A "Boeing banana" ?

This is from a Boeing 787 MFD.

* Orest

Makes CDAP approaches a snap. Helps you organize your descents and ascents, would work wonderfully with the available altitude constraints in the IFD, for each waypoint.

And it would be a first in the GA world in a GPS/COM.

* Orest

It works with the same altitude constraints that you put in manually (or an approach puts in automatically) that generate the VSR and TOD in the IFD now. You can kind of think of the "Banana" as a TOD descent mark in reverse, the "Bottom of descent" point -- it is the place where you will reach the altitude in question, vice the place where you need to descend to get to that altitude.

Simple example: Say you've manually set an altitude constraint of 1000ft above your destination airport, let us say that is 1800ft MSL. As you are flying along at 6000ft, you get to the calculated TOD mark, get the aural descent indication, and so you start your descent. Moments after that you get the 20* green arc appearing on the screen, and as your descent settles in to your planned descent rate, the green arc will be shown right at the airport. Based on your current descent rate that will be the point at which you will descend through 1800ft AGL. If you increase your descent rate, then the green arc will start moving towards your own ship position. If you decrease your descent rate, the green arc will move further away from your own ship, eventually being drawn further away than your arrival airport. Of course this will be affected by the wind backing or shearing, or any airspeed changes, but it allows you to adjust as required. And, in this way you get an immediate visual confirmation of your expected descent progress.

On a non-precision approach, with the target altitude being the MDA, you can just start your descent and adjust so that the green arc is right on the arrival end of the runway, or just short. Before the days of the +V indication in GA and IAN in Boeings, it made a constant descent profile very easy to generate.

Of course, it works just the same in ascent. It really is the best thing since sliced bread.

Now, it works a little differently in the big boys, the Boeing Banana will be generated by the target altitude set in the mode control panel (MCP), rather than the altitude constraints set in the flight plan, which is even more flexible -- but functionally the idea is the same. 

* Orest

However, did also request an APPROACHNG FAF, to help trigger a landing checklist. That might have a better chance.

* Orest

Ken

Happy Skies,

Old Bob

* Orest

OK, as long as we are still talking about it ...

It has the potential to be a unique, "Gee Whiz" feature in its niche.

* Orest

WHEN DO WE WANT IT? ONCE THE FEATURE HAS BEEN SPECIFIED, CODED, TESTED, AND APPROVED FOR RELEASE BY THE FAA!

Just keep the noise down. We like to hear the jets flying over the office.

* Orest

http://forums.avidyne.com/forum_posts.asp?TID=1467&title=the-boeing-banana

Not sure if there are enough data blocks transmitted that the ASPEN can make that calculation/annunciation, but IAC you'd have to get the ASPEN folks to do that. 

It would be nice, but I surely would not hold my breath.

* Orest

The Aspen 1000 MAX PFD does its own Banana driven by the altitude bug.