Today ended up being a bit more delicate in the backcountry than expected. After studying the forecast and being out in the snow the last couple days we decided to head for the south facing aspects off Pheifferhorn, Airplane and Chipman in search of deep stable snow. Expected forecast was partly sunny with scattered small storms coming in the afternoon so we knew an early start would be needed to beat any potential weather. That early start got us to the summit about an hour and a half after sunrise. A run down the south face told us the wind had been present at the upper elevations, as forecasted, and skiing down just a few hundred feet from the summit provided excellent smooth turns.

We had to make a decision at the bottom while transitioning, since the cloudy skies we were expecting did not come in and the sun was starting to heat things up a bit. Deciding to pass on Airplane peak we headed for Chipman after scoping terrain and finding a good ridge to safely ascend with good bail options in case things heated up too quick or came across any red flags. The base of the ridge was steep for about 100 ft before lowering angle so we booted up that. The first person in the party triggered a very small 10 feet wide slide appearing to be sluff, which didn't even move him and he continued up. The rest of the party waited in a safe zone until skier 1 was above the steep zone. Once he cleared the rest of the party moved up experiencing no instability but noted that the slide was actually a small wind slab about 2 inches deep and 10 feet wide, south facing. After talking through the incident as a group we decided this was manageable size slide and the rest of the climb was all safe travel on the ridge proper. After skinning up another 300 ft we switched over to booting for the last 200 ft to a flat section prior to the summit push. We observed the snow felt stable and wasn't taking on too much heat which gave us hope that wet slide activity wouldn't be as big a concern.

About 50 ft from the the flat area the ridge fizzled out and we were forced onto a lower angle slope to finish off the last little bit of climb. At that moment skier 1 yelled avalanche after realizing the snow fractured about 6 feet above him. Skier 2 was about 30 ft down and to the side with skier 3 about 15 ft further back. Skier 1 started to slide while skier 2 and 3 tried to skirt to the side to avoid getting swept down. The avalanche propagated about 300 ft across the top and took all three for a ride. Skier 2 was able to self arrest about 150 from the starting point, 15 ft before going off a 50 foot cliff. Skier 1 and 3 were unable to self arrest and went over the edge. After another 600 ft, both skier 1 and 3 came to a stop on top of the snow. Neither Skier 1 or 3 experienced any trauma from the cliff and were able to get up and out of safety as skier 2 radioed down to others that he had self arrested above the cliff.

We had a solid plan for the day with bail options and back up plans in place. Our mistake today was not taking the small wind slab encountered earlier, as the serious red flag it was and continuing on to more exposed terrain with higher consequences. Only minor injuries coming from this catch and carry but it was a very humbling experience and a reminder that an avalanche can be much worse when in higher consequence terrain.