Full length Taxi

[bmwstormer]

Hi, I am new to listening to ATC (KLAX).  I frequently hear ATC give the command, "taxi full length."  Does this mean that the plane has clearance to take off using the full length of the runway? Or is an instruction to taxi the entire length of the taxiway instead of an earlier point?  Thanks very much for the help. If someone has a list of explanations of common terms that would be more than helpful!

[Chananya Freedman]

your right! when LAX says "full length" You can use the full length of the runway to take off. When they say clear for take off from taxi way fox tort or from echo 8 from north side that means they are not using full length. When they are using taxi way fox trot, you are listening to frequency 120.95 tower south! When you hear echo 8 or run way 24 that mean your on the north side 133.9. Hope this makes it a lil clearer! 

[bmwstormer]

Thanks for the reply.  Is the full length taxi used mostly for heavies? Or to conserve fuel by having to use less power?

[Chananya Freedman]

that you may have to ask somebody else about! And it may also depend on what type of Air Craft preceded that plan. Any one with more info could help because I would love to know also.

[atcman23]

Sounds like there are traffic initiatives at LAX.  While the "taxi full length" would literally mean to taxi the full length of the runway, it's not something that you hear at every airport (you'll usually hear "taxi to runway 2-8 via taxiway Echo, Golf, Hotel, Hotel One... etc).  Someone familiar with LAX operations may be able to clarify why the "taxi full length" is used.

As for the takeoff, when you hear "<Callsign>, runway 2-8 FULL LENGTH cleared for takeoff" that means the aircraft is LOCATED at the end of the runway and that aircraft is cleared for takeoff.  When you hear "<Callsign>, runway 2-8 at Bravo (or other intersection), cleared for takeoff" it means that the aircraft located at that intersection is cleared to takeoff from that intersection. 

The difference?

Controllers must use these terms when one aircraft wants to use the entire length of the runway for takeoff and another only wants to use a certain length of the runway (larger aircraft needs more runway to takeoff than a smaller aircraft that were both taxied to the same runway for takeoff).  If they have two aircraft holding short of the same  runway (one at the end and another at an intersection), they must mention either full length to the aircraft at the end of the runway or the intersection name to the aircraft departing from an intersection.

It's not exactly easy to understand right away and it's easier when you can both see and hear the instruction in use at an airport to better understand, but I hope this helps a little bit!

[jmx53]

I wonder about this instruction also. 

GROUND: If a pilot is instructed by ground to taxi to a runway, isn't it assumed that the instruction indicates taxi to the holding point next to the threshold (or displaced threshold if there is one) of that runway unless a taxiway intersection is specified?  Why would "full length" need to be added?

TOWER: If an aircraft is already at the threshold holding point before contacting Tower for take off, why would tower need to add the "full length" instruction when the aircraft would be entering the runway from there anyway?

I have heard the "full length" instruction while listening to tower at KBOS and KLAX usually added to the "position and hold" instruction.

[atcman23]

Local control will use the "full length" term only when one aircraft is holding at the departure end and another is holding at an intersection of the same runway.  It is there to clarify exactly which aircraft is supposed to taxi onto the runway.

The same applies for the aircraft at the intersection (...Runway 2-8 at intersection Bravo, cleared for takeoff).  If ALL aircraft are departing from the departure end of the runway, the phrase is not used.

[w0x0f]

This deadly runway accident was the impetus for "full length" and "runway XX at intersection X" requirements for the tower controller.  "Full length" is required when intersection departures are advertised on the ATIS or when another aircraft is taxied to an intersection for departure on that runway.  Take the time to read this NTSB report.  It's like they say, it is usually not one incident, but a chain of incidents which lead to an error or accident.   

http://www.ntsb.gov/Recs/letters/2001/A01_23_26.pdf

w0x0f

[tyketto]

The other thing to consider at LAX is that when Tower gives the call to taxi full length, it means to go to the full length of 25R. Quite often there are intersection departures at taxiway F, which also happens to be the easternmost taxiway that can access 25L full length. Props for the most use F, as well as those GA and cargo aircraft coming off the south side parking to turn left on B for the full length. Not only does that help with the sequencing, but provides additional separation between the jets and the props when they depart 25R.

Also, Jets may use F for departure if they have flow time/metering to meet at their destination.

BL.

[jmx53]

Thanks for the posting that NTSB report.   

[atcman23]

That's the accident that I remembered.  Just didn't have time to pull up the report.  Thanks for posting it though; you can learn a lot from it (and others).