Mont Blanc du Tacul is easily accessible from the Aiguille du Midi, which makes it a very popular summit. The E face of this summit has many routes including Couloir Jager, which after Couloir Gervasutti, was the second couloir to have been climbed on the face.
Couloir Jager is a long route at altitude, sometimes used as a training climb for a more serious outing.  The only escape route is by re-descending the gully.  Prone to snow sluffs/avalanches after a recent snowfall.

Approach1h

From Aiguille du Midi, descend the ridge completely to the E until the altitude of 3670m. From there, pass the bergschrund and cross the Col du Midi plateau to go between the Grand Rognon and Pointe Lachenal. Skirt the S face of Pointe Lachenal and head towards the base of the gully. Couloir Jager is situated to the right of the more evident Couloir Gervasutti.

Route

Pass the bergschrund which is more or less open, depending on the season and go up the gully primarily via its true left bank. It steepens the last 100 meters to reach 60°. Exit taking the easiest line through the cornice.  It takes approximately 3 hours to climb the gully, depending on the quality of the snow. Once past cornice, go up the snow ridge until the summit of Mont Blanc du Tacul, (1h).

Descent2h30

By the "Voie Normale".  From the summit, head towards the shoulder of Mont Blanc du Tacul and around 4080m, descend due N then in the direction of the base of the triangle of Tacul by passing successively 2 bergschrunds which can be steep depending on the season. From here it is easy to reach Col du Midi then to go back up to Aiguille du Midi.