Runway Line Up Technique

[777boeings]

It was mentioned to me a couple of years ago, that when lining up on a runway for take off, the yellow line should be followed throughout the line up. The yellow line however, often describes a shallow turn and therefore uses up more available runway.
Prior to this I had always practiced a ninety degree turn in order to maximize take off distance.
Does anyone know if there is any formal documentation to support line up following the line?
I’m not really looking for opinions here but rather some validation of the recommended technique so I can pass the information to my trainees.

[The Actuator]

The yellow line is a turn off line from the runway to the taxiway. Line up using a 90 degree turn, to maximise runway length so as to validate your take off speeds and distance calculations.

[SuperRanger]

I agree with Actuator, yellow line is for led-out not led-in. Personally, I use 90deg to maximize the runway. Our specific takeoff charts calc allows for 75' of line-up.

Sr

[de facto]

Max alignment distance should be in your perf data.(under ASDA line up).
Boeing recommends if at all possible use shortest line up every flight(most of time it is a 90 degree line up), every meter saved is a good meter!

[BOAC]

It is not uncommon for runway performance charts to specify the line-up manoeuvre used for the relevant calculations.

[Checkboard]

The entire runway surface is inspected for FOD (Foreign Object Damage), is built to the same weight spec and has the same wing clearances at the edges for obstacles - so there is no reason to specifically follow a yellow line on a runway (providing you don't taxi off the edge, of course!)

On a taxiway, however, different areas are built to different weight spec, the lines are painted specifically to guarantee wing clearance, and off the yellow line you find much more FOD.

I once took a shortcut, off the yellow lines, on the apron and picked up a nail in a tyre - so spent four hours with an AOG aircraft waiting for a replacement. :O At least if you follow the lines, you have a good chance that the aircraft ahead has followed the lines, and picked up any FOD before you.

[break_break]

Actuator has answered correctly as far as the yellow line is concerned.
In addition, to date, there hasn't been one single case of heavy MTOW (even pass the 1000K IBs mark) running off the other end due to poor line up technique. However, you can easily name quite a few incidents of big tubes scrubbing some mud/grass/taxi edge lights or even getting stuck during line up due to the every-inch-counts mentality (well at least that's how most of us were taught anyway).
The performance does allocate some sacrifices and conservatism, depending on a/c type. I personally will neither follow the yellow nor a 90deg, somewhere in between, with careful judgement of my wheel clearance being the priority is IMHO, the most practical way to line up.

[GlueBall]

Not all taxiways are equal width, the yellow line is just a guide denoting pavement center relative to the turn radius. If your airframe is a long tube, at some airports your outboard mains could clip an edge light if you were to keep the nose wheels on the line in a turn. :eek:

[capt. solipsist]

it is documented in airbus fcoms, it is called the oversteer technique. there are also figures in how much asda you eat up for different line up techniques.

[Capn Bloggs]

It is not uncommon for runway performance charts to specify the line-up manoeuvre used for the relevant calculations.
Not Uncommon? Every crew should know what their RTOW charts use as the lineup allowance.

[BOAC]

Every crew should know what their RTOW charts use as the lineup allowance.It would appear some may not?

[320 driver]

Taxiway clearance is defined in the license for most UK aerodromes and for most the geometry must guarantee that gear remains on the defined surface with either pilot over the yellow line for all types approved for the aerodrome, so you can usually rely on staying on the concrete if you follow the lines.

A full 90 degree turn on is, IMHO, counter productive. Extra tyre wear/damage, more torsional stress for gear (especially on bogey types) and as anyone who operates out of LHR or LGW will know a very, very high price in occupancy and thus capacity/congestion. The risk of coming to grief on account of 10-20m? I would say miniscule.

I use and train that a comfortable moderate turn typical of a 90degree turn on a large taxiway does the job.

As for those who seem to be doing the shocked maiden aunt act at those who don't know the exact line up allowance, it would be worth taking a realistic view that there is a mountain of information that is far more likely to hurt you through ignorance. Claiming that accurate knowledge of this figure is some kind of absolute is ridiculous, concentrate on the stuff that kills people every year.

[good spark]

777
if you do a 90 on to the centerline are you sure the gear on your type can stand that? ( triple axle truck beams) how long are they, please tell me




gs

[DERG]

Anyone any idea just what the forces are on the main gear when you do a turn like that?

"A full 90 degree turn on is, IMHO, counter productive. Extra tyre wear/damage, more torsional stress for gear (especially on bogey types) and as anyone who operates out of LHR or LGW will know a very, very high price in occupancy and thus capacity/congestion. The risk of coming to grief on account of 10-20m? I would say miniscule."

An understatement.

[de facto]

DERG,

counterproductive?Boeing disagrees with that for sure and so do I.
increased tyre wear?thats funny!
Taxiing fast yes i would agree would wear the nose tyre (737) but a properly made 90 turn(proper speed with thrust idle) would do nothing to your tyre.
However using improved climb speeds and rejecting at V1,will get you off the end,that day you may have wished to saved these precious meters as recommended by Boeing....

[ImbracableCrunk]

I think the nose wheel would be fine, but a double or triple bogey would grind a few wheels, I should think.

[DERG]

You misunderstand. I mean the TWIST forces and the MAIN GEAR. The nose gear is not the issue.

See what I mean?...the diameter of the wheel sets are not that great in comparison to say the total load of 400 plus tonnes shared across the set.

Think Lufthansa had a failure other week on a B74 at FRA. The main gear struts take a HELL of a twist load. Bally dance pirouet stuff. See?

In fact it would be interesting to learn how FedEx adresses this issue at Memphis. I would bet they use nice big arc turns...

[320 driver]

increased tyre wear?thats funny!

Can you confirm that you actually believe that such a turn will produce no tyre wear. If so I am astounded.

A sharp 90 degree turn WILL produce tyre wear on any type since the inside wheel will be rotated to some extent about its contact point and will scuff just like a car tyre when doing a low speed turn. On a bogey type there is also a substantial sideways force on the wheels as the bogey turns (Boeing officially recognise this). Perhaps an idea to check the technical details before you laugh.

[de facto]

UNHOOKED,

TODA line up is based on the main gear from start of runway not the whole fuselage.
ASDA line up is based on the nose gear.

Ill leave the twisting issue for maintenance,and will continue to follow Boeing takeoff safety guidelines.

320 driver,
i thought funny not to consider 90 turn because of increase tyre wear,fast taxy for example will increase tyre wear by much more.

[320 driver]

i thought funny not to consider 90 turn because of increase tyre wear,fast taxy for example will increase tyre wear by much more.

Where have you found this information. It sounds dubious to me as I always understood tyre wear when taxying in a straight line is negligible. Remember being told in tech course for ATPL that braking and turn were the chief cause of tyre wear. Can you confirm the source of your information.

[DERG]

Tyres are cheap. The stress is on the members and wing roots. Hard turns are not good. Can happen quite fast in the life of the airplane. I bet Japan operators have these issues on the short hops. As well as the freight guys of course. See FedEx at Memphis.

[fireflybob]

With my operator 90 degree turns are limited to 10 kts max to minimise tyre wear (monitored by OFDM so no cheating!)

[de facto]

32o driver,

Flight crew training manual will give you such info about NOSE wheel tyre wear during fast taxi...(B737).

Concerning the line up thing,here is the copied info taken from boeing safety guide:
2.3.6.3 Runway Lineup
Positioning the aircraft on the runway in
preparation for takeoff is an important element
in maximizing the amount of pavement available
for a possible RTO maneuver. Correction to the
available runway length can be made to the
takeoff analysis on those runways where it
is not possible to position the airplane at the
beginning of the published distance.
Correct runway lineup technique should always
be practiced regardless of whether or not there
is excess runway available. Even if an allowance
has been made, it is up to the crew operating
the flight to align the airplane on the runway
using the shortest possible distance. If they
can do it in a shorter distance than taken into
account by their company, then there is that
much extra margin for the takeoff.'

As i said i let the wear/tear for the airline to check, Im concerned about my flight,my passengers on the particular day.

FIREFLY<
On a 737/800-900, a 9 kts entry followed by a 6-7 knots turn will get you lined up without thrust.10 kts into the turn is bit too fast i think.

[320 driver]

DERG, I agree that member/strut/root strain is a major concern. However, if your tyres are cheap can I have the name of your supplier. Although one wonders whether Air France still use cheaper retreads since the Concorde accident.

[DERG]

"line up and wait" hope the main gear is OK....

"line up and hold" hope the main gear holds up

320

That whole Concorde tyre thing was a JOKE.
As though Michelin was above making the proper tyre
which they could so easily have done. It was a French thing.

[320 driver]

de facto

airbus give reference to tyre wear at high speed but specifically refer to turning at high speed as the issue.

An aircraft manufacturer does not have to take account of the commercial environment. A Captain does (or should) and any Captain who states that wear/damage issues are someone elses concern would be very unwelcome in my airline. Its your job to balance these issues not just take a blind view.

On a limiting runway I absolutely agree that one should maximise the TORA but on a generous runway operating well inside liimts (LHR27L on a moderate weight medium twin) there is NO EXCUSE for the additonal inconvenience/cost to others and your own airline.

[de facto]

airbus give reference to tyre wear at high speed but specifically refer to turning at high speed as the issue.

NOt boeing, high speed taxi on a straight line will damage the side walls of the nosewheel.

If you give me the info every flight about this extra runway based on my calculated V1 (assumed thrust or not) (medium weight or not)and I will consider using the extra distance for line up..
I have other ways to save money to my airline but thanks.It seems Im excused as we are closely monitored....

No EXCUSE? THAT is funny:E

[DERG]

What brand tyres are used in China please?

Has Hankook got round to this yet.... or are they mostly Bridgestones?

[de facto]

Certainly better quality than those you use in your LOCO airline.:E

[DERG]

We get ours at the wreckers yard..

[320 driver]

de facto

If you think it is acceptable to inconvenience others and cause delay and cost to them just because you aren't bright enough to work out when it is or is not appropriate to take a practical approach to your operation then I can only sigh with relief that you are not UK based. Please tell me you're not a Captain. That would be scary.

[de facto]

:hmm:
I am causing delay now?
I am well familiar with loco UK airports...never had any issue on my 'lenghy' costly line up method.
If im asked to expedite,i will...dont take me wrong...but a long line up followed by a stop and then a take off roll, i say N0.
Ill leave that to your superior UK captainship.

OH and i do this crazy stuff based on a UK caa issued ATPL...thats food for thought.:ugh:

[DERG]

I'm losing the plot here......this "LOCO" stuff is confusing me..

Here we go: "Loco is Crazy in Spanish"

Could be BA "speak" due to merger with Iberia?

[de facto]

:E

Or maybe LOCA....

[DERG]

A song?

http://en.wikipedia.org/wiki/Loca_(Shakira_song)

right....

[de facto]

seriously A320

If Im 3 T below my runway limit weight...how much extra stopping distance would that give me? 200m?100m?50m?
What about 4Tonnes?or 5T?
Does BA give you this info?

What if on that day,i were slower to initiate reject that day?(tired..)..how much these few extra knots convert into meters?

Yes we must balance between many factors, if im cleared for immediate take off, i will use shallow entry as thrust is increased during the line up which counteracts the loss of runway length./or shallower entry if runway is covered by snow or narrow runway...

But please get off your BA HORSE and keep your Captain worth recommendations for your cadets..:suspect:

[DERG]

320 is off line...If there is doubt about runway length...why not

At the hold position...spool up the engine with the brakes on..then release say with throttle at 75%..

Or is this a big NO NO?

[de facto]

DERG,

Are you flying Jets?

[DERG]

at moment a Toyota Corolla until I get the Porsche insured..

jets are diff?

seriously...are jets diff to anything else?

are we talking jet blast behind here or what?

complaints from the tree huggers?

[Right Way Up]

BA may have an issue with 90 degree lineups since the incident up in ABZ a few years ago.

http://www.aaib.gov.uk/cms_resources.cfm?file=/Boeing%20737-436,%20G-DOCT%2006-07.pdf

[de facto]

Nothing wrong with a good old corolla...
Cant open the link, would be interested to read this report..most probably happened to a wide body.
Just read it briefly, he used more than 90 deg line up...and he stepped on the brakes until full thrust was set..

[DERG]

Tennis courts have a better surface than that :mad: runway had. Sir Robert McAlpine will be turning in his grave.

AAIB Bulletin: 6/2007 G-DOCT EW/C2005/07/01

[de facto]

My question wether you are flying a jet or not is that standing on the brakes with full thrust is useless and will increase the risk of foreign debris ingestion especially in crosswind conditions.
Rolling take off is preferred, line up, increase thrust,stable then full thrust.NO BRAKES.
Brake only if static run up is required due to icing conditions.

[de facto]

Good read.
the last text could be interesting for our BA friend:Safety Recommendation 2007-032
The Civil Aviation Authority should, during routine
audits of operators of ‘Performance A’ aeroplanes,
ensure that operators’ takeoff performance calculations
are consistent with the operation of their aircraft,
specifically with respect to the line-up position

[DERG]

Thats why I am NOT a line pilot....I love the MD-11 moments:E

As far as surfaces are concerned..

"For aircraft such as the Boeing 747, a 10 cm layer should be used"

A layer of what? Are these folks serious?:mad:

[320 driver]

de facto

At airports like LHR and LGW you are required to be in position to roll by the time the previous aircraft lifts off. If you are still p***ing about lining up when you are cleared for take-off you have wasted very valuable runway capacity. At these and many other airports the cumulative wasted capacity has an enormous cost in congestion, wasted fuel while queueing, arrival/departure delay costs. The cost runs into millions for the airlines concerned and has a significant environmental impact too. If you think its okay to take your own sweet time unless ATC have told you to expedite you are not only selfish and wasteful but are also in breach of the UK AIP.

[de facto]

And the time difference between your lining up and a 90 time is what?
If ATC clears the traffic for takeoff and then a tells you to line up,hiw long dies it take a jet to get airborne???
Are you really that bright?or just trying to be a smart @@?
Please fwd me the AIP where it mentions any line up time allowance,id be most grateful.

[DERG]

Last one I timed was in the A32/B73 class and I think it took 23 secs from roll to take off.

[777boeings]

de facto,

Much appreciated, the reference you posted from the Boeing Safety Guide was exactly what I was looking for.

[de facto]

777,
you are very welcome.

[Ex Cargo Clown]

de facto,

I would love to know what type you fly, is it an An-224 with four engines turned off, or maybe a B-52

Are you honestly saying you need every single inch available for ASDA purposes on a 4000m runway?

Having just done a "fag packet" calculation, you'd lose more than 20m in distance if about 40 pax were overweight on the standard by 20 Kgs in an A320, but you would rather put stress on a piece of very highly stressed metal to save yourself 20m. The mind boggles.

[lexxie747]

mr clown!
consider yourself reactivated...

[Right Way Up]

Just a couple of thoughts:

1) On a flex/derated takeoff there is a fair extra margin already gained from the actual temperature being lower than flex temp. (lower TAS), so not doing a 90 degree turn will not be a problem. (as long as the line up is sensible)

2) On a performance limited runway it will be an issue. If you feel incapable of performing a 90 degree turn then adjust your performance to counter the extra distance used in lining up.

[de facto]

Correct that using ASSUm Temp, your stop distance will be less.(lower TAS).
By how much?I dont know.
The only thing is that any time my weight is below the Runway limit weight ill get some extra distance margin,but how much?
I leave the stopway to the CLOWN above.

As far as im concern im done here, initial poster obviously was satisfied by the BOEING recommendation i posted.

[Denti]

We had a question about that issue some time ago when a colleague trying to do a 90° lineup on a non-standard cleared 4000m runway slipped into the grass on the opposide side (the airport only cleared 10m around the yellow line). The interesting answer from boeing was that a minimum distance lineup is considered in the performance software with a usual distance between end of runway and maingear between 2 and 6m. The difference between actual and assumed temperature is taken into account and with derate plus assumed temperature plus improved climb speed schedule a 4000m runway can become very short indeed even for a lightweight 737-700.

Lately they introduced an option for increased lineup allowance which allows distances up to around 100m from the end of the runway, how much is shown for each runway. However, it is the operators choice if he makes that option available or standard for the performance calculation.

[Ex Cargo Clown]

Spot on Denti, why risk the chance of a runway excursion for the sake of trying to "steal" a couple of metres of tarmac.

Even something as stupid as a temperature change will effect your performance by more than 10 metres, I think that for every two degree increase there is a 0.08 difference in EPR roughly on an A320, so say you do an assumed temp T/O with a slightly off ATIS temp or TAT reading then you will increase your T/O length.

[Lord Spandex Masher]

And yet you want to reduce it even more?!

[misd-agin]

If Boeing didn't want the aircraft making 90 degrees turns they'd have it listed as a limitation.

As previously noted some aircraft do have 10 kt restrictions on 90 degree turns.

[de facto]

Cargo clown,
did you read post 37 and the whole Denti post?can you read?

[Joesoap]

Hi there!

Can you please name an official document where it says that the yellow line at the end of the runway is a "taxi-out" line and not a "taxi-in" line? Hard to quote to a trainee without documentary proof

Thanks

[Amadis of Gaul]

Just tell the trainee to do as you tell him, cooperate and graduate.

[Intruder]

Can you please name an official document where it says that the yellow line at the end of the runway is a "taxi-out" line and not a "taxi-in" line? Hard to quote to a trainee without documentary proof
Especially if you're wrong...

FAA AIM 2-3-4.b:
b. Taxiway Centerline.
1. Normal Centerline. The taxiway centerline is a single continuous yellow line, 6 inches (15 cm) to 12 inches (30 cm) in width. This provides a visual cue to permit taxiing along a designated path. Ideally, the aircraft should be kept centered over this line during taxi. However, being centered on the taxiway centerline does not guarantee wingtip clearance with other aircraft or other objects.

AIM 2-1-5:
c. Taxiway Centerline Lead−Off Lights. Taxiway centerline lead−off lights provide visual guidance to persons exiting the runway. They are
color−coded to warn pilots and vehicle drivers that they are within the runway environment or instrument landing system/microwave landing system (ILS/MLS) critical area, whichever is more restrictive. Alternate green and yellow lights are installed, beginning with green, from the runway centerline to one centerline light position beyond the runway holding position or ILS/MLS critical area holding position.

d. Taxiway Centerline Lead−On Lights. Taxiway centerline lead−on lights provide visual guidance to persons entering the runway. These “lead−on” lights are also color−coded with the same color pattern as lead−off lights to warn pilots and vehicle drivers that they are within the runway environment or instrument landing system/microwave landing system (ILS/MLS) critical area, whichever is more conservative. The fixtures used for lead−on lights are bidirectional, i.e., one side emits light for the lead−on function while the other side emits light for the lead−off function. Any fixture that emits yellow light for the lead−off function must also emit yellow light for the lead−on function. (See FIG 2−1−14.)

[Joesoap]

Nice info thanks. This seems though, to pertain to lead-in and lead-out lighting/marking as per FAA rules. Even without lighting involved, lead-in / lead-out marking is mandatory as per FAA circular 4.2.b.(2) https://www.faasafety.gov/files/gslac/courses/content/25/181/150_5340_1K_change1.pdf
However according to ICAO, there exists a requirement to have a lead-out line when a taxiway is meant as an exit - there is no mention of a lead-in.
Ref 5.2.8.7 Visual aids for navigation annex 14, it recommends a curved lead-out line when a taxiway serves as an exit to a runway
http://www.orga.nl/pdf/Chapter%205%20-%20Visual%20Aids%20for%20Navigation.pdf

I guess one can use a lead out line as a lead-in when one exists, as long as regard line up requirements for the runway in question, are met. Most airlines these days lay out their own line up techniques with runway length loss built into their OPTs and outlined in their Ops manuals.

Cheers

[de facto]

Hard to quote to a trainee without documentary proof
Would have thought it being basic knowledge...

[despegue]

Unbelievable!

Are there any Airline Pilots on this site?!

Line-up technique is simple! Basic airmanship and taught during first line training...

When at the holding point and ATC tells you " line up and wait", you line up according to what your performance calculation has given you as distance. Normally, this means a 90 degree turn on the runway. Then you hold at that position untill cleared for TO. Unless a run-up is necessary( icing conditions,...) or when short field performance, no need to run-up. Release brakes, increase thrust to " stable value" and then prss TOGA.

When at the holding point and cleared for TO, do a rolling take-off, trying to have TOGA when aligned with the runway. No rolling take off in case of contaminated runway or if TS in the vicinity of the field ( wx-check of initial climbout path)
ALL basic Airmanship ladies!

And no, I do not give a damn about any ATC screaming. Not my problem. My ONLY responsibility when cleared TO is to operate the aircraft in the safest way possible and in accordance to the Manufacturer FCTM.

[No Fly Zone]

Three simple thoughts:
1. If I could, I line up that then BACK UP to get he rear most wheel at the edge of the RW. I know... the chiefs and the MX folks take a a dim view of backing up with jets, but it IS possible.
2. When not comfortable with taxi markings - and even at the risk of being un-cool, I'd stop and request a guide.
3. When all else fails, one can also SLOW the taxi pace to walking or less through critical turns. Being a little slow is always better than dropping a wheel or an entire truck into the mud. :ok:

[Skyjob]

Can you please name an official document where it says that the yellow line at the end of the runway is a "taxi-out" line and not a "taxi-in" line? Hard to quote to a trainee without documentary proof

The painted line have NOTHING to do with lineup distance.

Aerodromes make use of intersection take-offs to maintain runway capacity and efficiency.

4.2 Due to the lack of consistent guidance, aerodromes have chosen 3 different origins to calculate the distance:

a) The downwind edge of the taxiway, extended ahead to meet the runway centreline;
b) The upwind edge of the taxiway extended ahead to meet the runway centreline;
c) The tangent point where the taxiway centreline curve meets the runway centreline.

4.3 When deciding on the origin of the intersection declared distance, consideration must be given to understanding that the origin of full-length declared distances is, in most cases, the end of concrete/asphalt; therefore, following aircraft line-up, the origin is behind the aircraft. An allowance for the length of the aircraft is taken into account when calculating the remaining distance. ICAO publishes the following in Annex 6 Part I, Chapter 5, paragraph 5.2.8.1: “In determining the length of the runway available, account shall be taken of the loss, if any, of runway length due to alignment of the aeroplane prior to take-off.” Aircraft performance manuals make the same calculation for line-up allowance irrespective of where that line-up occurs along the runway. Therefore, flight crews would expect to calculate a similar correction distance at an intersection departure as for a full-length departure, regardless of where the origin is located.

4.4 The use of the downwind origin as the basis for calculating declared distances from a runway intersection provides consistency with the full-length calculation.

[Intruder]

The painted line have NOTHING to do with lineup distance.
Your quoted clause 4.2.c appears to contradict that.

[Skyjob]

Your quoted clause 4.2.c appears to contradict that.

Maybe the word NOTHING should've been replaced with USUALLY as it is valid in 2 out of 3 cases, apologies.

[Skyjob]

Allow me also include the UK guidelines from CAP 168 (https://www.caa.co.uk/docs/33/CAP168.PDF) which can be found in 13.5 Declared distances from runway intersections.
Declared distances from a runway intersection shall be calculated from the downwind edge of the taxiway.
Contained within are Figures 3.14 through 3.16 which show that the distance calculated is NOT coinciding with the markings and lines, validating my earlier statement that the lines (in UK) had nothing to do with lineup from intersections.

Furthermore, the document shows that any lead-in lines onto runways are not taken into account for takeoff distances available, merely aid the pilot to position on the runway.
The origin of full-length declared distances is, in most cases, the end of concrete; therefore, following aircraft line-up, the origin is behind the aircraft. An allowance for the length of the aircraft is taken into account when calculating the remaining distance. ICAO publishes the following in Annex 6 Part I, Chapter 5, paragraph 5.2.8.1: "In determining the length of the runway available, account shall be taken of the loss, if any, of runway length due to alignment of the aeroplane prior to take-off." Aircraft performance manuals make the same calculation for line-up allowance irrespective of where that line-up occurs along the runway. Therefore, flight crews would expect to calculate a similar correction distance at an intersection departure as for a full-length departure, regardless of where the origin is located. The use of the downwind origin as the basis for calculating declared distances from a runway intersection provides consistency with the full-length calculation.