T-38 Down @ DLF

[Breckey]

1 hour ago, MooseAg03 said:

I know it’s tragic, but it should be emphasized that these guys delayed ejection specifically to protect those innocents on the ground from having a flaming ball of wreckage dropped on their houses. Heroic. Just wish they both could have made it out...

The SIB had a pretty good discussion on the decision to delay ejection.

 

 

[HuggyU2]

Is the pin pulled in the chocks?  Or just prior to pulling on to the runway?

[hindsight2020]

3 hours ago, MooseAg03 said:

I know it’s tragic, but it should be emphasized that these guys delayed ejection specifically to protect those innocents on the ground from having a flaming ball of wreckage dropped on their houses. Heroic. Just wish they both could have made it out...


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I get that's a common sentiment in order to show gratitude to the departed, but that's not at all how it went down in reality. It's also not the first time I've buried a co-worker where the folk tale gets pressed that there was a heroic suicide for the sake of the people on the ground, later to reveal a more simple and less flamboyant answer (spatial D and mental unwillingness to get out, as was the case with my UPT SRO and his Hornet crash). You don't have to rub it in the surviving's faces at the funeral. But for us who still remain and do the job tomorrow, damn right we owe the departed some roasting, if we are to honor the legacy of his sacrifice, and learn a god damn thing or two instead of repeating it.

The conversation about collateral damage in the jet was to me, simply ancillary to a suspension of disbelief that stemmed from the fact they (and I am also not above reproach in that fallibility) did not immediately internalize the absolute nature of loss of control once dual hydraulic failure ensues. The common urban legend is that you can steer with windmilling hydro when the engine fails but windmills. First of all, not true enough to warrant consideration. BUT, this is worse than merely windmilling hydraulics, because the gearboxes were severed and thus there would have been actual zero input to the pumps. That means no shit, other than the engines effecting pitching moments of little consequence as they throttle jockeyed, the aircraft was immediately ballistic.

The decision to delay ejection was neither the correct one nor one that saved lives on the ground. It may have actually killed the deceased, if one is to conjecture that he would have had extra time to gather enough presence of mind to get his sh*t together, un-f*ck his own seat from the way he left it on takeoff, and punch. But this is conjecture since we will never know if he failed to punch himself out due to incapacitation (due to the incorrect sequence selected, and the FCP seat blasting him with the rocket) or inappropriate reaction to stress (aka frozen by panicking).

As to the latter, the SIB had some insights into that question which now the AIB sort of refutes, and paints the survivor in a not so positive light. I'm a little bit disappointed by this reversal in findings, but that's for the survivor to live with. Never miss an opportunity to STFU when it comes to USAF interviews is all I got to say about that one. I also don't trust the safety process enough to open my trap, but that's my bias.

1 hour ago, HossHarris said:

Unfortunately, with zero hydraulics a T38 is gonna go where it’s gonna go ....

Exactly. And you're being kinder than I.

1 hour ago, HuggyU2 said:

Is the pin pulled in the chocks?  Or just prior to pulling on to the runway?

Generally the checklist now allows for anywhere before takeoff. Most people either stow them in the hammerhead, or all the way back before pulling chocks. I do the latter, but sometimes I break order and do it in the hammerhead. And I'll challenge anybody here who flies these things come and assert they've never forgotten to arm their seat until they get to the MOA and go "..oooh shit...*muffled cllllllick* ". I only say that so people don't misinterpret my criticism for the complacent CRM in the conduct of a requal sortie that was conducted with a CT atmosphere (they all are) as some sort of gratuitous aspersion, when in reality we have all been guilty of it at one point or another.

The lesson learned for me is exactly that: treat CT rides with respect. And treat requal guys like idiot UPT students. Sure, don't verbalize that to them, but treat them with the same skepticism. The fact is, we don't as a collective. I also don't agree with the shortened "feed the fight" figther-centric thing we got going on at the schoolhouse, with shortening the callouts. Not so much because it's somehow blasphemy, but rather because the UPT bases, Red Bulls in particular, are actually going the opposite direction, precisely because of this accident. But I'm preaching to the choir here. Stay safe out there.

 

[MooseAg03]

Thanks for informing me of the nature of the emergency, from reading their conversation I thought they had some sort of control left. So the T-38 has no mechanical backup? I guess with two drive shafts that are designed to shear, I can’t believe there would be no backup for control.


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[SurelySerious]

13 minutes ago, MooseAg03 said:

Thanks for informing me of the nature of the emergency, from reading their conversation I thought they had some sort of control left. So the T-38 has no mechanical backup? I guess with two drive shafts that are designed to shear, I can’t believe there would be no backup for control.


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Aviation design is always about trade offs, and for a light jet trainer, dual redundancy is pretty good. 

[HossHarris]

26 minutes ago, MooseAg03 said:

 So the T-38 has no mechanical backup? 

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None. 

 

As mentioned, the only direct connection you have is to the throttle. If you have no shit zero hydraulic pressure on both sides, you are simply along for the ride and can only control how fast you get to the crash site. Of note, there is little to no pitching moment with throttle changes from idle to full ab. 

Systems knowledge will set you free 

[Hacker]

49 minutes ago, hindsight2020 said:

The common urban legend is that you can steer with windmilling hydro when the engine fails but windmills. First of all, not true enough to warrant consideration. BUT, this is worse than merely windmilling hydraulics, because the gearboxes were severed and thus there would have been actual zero input to the pumps.

This immediately stuck out to me reading the AIB.

With a dual engine failure is when the "windmilling hydraulics" discussion is relevant.

With a dual gearbox (and thus dual hydraulic) failure, there is no longer a connection between the stick and the flight controls.  Those engines can be pumping out as much RPM as you please, but you're along for the ride at that point.

And just that much error in analysis is what causes delays to eject and fatalities.

[Hacker]

38 minutes ago, MooseAg03 said:

Thanks for informing me of the nature of the emergency, from reading their conversation I thought they had some sort of control left. So the T-38 has no mechanical backup? I guess with two drive shafts that are designed to shear, I can’t believe there would be no backup for control.

Let's remember that the T-38 was designed as the first supersonic trainer back when the century series fighters were out.  Not everything about designing aircraft for trans-sonic and high-Q flight was well understood, but one of those issues was flutter of flight control surfaces. 

The common answer was to only have surfaces actuated (and thus held rigidly in position during flight) by hydraulics.

We didn't have the electronics technology that we do today to have self-isolated hydraulic servos to move flight controls that can be actuated hydraulically, electrically, or mechanically.

[dannoc]

Reese AFB '78 or '79 was an FCF pilot.  My boss on a T-38 FCF couldn't get one engine started after shutting one down for a restart check.  For some stupid reason, he still decided to do an inverted flight check, and the hydraulic cap on the good engine blew off and dumped all the fluid.  So now he had one good engine, but no hydraulic pressure, on that side.  Windmilling hydraulics on the other engine provided plenty of control for him to talk to homeplate and fly around for another 30 minutes before (as recommended) he proceeded to the controlled bailout area and ejected.  Thankfully he was uninjured but was faulted on his judgment.  

Edit:  I know this doesn't apply here with dual shaft failure and absolutely no hyd. pressure, but just commenting on the fact that you still fly the aircraft with decent windmilling rotation on an engine that's not working...just don't get slow.
 

Edited August 25, 2018 by dannoc

[Majestik Møøse]

10 hours ago, dannoc said:

For some stupid reason, he still decided to do an inverted flight check, and the hydraulic cap on the good engine blew off and dumped all the fluid.  So now he had one good engine, but no hydraulic pressure, on that side.

...so “roll inverted and pull” isn’t a valid COA during an EP?  I need to get back in the books.

[HuggyU2]

34 minutes ago, Majestik Møøse said:

...so “roll inverted and pull” isn’t a valid COA during an EP?  I need to get back in the books.

No, it's totally valid.  Yes, you need to get back in the books.  

What you shouldn't do is push.

You're welcome.  

 

[HuggyU2]

One year ago today.  

Stuck was a great guy.  

[HuggyU2]

I have a humorous request... 

A few years back (I think it was March 2012), Stuck was part of the crew that flew a B-52 to the El Centro Airshow in Southern California.   Coincidently, I was the airshow announcer, and we had a great time at the Club both nights.   

If any of you were on that crew or know the guys that were, could you have them contact me?  Long shot, I know.

Or... if you happen to currently be in Stuck's old Barksdale B-52 squadron, that might work too.  

Drop me a note and I'll explain.  

Edited October 8, 2019 by HuggyU2

[DuckHunter]

6 years today.  All gave some, some gave all.  🥃