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Post by Diamondback on Feb 6, 2012 1:28:08 GMT 9
Gents (and rarer but no less valued Ladies), a discussion came up on another board: a contact tried to argue that the Six was Fly-By-Wire and wanted to know whether it was pre- or post-QF, and my bet was it was pure hydraulic/mechanical.
So, the big questions are, how did the MA-1 interface with the control surfaces, and which of us is right?
Thanks!
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MOW
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Post by MOW on Feb 6, 2012 5:37:26 GMT 9
From my MA-1 / SAGE page www.f-106deltadart.com/sage_system.htmThe F-106A Delta Dart operated in conjunction with the SAGE (Semi-Automatic Ground Environment) network linked via the Hughes MA-1 fire-control system to the F-106. It operated by plotting the course needed to intercept an enemy aircraft, automatically sighted the target, fired the air-to-air missiles, and then automatically placed the F-106 on the correct course to disengage. The F-106 could actually be computer-flown during most of its mission, the pilot being needed only for takeoff, landing, or in case something went wrong with the automation. I don't know how all this happened, need the smart guys here to answer that, but this is of course all pre-drone. |
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Post by bear (Deceased) on Feb 6, 2012 8:13:59 GMT 9
I believe they were called HEP and HIP valves and they controlled either mechanical or electrical. There were position pots on both Elevon Actuators in the engine bay and one on the rudder actuator. They were use for TO Trim and all AFCS modes, only Auto AFCS was completely Hands off flying which could be a wild ride with hot dot, or erratic steering. Auto AFCS was suppose to be good to 50ft AGL. So I guess you could say it was both.
Bear
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Post by Diamondback on Feb 7, 2012 9:07:21 GMT 9
Thanks, gents. KJ had a followup about "sighting" the target and what you mean by that, and I told her that my guess was a better term would be "acquire and lock onto". Is that a fair assessment?
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Post by lindel on Feb 7, 2012 9:43:54 GMT 9
Pat's right. The Six was never "fly by wire", but was hydraulic with electrical controls. Once off the ground the SAGE could take over for the rest of the mission. At least that was my understanding.
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Post by bear (Deceased) on Feb 8, 2012 0:09:29 GMT 9
I agree, but I disagree. In the engine bay was a mixer assembly which combine the inputs from the stick and rudder pedals and linked them to the valves for the elovons and rudder, as long as you had hdy pressure the control surfaces would move. Pitch and Yaw position made flying a little easier. Pilot Assist made it even smoother. Auto depending on alot thing could be very smooth or bounce the pilots helmet off the canopy. Very few pilot ever flew full auto for the whole mission. Why because if Auto didn't work they had to fly the airplane and what did was fly training mission.
Bear
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Post by LBer1568 on Feb 8, 2012 2:41:19 GMT 9
True the six had mechanical/hydraulic controls. In the event of loss of hydraulics the pilot would "drop" the Ram Air Turbine "RAT" which would drop a small unit into airstream and it would power Essencal DC Gen and Flight Controls. It was located on left side behind weapons bay. It was useful until under 125 knots when landing.
BUT, the MA-1 System, or AN/ASQ25 on "B" Models, provided electrical inputs to flight control system. This included the reversal of controls when going supersonic. With the Delta Wing and Elevons the air going over control surface separated in supersonic flight and controls would reverse directions. The Automated Flight Control System (AFCS) amplifier was over right wing and was unit that trimmed flight controls ; ie took mechanical positions and aligned with electronic controls.
MA-1 had Pilot Assist Mode which was basically the auto pilot in most other aircraft. The "Auto" Auto pilot input would accept inputs from SAGE and Automatically fly to designated point. The "Auto" also would Automatically fly to Navigation "points" selected by pilot. SAGE could control both direction and altitude, the Way points only directed to navigation Points, not altitude.
While the six had the most advanced Avionics of any Fighter, it was not a Fly by Wire, since there was a mechanical linkage to the AFCS and needed hydraulics to make the controls do what the AFSC directed electrically.
Most other aircraft had actual mechanical controls to all flight control surfaces, but had hydraulic assists. So without hydraulic power the six was not controllable by Pilot. So any Pilots who claim to have made a dead stick landing after engine seigure was actually flying with hydraulics provided by RAT.
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Post by Jim on Feb 9, 2012 14:47:24 GMT 9
OKAY no MA-1 sys operating, no AFCS on---------- The F-106 is flying with a system called mechanically selected and hydraulically actuated flight control surface movement. The mixer assembly was a device that allowed the elevons to act as elevators and ailerons at the same time utilizing mechanical linkage from the stick (push pull rods), mixing it up and sending it out to the HEP valves which actually tells the actuators what to do.. (don't remember any rudder connections to the mixer). Most a/c of the 27th were rec'd with the entire mechanical sysytem out of rig according to the Tech Order- this was brought to light when pilots reported various shift problems when going into or out electronic controlled flight (another story posted several years ago here)...... The rudder was conventional cables back to the HRP valve (HEP = Hydraulic Elevon Package) (HRP = Hydraulic Rudder Package)......
Lorin is right, if the pilot said dead stick landing- he meant dead engine landing The RAT delivered a limited fluid volume at a minimum pressure to both elevons and rudder. There were no sudden surface movements or the RAT would cavitate and it would take a while to catch back up... AND below 125 knots, you had better be lined up, because there wasn't enough airflow to ensure proper operation of the RAT!!!!!!!!!
I can't be 100% positive, but I think that the last jet in the AF that could have made a dead stick landing was the F-94C- it was all mechanical linkage and cables.. I believe the ailerons had aileron boost ala the T-33.... All others would have been nylon controlled desent.
Fly by wire is all by electrical/electronic signals, whether it is from potentiometers actuated by stick or peddle movement, auto pilot or computer... There is no mechanical system what so ever... The stick/column and peddles are nothing more than large joysticks operating servo motors that in turn operate valves that operate actuators. In the days of the SIX, the pilot could take over at any time. Today, it is tough crap
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Post by dude on Feb 11, 2012 10:05:52 GMT 9
 First production fly-by-wire was the F-16. As many indicated the MA-1 did not have to be on for the pilot to affect the control surfaces. From the MA-1 side, it depended on what AFCS mode you were in. YAW and PITCH DAMP got you a turn rate transmitter for turn coordination and rate gyros that would monitor oscillations and provide feedback to hydraulic valves that controlled the hydraulic actuators for surface control. ASSIST got you the dampers plus Altitude and Heading Hold. Primary inputs for ASSIST came from the Stable Table. In ASSIST you also picked up the Pitch G Limiter in the right wheel well that would drop the system to dampers if the MA-1 tried to take you on a sleigh ride. There were three "modes" of AUTO: AUTO NAV, Data Link and ILS. Auto Nav worked with TACAN homing points for cross-country flights. ILS was for landing appoach. As far as Data Link, there is a treatment elsewhere here on the site that details SAGE and the various methods of control. MA-1 flew the airplane by sending commands to position potentiometers that sat on the hydraulic actuators for the control surfaces. Control came via the 821 unit that sat above the 846 unit in the computer bay. THe 821 had the adjustments to "null out" the surfaces so everything was flying on the same page so to speak. Whenever an engine was pulled for PM, MA-1 would go in and either replace or align the elevon pots. You could also use the computer to call up the pitch & yaw paremters and use the readout for alignments instead of eyeballing the control surfaces.
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Post by Mark O on Feb 11, 2012 11:19:26 GMT 9
Thanks so much for the info on the Six, and the MA-1 Dude!
I hope I'll be able to remember which seat I sat in as a C-130 FE after I've been away from the aircraft that long, much less my bold face or system limitations! :confused
(Remind me it was the seat in the middle if I ever forget guys!)
Seriously, that's some good info.
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tmbak
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Post by tmbak on Feb 12, 2012 1:54:47 GMT 9
I don't ever remembering the RAT providing any electrical power. It was strictly used for hydraulic power to operate the flight controls when there was a hydraulic failure.
If you remember there was a bellows assembly in the mixer assy that was controlled by ram air from a pitot tube on the vertical stab. The faster the aircraft went the more air was sent to the bellows assy. This was connected to to the mixer by a cable which would limit the amount of input the pilot would ask for by stick inputs. When the aircraft was super sonic the pilot could put full stick inputs but the mixer would only allow so much movement to the flight control surfaces due to the bellows assy.
I think the Old Sarge is right about the rudder. The rudder cables ran down the backbone of the aircraft to the Actuator control. If the pilot pushed hard enough on the rudder pedels, during a hydraulic failure, he was able to get slight rudder imput if needed.
One thing for sure the guy that thought up the mechanics of the f-106 flight controls was one smart fellow!
Tom
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Post by oswald on Feb 12, 2012 2:20:20 GMT 9
Hey, does anyone out there still have a rat hook? maybe a picture of one?
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Post by dude on Feb 12, 2012 2:41:23 GMT 9
I don't ever remembering the RAT providing any electrical power. It was strictly used for hydraulic power to operate the flight controls when there was a hydraulic failure. If you remember there was a bellows assembly in the mixer assy that was controlled by ram air from a pitot tube on the vertical stab. The faster the aircraft went the more air was sent to the bellows assy. This was connected to to the mixer by a cable which would limit the amount of input the pilot would ask for by stick inputs. When the aircraft was super sonic the pilot could put full stick inputs but the mixer would only allow so much movement to the flight control surfaces due to the bellows assy. I think the Old Sarge is right about the rudder. The rudder cables ran down the backbone of the aircraft to the Actuator control. If the pilot pushed hard enough on the rudder pedels, during a hydraulic failure, he was able to get slight rudder imput if needed. One thing for sure the guy that thought up the mechanics of the f-106 flight controls was one smart fellow! Tom Agree the RAT was hydraulic only and tied to the primary hyd lines. The pitot tube was called a q intake and was used by the pneumatic system to drive cylinders on the stick and rudder pedals to provide what they called "feel force regulation" (a.k.a. artificial feel). I believe ac back up on the electrical side (CSD failure) came from a hydraulic driven emergency generator as well as a the pneumatic driven ATG (Air Turbine Generator). And 28vdc came off the aircraft battery. |
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Post by Jim Scanlon (deceased) on Feb 12, 2012 3:09:09 GMT 9
I think I still have a Rat Hook.
Will have to look through some of my "old" tools.
Basically, it is a round 1/8" piece of rod, welded in to a circle, with a hook about 1/2" long welded to it.
Some had a "remove before flight" type cloth on them.
I'll see if I can find mine, and get it posted.
I might still have a "Dzus-all" in the same box.
Jim Too
:god_bless_usa
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Jim Scanlon (deceased)
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Post by Jim Scanlon (deceased) on Feb 12, 2012 3:35:29 GMT 9
Tom said:
Was he/they a real smart fellow, or a certified maniac?
Having done quite a few Mixer check and alignments, including all the flight control checks with the tester hooked to both air intakes on the vertical stabilizer.
It was a rather lengthy procedure to do the complete check, even had to have an MA-1 weenie there to run their systems.
But first, we had to do a mixer check, using the box of "Pip Pins". Each pin had to go in in sequence, and when you found a hole the pin wouldn't go in, you stopped and did what adjustments you needed to get the thing going.
I have spent hours and hours, just trying to get the mixer set the way the book said.
Very often, Don St. Pierre our Convair Tech Rep, was in the bay with us, as we did the alignment.
Then came the test hop, and if there was anything wrong, Col. Chandler would let you know.
Fun job, that could last an entire shift if there were problems.
One thing for sure, once you started it, you didn't quit until it was done. There was no changing shifts on the job, as it would mean starting all over.
So, we began the check at the beginning of a shift, and worked it until it was done.
If the mixer was off kilter, everything else was.
Of course, we took coffee breaks and at lunch, but didn't go very far from the bird.
Jim Too
:god_bless_usa
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Post by Jim on Feb 13, 2012 5:50:09 GMT 9
Tom said: Was he/they a real smart fellow, or a certified maniac? Having done quite a few Mixer check and alignments, including all the flight control checks with the tester hooked to both air intakes on the vertical stabilizer. It was a rather lengthy procedure to do the complete check, even had to have an MA-1 weenie there to run their systems. But first, we had to do a mixer check, using the box of "Pip Pins". Each pin had to go in in sequence, and when you found a hole the pin wouldn't go in, you stopped and did what adjustments you needed to get the thing going. I have spent hours and hours, just trying to get the mixer set the way the book said. Very often, Don St. Pierre our Convair Tech Rep, was in the bay with us, as we did the alignment. Then came the test hop, and if there was anything wrong, Col. Chandler would let you know. Fun job, that could last an entire shift if there were problems. One thing for sure, once you started it, you didn't quit until it was done. There was no changing shifts on the job, as it would mean starting all over. So, we began the check at the beginning of a shift, and worked it until it was done. If the mixer was off kilter, everything else was. Of course, we took coffee breaks and at lunch, but didn't go very far from the bird. Jim Too  Oh yeah, some of the control shifts after the mechanical and the mixer were all rigged showed how the AFCS people played with adjustments. Once all sytems were put back in sync, sometimes you could barely feel the elevon twitch during a change over..... The FCF pilots would come back with a big crap eatin grin on their face and a HOLY MOLY, I had to do it several times to believe it!!!!!!!. A bad situation at Loring caused the establishment of unit flight control teams. Per ADC orders, these were the only people that did the actual rigging and adjustment of flight controls.... It was like JimToo said, there was no shift change. As Team leader, I saw many 18hour days, some longer because I also had to debrief the FCF pilot. I had forgotten that the Q intakes supplied imput to provide "artificial" feel to the pilot....... For the rest of my career (ret. Dec 77) I was always involved in flight control work, including being a member of the Rep of Korea AF F-5 accident investigation team for an accident involving flight controls and another "mixer" assembly. The Old Sarge |
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Post by lindel on Feb 13, 2012 8:19:54 GMT 9
First production fly-by-wire was the F-16. As many indicated the MA-1 did not have to be on for the pilot to affect the control surfaces. From the MA-1 side, it depended on what AFCS mode you were in. YAW and PITCH DAMP got you a turn rate transmitter for turn coordination and rate gyros that would monitor oscillations and provide feedback to hydraulic valves that controlled the hydraulic actuators for surface control. ASSIST got you the dampers plus Altitude and Heading Hold. Primary inputs for ASSIST came from the Stable Table. In ASSIST you also picked up the Pitch G Limiter in the right wheel well that would drop the system to dampers if the MA-1 tried to take you on a sleigh ride. There were three "modes" of AUTO: AUTO NAV, Data Link and ILS. Auto Nav worked with TACAN homing points for cross-country flights. ILS was for landing appoach. As far as Data Link, there is a treatment elsewhere here on the site that details SAGE and the various methods of control. MA-1 flew the airplane by sending commands to position potentiometers that sat on the hydraulic actuators for the control surfaces. Control came via the 821 unit that sat above the 846 unit in the computer bay. THe 821 had the adjustments to "null out" the surfaces so everything was flying on the same page so to speak. Whenever an engine was pulled for PM, MA-1 would go in and either replace or align the elevon pots. You could also use the computer to call up the pitch & yaw paremters and use the readout for alignments instead of eyeballing the control surfaces. And I used to hate when they (MA-1 Flight Line) would bring in an 821. Never could duplicate any of the write ups, and it made trying to t/s a real pain! |
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Post by bear (Deceased) on Feb 13, 2012 12:15:39 GMT 9
Anyone forget to pull the Vari-ramp fuse when running these checks? Had CC emerg retract them I think it took 2 days to get the air out of hdy system.
Bear
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Post by Jim on Feb 14, 2012 1:38:53 GMT 9
Anyone forget to pull the Vari-ramp fuse when running these checks? Had CC emerg retract them I think it took 2 days to get the air out of hdy system. Bear AND more than a 55 gal drum of fluid that was considered contaminated because 6 months later the fluid was still pink and frothy in the barrel. Don't remember what we had to do to prevent a CG fuel transfer- I think we defueled the bird before bringing in for PE or flight control rig and did something with the landing gear switches..... Same thing with emergency gear extension and you had to remember to remove the reservoir cap and reduce the speed of retraction to more than a minuit full down to full up or you had a mess all over the hangar!!!!!!!! |
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Post by dude on Feb 14, 2012 9:27:10 GMT 9
First production fly-by-wire was the F-16. As many indicated the MA-1 did not have to be on for the pilot to affect the control surfaces. From the MA-1 side, it depended on what AFCS mode you were in. YAW and PITCH DAMP got you a turn rate transmitter for turn coordination and rate gyros that would monitor oscillations and provide feedback to hydraulic valves that controlled the hydraulic actuators for surface control. ASSIST got you the dampers plus Altitude and Heading Hold. Primary inputs for ASSIST came from the Stable Table. In ASSIST you also picked up the Pitch G Limiter in the right wheel well that would drop the system to dampers if the MA-1 tried to take you on a sleigh ride. There were three "modes" of AUTO: AUTO NAV, Data Link and ILS. Auto Nav worked with TACAN homing points for cross-country flights. ILS was for landing appoach. As far as Data Link, there is a treatment elsewhere here on the site that details SAGE and the various methods of control. MA-1 flew the airplane by sending commands to position potentiometers that sat on the hydraulic actuators for the control surfaces. Control came via the 821 unit that sat above the 846 unit in the computer bay. THe 821 had the adjustments to "null out" the surfaces so everything was flying on the same page so to speak. Whenever an engine was pulled for PM, MA-1 would go in and either replace or align the elevon pots. You could also use the computer to call up the pitch & yaw paremters and use the readout for alignments instead of eyeballing the control surfaces. And I used to hate when they (MA-1 Flight Line) would bring in an 821. Never could duplicate any of the write ups, and it made trying to t/s a real pain! We did it on purpose. Often referred to it as Mock-Up Interruptus. :rofl |
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First production fly-by-wire was the F-16. As many indicated the MA-1 did not have to be on for the pilot to affect the control surfaces.
