Tacit Rainbow: Northrop AGM/BGM-136 Anti-Radar Drone

TinWing

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Does anyone have an idea how far work on the ground-launched BGM-136B got? And, for that matter, on the ground-launched MGM-137B TSSAM variant?
Also, why the ground-launched Tacit Rainbow was designated BGM and the TSSAM MGM although they both were to be launched from MLRS launchers?
 
Meteorit said:
Does anyone have an idea how far work on the ground-launched BGM-136B got? And, for that matter, on the ground-launched MGM-137B TSSAM variant?

I don't know for sure, but I'll risk a guess (well, two guesses, actually ;) ).

The TACIT RAINBOW was essentially a USAF program, and I wouldn't be surprised if the Army's BGM-136B variant was more like a formal statement saying "See, this is a joint program, so we deserve more money ..". In reality, I've never read anything about the ground-launched variant except that it "existed" (formally, at least).

As for the ground-launched TSSAM, I'd guess that this reached the flight test stage. The Army was in the program for 7 years (1986-93), and it would be rather strange if they had just watched the development of the air-launched missile all the time. Unfortunately, it appears to be rather difficlut to get any firm information on TSSAM at all, including e.g. a decent photo.

Also, why the ground-launched Tacit Rainbow was designated BGM and the TSSAM MGM although they both were to be launched from MLRS launchers?

Theoretically, it could mean that the ground-launched TACIT RAINBOW had only few modifications, so that it was still air-launchable as well. This would justify the B letter (denoting "Multiple Launch Options"). OTOH, it could also (and at least as likely) be just another screwed-up designation :) .
 
Thanks for the reply, Andreas. And welcome to the forum!
 
Andreas Parsch said:
Meteorit said:
Does anyone have an idea how far work on the ground-launched BGM-136B got? And, for that matter, on the ground-launched MGM-137B TSSAM variant?

I don't know for sure, but I'll risk a guess (well, two guesses, actually ;) ).

The TACIT RAINBOW was essentially a USAF program, and I wouldn't be surprised if the Army's BGM-136B variant was more like a formal statement saying "See, this is a joint program, so we deserve more money ..". In reality, I've never read anything about the ground-launched variant except that it "existed" (formally, at least).

As for the ground-launched TSSAM, I'd guess that this reached the flight test stage. The Army was in the program for 7 years (1986-93), and it would be rather strange if they had just watched the development of the air-launched missile all the time. Unfortunately, it appears to be rather difficlut to get any firm information on TSSAM at all, including e.g. a decent photo.

Also, why the ground-launched Tacit Rainbow was designated BGM and the TSSAM MGM although they both were to be launched from MLRS launchers?

Theoretically, it could mean that the ground-launched TACIT RAINBOW had only few modifications, so that it was still air-launchable as well. This would justify the B letter (denoting "Multiple Launch Options"). OTOH, it could also (and at least as likely) be just another screwed-up designation :) .

I would think that after the Army lost its GLCM inventory to an arms reduction agreement, the ground launched Tacit Rainbow might have seemed like an orphan.

If the GLCM represented a core capability in the European theatre, the BGM-136B might always have been seen as a subsidiary system - hard to justify in the face of declining budgets.
 
MGM-137B got as far as early flgiht test demonstrations (five if memory serves me correctly after more than a decade) which showed a few development problems. The flight test that would've demonstrated the resolution of the majority of these problems was fueled and ready to go at the test site when this variant of TSSAM was cancelled. The Army version did have some distinct differences from the air-launched versions in order to maximize volume usage and payload while staying within the length envelope of the MLRS "box". It was propelled from the launcher to operating speed by two 10 ft. long, six in. dia. solid rocket moters that boosted it from a stand-still to Mach 0.4 in 10 seconds. How do I know all this? Simple, I was an engineer on TSSAM from early 1989 through the end of the program and most of that time I specialized in certain aspects of the Army variant.
 
TinWing said:
I would think that after the Army lost its GLCM inventory to an arms reduction agreement, the ground launched Tacit Rainbow might have seemed like an orphan.

The GLCMs were never an Army asset, they belonged to the USAF
 
Ground-launched TSSAM was in the first round of development flight tests. The final test of this round was due to go the day after the US Army cancelled it's participation in the program. This test would've tested a number of fixes from problems we'd found in the previous tests. Believe me, the test footage of the launch was always quite impressive; the footage of the last actual test flight was rather less so due to problems that were found and subsequently corrected. The test previous to that one was nearly picture perfect. I know, I was on that program with special responsibilities for the Army variant. If the Army hadn't pulled out, there was also an extended-range variant under preliminary design that traded a modest drop in payload for significantly more range.

Now, yes, I know the differences between the air-launched and ground-launched versions, but I'm not at all sure if I'm yet allowed to get too detailed here.

Oh, there was also a very preliminary study on combining aspects of the ground-launched and air-launched vehicles to produce a ship-launched one.
 
elmayerle said:
Ground-launched TSSAM was in the first round of development flight tests. The final test of this round was due to go the day after the US Army cancelled it's participation in the program. This test would've tested a number of fixes from problems we'd found in the previous tests. Believe me, the test footage of the launch was always quite impressive; the footage of the last actual test flight was rather less so due to problems that were found and subsequently corrected. The test previous to that one was nearly picture perfect. I know, I was on that program with special responsibilities for the Army variant. If the Army hadn't pulled out, there was also an extended-range variant under preliminary design that traded a modest drop in payload for significantly more range.

Now, yes, I know the differences between the air-launched and ground-launched versions, but I'm not at all sure if I'm yet allowed to get too detailed here.

Oh, there was also a very preliminary study on combining aspects of the ground-launched and air-launched vehicles to produce a ship-launched one.


Gotta quesiton for you. A while back in the Correspondence section of AvWeek a writer commented on a JASSM photo that was run of it flying through the door of a bunker or something. They said essentially it wasn't such a great feat as they'd done the same thing with TSSAM years earlier and that THAT photo had also been run in AvWeek. I vaguely remember the picture. Any chance you might have it for upload? ;)
 
I don't have it for upload after this time (not even certain I can find the bloody thing), though the unclassified video of it is part of a declassified sales tape that I've got in with all my other VHS tapes. The flight test was one of the first of the Navy air-launched versions and was picture perfect, hitting the center of the simulated window so close that it took out the camera behind the window.
 
I had occassion to check with a co-worker who used to work on Tacit Rainbow, the ground-launched version never got beyond the proposal stage. *chuckle* He tells me that there was a joke about doing a scaled-down version for use by autos against police radar. :D
 
elmayerle said:
I had occassion to check with a co-worker who used to work on Tacit Rainbow, the ground-launched version never got beyond the proposal stage. *chuckle* He tells me that there was a joke about doing a scaled-down version for use by autos against police radar. :D

OK, so the "mystery" has been solved. Thanks for your valuable input, Evan.
 
Elmayerle confused this topic a little by introducing information on the TASSM stealthy cruise missile program run out of Northrop Aircraft Division in Hawthorne. The Tacit Rainbow, later the AGM-136A, was an anti-radar loitering drone and was done by Northrop Ventura Division at Newbury Park. It was a joint Navy/Air Force effort and flight test was accomplished at China Lake with Navy assets. The Air Force provided their aircraft when needed (F-16, B-52) and some captive flights launched out of Edwards. The Air Force were responsible for the container.

I got to the program as production design was starting, so had nothing to do with the configuration. As to the question about Army involvement, I saw a video of a test article being ejected out of a launcher (MRLS?) but it was not too successful as the item sort of trickeled out of the end. By '85 there was no sign of Army involvement.

Attached are some of the information I collected when the project was revealed to the public. Since a significant number of missiles were flown before it was cancelled. perhaps this topic should be moved to Military.
 

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And a few more.
 

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YES! Thanks BillRo, you made my day. I had been waiting for a long time to get better info on Tacit Rainbow. One thing in particular puzzles me: the wing swivels 90 degrees upon deployment, but does it also get 'sucked up' to nest itself between the front and aft belly fairings?
The picture labeled 'TR assy' and the picture with three AGMs on an F-16 show something that looks like a fixed triangular horizontal surface that is not present in all the other pictures. Was that a result of flight testing? not enough static margin?
I am also curious about the way the fuselage end with a 'double-bubble' cross section. The top circle is for the engine, but what was the bottom one for?
Sorry about all the questions, but Tacit Rainbow is a pretty neat vehicle with lots of curious solutions!
 
The wing had a post on it and it fitted into a socket on the body with a cam track; as the wing rotated by spring power it popped up into the gap making a nice faired surface. The bomb lugs on the top also were spring loaded to fair into the upper surface. The spade at the back was for air launch to stabilize the bird until the tails deployed; it was then jettisoned. There are two versions, one for fighter carriage as on the F-16 TER and the smaller one for the B-52 rotary bomb racks, a geometry issue.
 
As to the aft fuselage shape I am not too sure; I thing we needed room for the rudder actuator and for aero drag reasons you cannot have surface closing angles greater than 7 degrees. If you continued the lower fuselage surface out, the missile would be a foot longer and heavier so they just chopped it off.
 
Thanks for the explanation - I am always curious to find out the reason behind unconventional technical solutions, and this air vehicle presents quite a few. :)
 
I looked at some pix of it in a structural test rig and it has a socket at the center of the lower bulged aft fuselage. I would not be surprised if the ground launch booster rocket was supposed to fit there - if that ever happened.
 
McDonnell Douglas Ground Launched Tacit Rainbow mugs
AGM-136A Test Team patch
 

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Interesting Flateric; the configuration on the cup and sticker (high wing, apparently cruciform tail) is not the same as the Northrop design as flown. Is it an early version or did McDonnel Douglas (as shown on the cup) have an unsuccessful competitor to Northrop?
 
BillRo said:
Interesting Flateric; the configuration on the cup and sticker (high wing, apparently cruciform tail) is not the same as the Northrop design as flown. Is it an early version or did McDonnel Douglas (as shown on the cup) have an unsuccessful competitor to Northrop?

Report on the Audit of the Acquisition of the Tacit Rainbow Anti-Radiation Missile System


In January 1990, the Air Force competitively awarded Raytheon
Company a $29.8 million fixed-price-incentive-fee contract with
an award fee as a second source producer of the Tacit Rainbow.

Pretty sure Raytheon, McDonnell-Douglas and E-Systems were all subcontractors/partners to Northrop on Tacit Rainbow, rather than a second proposal team. The drawing may be notional - was Tacit Rainbox shape classified?

[edited - I was wrong - see below]
 
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Shape was classified. We had to come up with a representative item to develop the container with the same dimensions, inertia and weight that looked nothing like TR; I called it the "Mule". I wonder what McDonnel-Douglas did. It had a Williams engine.
 
Does anyone have an idea how far work on the ground-launched BGM-136B got? And, for that matter, on the ground-launched MGM-137B TSSAM variant?
Also, why the ground-launched Tacit Rainbow was designated BGM and the TSSAM MGM although they both were to be launched from MLRS launchers?
Northrop did a single zero-length launch (JATO assisted) at Hill AFB in 1984 from a representative MRLS cannister. The sabots were new and conformal to the missile. Wings, vertical, elevons and rudder were all folded. This was the first and only use of a newly developed solid rocket motor for the launch. Upon firing and exiting the launch tube, a sabot impacted and broke a JATO fin casting causing a shift in the assembly CG and a subsequent thrust mis-alignment. The vehicle traveled approximately 1200 feet down range and disintegrated upon impact. The US Army backed out of the program in favor of the still dark TSSAM weapon program
 
McDonnell Douglas Ground Launched Tacit Rainbow mugs
AGM-136A Test Team patch
Was Northrop Grumman.

Ground Launched Tacit Rainbow was assigned to a team of Raytheon, McDonnell Douglas and E-Systems.


Raytheon Team Selected to Develop Ground-Launched Tacit Rainbow

JOHN D. MORROCCO/WASHINGTON

The team of Raytheon, McDonnell Douglas and E-Systems has been selected to develop a ground-launched version of the Tacit Rainbow antiradar weapon for the U. S. Army. The Raytheon-led team also was picked to qualify as a second-source producer of the AGM—136A air-launched version of the weapon now produced by Northrop.

The contracts will be awarded by the Joint Tactical Autonomous Weapons Systems program office at the Air Force’s Aeronautical Systems Div., which runs the Tacit Rainbow program. The fixed-price incentive contracts are to be awarded following a Defense Acquisition Board meeting scheduled for the end of October.

Raytheon and its partners were selected over two other contracting teams led by Boeing and Northrop. Boeing was competing for both contracts while Northrop was competing to develop the ground— launched version. The selection was made 'based on weapons trade studies conducted by all three teams.

Raytheon’s Missile Systems Div. will act as systems integrator and develop the guidance system for both missiles. Mc- Donnell Douglas Missile Systems Co. is responsible for the airframe, payload and propulsion system. E-Systems Melpar Div. will develop the missile electronics for the ground-launched version.

Under the second source program, Northrop will transfer technical data on the AGM-l36A to Raytheon over the next one to two years, according to Chauncey P. Dewey, Jr., Tacit Rainbow program manager at Raytheon. The Air Force will then begin a 30~month program to evaluate and qualify the Raytheon design, including five flight tests.

Raytheon plans to use the same Texas Instruments seeker employed by Northrop for the testing program. Dewey said, however, the firm will eventually develop its own seeker. The Air Force plans to split missile purchases between Northrop and Raytheon in 1994. The two firms will then begin competing for annual production buys in 1995.

The ground-launched program is scheduled to enter full-scale development concurrently with the second-source effort. The Army plans to include in its development contract two low-rate initial production options. The first of these options will be exercised in mid-1992, before the 4-year full-scale development program is completed. The ground-launched version will be employed on the Multiple Launch Rocket System (MLRS), which the Army wants to use for all of its deep strike weapons. Both versions of the lethal missile are designed to loiter over a designated target area searching for hostile radar emitters.

NEW AIRFRAME DESIGN

Contractor flight tests are scheduled to begin in the fall of 1991. Dewey said the ground-launched version will include a brand new airframe design to make it compatible with the MLRS, as well as a new propulsion system developed by Teledyne. Dewey said he that contracts for both programs would be awarded in December, pending the outcome of the upcoming Defense Acquisition Board review.

The board will meet to determine whether to proceed with full-scale development of the ground-launched version. At the same time, it will review progress toward meeting requirements it imposed on the air-launched program late last year. The senior-level review group recommended against moving into low-rate initial production of the missile because of testing problems and set a series of testing criteria to be met before additional purchases could be made.

The testing program appears to be back on track, however, following the fourth successful test launch of the airlaunched AGM-l36A on Aug. 31 (AW&ST Sept. 11, p.33). The Air Force seems to be well on its way to meeting the requirement of successfully completing five of eight test launches by October. A total of 25 development and operational test launches are to be conducted from Navy A-6 aircraft and Air Force B—52 bombers. Air Force officials are hopeful that a decision to enter low—rate initial production of the missile could come in the second half of 1990. A key issue at the DAB meeting will be whether the Navy agrees to rejoin the program. The Navy dropped plans to procure the air—launched version of the missile but is continuing in the full-scale development portion of the program.

UNIT COST

Without Navy participation, the unit cost of the missile will increase by more than 20%, according to an official in the Pentagon’s tactical warfare programs office. Defense Dept. officials are hopeful of reaching some decision on Navy participation at the DAB meeting in order to complete work on the Fiscal 1991 budget. Initial budget requests from the individual military services were due
Sept. 15.

While questions about the affordability of Tacit Rainbow linger, the program was endorsed by a joint operational requirements study. The report, which assessed the operational and employment concepts of the loitering missile, expressed strong support for the program. Deputy Defense Secretary Donald J. Atwood has reviewed the report that is scheduled to be delivered to Defense Secretary Richard B. Cheney this week.

Raytheon and its partners were selected over two other contracting teams led by Boeing and Northrop
 

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“This, milord, is my family's axe. We have owned it for almost nine hundred years, see. Of course, sometimes it needed a new blade. And sometimes it has required a new handle, new designs on the metalwork, a little refreshing of the ornamentation . . . but is this not the nine hundred-year-old axe of my family?​

This Terry Pratchett quote comes to mind. Its a version of Tacit Rainbow with a new airframe, and engine, and eventually a new seeker.
 
This Terry Pratchett quote comes to mind. Its a version of Tacit Rainbow with a new airframe, and engine, and eventually a new seeker.
So is Tacit Rainbow being dusted off and updated for the 21st century?
The original mission requirement was for a low-cost Suppression of Enemy Air Defense (SEAD) weapon. At the time, the SEAD mission was largely fulfilled by the F-4G Wild Weasels with the APR-38 receiver and a HARM weapon. Was very costly both in terms of dollars and human life. The SEAD mission still exists today on the modern battlefield anytime an adversary wants to challenge contested airspace. Today there are other manned aircraft launched weapons that are effectively "beam riders". As Unmanned Vehicles take on increasing roles in modern warfare, they are the obvious choice for this mission and others. Selective precision attack has been the new norm. Tacit rainbow was unique for it´s time. Fire and forget launched from behind the FEBA from virtually anything with a BRA launcher, a prioritized target list, loitering, attack, abort, re-attack and very low observable w/ a 600 mile range (START II limit). Challenge really was the TI Seeker development.
 
McDonnell Douglas Ground Launched Tacit Rainbow mugs
AGM-136A Test Team patch
Was Northrop Grumman.

Ground Launched Tacit Rainbow was assigned to a team of Raytheon, McDonnell Douglas and E-Systems.


Raytheon Team Selected to Develop Ground-Launched Tacit Rainbow

JOHN D. MORROCCO/WASHINGTON

The team of Raytheon, McDonnell Douglas and E-Systems has been selected to develop a ground-launched version of the Tacit Rainbow antiradar weapon for the U. S. Army. The Raytheon-led team also was picked to qualify as a second-source producer of the AGM—136A air-launched version of the weapon now produced by Northrop.

The contracts will be awarded by the Joint Tactical Autonomous Weapons Systems program office at the Air Force’s Aeronautical Systems Div., which runs the Tacit Rainbow program. The fixed-price incentive contracts are to be awarded following a Defense Acquisition Board meeting scheduled for the end of October.

Raytheon and its partners were selected over two other contracting teams led by Boeing and Northrop. Boeing was competing for both contracts while Northrop was competing to develop the ground— launched version. The selection was made 'based on weapons trade studies conducted by all three teams.

Raytheon’s Missile Systems Div. will act as systems integrator and develop the guidance system for both missiles. Mc- Donnell Douglas Missile Systems Co. is responsible for the airframe, payload and propulsion system. E-Systems Melpar Div. will develop the missile electronics for the ground-launched version.

Under the second source program, Northrop will transfer technical data on the AGM-l36A to Raytheon over the next one to two years, according to Chauncey P. Dewey, Jr., Tacit Rainbow program manager at Raytheon. The Air Force will then begin a 30~month program to evaluate and qualify the Raytheon design, including five flight tests.

Raytheon plans to use the same Texas Instruments seeker employed by Northrop for the testing program. Dewey said, however, the firm will eventually develop its own seeker. The Air Force plans to split missile purchases between Northrop and Raytheon in 1994. The two firms will then begin competing for annual production buys in 1995.

The ground-launched program is scheduled to enter full-scale development concurrently with the second-source effort. The Army plans to include in its development contract two low-rate initial production options. The first of these options will be exercised in mid-1992, before the 4-year full-scale development program is completed. The ground-launched version will be employed on the Multiple Launch Rocket System (MLRS), which the Army wants to use for all of its deep strike weapons. Both versions of the lethal missile are designed to loiter over a designated target area searching for hostile radar emitters.

NEW AIRFRAME DESIGN

Contractor flight tests are scheduled to begin in the fall of 1991. Dewey said the ground-launched version will include a brand new airframe design to make it compatible with the MLRS, as well as a new propulsion system developed by Teledyne. Dewey said he that contracts for both programs would be awarded in December, pending the outcome of the upcoming Defense Acquisition Board review.

The board will meet to determine whether to proceed with full-scale development of the ground-launched version. At the same time, it will review progress toward meeting requirements it imposed on the air-launched program late last year. The senior-level review group recommended against moving into low-rate initial production of the missile because of testing problems and set a series of testing criteria to be met before additional purchases could be made.

The testing program appears to be back on track, however, following the fourth successful test launch of the airlaunched AGM-l36A on Aug. 31 (AW&ST Sept. 11, p.33). The Air Force seems to be well on its way to meeting the requirement of successfully completing five of eight test launches by October. A total of 25 development and operational test launches are to be conducted from Navy A-6 aircraft and Air Force B—52 bombers. Air Force officials are hopeful that a decision to enter low—rate initial production of the missile could come in the second half of 1990. A key issue at the DAB meeting will be whether the Navy agrees to rejoin the program. The Navy dropped plans to procure the air—launched version of the missile but is continuing in the full-scale development portion of the program.

UNIT COST

Without Navy participation, the unit cost of the missile will increase by more than 20%, according to an official in the Pentagon’s tactical warfare programs office. Defense Dept. officials are hopeful of reaching some decision on Navy participation at the DAB meeting in order to complete work on the Fiscal 1991 budget. Initial budget requests from the individual military services were due
Sept. 15.

While questions about the affordability of Tacit Rainbow linger, the program was endorsed by a joint operational requirements study. The report, which assessed the operational and employment concepts of the loitering missile, expressed strong support for the program. Deputy Defense Secretary Donald J. Atwood has reviewed the report that is scheduled to be delivered to Defense Secretary Richard B. Cheney this week.

Raytheon and its partners were selected over two other contracting teams led by Boeing and Northrop
1631455292228.png
 
The F121 expendable turbofan developed for Tactit Rainbow was actually tested by a Naval Postgrad; who did detailed testing after he obtained the engines for use as a test rig for fuel additives.


If my calculations are correct; F121 had 0.34~ lb/hr/hr TSFC (versus 0.68~ for the early F107-WR-400 on the TLAM)
 

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