Air Carrier Captain reported the LAS Choww3 STAR Runway 01 transition charts the fix CHOWW at or below 16;000 feet and the subsequent fix PACKK at or above 16;000 feet.
Synopsis
Air Carrier Captain reported the LAS Choww3 STAR Runway 01 transition charts the fix CHOWW at or below 16;000 feet and the subsequent fix PACKK at or above 16;000 feet.
Narrative
While on the CHOWW3 arrival going into LAS; we were approaching CHOWW (approximately 10 miles out) and looking at our VNAV guidance; determined that we would be about 750'-1;000' feet high (CHOWW below 16;000'). ATC was metering traffic into LAS. We were at FL280 and 270 KIAS when ATC told us to slow to 260 KIAS and to descend and maintain FL240 at pilot's discretion. They then switched controllers at approximately 20 miles NE of CHOWW; the new controller slowed us to 250 KIAS and told us to descend via the CHOWW3; runway 1R transition. Once we reprogrammed the box with the new speed and started down (past the new top of descent - TD); that's when we discovered that we would not make the below 16;000' restriction at CHOWW. At 10 miles out we asked for relief from the controller as we would be high at CHOWW. The controller was adamant that we had to be below 16;000' at CHOWW. We told her we could give her speed (250 KIAS) or the below 16;000'. The controller said make the altitude over maintaining the 250 KIAS for spacing. I thought I heard the controller giving other airplanes that were being metered behind us; descend and maintain 14;000'. At approximately 7.5 miles from CHOWW; I set 15;000' in the Mode Control Panel (MCP) and the FO (Pilot Flying) opened the speed window and set 300 KIAS and pressed LVL CHG to increase our rate of descent to be below 16;000' at CHOWW. We passed 16;000' approximately .5 miles prior to CHOWW. After we were below 16;000' I focused on reprogramming the FMC to re-engage VNAV for the arrival. We were now headed towards WOLPH. WOLPH has an inset box for aircraft continuing after WOLPH to runway 26. WOLPH is where the STAR has three possible routes; based on the runway transition. TATUU is the point after WOLPH and has an altitude between 10;500'-9;500'. I set the altitude in the MCP to 9;000' for the bottom at VANDL and immediately saw that we had to be above 16;000' at PACKK. The next point after CHOWW was WOLPH followed by PACKK above 16;000. After making the below 16;000' at CHOWW; I was focused on getting the FMC back into path and saw our next point was actually PACKK at above 16;000'. The FO hit the ALT HLD at approximately 14;500'; leveled the aircraft and started a climb back up to 16;000'. Just as we started the climb back up to 16;000'; LA Center told us to climb and maintain 15;000'. We were at approximately 14;700' when given that clearance and they switched us to Las Vegas approach. We were at 15;000' when we checked on with Las Vegas approach. We reached 15;000' about 6-7 miles prior to WOLPH and crossed WOLPH at 15;000' per Las Vegas Approach. Approach told us to setup for the visual for runway 1R. The two airplanes that checked on with approach after us were at 14;000' per the previous controller. Las Vegas approach told them to climb and maintain 15;000'. We flew the rest of the arrival and visual (backed up by the RNAV 1R) uneventfully.
Second reporter narrative
While descending on the CHOWW3 arrival. ATC was metering traffic before clearing to descend via. We were given 270KIAS; and then 250KIAS; when we were given the slower speed we reprogrammed the box and pilot monitoring pointed out we would be about 1;000 feet high as we were closing in on CHOWW with the BELOW 16;000 restriction. We contacted center with a a request for relief on the altitude. We expected to receive altitude relief rather than speed; However the controller was adamant that she needed us below 16000 at CHOWW rather than the speed. I focused on making sure we would comply with the ATC request. I entered level change with a speed of 300 KIAS and we began a high rate of descent. Pilot monitoring set 15000 in the altitude window. As we were rapidly approaching CHOWW; I briefly looked at the arrival chart and confirmed that CHOWW was at or below 16000 therefore I agreed with setting 15000 in the window; with CHOWW being a below 16000 I saw it very unlikely that the next bottom altitude would be in between 15000 and 16000. As soon as we made CHOWW pilot monitoring and I began the process of getting FMC back into VNAV and ATC issued a handoff to approach control. Pilot monitoring and I simultaneously realized the next fix on our descent path was PACKK which was in fact at or above 16000. We set 16000 back into the window and began to level off and climb back up to 16000. We leveled around 14;700 and were on our way up to 16000. We believed we could climb back up to 16000 to comply with the at or above 16000 at PACKK. Center control issued an immediate climb up to 15000; we complied and then were handed off to approach control. after crossing PACKK we were then instructed to descend via and we continued to an uneventful landing
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.