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I had an interesting occurrence at the start of a recent flying lesson, at an aerodrome with ATC service. We were holding at A and completed our power checks. We hadn't requested nor been offered an intersection departure, and that is not a usual procedure at this aerodrome.

"G-AB ready for departure"
"G-AB via A line up and wait runway 23"
"Via A, line up and wait, runway 23, G-AB"

Following this, I entered the runway and turned to backtrack to the threshold. At this point my instructor said I should have turned the other way to line up at the intersection, because they didn't clear us to backtrack. Was he right to complain, or was I correct to use the full runway length?

Notes

A is only about 20 m from the runway threshold, and this runway is huge, so it makes little practical difference in this case.

At this aerodrome, they usually give LUAW instructions as "via [point], enter, backtrack, line up and wait runway 23". I checked CAP 413, and it doesn't mention "enter, backtrack, line up and wait" as phraseology, so I'd expect a clearance to LUAW entitles you to the whole runway unless you've already agreed an intersection departure. However, it's CAP 413 section 4.24 that introduces the "via A" phrase, and it has this to say:

When line-up will take place at a position other than for a full-length runway departure the intermediate 'Holding Point' designator shall be included in the line-up instruction. Controllers may include the runway 'Holding Point' designator in any other line-up instruction when considered necessary.

It gives an example, and the only other example with "via" is in the context of an intersection departure. As I said, at this aerodrome they usually include the "via"; maybe they just always consider it necessary. Is not saying "backtrack" here significant, even though it's not a standard part of a LUAW instruction?

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  • $\begingroup$ If in doubt, ask the controller. For what it's worth, if I were the controller in this situation, I would not have expected you to backtrack. But I don't work in the UK, so your rules may be different. $\endgroup$ – J. Hougaard Aug 12 '18 at 13:36
  • $\begingroup$ Good question and I am interested in an authoritative answer. I don't have a reference but I seem to remember the FAA in the US gives explicit permission for back tracking - mainly because of the extra time involved. ATC uses the words "permission granted" or back taxiing "approved" which implies they have and enforce authority to do it. $\endgroup$ – jwzumwalt Aug 12 '18 at 15:56
  • $\begingroup$ I suspect if you had asked to backtaxi to use the full runway, tower would have come back with "Nxxxxx, cleared to backtaxi runway xx" or "Nxxxxx, negative, hold for traffic on base" (with the plane type called out), or perhaps "Nxxxxx, cleared to backtaxi runway xx, expedite for traffic on base (or final)" with the plane type called out". And you would read back the clearance, and then backtaxi or wait. Otherwise you might expect to be scolded by the tower, especially if you caused a go-around situation for another plane. $\endgroup$ – CrossRoads Aug 13 '18 at 0:10
  • $\begingroup$ If you can put the airport diagram it would be more clear. Everybody is trying to answer as if it’s a intersection takeoff, but your’s is definitely not. $\endgroup$ – Kolom Nov 17 '19 at 8:38
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Your instructor was correct. According to the CAA Radiotelephony Manual[pdf], since the clearance you received included "via A" your clearance was not for a full length takeoff.

From the Radiotelephony Manual, chapter 4:

enter image description here

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  • $\begingroup$ That's the same section I quoted in the question, and it doesn't clearly imply what you claim. It says that if it's an intersection departure, they must say "via A", and in any other line-up instruction, they may say "via A". $\endgroup$ – Dan Hulme Aug 13 '18 at 16:22
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    $\begingroup$ But in your question you indicated that they did say "via A," so that indicates that is was an intersection departure. $\endgroup$ – TomMcW Aug 13 '18 at 16:25
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I would say that backtrack, takeoff, holding on the runway, and entering the runway for any other reason (for example to cross) are distinct actions that require readback.

ICAO's Annex 11 (here reproduced from Appendix A of their Manual of the Prevention of Runway Incursions) regards all these items to require specific readbacks as clearances or instructions, and itemises them individually. The logic being - a clearance to take off is not entailed by a clearance to enter the runway, or to line up, or do anything else. Why should a clearance to backtrack be so thought of?

In Australia (my jurisdiction) this para from Annex 11 is reproduced pretty much verbatim in our own AIP and MATS.

I have seen in Australian Pilot Guides (advisory documents) that backtrack approval is specifically required, though I haven't seen that replicated in the AIP itself. A cursory glance through the CARS etc hasn't turned up anything either. The ATC Manual Of Air Traffic Services in Australia, however, says specifically as 12.3.2.8

Backtrack clearance

When the pilot has requested backtrack with the 'READY' or 'REQUEST LINE UP' report, give the instruction to 'BACKTRACK RUNWAY (number)' before the line up instruction.

Note: An ATC clearance to line up does not authorise the pilot to backtrack on the runway.

And at 12.3.2.9

When entry to the runway will be from a position that is not adjacent to the runway threshold and a pilot reports 'READY' without requesting or accepting an intersection departure, or requesting backtrack, ascertain the pilot's intentions prior to authorising entry to the runway.

Given this, if we were able to extrapolate something similar to your procedure (and most of our procedures are quite like yours and ICAO on things like runway separation, we have conditional clearances etc and use standard phraseologies), I would say what SHOULD have happened in this scenario is that you should not have initiated backtrack on the runway without specifically hearing and reading back the instruction to backtrack (a takeoff is not a line up, and neither of those are a backtrack), but that ATC should also have queried your intentions because you had neither requested a backtrack nor an intersection departure.

I can't speak certainly for UK ops, but I'd say we're probably fairly close. We even just adopted your "flight level two hundred" phraseology! :D

Also, if you think about things like runway sep and flow to the runway, it makes sense why it would make a material difference to ATS if you needed to backtrack or could depart via the intersection, and why they would want to know before letting you into the runway. Flying GA out of a smaller airport it would matter, but it's easy to imagine at busy airports with maybe a couple of minutes between subsequent arrivals it makes all the difference in the world.

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  • $\begingroup$ Your source is really good and unambiguous. If it were for my locale I would accept your answer for sure. I don't accept your other reasoning though. A clearance to take off or line up does imply a clearance enter the runway (though sometimes controllers do say that explicitly), so I don't buy them being "separate actions". Also, while I agree that intersection departures are useful for operations, that doesn't mean I should expect one without having talked about it. "Land after" and "behind" clearances are similarly useful but they still need to be explicitly agreed! $\endgroup$ – Dan Hulme Nov 15 '19 at 19:36
  • $\begingroup$ Well, I can certainly see how you would be leery of accepting because of jurisdiction (though we're pretty closely aligned as far as a lot of this most fundamental ICAO stuff goes), but I would disagree with the rest of your reasoning. Yes, a clearance to t/o, backtrack, cross etc DOES include a clearance to enter the runway (by necessity), but that doesn't imply the reverse is also true. If I've crossing a runway, that does not allow me to stop on the runway, which a line up does. They (cross, backtrack, takeoff, line up) are distinct in ICAO for good reason. $\endgroup$ – nubbins Dec 9 '19 at 11:12
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You were correct in using full length. When intersection departure is initiated by ATC it shall be accepted by the pilot. As ATC did not mention intersection depature, which also means you did not accept a departure from Alpha, the clearance from ATC is for full length. Also take note that the aerodrome your using has to comply with conditions of 6.5.2.2 to 6.5.2.6 in the regulations below in order to be able to use intersection dep.

Below you can see the regulations. This is from the current editon ICAO DOC 7030 (Regional Supplementary Procedures).

6.5.2 Intersection take-off

6.5.2.1 An aircraft may be cleared to depart from a published intersection take-off position upon request of the pilot, or if initiated by ATC and accepted by the pilot, provided that all of the conditions of 6.5.2.2 to 6.5.2.6 are met.

6.5.2.2 The declared distances for each published intersection take-off position shall consist of the following: a) take-off run available (TORA) from the intersection take-off position; b) take-off distance available (TODA) from the intersection take-off position; and c) accelerate-stop distance available (ASDA) from the intersection take-off position. 1/11/13 No. 8 EUR 6-4 Regional Supplementary Procedures

6.5.2.3 The reference point from which the runway declared distances for a published intersection take-off position are measured shall be in accordance with the relevant provisions in the Air Navigation Plan — European Region, Volume II — FASID (Doc 7754), Part III — AOP.

6.5.2.4 Declared distances for an intersection take-off position shall be published in the relevant AIP, clearly distinguishable from full runway declared distances.

6.5.2.5 Information on the TORA from the intersection shall be issued when requested by an aircraft or whenever deemed necessary by the controller.

6.5.2.6 Signs shall be in accordance with Annex 14, Volume I.

Christian Speichert, ATCO.

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  • $\begingroup$ Disagree. Sure, the pilot has to accept the shorter distance, but it is up to the pilot to make the controller aware if backtrack is required. $\endgroup$ – J. Hougaard Nov 4 '19 at 17:32
  • $\begingroup$ The pilot should request clarification if unsure, that’s true. But it’s also up to the controller to issue the proper clearance in the first place. Which in this case should have been “G-AB, via (Alpha and) RWY 05, line up and wait RWY 23”. As the clearance here was "only" missing the “via RWY 05” I can understand why the pilot would assume that he is cleared for full length. In this case the intersection was not far from threshold, but in another you could have a significantly reduced TODA. $\endgroup$ – Christian Speichert Nov 6 '19 at 19:48
  • $\begingroup$ If proper phraseology is not used by the controller an assumption that the pilot should accept an increase in risk due to reduced TODA is unreasonable in my view. So, I agree Mr. Hougaard, the pilot should check that he is cleared to taxi on the RWY if unsure or given an inadequate clearance. But in aviation, sometimes, clearances are not always uttered in accordance with regulations and are based on an assumption of mutual understanding. In this case, my opinion is, that the more correct action was to proceed with the taxi for full length rather than set up for intersection departure. $\endgroup$ – Christian Speichert Nov 6 '19 at 19:49
  • $\begingroup$ Also, and this is not known in this instance, unless the intersection has published distances it is not allowed to be used for departure. In such an instance the controller would not only be breaking the rules if the pilot would line up and depart form intersection A, he would also “force” the pilot to break the rules. (I use the term “force” loosely as it is of course the responsibility of the PIC to not accept any clearance blindly) $\endgroup$ – Christian Speichert Nov 6 '19 at 19:49

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