The International Cessna^® 170 Association

Q for the pros amongst us using a glass cockpit; Under what condition would you use a DME lock when tuning to another VOR station. Thks

When shooting an ILS/DME approach (which uses DME from a navaid other than the localizer) such as the ILS/DME 19C at KIAD, or a similar approach. (It has nothing to do with whether or not a "glass cockpit" is present.)
http://204.108.4.16/d-tpp/0809/05100ILD19C.PDF

Thanks George, I thought you'd know the answer. I referred to the glass cockpit as I've not seen an installation that has auto tuning of the Nav receivers in anything other than a glass cockpit. I'm taking a maintenance course on the Emb 170-190 family, interesting plane.