An F-111B Configuration Update

 6 April 2026: I should have prefaced this post as being a preliminary draft, i.e. corrections and additions to come.

The Configuration Difference matrix has been updated 

CAT4 is in the process of releasing decals and conversion sets for the F-111B. As a result, I'm reviewing and updating previous F-111B posts providing modeler-oriented configuration details of the seven that were built and flown. This was the original post from 2009 that summarized them:

 https://tailspintopics.blogspot.com/2009/10/grumman-f-111b.html

A comparison summary by BuNo:

For the difference in the inflight refueling installation for the short vs. long nose, see https://tailspintopics.blogspot.com/2012/01/f-111b-inflight-refueling-probe.html

For the landing gear and inlet differences, scroll down here: https://tailspintopics.blogspot.com/2009/10/grumman-f-111b.html

For more on note 2) above, https://tailspintopics.blogspot.com/2011/09/f-111b-aft-main-landing-gear-door.html. Also, the F-111B aft main landing gear door extends a bit farther aft than the USAF production one because it had to be trimmed to clear the bottom of the fuselage when the landing gear was extended.

For more on changes to the main landing gear for production, see https://tailspintopics.blogspot.com/2017/02/the-f-111b-production-main-landing-gear.html 

 For the ejection system difference between the first three F-111B with ejection seats, see https://tailspintopics.blogspot.com/2016/07/f-111ab-ejection-seats.html

 The rotating glove was added to the fuselage adjacent to the leading edge of the wing to increase lift for takeoff and landing, offsetting the increase in gross weight.

 The auxiliary flap was a late addition to further increase the lift on takeoff and landing. See https://tailspintopics.blogspot.com/2014/09/f-111-auxiliary-flaps.html

The original venting of some of the boundary layer air kept out of the inlet was on the side of the fuselage under the wing. Ducts were added to increase the suction.

 

The venting was subsequently moved to the top of fuselage.

 

 

 A comparison of the "A" and "B" boat tails (in this instance, A and B do not represent the F-111A vs the F-111B).

Not included in the comparison above are the two different engine exhaust shrouds that were present on the F-111 prototypes. These shrouds were mounted on the engine behind the afterburner, probably to provide sonic and thermal protection to the adjacent aircraft structure. Free-floating "blow-in" doors were located forward of the shrouds. My understanding is that these were either open or closed in flight depending on the difference in external and internal (engine bay) pressure. The shrouds were originally just slightly tapered metal cylinders. In production, at least the aft portion of the shrouds consisted of linked longitudinal panels resembling an afterburner nozzle but were not controlled and had only limited movement, probably to relieve stress from thermal expansion of the shroud; the nomenclature changed from "shroud" to "feathers". The blow-in doors were also then fixed in the open position.

There were two different shroud lengths. The original ones were longer and the shorter ones possibly introduced as a weight reduction change that was short-lived.

 Note that 151970 originally flew with long (green arrow) shrouds but was photographed at Edwards AFB with short ones (red arrow). 151973 was also flown with both short and long shrouds.