4 or 5 DC-9-33's were built for Overseas National Airways (ONA
) with 2 rocket bottles mounted in the aft end of each wing fillet fairing below the wings.
They were intended to be used in case of an engine failure during a high altitude hot day take-off.
The wags stated that their intent was to make sure the wreckage ended up off of the airport property.
Most of these airplanes are now flown by ABX
Air, but without the rocket bottles. If you know where to look you can see the bulges in the fairings where the bottles used to be installed.
People I know that worked for ONA
said that they never heard of them being used for their intended purpose. The rocket bottles had a hard time or a time limit after which they had to dispose of them. Since a fuelled rocket bottle is an extreme case of hazardous material; what ONA
would do is a rocket assisted take-off at their Wilmington, Ohio (now operated by ABX
Air) base in order to expend the fuel.
I understand that these were great fun to watch and the rocket bottles gave a real kick in the pants to the crew.