an "I" or a "V" in the box, the type is GA (G), Military (M), Scheduled (S), Non-scheduled (N) and Other (X). Field 9 is the number, type and wake turbulence class, put more than 1 if this plan is for a group of aircraft, the type is C172, A36, or whatever your aircraft type is per ICAO 8643, and the wake turbulence is Heavy, Medium or Light depending on aircraft weight.

Field 10 is the big winner in this form. What does a /U represent on the old 7233-1 form? Well field 10 there is no guessing. The equipment you want to use on this flight can be specified here, in all it's glory. Got a VHF comm radio, put a V there. Have a VOR Nav radio, put in a O (vOr), how ab out GPS, put in a G.  If your aircraft has CPDLC use a J with some numbers depending on your type to put here, Mostly, the letters for the common stuff are:


  • A - GPS Landing system
  • F - ADF
  • G - GPS (or other global navigation system)
  • H - HF radio 
  • I - Inertial Navigation
  • L - ILS
  • O - VOR
  • P - Performance Based Navigation (can include various RNAV equipment see FAA Doc 9613)
  • V - VHF radio (12kHz spacing)
  • W - RVSM

Field 10 also includes the type of transponder the aircraft will use. The common values are:

A - Mode A only (squawk code only)
C - Mode A/C (altitude encoding)
E - Mode S with extended squitter (ADS-B)
S - Mode S with altitude and aircraft ID
N - No transponder

There is no field 11, 12 or 14, so there is even less to fill out!

Field 13 is where the flight originated from, all four letters/numbers ICAO format (IE KORD) and time in UTC.
Field 15  Cruise Speed, Level and Route. This is probably the most flexible part, especially the route.
The cruise speed is the cruise speed the aircraft will initially be flying at once at cruise altitude. The Level is the altitude the aircraft will fly at, preceded by the type of information. For flight levels, use an F and the flight level (IE for flight level 180, put F180), or for hundreds of feet use an A followed by the feet (IE for 8500 feet, use A085). The route will be all the waypoints between the departure airport and the destination airport. These waypoints can be specific named waypoints (IE MINEE), lat/lon coordinates (IE 46 degrees 20 minutes N 78 degrees 5 minutes west would be specified as 4620N07805W), or fix radial distance (FRD) coordinates (IE 30 miles south of the Kankakee IL VOR would be specified IKK18030).

Field 16 is the destination, the Estimated Enroute Time (not the arrival time) and the first and second alternates if needed. If it will take 2.5 hours to get to Oshkosh, field 16 will be KOSH0230, if you need to use Milwaukee for an alternate, then the field 16 is KOSH0230 KMKE.

There is no field 17 either, so there is even less to fill out.

Field 18 is labeled "Other Information" which seems casual, but it is really formatted other information. I hinted that if in field 10 the aircraft is RNAV capable a note can be added to field 18 to tell the ATC what kind of approach you may want, as in: NAV/RNVD2 to use a GPS receiver to do a 1 mile approach. (RNP will take specific pilot training). If you just want a note to be put on the flight plan, the RMK/ can be used followed by the text of the message. Other specific field 18 values are:


  • HAZMAT: For a flight carrying hazardous material;
  • HOSP: For a medical flight declared by medical authorities
  • MEDEVAC: For a life critical medical emergency evacuation
  • SAR: For a flight engaged in a search and rescue mission

The one place that gets ugly is the ADS-B specifications. If the aircraft ADS-B installation is DO-260B then the field 18 must contain SUR/260B or if the ADS-B installation is DO-282B compliant then SUR/282B should be specified in field 18, (DO-260B is the specification for a Mode S transponder with Extended Squitter or 1090ES, DO-282B is the specification for UAT radios). I hope that clears that mess up.

An example field 18 can look something like:

   SAR NAV/RNVD2 SUR/282B RMK/Aint we got fun

That would be a search and rescue flight with GPS capable of RNAV 1, using ADS/B UAT radio, telling the controller we might be having fun.

Are we ready for fall? That is when this all will be happening.

Thursday, November 7, 2013

CPDLC - Texting For Pilots

Texting and driving is against the law. Texting and flying, no problem. 

Ok, we aren't talking about your family  asking you to stop by the grocery store pickup some milk on the way home. On most commercial aircraft there is a text based communications system. This is usually the ACARS system, the Aircraft Communications And Reporting System. This display and keyboard is right there usually in the panel, and encouraged to be used in flight.

The ACARS communications start early in the flight. Most airlines participate in the Pre-Departure Clearance (PDC) program where the pilots get the clearance right from the tower on the ACARS screen. The pilot is required to request the clearance before the flight, and the tower will automatically deliver the clearance to the screen.

The ACARS system is also connected to the aircraft maintenance department. The engine and other parts of the aircraft are connected to the computers that are connected to the ACARS system. When the aircraft is in a certain state, an automated message will be delivered to the ground. Engine status will be delivered when the aircraft is in cruise state, and not accelerating (stable cruise report). On ground time will be delivered when the aircraft has main gear down.

Recently, ICAO has standardized the phraseology and the FAA have started delivering ATC messages to the cockpit. The messaging is called Controller Pilot Data Link Communications (CPDLC).  There are some limitations to these messages, generally they will be standard communications. Things like "turn left heading 240 degrees", or "climb and maintain 360". These are normal mundane type messages that the controllers say everyday over and over. The ATC screen has templates of these standard messages, where the controller only need to enter the heading and altitude.

The messages must be acknowledged, or they will be assumed to not be received. The pilot can acknowledge the message or say unable. The controller has the option of using the voice to find out more, or offer a better different message.

There is a huge misnomer, Air Traffic Controllers don't actually control aircraft. The controllers offer suggestions to pilots. Pilots can always do what is needed to operate the aircraft safely, regardless of what the controllers are telling them to do. Normally following the controllers directions will be the safest thing to do, but there is always the option.

The ICAO 4444 document Procedures for Air Navigation Services Air Traffic Management has a chapter on the CPDLC messaging.

    CHAPTER 14. CONTROLLER-PILOT DATA LINK COMMUNICATIONS (CPDLC).


There is another document 9694 Manual of Air Traffic Services Data Link
Applications
that has additional guidance. These CPDLC messages have various levels of urgency, and alerts, and are outlined better in these two manuals.

There is a fear that using CPDLC will prevent pilots from eavesdropping on other pilots. There is a possibility that may occur. CPDLC message are addressed to a specific aircraft, and to a specific ATC center. Normally, when ATC is talking (using voice communications) to the aircraft in an area, they talk on the one frequency that all aircraft can hear. The benefit to that is that if aircraft are near each other, and a command will make another pilot question the intention, the eaves dropping pilot can ask for clarity. Sometimes controllers make mistakes, and pilots can ask. If someone is put on the same altitude and opposite course as another aircraft, the pilot not getting the command make question the controller. With CPDLC addressed messages, other aircraft cannot "hear" those commands.

Mostly the CPDLC systems are in use in the oceanic realm. There is quite a bit of separation going on in that area, and communications has been poor over the ocean. In the past, the oceanic communications, has been over HF voice channel. CPDLC has actually improved the performance of the communication over the ocean.

Long term, some CPDLC messaging will be added to the enroute area. Perhaps to a limited extent, the TRACON will start to get some CPDLC messaging.

Friday, June 28, 2013

DME's

Distance Measuring Equipment (DME) what is it and how does it work? Most large aircraft and some smaller aircraft have DME equipment. It seems to be so easy to use, and when it is there, we just tune to a frequency, and it tells us how far away you are from that station.

The simplest explanation is that the DME box is a transceiver that has a computer in it. The transmitter part sends a signal out to a ground station, usually co-located with a VOR. The ground station then will send a signal back to the DME receiver on the aircraft. The time between the signal being sent, and the return signal being received will be computed by the computer, and converted into miles.

The DME signal isn't actually on the frequency that you tune into. The VOR frequencies and the DME frequencies are paired. The pairing is outlined in the AIM, and other documents. A VOR on 111.0 will be paired with a DME on channel 47 (Aircraft Transmits on 1072MHz, Ground transmits on 1009MHz). The channel concept helps us think about the transmit/receive frequencies.

Each DME transceiver sends a unique set of pulses. The ground station sends the same set of pulses back. If their are several aircraft near the same DME ground station, the aircraft only will do timings on the signal with the matching pulses. The aircraft transmitter will listen for quiet time before transmitting to prevent signals colliding. Most ground stations are capable of servicing about 100 unique aircraft at a time.

The distance measured will be straight line. That means, that if an aircraft is flying at about 10000ft straight over the top of the DME ground station, the DME indicator will read 2miles, not 0. The DME system will try to maintain about a quarter mile, per ICAO requirements. The system will include the ground station and the aircraft equipment.

Some of the RNAV and RNP requirements can be met by using two DME systems along with the inertial reference unit (IRU). Approach plates will sometimes be labeled DME/DME/IRU as needed to meet the requirements of the approach.

GPS is making some of the DME capabilities obsolete. Will the FAA begin decommissioning them any time soon? Probably not. Aircraft upgrades are expensive, and the DME systems are quite reliable, and low maintenance. Potentially when all aircraft are equipped with GPS will the FAA consider removing DMEs from the NAS.

Is this helpful?


Sunday, May 19, 2013

ICAO vs. 7233-1


We all grew up using the plain old FAA flight plan form (7233-1) that was in the AIM or in the manual we got in ground school. It is the information that the FAA says we need in the order they want it right?
Yes, it is still in the AIM, and it will allow us to get flight following, and all kinds of services. It works in the US.

The 7233 form is in need of updates. This form will still let the FAA know if you have a LORAN equipped aircraft, just use the /I, /C, or /Y. The current set of suffix codes allows the controllers to know if the aircraft is RNP capable, using the /R suffix, but doesn't show how the aircraft meets the requirements, of if the aircraft is RNP10, RNP4 or RNP0.1.

How about that fancy question regarding equipment? If the aircraft GPS equipped, a /G should be filed, or still and older plane with only an ILS and DME, what should be filed. The FAA has plans to change many of the equipment suffix codes August 2013. Mostly the FAA isn't going to care about any performance based navigation (PBN) using the 7233 form. Most of the changes only affect aircraft in the flight levels, that are RVSM capable. The big changes are:

All Mode C transponders (at least, including mode S)
  • /Q - RNP (obsolete)
  • /W - RVSM no RNAV (no change)
  • /Z - RVSM and RNAV with no GNSS (new)
  • /L - RVSM GNSS (any GNSS capability is new)
  • /J - RVSM DME/DME/IRU (obsolete, similar to /W)
  • /K - RVSM FMS with DME (obsolete, similar to /W)

The reality is, and the FAA folks in the know will tell you this, the time has come to retire this old friend. Controllers are like pilots, they grew up on this format, and their flight strips will still use some of this format for a couple years, but mostly, they are being trained on something else.

ICAO form

If you have ever flow to Mexico or Canada you probably had to fill out the ICAO flight plan. Canada calls it the Nav Canada form. It looks intimidating, but it leaves a lot of the guess work out of the above form.


Everything before the "FPL" is not needed. There are links to various instructions for filling out this form. Everything after the remarks (Item 18) is optional. The ICAO has a document 4444 "Rules of the Air and Air Traffic Services" about 4000 pages similar to the FAA AIM for both ATC and pilots. Appendixes 2 and 3 cover the flight plan form, and what text to put where. If the above links are followed the form is easy to deal with. 

The big advantage to using this form is specifying your equipment. If your aircraft has at least one Com radio you put in a V (VHF Radio Telephone), if you have a DME, you put a D, if you can fly in RVSM airspace you put in a W. The suffix is either a C for a mode C transponder, S for mode S transponder or an N for no transponder. Then the suffix beyond that would be for ADS/B. PBN levels can be specified using the R in field 10, but the PBN details must be entered in field 18.


You get to tell the FAA exactly what equipment you want to use for your flight, without interpretation and the FAA will pay attention, and let you use it.

That does mean the air traffic controller may put an aircraft on a GPS approach without asking. That should be a good thing, since it is a little more efficient. You can negotiate the ILS or VOR approach if you prefer still. The ATC computers are reading the flight plan, and offering controllers the most efficient reroute based on capabilities specified.

Going Forward


To start using the ICAO flight plan, most of the flight plan filing services will offer ICAO plans is specified. Select that option, and fill out the plan as before. Specific details for the aircraft will need to be specified when setting up the aircraft, but once set, they will continue to be used for plans going forward.

It would be good it the FAA quit publishing the 7233 form, but that doesn't seem to be in the cards any time soon. There are many publications that still refer to the 7233 form, and they also will need to be changed. We are well past the transition phase, most of the FAA employees are familiar with the ICAO form, and are capable of processing instructions in ICAO format.