|
Post by dude on Aug 18, 2012 9:07:50 GMT 9
Sometime circa 1980 the Stable Coordinate Reference Group (SCRG) in the Six was replaced by the Attitude Heading Reference Group (AHRG). I assume that meant a change out of the stable table (289 unit), but not sure. Any MA-1s, etal working the Six during that time that could shed some light? Did it affect other units in the 05 compartment? What was the big advantage gained with the change?
|
|
squirrel
F-106 Qualified
Currently: Offline
Posts: 8
Location:
Joined: March 2012
|
Post by squirrel on Aug 20, 2012 11:55:26 GMT 9
It was a good mod. No more tumbled table troubleshooting or 118 test set. 289 and rack tossed. counter weights placed for balance I think.
|
|
tman
New to the Flightline
Currently: Offline
Posts: 2
Location:
Joined: September 2009
|
Post by tman on Aug 20, 2012 12:19:09 GMT 9
: Kind of fuzzy after all of these years but the reliability went through the roof. No more tumbling issues. I believe most units were replaced in the 05. Ballast in place of the 289. (Did you ever see the inside of a 289? We took one from a crash waiting to be loaded on a barge and took it apart. Neat gyro inside.) I was just becoming a competent technician when we switched to the F15 at Tyndall. So many of my years were spent learning and coping with the complexity.
|
|
MOW
Administrator
Owner/Operator
Currently: Offline
Posts: 5,821
Location:
Joined: September 2003
Retired: USAF, Civil Service
|
Post by MOW on Aug 20, 2012 14:46:16 GMT 9
:welcome Back tman! Where you been?
|
|
|
Post by dude on Aug 24, 2012 9:58:37 GMT 9
Kind of fuzzy after all of these years but the reliability went through the roof. No more tumbling issues. I believe most units were replaced in the 05. Ballast in place of the 289. (Did you ever see the inside of a 289? We took one from a crash waiting to be loaded on a barge and took it apart. Neat gyro inside.) I was just becoming a competent technician when we switched to the F15 at Tyndall. So many of my years were spent learning and coping with the complexity. Never saw the inside, but once watched a guy dance with a 289 on the flightline.
|
|
sixerviper
F-106 Skilled
Currently: Offline
Posts: 209
Location:
Joined: July 2007
|
Post by sixerviper on Aug 25, 2012 5:21:23 GMT 9
It happened after I got off the airplane, but sometime around that time they took the attitude gyro, amp power supply and compass adapter out of the 05 and hooked the ADI and HSI up to the stable table. Whether it was a new unit or not, I don't know; I was not an MA-1 weenie. I was an Instrument weenie. As I understand the stable table (289 unit?) it was pretty much the first fighter-borne INS system in the USAF. Is this true? Was this mod in conjunction with the PUP mod?
|
|
|
Post by dude on Aug 26, 2012 5:23:08 GMT 9
As I understand the stable table (289 unit?) it was pretty much the first fighter-borne INS system in the USAF. Is this true? Was this mod in conjunction with the PUP mod? No PUP was much earlier, circa 73-74 I think. Not sure if the Six was the first with INS. Seems like there should have been others...if not fighters, then certainly bombers??? Thought the Six's big claim to fame in that arena centered on the Autopilot. Found some more data... The SCRG consists of a platform, three gyros, an accelerometer and a system of three gimbals, the innermost holds the platform. The platform can precess 360 deg about the roll and azimuth axis and +/- 85 deg about the pitch access. Manuevers in excess of +/- 85 deg in pitch will cause the platform to tumble. THe AHRG consists of a displacement gyroscope assembly, the electronic control amplifier, the compass system controller and the stable coordinate converter. The gyros can rotate 360 deg about the roll, pitch and heading axis.
|
|
|
Post by lindel on Aug 31, 2012 21:59:40 GMT 9
It was in the early 80s, at Tyndall. What do you want to know about it? I can probably dredge up some memories.
I was the lone mock up troop on the mod team. I checked every system before install, right after I had to fix the mock up stand they said I could use.
|
|
|
Post by dude on Sept 2, 2012 10:57:04 GMT 9
It was in the early 80s, at Tyndall. What do you want to know about it? I can probably dredge up some memories. I was the lone mock up troop on the mod team. I checked every system before install, right after I had to fix the mock up stand they said I could use. Mainly just curious about what went, what stayed and why it was done. Per prior data it appears to have eliminated the tumble. But since you were on the mod, maybe you can add a little more to it... 1. How did the SSGC change? As in did it get any better? 2. Did anything change to the computer vis a vis the axis parameters, etc.? In other words, could you still call up the parameters and monitor the axis as the table/gyro precessed? 3. Was it a complete change out of the SCRG rack as well? 4. There seemed to be some changes in the cockpit instrumentation (i.e. heading indications, etc). as a result of the mod. What was that for?
|
|
|
Post by lindel on Sept 3, 2012 1:08:09 GMT 9
1. It was a total change out. The SCRG system was completely removed and ballast was added to make up for the weight difference.
2. You could still call up the parameters, but they didn't move much, if any. The AHRG system was the INS system used in the A-10 at the time.
3. All bits and pieces of the SCRG system went away (Thank God!)
4. Can't tell you about the changes to the instrument panel, I didn't mess with the instruments at all during that TDY.
Side note...you still had to wait about 15 minutes before you moved the gyro, only this time it was to prevent damage to the gyro, not you! It weighed about 10 lbs and was about the size of a loaf of bread.
The new system was a lot more stable and accurate. When I tested the system, I had to monitor several different things and look at quite a few signals, make measurements and so forth. Only had one bad system from Fairchild ( think it was Fairchild) out of the lot.
Had to fix several more MA-1 problems than AHRG problems...go figure!
|
|
zipper730
F-106 Skilled
Currently: Offline
Posts: 214
Location:
Joined: September 2016
|
Post by zipper730 on Nov 7, 2018 11:02:29 GMT 9
I'm not sure what USAF aircraft had the first inertial system, but the B-58 definitely had such a system as did all of the A-12 (A-12A/B) and derivatives (YF-12A, SR-71A/B, M-21): It used an inertial system updated by a star-tracker.
|
|