deadly threat radar brightness control in airbus?
 

every pilot admits it has happened to him or to her that this knob was fully closed when switching on radar for wx watch, resulting in a "happy situation" with no visible echoes.
some of the aircraft still give a minimal brightness in full dark position, alerting that something might be wrong, while others really give full dark.

suggest to limit minimum brightness to about 50%.
if this is not possible suggest to disable brightness control in full bright.

for non airbus pilots having ONE switch for radar picture:
on airbus radar picture is shown in nav display.
nav display has a brightness control.
radar picture has a separate brightness control which enables balancing brightness of radar echoes against rest of nav display.

idea was ok but has proven to be wrong...

stick to SOPs (expanded checklist in Ops Manual) and problem gone!

SOP's..... amazing! They are written in blood.
Stick to them lest your blood writes the next one.

Functional test of wx radar at altitude is easy. Point down full, paint the surface, adjust the brightness and range scale, and return the the scan angle to -5 degrees. At 200 mile range, will get anything popping over the horizon.

Takes as long as it took you to read this. Not doing it is.... lets see... LAZY!

Quite agree, it's a poor design not helped by those "helpful" folks who turn it down when leaving the flightdeck. Far to easy to say "just follow SOP", a bad design can only be rescued so many times by procedure, eventually someone will get caught out.

It needs to be an electronic dim control that resets to full bright every time the radar is powered up.

Indeed, Max Angle, this is one of the switches that for me has only one position: max bright. Why anyone would want to turn it all the way down after flight baffles me. It does no one any good and it just puts an extra hole in the proverbial swiss cheese.

Slightly off track, some maintenance colleagues (for all of whom I have a deep seated respect) have the habit of switching off every single switch in the cockpit. So yes, last time I found out in the air that my radar screen was not showing any returns was after a night of heavy maintenance...

Not passing the blame, just an observation.

Ergonomics
 

I put it bright when passing through it in my scan flow every flight.
I think this is not in the SOP cockpit preparation, is it?
I do it after one day It happened to me that i was not seeing CBs ahead. I also check it is not in minimum gain, after the day I was puzzled because I saw slight magenta returns, but not even a single green return. When I realised and turned it auto gain we had damned family of CBs ahead. In that model, auto was just the "click" after minimum gain...
With a more ergonomic model, Auto cal is next to max cal.
This may seem unimportant, but if a major airline airplane goes down in a TS and the investigation finds the cause being one of this things, a few more blood ink lines would be written in the SOPs.

I had the same prblem once turn the radar on and nothing, but since then now I always set the knob full open during my cockpit preparation and I always suggest to my copilot to do the same to avoid any surprise

Leaving the VOR/ADF switch in the middle (OFF) position is another one. Why do they do it ?:ugh:

Every quirk in a cockpit can be traced to the ego of some airline's chief pilot. TWA's Gordon Grainger insisted on the very light stick force to kick off the altitude hold in the L-1011, and Eastern suffered the Everglades accident.

He also insisted on radio altimeter indicators that went only 0-1500 feet, resulting in the 1975 TWA 727 CFIT that triggered mandatory GPWS.

He also put all the overhead switches backwards from every other airline.

GB

I have never heard of this before or ever been trained that we MUST do it :confused:

Not doing it is...lets say....I DID NOT KNOW THAT WE MUST DO IT :p

I can't find any such reference to do this anywhere in the Airbus manuals.

I agree that brightness control is trap which both I :O and many other pilots have been caught by.

Why don't Airbus use the large knob to adjust the brighness of the ND if the large knob is used the adjust the brightness of the PFD ? :confused:

In the airbus, you use :
- the large PFD knob to adjust the PFD brightness
- BUT the inner smaller knob to adjust the ND brightness. Why not also the large knob ? :confused:

The large ND knob will NOT adjust brightness of ND but will adjust the radar brightness.

I believe the radar brightness should be the inner knob and the ND brightness the outer knob. The screen brightness should be controlled by the large knobs for both screens.

I think people set up traps when dimming the screens at the end of the day, and initially turn the both large knobs anti-clockwise (or just turn all the knobs anti-clockwise). There is no need to turn the large knob on the ND display, but people still do, maybe because of the similarity to the PFD knob.

With the weather radar off on the ground, unless you check the brightness control, you won't know that the brightness has been fully turned down.

It will NOT be obvious to you that it is fully dim and this is the trap, its not obvious.

Sure its easy to say to just follow SOP's and that you do not need any warning / obvious attention getter's that something is wrong.

But its a bit like the gear not down and locked warning. Pilots will occasionally forget to put the gear down as long as humans exist unless something brings our attention to it.

The weather radar is just another trap with potentially distarous consequences.

Nothing inside the aircraft will obviously bring our attention to it that it's fully dim (unless you carefully scan/touch the brightness control knob).

I believe there needs to be some other kind of defence in place to prevent many of us falling into this trap.

I believe SOP's as the only line of defence are not good enough. Refer landing gear up example.

John C.

You'll note that it is (in the AB) in the EXPANDED SOP's in the ops manual.

Not in the checklist.

It's why you didn't get in the habit of doing it.

It's kinda like stumbling into the tops of a rapidly building CB.

You'll only do it once in your life. And hopefully live to tell about it.

I pointed out in a previous post (that was deleted) that in the 717, the radar display on the ND cannot be dimmed to zero. It goes down a fair way but still can be seen. Sound like Airbus needs to do the same.

I am (predictably!) shocked by the fact that some pilots appear to be using a system without knowing if it is working. First time you put the radar on because you think you need it......................? What's that word again, 'airmanship'? I would venture to suggest that the 'deadly threat' does not lie in the equipment?

Confucius say "Turn on equipment, check it working". That has stood the test of time for ages.

Mind you, on the plus side(?) I sat several times alongside some young hopefuls who had the radar on at 5 deg up ('SOP' shutdown setting), at least with the correct screen brilliance set, on a CAVOK cruise for HOURS until I asked if they could see any weather in space...........................:rolleyes: Lucky for all on board there was nothing on their screens.

It's far too late for AB to change the knobs, but they could make it so the WX display cannot be turned down to 0.

There's more. The GAIN knob is engineered that should you or the previous crew took it incidentally out of the "CAL" setting, even by a milliemeter, you get manual gain at MIN level. The max manual gain position is all the way on the other side of knob-turn.

Yours,
FD (the un-real)

- that is as may be, but is it too late to retrain some pilots to use some intelligence? It is a bit like snagging the ADF for 'no ident' when the volume is turned right down.

Cal vs Min Gain
 

Again, it probably depends on the chief pilot. In many WXR control panels, Min is the same as CAL, and the gain only goes up from there, even though the gain display is in negative numbers. It's mislabeling of the highest order. With other panels, Min is indeed less than Cal. You have to play with it to know.

GB

I guess it was cavok during the daytime to sit there for hours thinking people were idiots for looking at space with the radar? If not then there was at least one more idiot on that flight.

Well, Slops, 5 up ain't going to show you an awful lot of weather in the cruise, day OR night, is it?

What ever happened to "Check Prior to Take-off", ....tilt down for ground return.... then select appropriate up? :ugh:

It's in the SOP / FCOM...FCTM... and BCS (Basic Common Sense)