popee
Posts: 151
Joined: Fri Feb 23, 2001 10:26 pm

Flight Path Vector?

Thu Oct 14, 2004 1:14 am

What is Flight Path Vector ? How is it displayed in C/p ? Do they bear same meaning / indication on B777 & A310 ? Thanx....
 
avioniker
Posts: 1099
Joined: Tue Jan 01, 2002 5:38 am

RE: Flight Path Vector?

Thu Oct 14, 2004 1:22 am

It's an icon displayed on the PFD or HUD that tells the pilot where the plane will be shortly if the flight controls and throttles aren't moved from their current position. It may be something as simple as a little box, a circle with wings, or an actual aircraft picture.
It's based on inertial data calculated in the IRU/ADIRU or HUD computer and fed to the FMS/DFGS/FCC/AFMC/or one of a variety of other acronyms depending on the type of aircraft and display manufacturer.
On landing if the FPV is placed over the threshhold of the runway as viewed through the HUD that's where the plane will touch down. (Or impact, the terminology being a function of speed and landing gear...)
One may educate the ignorance from the unknowing but stupid is forever. Boswell; ca: 1533
 
popee
Posts: 151
Joined: Fri Feb 23, 2001 10:26 pm

RE: Flight Path Vector?

Thu Oct 14, 2004 1:48 am

" It may be something as simple as a little box, a circle with wings, or an actual aircraft picture."

Can u pl explain me a little about it. will it need not to be a straight line (or curved) to show its future position ?? I wud appreciate if i may hv a photo of it. THANKS again.

POPEE
 
AAR90
Posts: 3140
Joined: Fri Jan 21, 2000 11:51 am

RE: Flight Path Vector?

Thu Oct 14, 2004 2:29 am

Can u pl explain me a little about it.

On AA 737s, it is a small circle with three small lines extending from it. One horizontal line on each side (representing wings) and one vertical line out the top (representing the tail).

will it need not to be a straight line (or curved) to show its future position

On the HUD, look thru the symbol to see where you are going. No lines, no curves. If the FPV symbol is above the visible clouds, you're going to pass above the visible clouds. On approach simply fly the plane so that the symbol rests on the end of the runway and that's where you'll impact the ground (if you do nothing).

Look closely at this photo and you'll see two small circles with the "wings" on the horizon line. The inner circle is the Flight Director command cue and the outer circle is the Flight Path Vector.

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Click here for bigger photo!

Photo © Bryan Weber



*NO CARRIER* -- A Naval Aviator's worst nightmare!
 
popee
Posts: 151
Joined: Fri Feb 23, 2001 10:26 pm

RE: Flight Path Vector?

Thu Oct 14, 2004 3:00 am

Thanx Avioniker. Thanks AAR90.

Popee
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: Flight Path Vector?

Thu Oct 14, 2004 4:21 pm

A bit of clarification: What it does is show what direction the aircraft is travelling in right now. There is no prediction and no time span involved.

Bit of nifty and useful fighter technology making its way into airliner cockpits. You can get a lot of information which is useful on the approach from the FPV, apart from the obvious issue of where you are going to impact the runway (impact, as the provision for actually hitting that spot is not flaring). The difference between the FPV and the fuselage reference gives you the AoA, and the position of the FPV on the pitch ladder is the glide path angle.

Put the FPV in the right place for the correct AoA (no need to worry about tabulated approach speeds any more; some fighters provide on-HUD brackets for the approach AoA), one the desired GPA on the pitch ladder and on the aimpoint on the runway and you are good. Just keep it there until the flare and you have a landing. Of course, some aircraft enables you to ignore the roundout as well, and even to keep the brakes full on even before impact...  Big grin

Regards,
Fred
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
popee
Posts: 151
Joined: Fri Feb 23, 2001 10:26 pm

RE: Flight Path Vector?

Fri Oct 15, 2004 3:19 am

I will be thankful if someone pl help me with pics showing FPV in action for better understanding.

Is it used during approach only or other than that also ?

Thanx.

Popee.
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: Flight Path Vector?

Fri Oct 15, 2004 4:34 pm

Here you go!

HUD symbology

The report is interesting, as it clearly displays that the pilots in the study had not grasped how to extract the extra information I referred to above from the HUD presentation but were rather trained on "how to use the display" rather than "how to interpret the display and fly accordingly".

It is stated that both the pilots who took correct action were trained in the military. It would have been interesting to see which pilots were trained on flying military aircraft with FPV symbology used to make approaches. The same two?

If you ever have the opportunity to attend a lecture by Amy Pritchett, one of the authors, by all means go for it!

Cheers,
Fred

[Edited 2004-10-15 09:55:15]
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
popee
Posts: 151
Joined: Fri Feb 23, 2001 10:26 pm

RE: Flight Path Vector?

Fri Oct 15, 2004 8:21 pm

Finally, the pilots used in this study were new to HUD's, the mode Flight Path Angle and the A320 Mode Control Panel. Being relatively untrained in the use of Flight Path Angle mode, their recognition may have been slower than that expected from flight crew trained on these systems.

Does it not weaken the case ? I mean if u r not trained on a particular system how can u be a subject of case study ?

Popee.
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: Flight Path Vector?

Fri Oct 15, 2004 9:53 pm

Uh-oh, busted! I didn't read the entire report and jumped to conclusions. My bad and good catch, Popee!

People, just ignore my last post, except for the link and the comment regarding the lectures.

Cheers,
Fred
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
popee
Posts: 151
Joined: Fri Feb 23, 2001 10:26 pm

RE: Flight Path Vector?

Sat Oct 16, 2004 2:46 am

Thats fine. But thanks for yr efforts...

Popee.
 
AAR90
Posts: 3140
Joined: Fri Jan 21, 2000 11:51 am

RE: Flight Path Vector?

Sat Oct 16, 2004 12:16 pm

..."how to use the display"

The basics which will get the flight accomplished (i.e. what the airlines typically teach).

..."how to interpret the display and fly accordingly"

The advanced techniques (i.e. getting the most out of the aircraft & its systems).

Those new to the HUD are happy with just the basics [usually "gee-wiz'd" out of their minds] but after a little while flying the line most really seek out the advanced information available (makes for smoother & more efficient flights).  Big thumbs up
*NO CARRIER* -- A Naval Aviator's worst nightmare!

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