twochai, re “The Dash 7 was the only FAR25 transport”; yes, but not quite.
AFAIR the certification standard for the Dash 7 (and similar aircraft) was a special condition, ‘STOL category’, which may have originated in Canada. FAR 25 may still not have a specific para.
Also, the airlines flying into Aspen, Vail, etc, operated to FAR 135.
The STOL certification category was developed into to certification Working Paper (705?), with Canada, and this was used as the basis of the UK CAA certification for the Dash 7 at LCY, and thence the BAe 146. This requirement was further developed and incorporated into JAR 25 and then CS 25.
Steep approaches to airports differ from those approaching a runway. The latter requires a full steep approach certification for the aircraft – straight in landing, whereas an approach to an airport can be steep (>4.5 deg), but is then followed by a ‘normal’ landing (<4.5 deg); this is often a circle to land procedure, e.g. old Aspen procedure.
IIRC the original approach to Lugano (LSZA) was also a hybrid. A steep approach would be flown into the valley with a GS origin positioned in the lake short of the runway; at DH the descent rate would be reduced to complete a relatively normal landing straight ahead.