Airbus Questions

[Trader]

Just wondering how some other companies handle their approaches:

1. For non-precision appr. we select a FPA according to the Jepp charts we use. Of course, Jepp doesn't provide FPA for every approach and so we have to pull out our calculators and use the gradient to calculate FPA!!! Anyway, we then proceed to fly the app in managed nav but selected vertical. Does anyone out there fly these approaches is managed vertical? Are there specific requirements to do so (e. I assume database requirements etc exist to do so)?

2. Using FPA you really have little idea as to the distance from threshold you will be upon reachig the VDP-at least not without some manual calculation. You only know that you cross the threshold at 50' (unless another alt is required by the governing authority). In fact, I would even think that it is possible to follow a constant descent path and reach the VDP BEFORE you have the required visual distance to see the runway/app lights (ie. before the MAP on a non-prec which is usually the runway)!!?? Is there an easy way to calculate that or am I missing something (again using Jepp plates--those AC plates sure were nice looking back now).

[J.O.]

Hi Trader.

At Skyservice, we fly fully managed NPAs and have for some time (provided that all of the FCOM stipulations are met). For those approaches where we cannot use fully managed guidance, we have a table which gives a flight path angle for the distance / height combination for the approach.

As to your second question, you may be over-thinking it just a bit. Ceiling and visibility limits for a straight-in approach are normally based upon the assumption that if you see the runway environment at the decision altitude, you should be able to continue to land without any major variation from a normal descent profile. It is unlikely that you would veer see an approach with a 1/2 mile visibility limit combined with a 600 ft ceiling limit, since it would be very difficult to make it to the runway from 600 ft when you're only 1/2 mile from the threshold.

If you'd like more info on the FPA table, send me a PM.

Jeff

[Trader]

Thanks Jeff, you're right I got a bit to into for the second question

We do have, for some approaches, a FPA presented on the Jepp chart as well as the alt vs. dist crosscheck chart. I assume you have a different table for such approaches.

On the 330 we don't do many NPA's (have only completed a few for practice/training) but the 320 could benefit from the ability to fly the managed profile. Now I'll have to find out why we don't!!!

Cheers,

Matt

PM on the way

[Guest long keel]

AC has provided us with an extra page with all the FPA's for each airport. It is an AC only page inserted just after the r/way diagram. It also lists the TOCA's, and company frequencies.

Can't say these Jeps are an improvement. It is sad that we let good Canadian jobs disappear, and ended up with what is an inferior product to what we used for years. With the exeception of Jeps enroute charts which I think are better than what we had, the plates are not nearly as nice to use. (Especially at night, with all that fine print... )

[Trader]

lon keel, I agree completely. LIDO charts, made by Lufthansa are similar to the old AC charts but with vast improvements--and colour!!! Best designed charts imo.

[Guest long keel]

Trader,

My buddy who was at SG showed me those Lido charts. The STARS, SIDS, and plates were by far the nicest I have seen. Its a shame AC went with Jepp. The LIDOs probably cost too much . I have heard that the Jepp electronic charts are really nice. That will be the standard accross the fleet soon. The Embraers should start seeing them by Christmas if the rumours are true.

[Trader]

At SG the LIDO chart quote actually came in at about 3/4's the cost of Jepps. Jepp may have been very competitive with AC to get the business.

[MAYDAY]

AC/JAZZ are currently paying nothing for the use of Jepps.

[Vsplat]

Good morning all.

I've done some work in this area, I'll offer a few thoughts in the hopes it helps.

1) The target for managed Flight Path Angles (FPA) is 2.9 to 3.5 degrees (not percent). Most approaches can meet this, several still don't.

2) The FMS generally bases FPA on the published FAF crossing height and min Threshold Crossing Height (TCH). It isn't always 50'. IF the FAF crossing height is too low, the FMS FPA might be too shallow to be usable on a managed approach. This can cause big problems on big aircraft, as it has led to the gear and other parts hitting items on short final.

3) When AC had Aero Services, Flight Path angles were calculated and published on the charts, as well as Constant Descent Angle (CDA) Vertical Speeds for those aircraft that did not have IRS-stable FPA's, like the RJ, DC-9 and, in some cases, the B767. These worked pretty well. Using the CDA required temperature compensation for the vertical speed in a manner similar to altimeter correction. Where the published FAF crossing height was too low, Aero would raise the altitude as high as they could and publish a CDA crossing value and FPA.

4) Whenever the calculated FPA did not line up with the FMS FPA, the crew could not fly managed vertical. It is a limitation of the aircraft and, in general, ARINC 424 standards are based on that limitation. Your choice is managed lateral, selected vertical, or selected/selected. AC elected to go selected/selected for a bunch of reasons I won't bore you with.

5) For a few Non-Precision Approaches that were commonly used (YOW NDB 25 comes to mind), Aero Services tailored the FMS database to permit a managed approach. This was well received by the crews, however labour intensive.

6) Along came Jeppesen. Goodbye tailored approaches and calculated CDA/FPA on the approach plate. It all moved to the 10-10 pages. There was a brief move to destroy even that information and force pilots to re-calculate the FPA every time. This was purely a cost-driven argument and there is significant push-back. The debate is ongoing, so it may yet happen.

7) The EFB will allow the airline a lot more flexibility to incorporate tailored data. In this sense, the move to Jeppesen made long term sense. Aero Services was simply unequipped to make the jump to fully digitial information without a huge investment, and the liability of service providers of Aeronautical Information was growing rapidly.

My own opinion: I liked the Aero product. I really liked the people behind it and their commitment. Very few users ever saw just how hard these folks worked and the conditions under which they were forced to live. A great deal of the advancements in charting and FMS data management world wide came out of this group. The demise of the capability at Air Canada is a loss to the larger community too, and could have been avoided entirely had the airline realised what they had just a few years back and started investing in the future. Alas, water under the bridge.

Vs

[Guest long keel]

Vs,

Thanks for the explanation.

What I liked best was the ability to text message aero directly with the ACARS. Changes would show up in notams the next day. I miss AC being the innovator, rather than a customer of other companies services.

Have you seen the jepp electronic product. How does it work?

Cheers,

lk