Technical Question on Super Sonic Ammo and "Breaking the Sound barrier"

Discussion in 'Silencers' started by BigEd63, Sep 3, 2019.

  1. Never pulled duty in a Squadron, I stayed an Intermediate Maintenance (AIMD) guy... Here's an F-14 engine (TF-30 P414a) At NAS Oceana Test Cell (1st Duty Station) and the Crew I worked with.. That's me 2nd from the right ... I don't miss the Military BS, but I still miss the People I served with.

    Oceans Test Cell - 1980's.jpg
     
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  2. TXplt

    TXplt Gun Toting Boeing Driver Forum Contributor

    The EF-111 had TF-30 P109s. I thought it a great engine but it was prone to compressor stalls particularly when going in and out of burner while at high AOA or up high. Didn’t help the jet had a long nose and tiny intakes. Had a dual engine stall over southern Iraq at high altitude which got our attention but they auto-relit after awhile when we pulled them to idle (obviously in a power off descent) and sped up. Really rugged engine though and I liked them.

    During the event my recently divorced right seater was lamenting his run of lousy luck. But all turned out just fine.

    Edit: Noticed the part of the F-14 lockouts (their wing sweep system was automatic I believe; ours was manual which I liked and after getting used to it was really intuitive. There was a fore-aft handle we raised and kinda 'trimmed' the wings for cruise to 4-5 units AOA. We used 16 for TO/Landing (moving 1 degree aft for every 1000 pounds of fuel below 8K for CG reasons), 26 for Econo-cruise, 44 for threat reactions (just outside of the spoiler lockout which happened at 45 degrees but also kept enough of a buffer to prevent overspeeding the wings--yes you could do this and there was a barber pole for max speed for wing sweep in the airspeed tape as well as a red 'reduce speed' light which did both mach heating and too fast for wing sweep) and 72 for max blast run like a scalded cat. The lockouts were at 26 and 68-ish degrees; the low side to keep you from going past cruise wing and the aft one to prevent fuselage damage if you were carrying BRUs and bombs.

    Amazing that stuck somewhere in the melon since we retired them in 1996.
     
    Last edited: Sep 19, 2020
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  3. jerry

    jerry Since 03-15- 2002 Forum Contributor

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    Engine back shop is good duty. Lots of good cookouts!


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  4. LOL Lot's of memories... I remember that too (that the 111's were manual vs. Automatic wing sweep) though not to the detail level you do as I was a "Knuckle Dragger". The P414a, had several changes over the P414's and part of that was a redesigned Inlet/front frame and some additional things meant to mitigate potential compressor stalls. Though we didn't have a test function for the ARS (auto Relight system) I found that on the Test Cell I could Hoarse the engine around enough to usually kick it in to check it's function.

    In the Navy they generally wanted us to "Diversify" our assignments, but I stuck with Test Cell because it was more Technical in nature and as I got deeper in realized that though the military didn't realize it Aviation (and most things) had become so complex that they needed core people with much more knowledge and experience than you can get doing 4 years of this or that and I ended up doing about 16 years of Gas Turbine testing and was planning on being a DOD Tech Rep for it when I retired until Uncle Sam decided to start messing around with Dual Retirement from Combined Military & DOD Service (it then became a last resort option after military retirement).

    I think I could still pretty much run the entire test sequence for an TF-30 with little need for a refresher after being out for almost 20 years. On my last shipboard Test facility I was deep enough in that I actually built self correcting run sheets for the engines I tested on my PC to correct all the data to Standard Day conditions for evaluation. (we would still do them by hand, but then plug them in). That was in the mid 90's and there was only one parameter I needed my Natec Rep's help with and LOL it was TF30 Fuel flow calculations... Had to get with Pratt & Whitney engineers to figure it out (and they couldn't tell us- but we did finally figure out the methodology). At that time I was the only Operator in the Navy doing such to my knowledge, and the Navy tried doing that same thing with the TF-30's in the early 80's with a 1.5 million dollar computer system that made testing take twice as long and half the time would dump the data when you were done (it was miserable enough that it fell into disuse after a very short time).

    Though it was not part of testing I would always Hoarse the engine around as hard as I could after it was tuned and verified, especially going in and out of afterburner as that was the weak point in the Hydromechanical Controls where the main fuel control and the Afterburner fuel control had to come to terms with each other. The way I looked at it was that it was Job to try and get the engine to fail if I could on the Cell. One of my early friends and mentors made a sign that read "When It's all Said and Done Would YOU fly this Engine to 40,000 feet for a Dogfight?", and I kept that Posted at every Test Cell I ran.

    That's the thing I think I miss the most with being in the Military, we had Good People with a Common goal including the retired military in DOD and I don't think there was a problem out there that we couldn't conquer, however the Military Dogma from the upper echelon's generally wasn't smart enough to realize just how capable their people were and turn them loose to reap the most benefit. Once I entered the Civilian Sector I realized that despite it's faults the military was generally light years ahead in methodology compared to Corporate America.
     
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  5. jerry

    jerry Since 03-15- 2002 Forum Contributor

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    Used to like sitting in the control booth in the hush house.


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  6. TXplt

    TXplt Gun Toting Boeing Driver Forum Contributor

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  7. animalspooker

    animalspooker G&G Evangelist

    My pop said he used to hear it when he pitched in high school. He was always full of it!!!

    This from the same guy who told me he once hit a line drive by the pitcher and as he rounded second, it hit him in the left ear...."eye roll"