Douglas A/B-26 Invader

Development - Rock Island Oil & Refining Co., Kansas conversion

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The Rock Island Oil & Refining Co. in detail

Rock Island Oil & Refining Co., Kansas conversion

Oddly named company had an aviation division that in the 1960s produced the very attractive Monarch-26s. The company purchased several dozen surplus Invaders and moved them to their aviation facility at Hutchinson, Kansas. A number of Rock Island aircraft were built up and they were basically stock looking but had a lengthened nose, passengers cabin with extra windows, and upgrade cockpit and avionics.

Monarch 26 - 1960's, longer nose, systems upgrades.

The Monarch 26 was a corporate aircraft conversion performed by the Rock Island Oil and Refining Co of Wichita, Kansas. The company purchased six surplus Invaders (ex-French AF aircraft that had served in Indochina) out of the Clark Field storage facility.

The original Invader airframe was extensively reconfigured with re-contouring and extensive re-skinning. In order to provide for more interior cabin space, an new wing spar was designed to replace the original straight-through configuration and new upper and lower fuselage structures were extended from the rear spar to the fin root fillet. The new cabin could accommodate up to six passengers in a low-density arrangement, and featured floor heating, a restroom, catering facilities, and panoramic windows. There was an airstair door on the rear starboard side. The extended nose was 30 inches longer than the original. Because of a fear of wing failures, the Rock Island engineers decided not to add wingtip fuel tanks, but added additional fuel cells in the outer wing panels, which raised the total fuel capacity to 1012 US gallons. The cockpit was fitted with dual controls, new instrument and overhead panels, and "metalized" double-paned cockpit canopies.

Anticipating more orders, Rock Island acquired 30 more surplus Invader airframes, this time from storage at Davis Monthan AFB. However, the Monarch had only limited success in the corporate aircraft marketplace, with only 4 being completed, including three in-house.

In addition, the Monarch found itself in competition with the first generation of corporate jets such as the Sabreliner, Jetstar, and Learjet. The majority of excess airframes that had been acquired were sold to parts brokers in 1969 but several examples went on to serve as aerial tankers in the USA and Canada. Some also ended up as flying warbirds, museum exhibits, and potential restoration projects.

Rock Island capitalized on its experience with Invader conversions by creating the Consort 26, which was designed for research and development purposes. All military equipment was removed, the bomb bay was sealed up, and a reinforced floor was added. Three Invader airframes were modified in this way and were sold or leased to aerospace companies as platforms for system development programs.

Associated reading

The Monarch 26 - By Robert Lindley

Air Enthusiast article by Robert Stitt

The Aviation index for Robert Stitt reference 1 

The Aviation index by Robert Stitt refence 2

Some more of Roberts work here

...and here