Airportgal
Posts: 72
Joined: Wed Feb 09, 2005 2:23 pm

777-200/-300 And 777-200LR/-300ER

Wed May 09, 2007 11:39 pm

How do air traffic control people at an airport visually differentiate between a 777-200 and a -200LR, or a 777-300 and a -300ER on the airfield?
 
User avatar
Stitch
Posts: 23214
Joined: Wed Jul 06, 2005 4:26 am

RE: 777-200/-300 And 777-200LR/-300ER

Wed May 09, 2007 11:45 pm

I imagine they don't, since the only real giveaway is the raked wingtips on the longer-ranged models, though if they have binoculars or darn good eyes they could probably detect that.
 
CHRISBA777ER
Posts: 3715
Joined: Thu Mar 01, 2001 12:12 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 12:32 am

Good question:

Its only an issue for dealing with PK, SQ, JL EK and NH though.

Airport/tower people will want to know when giving taxi instructions really - thats the only reason you'd need to know:

i.e.:

"Shamrock 12 behind Emirates triple seven taxi and hold Foxtrot one one"

Imagine if the airport in question was DXB, and you have complicated taxi instructions - there are five EK 777s and a load of other traffic around - being told "behind Emirates triple seven" isnt really very helpful. This is where you need everyone to know exactly which holding point F11 is.

Now if you imagine there are two holds in use, and F11 has three EK 777s lined up - you would have to be more specific, but usually they say what number you are for departure - so they would say which EK777 to line up behind and I cant see anyone needing to be able to say "line up behind Emirates triple seven 300ER etc" - i doubt most ATC/Tower people could tell the difference from any significant distance and you would be very unlikely to need to I would think.

Its a bit like if you tell someone to hold at N11 at 9R at LHR "behind Speedbird A three nineteen" you've got the same problem and probably a lot more often - look up the taxiway and you'll see hundreds of BA A319s! You'll have to be more specific!

If you are curious about how to tell the difference between the types - I always look at the engines. If you see those monstrous GE90-115bs under the wings as opposed to the noticeably smaller Pratt 4090 and Trent 890 donks then you know its an 300ER. The wingtips arent usually that obvious if the aircraft is on the ground so the engines are your best bet. Theres usually a PW, GE90, or RR logo on the side (but not always) and the GE90 has a distinctive inlet on the outboard side of the cowling - hard to miss even from a distance.

If you look at NH -

300A - PW4090-powered.
200A - PW4080-powered.
300ER - GE90-powered.

If you look at JL -

300A - PW4090-powered.
200A - PW4080-powered.
300ER - GE90-powered.
200ER - GE90-powered.

If you look at SQ -

300A - Trent890-powered.
300ER - GE90-powered.
200ER - Trent890-powered.

If you look at EK -

300A - Trent890-powered.
200A - Trent877-powered.
300ER - GE90-powered.
200ER - Trent890-powered.
200F - GE90-powered.
200LR - GE90-powered.

If you look at PK -

200ER - GE90
300ER - GE90
200LR - GE90

[Edited 2007-05-09 17:33:15]
What do you mean you dont have any bourbon? Do you know how far it is to Houston? What kind of airline is this???
 
deltagator
Posts: 6170
Joined: Fri Sep 23, 2005 9:56 am

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 12:42 am

Quoting CHRISBA777ER (Reply 2):

Yowzers! Good description.

Quoting AirportGal (Thread starter):
How do air traffic control people at an airport visually differentiate between a 777-200 and a -200LR, or a 777-300 and a -300ER on the airfield?

Does it really matter? They wouldn't be able to make out those differences at night. Chris gives a good explanation though of the holding points on various taxiways. I never heard any controller say that someone needed to hold behind the 777-200ER but slip in line before that blasted 300ER came through. Everything I have ever heard was for the plane to hold or taxi or whatever behind the comapny jet if it was the same carrier or the name and model of someone else's plane.
"If you can't delight in the misery of others then you don't deserve to be a college football fan."
 
CHRISBA777ER
Posts: 3715
Joined: Thu Mar 01, 2001 12:12 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 12:43 am

Quoting DeltaGator (Reply 3):
Quoting CHRISBA777ER (Reply 2):


Yowzers! Good description

LOL I'm not bored at work or anything like that LOL  Wink
What do you mean you dont have any bourbon? Do you know how far it is to Houston? What kind of airline is this???
 
Airportgal
Posts: 72
Joined: Wed Feb 09, 2005 2:23 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 12:49 am

thx all for the input.....

the question has to do with lumping all 777's in the same category, and maybe forcing the smaller wingpsan models to taxi on a less then optimum route in order to maintain proper wingtip clearances on the airfield.
 
LAXspotter
Posts: 3227
Joined: Sat Jan 27, 2007 4:16 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 12:53 am

controllers never give specific models of aicraft. For example ..... "Cleared to land runway 24R southwest XXXX, you are following a Boeing 747 on final". Never the specific type.
"Patriotism is the last refuge of the scoundrel" Samuel Johnson
 
WestWing
Posts: 1133
Joined: Thu Feb 03, 2005 2:01 am

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 1:06 am

The difference between the wingspan of the (-200, -200ER, -300) and (-200LR, -300ER) is approx 4m (or 2m from centerline - which is what counts for clearance). Would ground controllers direct different models on different taxiways based on a 2m difference in clearance?
The best time to plant a tree is 40 years ago. The second best time is today.
 
CHRISBA777ER
Posts: 3715
Joined: Thu Mar 01, 2001 12:12 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 2:23 am

Quoting AirportGal (Reply 5):
maybe forcing the smaller wingpsan models to taxi on a less then optimum route in order to maintain proper wingtip clearances on the airfield.

Why would you want to do that? Surely it is the larger wingspan models which would have to take the less optimal routing?
What do you mean you dont have any bourbon? Do you know how far it is to Houston? What kind of airline is this???
 
Airportgal
Posts: 72
Joined: Wed Feb 09, 2005 2:23 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 2:52 am

Quoting CHRISBA777ER (Reply 8):
Quoting AirportGal (Reply 5):
maybe forcing the smaller wingpsan models to taxi on a less then optimum route in order to maintain proper wingtip clearances on the airfield.

Why would you want to do that? Surely it is the larger wingspan models which would have to take the less optimal routing?

No airline wants ATC to do that, for obvious reasons. I had heard at one airport this was the way they expected to handle the 777's - just wanted to see if this was the case at other airports, and if not, how they were easily able to tell the difference.
 
CHRISBA777ER
Posts: 3715
Joined: Thu Mar 01, 2001 12:12 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 3:04 am

Quoting AirportGal (Reply 9):
Quoting CHRISBA777ER (Reply 8):
Quoting AirportGal (Reply 5):
maybe forcing the smaller wingpsan models to taxi on a less then optimum route in order to maintain proper wingtip clearances on the airfield.

Why would you want to do that? Surely it is the larger wingspan models which would have to take the less optimal routing?

No airline wants ATC to do that, for obvious reasons. I had heard at one airport this was the way they expected to handle the 777's - just wanted to see if this was the case at other airports, and if not, how they were easily able to tell the difference

Does the 4m extra make really that much difference?
What do you mean you dont have any bourbon? Do you know how far it is to Houston? What kind of airline is this???
 
User avatar
zeke
Posts: 9944
Joined: Thu Dec 14, 2006 1:42 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 4:02 am

Quoting WestWing (Reply 7):
Would ground controllers direct different models on different taxiways based on a 2m difference in clearance?

Some taxiways do not have the wing tip clearance going past structures or the box of a particular aircraft stand, and they maybe limited to aircraft of a certain wingspan. Some taxiways and runways may not have the "pavement strength" to handle very high pressure tires.

The 5.3 m of additional length between the nose wheel and main gear limits the 300/300ER to take specific taxiways at airports (as the additional length increases the turn radius) that do not meet the normal standards for aircraft that long.

Hence airports are classified based on the maximum length and wingspan tire pressure they can handle without restriction, they may accept other aircraft, but would have specific procedures in place for them.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
 
flydreamliner
Posts: 1928
Joined: Sat Jan 07, 2006 7:05 am

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 4:10 am

I find that the easiest way to tell them apart are the engines. All 3 families of engines available on the 777 look distinctive. The PW4000s do not have the spiral painted on the screw of their fan (they have an offset straight line instead), the GE90 and RR Trent 800 both have the spiral on the screw, but are noticably different in proportion, with GE90 having a broader fan. In any event, the eccentric fan blades on the GE90-110/115b make the 77H/77L easy to discern when it is sitting still, the winglets give it away when in flight (or when viewed from above).

Quoting Zeke (Reply 11):

Some taxiways do not have the wing tip clearance going past structures or the box of a particular aircraft stand, and they maybe limited to aircraft of a certain wingspan. Some taxiways and runways may not have the "pavement strength" to handle very high pressure tires.

777-300ER fully loaded has the highest load per tire of any aircraft, if I am not mistaken. I believe that oddly enough, the 727-200 had the highest loading per tire previously (if you'll notice, 727 has only 2 tires on each of its main gear) i believe.
"Let the world change you, and you can change the world"
 
Airportgal
Posts: 72
Joined: Wed Feb 09, 2005 2:23 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 5:37 am

Quoting FlyDreamliner (Reply 12):
777-300ER fully loaded has the highest load per tire of any aircraft, if I am not mistaken

you are completely mistaken..... consider max ramp weight and number of main gear tires of twin aisle aircraft.... (777,000 lb, 12 wheels vs 840,400 lb, 12 wheels, for example)

Quoting Zeke (Reply 11):
Some taxiways do not have the wing tip clearance going past structures or the box of a particular aircraft stand, and they maybe limited to aircraft of a certain wingspan. Some taxiways and runways may not have the "pavement strength" to handle very high pressure tires.

yup - many Jepp charts clearly state no 747-400 / 777-300ER on certain taxiways, for example, based on wingspan - whereas 777-300 should not be restricted on these routes.

Just asking if there are airports out there making the extra effort to differentiate between the models - on behalf of the airlines who don't opperate the larger models.
 
Tornado82
Posts: 4662
Joined: Thu May 26, 2005 10:19 am

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 7:11 am

Quoting LAXspotter (Reply 6):
controllers never give specific models of aicraft. For example ..... "Cleared to land runway 24R southwest XXXX, you are following a Boeing 747 on final". Never the specific type.

And, at least from my experience, they don't specify from ERJ's and CRJ's. It's just "Cherokee 6 Foxtrot Lima cleared to land runway 6, you are following an RJ on 3 mile final" or something of the sort... whether it's a Skywest CRJ-700 or an ExpressJet ERJ-135.
 
Airportgal
Posts: 72
Joined: Wed Feb 09, 2005 2:23 pm

RE: 777-200/-300 And 777-200LR/-300ER

Thu May 10, 2007 9:31 pm

does Ground Control have information on the flight strip to determine whether the a/c they are "seeing" is a -200/-200ER or a -200LR?
 
OldAeroGuy
Posts: 3208
Joined: Sun Dec 05, 2004 6:50 am

RE: 777-200/-300 And 777-200LR/-300ER

Fri May 11, 2007 1:41 am

Quoting FlyDreamliner (Reply 12):
777-300ER fully loaded has the highest load per tire of any aircraft, if I am not mistaken.



Quoting AirportGal (Reply 13):
you are completely mistaken..... consider max ramp weight and number of main gear tires of twin aisle aircraft.... (777,000 lb, 12 wheels vs 840,400 lb, 12 wheels, for example)

Airport Gal is correct in describing the difference between a 773ER (first set of numbers) and a A346IGW (second set of numbers).
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
KELPkid
Posts: 5247
Joined: Wed Nov 02, 2005 5:33 am

RE: 777-200/-300 And 777-200LR/-300ER

Fri May 11, 2007 2:39 am

Quoting AirportGal (Reply 15):
does Ground Control have information on the flight strip to determine whether the a/c they are "seeing" is a -200/-200ER or a -200LR?

That's exactly what I was thinking, the type information is on the flight strip....

but when you get right down to it, other than the taxi routes mentioned above, since when does a controller need to know that, say, 747 #1 is a 747-100 and 747 #2 is a 747-400ER?  Wink
Celebrating the birth of KELPkidJR on August 5, 2009 :-)

Who is online

Users browsing this forum: No registered users and 10 guests