dixi188:
DC-8 with stove pipe engines was allowed to reverse inboards in flight. Not allowed on the CFM56 powered ones though.
While discouraged for structural and passenger comfort reasons, reverse inflight IS allowed on CFM56 powered DC-8's, just as the earlier powered ones. Inboards only (the outboards are locked out with the gear up). Inflight reverse stops limit amount of reverse, and stowing should be with an IAS of less than 300kts. Very effective, and will peg the 6,000fpm VSI during an emergency descent.
The Emergency Stow Pump still exists, as it did prior to the CFM engine mod.
The spoiler system is only for roll control assist with the gear down and for spoiler deployment after touchdown. No speedbrake duties.