Amending a clearance?

[Grigri]

Evening all... I hope I'm in the right place, but I've been having a nagging question of late.

I'm an Approach radar and tower ATC and as such we were taught the basics of what goes on in a cockpit in terms of clearances etc.
I was taught that one should always try avoiding the issued clearance if at all possible.

My question is this...

Number 2 is ready to go, but can't do because the SID he's on will conflict with other traffic. But it will only do so for another minute or two.
Would pilots prefer to wait the minute and stick with the clearance they were given and have briefed, or get an amended clearance and go straight away?

How much work actually needs to be done on their part?

[JABBARA]

Depending on airport and depending on the likelihood of complexity of amended clearance. From an average airliner`s perspective, after acknowledging the amended clearance, pilot needs to make some FMS modification and brief them in rush, this may also take another 2 minutes at least. Rather than this, I would prefer to wait, for example from LGW

[bucket_and_spade]

I'd prefer to wait, even if it's for a few minutes. The Flight Management System will have been programmed with the original departure, the navigation aids and Mode Control Panel (autopilot/flight director interface) will have been set up and the original departure will have been briefed/discussed by the crew.

Yes, we can change all of the above pretty quickly if needs be but the potential for missing something or making a mistake is higher with time pressure.

Happy to be flexible - sticking with the original plan would nornally be my usual preference though.

[Rainboe]

A minute is a minute! Gimme radar vectors and an altitude and I'm more than happy to blast off NOW! It's how I used to do it for the first 20+ years of my career and I'm not afraid of doing it anytime, and hang the programmed SID! I can do happily without it when I've got a schedule to keep and everybody is trying to mess it up! Who are these pilots frightened to take it out of LNAV? As for 'not following the briefing!', stuff it! A pilot who can't go raw data at a moment's notice is being lazy! Save me a minute and I'm eternally grateful!

[DC-ATE]

Oh Rainboe, you're forgetting that pilots now-a-days can only fly in automatic, pre-programmed mode. I'd sure hate to see what happens when they lose all that stuff.

[PaulW]

The ammendments to clearances that I have experienced tend to take the form of a radar heading and a different stop altitude/level instead of the original departure instructions or SID. Its not complicated to rebrief, very little if any programming required. In my company more often than not we will thank the controller for thinking commercially and take the ammendment.

Please continue to offer this option to us, some will take it some will not, but we appreciate being given the option.

Someones beaten me to it, its basic flying dont get caught up with your head down in the cdu and fly the plane. K.I.S.S.

[Denti]

If the amendment is a heading and a different level off altitude im more than happy to take it. However if it is another SID, even worse if it's a RNAV SID i rather not. RNAV SIDs cannot be followed by raw data as they are not based on conventional nav aids and have to be put into the FMC to be able to even show them, the FMC waypoints then have to be confirmed by crosschecking with the appropriate chart and that alone takes at least a minute.

However heading and altitude and off i am. So if you do it that way, happy to have it.

[411A]

A minute is a minute! Gimme radar vectors and an altitude and I'm more than happy to blast off NOW! It's how I used to do it for the first 20+ years of my career and I'm not afraid of doing it anytime, and hang the programmed SID! I can do happily without it when I've got a schedule to keep and everybody is trying to mess it up! Who are these pilots frightened to take it out of LNAV? As for 'not following the briefing!', stuff it! A pilot who can't go raw data at a moment's notice is being lazy! Save me a minute and I'm eternally grateful!

Can't say I disagree with any of this.
At JED, especially at Haj time, this is done all the time with good effect.
Pilots, whether flying old steam gauges (yours truly) or....brand new equipment, have to be, on occasion, rather flexible at times.
If not...they hold up the show for everyone, and make no mistake...it is not appreciated by many.
Departures...or arrivals.

[Mercenary Pilot]

While a agree with Rainboe and 411A, for the sake of 60 seconds I would rather wait unless you are offering a heading or Direct-To an enroute waypoint and an altitude which doesn't require a level off at 1000-3000 AGL, as that will waste more fuel than sitting on the tarmac for 1-2 mins anyway.

[kijangnim]

Greetings,
Since most Sids include minimum noise routing, a radar vector amended departure will require reconsidering Noise abatment procedure, and thus a look at noise sensitive area charts, and a reprograming of the Thrust reduction altitude AGL + 1500 and Acceleration Altitude AGL + 3000, so little time is needed :ok:

[Grigri]

Thanks for all the info guys...

The funny thing is, I didn't expect to get anything less than two completely different answers:ok:

What I'll try and do from now on is offer the amendment. It's usually something pretty easy like "climb straight ahead to 6000ft", we'll see where it leads.

Thanks again for the insight...

[Pub User]

I think the vast majority of conscientious and professional pilots would prefer a small delay to a hurried re-plan of the departure.

No one is afraid of reverting to raw data when necessary, but it's exactly that type of thing that leads to a reduction of situational awareness in the crew, with all its attendant dangers.

Years ago we did it all the time, nowadays we have a lot less accidents. Perhaps there's a connection there?

Better a few seconds late in this world, than a few years early in the next.

[DC-ATE]

Pub User -
Better a few seconds late in this world, than a few years early in the next.

I'll buy that philosophy, but not:

...reverting to raw data when necessary, but it's exactly that type of thing that leads to a reduction of situational awareness in the crew...

[DC-ATE]

Pub User -
So if LNAV, EHSI map etc do not increase SA, why do you think we have them?

You have them because it's called "progress", but we seemed to find our way around for a hundred years without all that stuff just fine.

[MU3001A]

So if LNAV, EHSI map etc do not increase SA, why do you think we have them?

If you are given a vector to fly you will still have the magenta line from the original programmed clearance displayed on the EHSI map, and the little aircraft symbol will indicate your position and progress in relation to it. Situational awareness preserved!? ATC will eventualy issue you a clearance to join the magenta line somewhere further down the line - panic over?

[galaxy flyer]

To put things into context, departing Rimini, IT last year; we were given three clearances to Milan-Malpensa. On a 4 minute taxi-out. Airborne, in the SID directed turn, the radar controller asks if we are proceeding to FER. We weren't cleared or flight planned to FER, but go there we did. SA is about dealing with changes, imposed by ATC, weather or the plane, not just following a script.

GF

[wonwinlow]

Rainboe is right, plus on all our US destinations SID's are followed 20% of the time, after departure, you get a heading and an altitude anyway and no one complains...

[Pub User]

I see the mod' has deleted my last post, as it contained a red-wine fueled expletive (asterisked-out).

You chaps are starting to get a little sanctimonious. I feel I must repeat something of what I said above:

No one is afraid of reverting to raw data when necessary, but it's exactly that type of thing that leads to a reduction of situational awareness in the crew

Note I said "REDUCTION" not loss or obliteration. You're right DC-ATE, it's progress, but it's progress for a reason.