Date: 201304
Local time of day: 1801-2400
Location: LFPG.Airport, FO
Aircraft: B757-200
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Initial Approach
ATC / advisory: Tower LFPG
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Training / Qualification
Second reporter function: Pilot Not Flying; Captain
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Contributing factors: Airport; Human Factors; Procedure
Primary problem: Ambiguous

Narrative: On arrival into LFPG we were executing the LORNI 1W transition to Runway 26L. We were in LNAV after passing PG520. This course set us up for an intercept with the localizer for 26L. Approaching the 26L localizer we were never given instructions to join. As we were passing through the localizer I initiated a turn using HDG to turn back to the localizer. At this point we were asked by the Controller if we intended to join the localizer. The Captain responded that we were in the turn to join. We rejoined the localizer from the south side and executed a normal ILS approach to landing.A better and more thorough briefing of this approach would have helped to prevent this deviation. LFPG has a general operating rule [2.6.3] that if you are given a heading within 70 degrees of the localizer course; you are expected to join the course without instructions to do so. I have never actually had to use that rule to intercept a course in LFPG and therefore typically await instructions to join a course. In this case it appeared we were expected to use that rule without prompting. Additionally; this is the only airport that I have operated into that has this expectation. Having never had to utilize this rule in practice throughout 1 year operating in the European theater had led me to develop an impression it was never used. Therefore; it was something that had been dropped from my approach briefing. In the future I will brief the expectation that without specific prompting from ATC; we will join the localizer course if our existing heading is within 70 degrees of localizer course.


Second narrative: While on an intercept vector at LFPG; we forgot to intercept the localizer automatically without verbal clearance from ATC. LFPG has a rule to turn on the localizer on your own; when on an intercept of 70 degrees or less; even if the Controller doesn't say anything. I've been flying into Paris for years; and especially in the last 6 months. I know about this 70 degree intercept rule; but I've always gotten a call to intercept before it came time to turn to localizer on my own. I was pilot not flying; and I had to check the QRH for an EICAS message regarding a stuck Engine Anti Ice valve. We were about 3-5 miles from the localizer. I was expecting a call for approach clearance from the Controller while reading the QRH. When we got a call; the Controller asked if we were turning on the localizer. I looked up from the book and we were about to overshoot final. We started a turn and then got a heading to intercept from the other side. We overshot by about 1 mile. It was Runway 26R and we were approaching from the northeast on the LORNI 1W approach transition. The vector was the FMS database heading of 211 degrees. We overshot to the south of the final; therefore there was no conflicting traffic on a parallel runway. We were in LNAV. After the Controller gave the heading of 300 to intercept from the south to correct the overshoot; we reported established and he cleared us to descend on glide path. Nothing more was said; and as far as I could tell; we did not cause any interference. Even though ATC did not appear to have a problem with this; I decided to write a report.I used to brief the 70 degree rule and also arm the localizer when on an intercept vector; but I had gotten away from the practice. Had I suggested that to the First Officer (pilot flying) we wouldn't have flown through. Also; I should have waited to check the QRH; since we were nearing localizer intercept. I was expecting to hear intercept clearance from the Controller while I was in the QRH; so my distraction allowed the overshoot. Had I not been in the book; I would have reminded the First Officer to turn; or at least called ATC to check. To avoid this error in the future; I will go back to my old practice of briefing and reminding my flight crew about the '70 degree rule' and also I'll arm the localizer when on a vector at LFPG. I'll be careful when I pull out the QRH so as to not limit my monitoring ability. Listening for a radio call wasn't enough monitoring in this case.


Synopsis: B757 flight crew reports not being instructed to join the localizer during approach to LFPG and overshooting before turning back to intercept. LFPG has a special rule about joining the localizer without being instructed to do so; which the crew had forgotten.