Aircraft type on clearance

[Thimo Koolen]

Hello all,

 

When flying in the UK airspace, when I request clearance, I always have to state my aircraft type. I haven't had this in Dutch or German airspace.

 

What's the reason we have to say our aircraft type? I thought the UK division is also using Euroscope, which shows the aircraft type already.

[Sean Harrison]

We don't ask for it in VATPAC either. I guess they have a reason.

[Ned Hamilton 1215492]

I'm glad you asked this question because I've been wondering it a lot myself. I fly most of the time in Germany and Swiss airspaces and always give my aircraft type. I do it because some ATIS ask for it and I figure I should give it because what harm does it do.

 

But the flight plan tells what aircraft type so really isn't it a waste (albeit a small waste) of time to do this?

[Andreas Fuchs]

In the UK they do it, because of the approach and departure separation. Usually airlines file repetitive flightplans and it can happen that a different type is used than filed on the repetitive flightplan.

 

This is one of the reasons. Our friends from the UK will certainly be able to give you more reasons, I am pretty sure there are

[Magnus Meese]

It's interesting, really. Considering London, possibly the most densely crowded and complex aeronautical region out there, they still take time to include phrases like "hectopascal", "descend with the glide" (what else are you supposed to do with an ILS clearance), QNH and the ATIS identifier, aircraft type on IFR, etc. Safety and redundancy is of course the major argument here, I'd imagine, but is it really that much of a factor when compared to how it adds occupied seconds to an already busy frequency (and the fact that these extra bits of info are skipped elsewhere)?

[Josh Glottmann]

I could only imagine it making sense for pushback... since "wingtip clearance is not guaranteed".

[Thimo Koolen]

In the UK they do it, because of the approach and departure separation. Usually airlines file repetitive flightplans and it can happen that a different type is used than filed on the repetitive flightplan.

 

This is one of the reasons. Our friends from the UK will certainly be able to give you more reasons, I am pretty sure there are

But that's mainly in the real world and I would understand that- but Vatsim is completely different in that aspect.

 

I'm glad you asked this question because I've been wondering it a lot myself. I fly most of the time in Germany and Swiss airspaces and always give my aircraft type. I do it because some ATIS ask for it and I figure I should give it because what harm does it do.

 

But the flight plan tells what aircraft type so really isn't it a waste (albeit a small waste) of time to do this?

Exactly what I thought. Most people fill in their type even twice: one at prefile on the Vatsim website, the second during connection to the network.

[Andreas Fuchs]

Well, we are trying to emulate the real world and these are the little details that make it nicer. Wouldn't it be boring if we had exactly the same rules and procedures everywhere?

 

@Magnus: this thing with the ILS clearance has the following background: ATC needs to make sure that the plane in question will stay at the last instructed altitude until established on the LOC and intercepting the GS. Theoretically pilots would be allowed to descend to a lower (standard procedure) altitude once they are established on the LOC. For example: the approach plate shows 3000ft as final approach altitude before intercepting the GS, but ATC tells you to maintain 4000ft to intercept the glideslope and then descend with the glide. They want you to maintain 4000ft regardless of the data on the approach plate, as they need you to be there for vertical separation to other aircraft. I hope that will make more sense to you now.

[Matt Middleton 1264577]

The reason we ask is, not all pilots file the correct ICAO Code for the aircraft (through lack of knowledge or laziness)

 

Common examples are B77F (B772 Freighter), B747 (which of the 5 variants of 747 is this?) A320-200 or B787 as I had today on Heathrow.

[Ned Hamilton 1215492]

The reason we ask is, not all pilots file the correct ICAO Code for the aircraft (through lack of knowledge or laziness)

 

Common examples are B77F (B772 Freighter), B747 (which of the 5 variants of 747 is this?) A320-200 or B787 as I had today on Heathrow.

 

Is it a small percentage who don't file an incorrect code? Because if so, why not have the controllers ask for the correct code form those so the rest of us don't have to report it during clearance?

[Randy Tyndall 1087023]

I'm confused...and playing the Devil's Advocate.

 

not all pilots file the correct ICAO Code for the aircraft (through lack of knowledge or laziness)

 

So...when they are asked for their aircraft type they are expected to "magically" say the correct type? No, they're gonna say what they put in their flightplan, which was already wrong... You already know they are in some form of B777 or B747, etc. Maybe I could understand that if the aircraft type was "KODI". Not a lot of people know that is the Quest Kodiak...or Kodiak Quest, depending on who you talk to. Or CVLP, the Convair 240, 340, or 440...maybe that would be the perfect time for a pilot to say their aircraft type is a "Convair 340" since one code stands for three different...but similar (how is that possible)...aircraft.

 

So, that cannot be the sole reason I would think, especially if it is done in the real world. Even though there may be times...rarely...when an incorrect aircraft type is filed RW, that cannot be why ATC expects you to say your aircraft type.

 

 

Randy

[Sean Harrison]

In virtuality, what changes between a 747-300 and a 747-400, or even between an B737-800 and an A320-200.

 

I'm not by any means an experienced controller, but I do hold a C1/O, and I haven't really had to worry too much whether an aircraft is a specific type. Sure, wake turbulence, runway separation etc between light aircraft and jets, but not whether it is a 737-600 or -800.

 

So why is it critical to get the type correct?

[Simon Kelsey]

In virtuality, what changes between a 747-300 and a 747-400, or even between an B737-800 and an A320-200.

 

I'm not by any means an experienced controller, but I do hold a C1/O, and I haven't really had to worry too much whether an aircraft is a specific type. Sure, wake turbulence, runway separation etc between light aircraft and jets, but not whether it is a 737-600 or -800.

 

So why is it critical to get the type correct?

 

The reason, as mentioned above, is because in real life many airlines file repetitive flight plans with a "canned" aircraft type. Occasionally a last minute sub may result in an aircraft in a different weight/wake category operating the flight. Obviously there's little difference between a B738 and B739, but for example BA have been known to sub Airbuses with B767s or even B777s on occasion -- clearly this would be a wake turbulence issue (and it's also worth mentioning that UK wake turbulence categories differ to ICAO). With regards to the pilot "magically" knowing their aircraft type on the radio -- they might not know the ICAO code, but they hopefully would know they were flying a Boeing 737. I don't think anybody would insist on the specific model, to be honest, unless it was significant for wake reasons (I think there may be a couple of types where one variant is in a different wake or speed category to another).

 

Is it important on VATSIM? Well, is anything? After all, nobody dies. But we strive to emulate the real world, and in the UK that means that you are required to report your aircraft type, stand number and current QNH when calling for clearance at most major airfields and your aircraft type and current and cleared level on first contact with most approach units. It's specifically asked for in the ATIS, and controllers are obliged to ask you for it if you don't give it, so it saves everybody time and h[Mod - Happy Thoughts]le if you just include the information requested first time round. It's just part of the rich tapestry of different procedures in different places that makes VATSIM unique -- I once tried Radar Contact, but very quickly got bored because the procedures, phraseology and vectoring was always exactly the same wherever I flew. If I fly to the USA I have to try and remember to add "Heavy" to my callsign, use inches of mercury and FAA minima, if I fly in China I have to use metric flight levels, if I fly to Moscow I have to use (or at least read back and then convert) metres QFE in the terminal area instead of feet QNH as I would in the UK.

[Luke Brown]

Most of the time I have to ask pilots it's because they've filed B747 or B787. The worst ones by far are all the B777 variants.

 

Theres a fair few people that don't know the difference between B772, B77L, B773, or B77W.

 

If we're trying to emulate the real world, then when I look out of the tower at Heathrow, all I see is a plethora of BA aircraft, I need to make sure that I'm talking to the right aircraft. So I need to ask for your aircraft type, stand number and the identifier of the information you have received. Once you get your clearance and set your squawk code correctly (important) the SMR then correlates your callsign with the information I have entered about where you are, so I can see you then. Until that point, you're just another yellow blob on my screen.

[Randy Tyndall 1087023]

After reviewing the Aircraft Type list on the ICAO website I see five codes listed for the Boeing 777. They are B772, which can designate either a B777-200 or a B777-200ER, B77L which designates a B777-200LR, B773 which designates a B777-300, B77W which designates a B777-300ER, and one I hadn't realized existed B778 which designates a B777-8.

 

A quick look at Wickipedia, not the most reliable source, but a source nonetheless shows the following difference.

 

From shortest to longest fuselage is a difference of only 33 feet, roughly 10 meters/yards. On an aircraft the size of a football field can you really spot that 10 meters at 1/2 mile from a tower 300' in the air? Maybe so.

 

Wingspan comes in a difference range of 12 feet, roughly 4 meters/yards. The extensions on the LR and ER are discernible though so I'll give you that.

 

All variants are the same width at just a little over 20' so no help there.

 

Tail height is the last comparison I looked and only 1 foot difference there, but the top of the tail is six stories in the air. Spot that foot difference from the ground.

 

So we are not talking apples and oranges here, just Red Delicious vs Jonathon vs Pacific Rose. I know there are those who can spot the differences between the four main B777 types, but the majority I suspect cannot.

 

And the unanswered question is where does this requirement to state your aircraft type come from. I [Mod - Happy Thoughts]ume it's asked for on VATSIM because it's asked for in real life in the UK. Why?

 

I understand the explanation of standing in the tower and looking out at a sea of BA birds sitting at the gates and wanting to know which aircraft you are talking to. If those BA birds are 3 B77Ls, 2 B772s, 1 B77W, and 4 B773s are you really gonna be able to tell from 1/2 mile when the pilot says he's the B77W. You may be able to narrow it down to 5 planes, but I think you still won't know for sure.

 

And please don't misunderstand me here. I give my aircraft type on call up and will continue to do so, but I think the "why" is a valid question and hasn't really been answered yet.

 

Randy

[Josh Glottmann]

... one I hadn't realized existed B778 which designates a B777-8.

Just noting that this doesn't exist to my knowledge (and according to ICAO Doc 8643).

I agree that we haven't really figured out why here.

I get the point made earlier about "correcting" plans that are using different aircraft. What I don't get about this statement however is why... why isn't the airline modifying the plan? Or why isn't the pilot in that case (and that case alone) telling delivery that they are no longer flying their Skyhawk across the pond but rather their A388?

 

I get that we like to simulate it... but honestly, it just seems to be a waste of time. Keeping it simple is just not a concept that seems to resonate at real world LHR. I understand that there are some concerns with not guaranteed wing-tip clearance, but why couldn't the pilot just correct their plan rather than every single plane announcing their aircraft type on frequency.

What could be

Miami Delivery, American Four-Fourty-Six-Heavy, information A, clearance to London Heathrow.

becomes

Heathrow Delivery, American Four-Fourty-Six, Stand 327, a Boeing Triple-Seven-Two-Hundred, information A, Q-N-H 1017, clearance to Miami.

The reasoning here is just... non-existant.

[Randy Tyndall 1087023]

In reference to the B777-8

 

Just noting that this doesn't exist to my knowledge (and according to ICAO Doc 8643).

 

Sure it does...at least the code anyway. Page 1-20, left column, sixth from the bottom. Directly below it is another new T7 code I didn't realize existed...the B777-9, ICAO B779

 

Randy

[Josh Glottmann]

Page 1-20, left column, sixth from the bottom. Directly below it is another new T7 code I didn't realize existed...the B777-9, ICAO B779 :D

I was looking at the end of thet section (past B772 and such). Oh well. Eww. :mrgreen:

[Simon Kelsey]

And the unanswered question is where does this requirement to state your aircraft type come from. I [Mod - Happy Thoughts]ume it's asked for on VATSIM because it's asked for in real life in the UK. Why?

 

because in real life many airlines file repetitive flight plans with a "canned" aircraft type. Occasionally a last minute sub may result in an aircraft in a different weight/wake category operating the flight. Obviously there's little difference between a B738 and B739, but for example BA have been known to sub Airbuses with B767s or even B777s on occasion -- clearly this would be a wake turbulence issue

 

. What I don't get about this statement however is why... why isn't the airline modifying the plan? Or why isn't the pilot in that case (and that case alone) telling delivery that they are no longer flying their Skyhawk across the pond but rather their A388?

 

Because RPLs are filed automatically by a computer, and if there's a last minute aircraft change the computer has no way of knowing it.

 

Of course, in an ideal world the airline/FTD etc will always be on top of that (amongst the million and one other tasks they have) and will always re-file a new plan with the correct type, and the new plan will always kick the old plan fully out of the system in all of the places and ATC systems it's meant to, and, and... but of course the world isn't perfect and people forget to do things, things don't always propagate through computer systems in a full and timely fashion and errors can creep through. I'm sure that 90% of the time the plans are amended, but given that most procedures in aviation are written, if not always in blood then certainly through hard experience, I would guess that LHR ATC have had their fingers burnt too many times in the past by incorrect aircraft types in FPs. Given the capacity at which the airport operates and the tight and accurate spacing required to achieve the required landing rate, there is a real flight safety issue -- obviously not if you're splitting hairs between a B77L and a B77W, but I sure as hell wouldn't want to be in a B737 on final stuffed 2.5NM behind a B777 because there was a last minute change from an A319 and the RPL wasn't amended or the new plan hadn't propagated properly to LACC for some reason.

[Sean Harrison]

-- obviously not if you're splitting hairs between a B77L and a B77W, but I sure as hell wouldn't want to be in a B737 on final stuffed 2.5NM behind a B777 because there was a last minute change from an A319 and the RPL wasn't amended or the new plan hadn't propagated properly to LACC for some reason.

 

ATC: BAW645 continue approach, number two to the scarebus.

 

BAW645: number two, but not to a Bus, looks like a T7

 

ATC: BAW645, reduce to min speed for sequencing.

[Kirk Christie]

Every one does things different, down under you dont report the ATIS letter untill you are ready to taxi, Heavy and Super are disappearing, domestic aircract can switch to tower and ground with out being told to.

 

In Germany you request start up.

 

In the USA they dont tell you the dep runway untill you start taxiing.

 

You dont need to request oceanic clearance to cross the paciffic or Indian ocean.

 

I dont understand how the FAA can allow you to clear some one to land and at the same time clear some one to take off on the intersecting runway, but thats how they do it.

Edited May 19, 2016 at 12:01 AM by Guest

[Simon Kelsey]

ATC: BAW645 continue approach, number two to the scarebus.

 

BAW645: number two, but not to a Bus, looks like a T7

 

ATC: BAW645, reduce to min speed for sequencing.

 

And in IMC?

 

Wake vortex aside, accurate aircraft type information is essential for controllers. An A340 and a B777 are in the same vortex category, but there's a world of difference between their performance capabilities. And in an enroute environment, the controller certainly won't have eyes on the aircraft to verify.

[Randy Tyndall 1087023]

Okay Simon...and Andreas,

 

In the UK they do it, because of the approach and departure separation. Usually airlines file repetitive flightplans and it can happen that a different type is used than filed on the repetitive flightplan.

 

I get this, but I'm not really sure what is meant by "repetitive flightplans". My understanding, being only a "cabin seater", is that commercial pilots rarely file their flightplans anymore. As I understand it, they are usually filed by a "company dispatcher" for the flightcrew, who get briefed on the filed plan.

 

I've looked at ICAO Doc 4444, especially Appendix A where it speaks of flight plans and repetitive flight plans (RPLs). I understand from that reading that, for example, BAW dispatcher(s) submits an RPL and in that RPL has to list the aircraft type. I also understand that the aircraft type listed on the RPL may not be the actual trip aircraft if a substitution is needed. Who is the RPL submitted to and how does the relevant controller responsible get that plan? Does someone in an office with no windows receive the RPL and forward it electronically to the appropriate Air Traffic Control Office? What do they do with it? How does it get to the Departure/Ground/Tower Controller?

 

I find it hard to believe that once an RPL is submitted that a commercial carrier in this day and age could actually "get away with" subbing a B777...sorry, B77L...for a B738 and the only failsafe to ATC knowing what actual aircraft is being flown is a pilot on first contact giving his or her aircraft type.. Are you saying that once an RPL is filed, if no one asks specifically what type aircraft is being flown that day...or offers the correct type on initial contact...that no one other than the pilot will know what type plane they are operating? Does it really boil down to "Clearance Delivery, Speed Bird 1234, Stand 405, type A320, IFR to Liverpool please" as being the only way ATC will know what type aircraft they are dealing with?

 

RPLs seem to be a common practice in many, many countries. How do those countries that do not require aircraft type on first contact ever find out what type aircraft is really flying?

 

So, while I understand that the practice of using RPLs and the need to know wake turbulence categories is a factor in the requirement in the UK to give your aircraft type on first contact, it cannot be the driving factor or it would be an ICAO requirement and all countries would be requiring it of pilots. Something else has made this a UK requirement I think, not RPLs, not wake turbulence, not the Tower guy wanting to visually "see" the aircraft he is talking to. There are plenty of "ATC blindspots" listed on the charts, yet aircraft there still get "controlled".

 

Finally, I feel the need to repeat. I have absolutely no issue with providing ATC with my aircraft type on first contact or any other time they may want it from me. I will do it gladly and with not the slightest hesitation. If truly RPLs are the driving reason for this requirement wouldn't it be simpler to rescind the section/privilege of RPLs and not allow them. Seems a lot more "practical" than expecting the pilot calling up to say their aircraft type...just saying?

 

Randy

[Simon Kelsey]

I get this, but I'm not really sure what is meant by "repetitive flightplans". My understanding, being only a "cabin seater", is that commercial pilots rarely file their flightplans anymore. As I understand it, they are usually filed by a "company dispatcher" for the flightcrew, who get briefed on the filed plan.

 

Correct (although in many airlines these days there may not even be a direct conversation with a dispatcher -- a "self-briefing" package is generated which the pilots download and check via the company intranet, though at least at BA at the very least there will be a FTD (Flight Technical Dispatch) contact named at the top of the operational flight plan should any queries arise).

 

I've looked at ICAO Doc 4444, especially Appendix A where it speaks of flight plans and repetitive flight plans (RPLs). I understand from that reading that, for example, BAW dispatcher(s) submits an RPL and in that RPL has to list the aircraft type. I also understand that the aircraft type listed on the RPL may not be the actual trip aircraft if a substitution is needed. Who is the RPL submitted to and how does the relevant controller responsible get that plan? Does someone in an office with no windows receive the RPL and forward it electronically to the appropriate Air Traffic Control Office? What do they do with it? How does it get to the Departure/Ground/Tower Controller?

 

No, an RPL (as I understand it) is submitted once, to the Eurocontrol central RPL database. It then automatically gets distributed via the Eurocontrol IFPS systems according to the schedule provided by the airline. The whole purpose is to save airlines having to manually fill out flight plan forms every day (or multiple times a day) for flights that happen at the same time and follow the same route seven days a week.

 

The flight plan data itself is sent to the relevant ATS units via the AFTN (Aeronautical Fixed Telecommunications Network) system -- if you've ever seen a real-world ATS flight plan, you'll probably have seen a bunch of ICAO codes which correspond to the different units that need to receive the plan: these are the addresses to which the plan is delivered through the system.

 

At a major airfield like Heathrow, the strip would then automatically appear in their electronic flight strip system. Smaller units may get a printout etc.

 

Of course, if there is a major change then the RPL must be cancelled for that day and an individual flight plan filed. Minor changes (such as aircraft type) can be covered by a change message.

 

I find it hard to believe that once an RPL is submitted that a commercial carrier in this day and age could actually "get away with" subbing a B777...sorry, B77L...for a B738 and the only failsafe to ATC knowing what actual aircraft is being flown is a pilot on first contact giving his or her aircraft type.. Are you saying that once an RPL is filed, if no one asks specifically what type aircraft is being flown that day...or offers the correct type on initial contact...that no one other than the pilot will know what type plane they are operating?

 

You'd be surprised! Who else is going to ask/check?

 

A couple of quotes from real ATCOs:

 

I was recently working an aircraft and only discovered that it was a different aircraft type when it requested climb to RVSM levels and the filed aircraft type was non-RVSM.

...in a TMA radar environment I was, apparently, working a PIA B742 which was flight-planned as a B777. This thing had flown all the way from OPRN, and no one en-route knew the aircraft's type.

 

Not all tower ATCOs all over the world are champions at aircraft recognition, and whilst I agree that the correct aircraft type should be on the FP, experience has shown that all too frequently it is not.

 

In addition, I believe there also is/was an issue whereby the Eurocontrol flightplan computer in Paris doesn't have the same range of aircraft type codes that the computer in London does, which can lead to discrepancies. This may have changed though -- but worth noting that this wouldn't just affect RPLs, it would affect everything that goes through the IFPS.

 

RPLs seem to be a common practice in many, many countries. How do those countries that do not require aircraft type on first contact ever find out what type aircraft is really flying?

 

As mentioned above -- more often than you might think, they don't!!

 

So, while I understand that the practice of using RPLs and the need to know wake turbulence categories is a factor in the requirement in the UK to give your aircraft type on first contact, it cannot be the driving factor or it would be an ICAO requirement and all countries would be requiring it of pilots. Something else has made this a UK requirement I think, not RPLs, not wake turbulence, not the Tower guy wanting to visually "see" the aircraft he is talking to. There are plenty of "ATC blindspots" listed on the charts, yet aircraft there still get "controlled".

 

Ultimately, to quote from another forum:

The procedure is in place to save your backside from ending up upside down in the middle of Hounslow old chap.

 

Heathrow (particularly) routinely uses the minimum spacing on final approach. It is a safety-critical phase of flight, and if the wrong (sometimes seemingly innocuous -- ATR42 vs ATR72, for instance, or E130 vs E190) type is on the strip for whatever reason you may end up closer than is safe.

 

There are plenty of things that are not in ICAO, and a plenty more that are and don't seem to make a lot of sense. How US ATC can possibly clear you to land number 5, for instance, is beyond me. But ICAO permit it. That's a different debate, however!

 

Finally, I feel the need to repeat. I have absolutely no issue with providing ATC with my aircraft type on first contact or any other time they may want it from me. I will do it gladly and with not the slightest hesitation. If truly RPLs are the driving reason for this requirement wouldn't it be simpler to rescind the section/privilege of RPLs and not allow them. Seems a lot more "practical" than expecting the pilot calling up to say their aircraft type...just saying?

 

I realise that you're not complaining -- and it's a debate in the real world as well. As mentioned above, RPLs aren't the only culprit -- there are also issues with the way in which data is transferred across ATC systems around the world. At the end of the day, reporting the aircraft type takes almost no time at all and makes certain that any errors are trapped before they become dangerous, rather than just crossing one's fingers and hoping it's right.

[Randy Tyndall 1087023]

Thanks for that explanation. It makes sense I guess. In a perfect world....well, nothing is perfect I guess.

 

Randy