A321
Air Traffic Control Fully Certified
Confusion; Situational Awareness
Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter CFTT / CFIT
Air Traffic Control Issued Advisory / Alert
Chart Or Publication
Aircraft X departed PANC [and was] assigned the ANCHORAGE EIGHT SID. The pilot appeared to begin their turn on time but seemed to be turning and/or climbing at an insufficient rate to preclude a terrain proximity alarm. Upon hearing the system alarm; I issued a Low Altitude Alert with instructions to immediately turn right and climb. The aircraft complied with my instructions and entered an area of lower terrain; at which point I assigned a normal rate of climb. There were no further issues with the aircraft. The ANCHORAGE EIGHT departure does not seem to be properly interpreted by most auto pilot systems as they omit the 2000 MSL ability to begin their turn. This can cause the aircraft to proceed all the way to 4 DME before initiating their bank. For most aircraft; this is no issue. For aircraft with limited maneuverability or low bank angle settings; the lagged turn can cause unnecessary proximity to the terrain. In its current state; the ANCHORAGE EIGHT departure almost needs to be 'hand-flown' by heavy aircraft in order to prevent the system from alarming. A NOTAM that would require pilots to 'hand-fly' the departure; by restricting the use of auto pilot systems; could prove immediately useful. As a more permanent solution; in lieu of RNAV procedures (currently underway); amending the legacy procedures to include a 'do not penetrate' DME arc and depicting terrain would be beneficial to aircraft unable to adhere to the upcoming RNAV SIDs. A graphical depiction of a DME arc; as a hard-line boundary; would serve as a visual queue to pilots that an important restriction exists. The current restriction we have in place is more of a footnote that is easily missed by imperfect scans when previewing the procedures; and does not seem to be read properly by automated systems. Nearly every pilot I speak to; during post-incident terrain alarms; advises that they are just then seeing the specific notes concerning when to begin the turn; or that their auto pilot was late with the turn and they had to take over manually. A graphical depiction of terrain would further serve to indicate the severity of the restrictions. As of right now; our east bound SIDs depict no such topographical challenge. An unfamiliar pilot on an IMC day could; potentially; be unaware of how rapidly the terrain rises. This could; possibly; exacerbate proximity alerts due to a pilot's lack of prioritizing their turn to a safe heading per design of the SID. I firmly believe that these small changes will have a positive and lasting impact for the Anchorage traffic during extended periods of RWY7 departure flows. An RNAV SID will be great in the future; however; these legacy procedures can serve as an archaic instrument for pilots who may be unable to perform the RNAV variants due to insufficient equipment or training. Designing a legacy (non-RNAV) SID that safely works for everyone is the best way to account for the lowest common denominator and mitigate hazardous departures.
First officer and I were departing PANC for ZZZ. First time in or out of PANC for either of us. We discussed the departure procedure; ANCHO8 during our departure briefing. The emphasis item that we did not FULLY brief was that a turn is made to the south off of runway 7L once passing 2000' or at D4.0 TED; WHICHEVER COMES FIRST. These last three words; which are not emphasized; are where we erred. So; we flew the proper ground track and the FO made the right turn at the 4.0 point off of TED. Once in the turn we received the verbal low altitude alert warning from the controller to turn right and climb immediately. We were well established in the turn when this occurred and there were NO terrain warnings or EGPWS alerts from inside the aircraft.Multiple factors were involved here.  Departure on the last day out of an unfamiliar airport with mountains off the departure end; obscured by smoke at about 4 miles visibility. Also; in my opinion; a poorly worded departure procedure and NO GUIDANCE on the company 10-7C page. Two items need to be clarified for this departure and others at PANC that have the same initial procedure off of the 7's. First ... It needs to be emphasized that the initial turn is made when EITHER you have reached D4.0 OR 2000' WHICHEVER COMES FIRST! There are not too many places that I have flown where this type of procedure is in effect. It can be easily done; but it needs to be much clearer to the crews. In addition; in the INITIAL CLIMB narrative on the 10-3 departure procedure it states; 'Advise ATC prior to departure if unable to be established on heading 199 by D4.0 TED EAST of TED VOR.' This is a difficult assessment to make for most crews.
A11 Controller and A321 Captain reported a CFTT event occurred while the flight crew was flying the Anchorage 8 SID procedure. Controller stated aircraft on the Anchorage 8 SID often fly it incorrectly; resulting in low altitude alerts.  Controller suggests a SID redesign.