Date: 201502
Local time of day: 1801-2400
Location: SCEL.TRACON, FO
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Descent
ATC / advisory: TRACON SCEL
Aircraft component: GPWS
Component problem: Design
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: ATC Issue All Types; Aircraft Equipment Problem Less Severe; Inflight Event / Encounter CFTT / CFIT
Detector: Automation Aircraft Terrain Warning
Result: Air Traffic Control Issued New Clearance; Flight Crew Took Evasive Action
Contributing factors: Aircraft; Procedure; Environment - Non Weather Related
Primary problem: Ambiguous

Narrative: On ANDES5 arrival; assigned 270 knots and in radar contact with Santiago. Cleared direct TEGEB (fix on the ILS Y 17L); and cleared to descend to 5000 feet. Dark night; good visibility; numerous ground lights in sight; a dark ridgeline in front and below us; and our ground track going direct was very close to Andes 5.  In the vicinity of PUMAR; I leveled at 5000; 250 knots and promptly got a caution terrain followed very shortly by a terrain warning. As pilot flying; I executed an immediate escape maneuver as per QRH. No radio altimeter readings at any time before or during this event. Coordinated a climb to FL120. I made a calming PA and requested vectors back around for another approach. This time Santiago kept us at FL075 until the turn just prior to Loc intercept approaching TEGEB and the approach was normal.Although we were in radar contact we should have been more conservative and followed the the company non-radar procedure of staying on course and complying with all step downs; especially the PUMAR FL070. The 21-1 Chart [ILS Y Rwy 17L] does not clearly depict terrain in the vicinity of PUMAR due to a holding pattern inset; although it appears that there is a low area of white on final; in fact the holding inset covers and removes all terrain depictions. The RADAR MNM ALTS chart is a little difficult to interpret in this same area; again showing all white; although there is a small  band where FL075 is the min altitude and I should have noticed that as well. The FL070 at PUMAR is the biggest clue; although no terrain is clearly depicted at 5000 feet in that area; I now know there is a dark ridgeline there. Although everything was briefed thoroughly; none of us had been there in many years; my copilots were low time pilots new to the company; and I hold myself fully responsible for this event. I will say that even though my mindset was that there was no terrain; my training kicked in and I immediately responded to the warning.


Second narrative: On the arrival into SCEL we flew the ANDES5. We received a radar vector clearing us direct to TEGEB for the ILS Y 17L. Almost level at 5000 feet; we received a yellow terrain indication and then alert. Immediate climb action was commenced with a climb to FL120. Followed by a normal landing. Better awareness from the ATC controller of our position.


Synopsis: B767 flight crew experiences a terrain warning at 5000 feet near PUMAR during flight direct to TEGEB on the ILS 17R at SCEL. Evasive action is taken and vectors received for a second approach.