What can controllers see?
 

Coming back in to a London airport this week, the director asked us to slow down to an assigned speed - due traffic ahead, which we could see on tcas. My colleague on the flight deck selected the speed but left the aircraft in vertical speed mode (V/S) which kept the descent going and the speed 30kts higher than asked, instead of using level change or open descent (Boeing/airbus). No more than 10 seconds later the director rightly asked us to reduce speed again, only this time to actually reach the speed requested!

My question is - what information can the controller see on his or her screen. In this case the correct speed was selected but not flown. I am also led to believe that the level set in the alt window is also visible to the controller, is this true?.
Best wishes,

Marvo

If you have Enhanced Mode S, UK Centres at Manchester and London can see Selected Flight Level, actual heading, actual IAS, actual rate of climb/descent, actual groundspeed, and aircraft ID.

Scottish Centre get the capability in December.

Marvo
If you are asked to fly a specfic speed due tfc ahead, why do you fly a speed that is 30kts faster than the speed requested

opnot
Good question. They saw the traffic on tcas yet elected to fly 30kts above assigned speed. What was the point of the exercise there? See if they could land on top of the other guy?

He probably used the infamous "TCAS separation".

"traffic eleven o'clock 8 miles, one thousand feet below, report traffic in sight"
"tcas contact, request visual approach"

Not an awfully good idea, Marvo. Modern technology is very clever but an experienced radar controller will quickly know if you're not playing the game!

A word of advise
 

I don't really know for the rest of the world but where I'm right now we usually have once a year meeting with a group of pilots and discuss this things just to explain them what is seen on the screen and that lying or not adhering to the instruction doesn't help at all.

After the first "seanse" most of them requested to visit the ACC and sit on the "jump seat" between the two controllers.If we can do it so should they.

Marvo,find some controller to get you in some ACC and explain you what is going on on the other side of the frequency,that will definitely help you.

To be honest,here we communicate much better after this meetings.

Cheers all,

Gianni

Marvo -
By the way - the director did not ASK you to reduce speed, it was an instruction. Speed control is just that - control. It is not called "speed advice".
Also - yes on radar, a lot of units have a lot of information displayed on the screen, but to be honest I don't need a read out of the speed to know whether the pilot has managed to press the right buttons and slowed down - I (and every other approach controller!) can tell whether aircraft have slowed or not by the distance betweens the radar returns.

The flip side of this is crews who don't tell the controller that they plan to slow right down on final approach, slower than instructed, thus reducing separation behind them. By this time they are usually on the tower frequency. I will send around the aircraft who is unable to fly the assigned speed and can't be bothered to tell the controller rather than punish the chap behind who has done exactly as instructed.

Controllers can work around anything the pilots are unable/unwilling - but only if we are kept in the loop, in sufficient time.

louby

We don't have mode S where we are but we see groundspeed depicted very accurately on our screens. If you're in the same wind band as another aircraft that we're applying speed control against, it's not hard to see when someone's cheating because the groundspeeds show a lot of variance.

When we determine who's doing the cheating, it can make for some interesting comments and vectors:ok::}

A lot of you have jumped on marvo, have you actually read his post? He wasn't the handling pilot at the time, and the point being made is that although his colleague selected an innapropriate mode of descent to achieve the requested speed promtly, there was very little time between the initial instruction and the follow up from the ATCO. I'm sure marvo would have said something had he been given time. It is useful to know you guys have all the info with the enhanced mode S, as it is blatantly obvious that some pilots, particularly at places like lgw, are not flying asssigned speeds, which completely wrecks the sequence causing problems for everyone.

Again using lgw as an example, it is a regular occurence that we may reduce from 220kts back towards 200-180kts on a loc intercept heading. This is nearly always due to a high workload for the controller resulting in a late instruction to reduce, and a busy frequency making it hard to get a call in, so we pre-empt slightly. Reducing below 170kts only ever happens once we are through 6dme (company policy - ezy).

I think speed control at later stages in the approach is sometimes badly complied with from our side of the fence because we regularly get left fast and often high on profile by some European ATC agencies who ask for "enthusiastic" speeds and then neglect/forget to cancel the restriction until it is basically too late, so slowing down without the nod from ATC, often a requirement when operating in some parts of Spain and pretty much the whole of Italy, becomes commonplace if there is any doubt that we are going to meet our stable at 1000'/500' policy.

Unfortunately not every country offers the level of ATC service we get throughout the UK. If you can get a jumpseat ride, get on a sector to Pisa - you'll be amazed at what ATC there expect us to do. The basic laws of physics and gravity don't seem to figure much in their MATS!

People, Marvo gave you the reason in his post....

He selected the incorrect mode, not deliberately... and the mode selected does not, necessarily, control the speed. Vertical Speed mode is a strange beast. It has it uses, and it also has its pitfalls.

Totally unfair on Marvo :ugh:

KK APP? High workload? Busy frequency? Shurely shome mishtake....:E

"What can controllers see?
Everything. :E

I see dead people.

Maastricht told me last week they could see what magazine I was reading. That started to freak me out a bit. :uhoh:

L337 -

Maybe Marvos' colleague needs some more sim time to fully understand the implications of switch selection (or non switch selection in this case)

Ther really is no excuse for a pilot not to know that leaving the A/C in VS mode will mean an inability to comply with a speed instruction in a timely manner (an instruction that is used not only for sequencing, but for safety).

Admit it, you were only looking at the pictures.
We were wondering how the threesome on Page 12 got into that position. :eek:

I know that this didn't happen in this case but it does amuse me when pilots think they can cheat the system and not slow down when told. The fact is that the landing time will be the landing time and it is slow down, hold or fly more track miles with vectors.

Having said that though I do find that the pilots in Europe are far more accommodating of speed control than their colleagues in Australia. I'm not sure if it's because of traffic density or expectations but it certainly makes life easier when everyone does as they’re told.

Give the guy a break. I'm tired of people on this forum jumping down peoples necks for their comments. At least he bothered to ask.

If ATC ask me to climb/descend slow down/speed up I do it!!!.....Let these guys do the job they are trained to and hopefully then they will allow us to fly the aircraft!! For someone to be asked to slow down and then still fly +30kts on the requested speed is pretty dam crazy!!...Come on guys ATC have it hard enough lets give them a frigging chance!!