md88The MD-88 has wider than usual aisles in the coach cabin at 22 inches. Maximum cruise speed for the MD-88 is 543 mph, 874 kmh, or 472 knots. Type Rating. Pilots must earn their typeDelta Air s Narrow Body Regional Jet McDonnell Douglas MD-88 (M88) Aircraft photos, review, seating chart, seat maps, first class, premium eco, comfort+, economy class.