T-6s Grounded; More OBOGS Issues

[FishBowl]

https://m.aviationweek.com/defense/usaf-grounds-t-6-trainers-after-hypoxia-events

The U.S. Air Force has grounded the Beechcraft T-6 Texan II training aircraft at Vance AFB, Oklahoma, after five pilots reported physiological episodes with hypoxia-like symptoms while flying.

The Air Force’s 71st Flying Training Wing enacted an “operational pause” of T-6 flying operations on Nov. 15 after four T-6 instructor pilots and one student pilot assigned to Vance reported physiological incidents since Nov. 1, spokeswoman Terri Schaefer told Aviation Week Nov. 29. 

In each case, the aircraft’s backup oxygen system operated as designed and the pilots followed the correct procedures, landing safely, Schaefer said.

The Air Force is investigating the incidents at Vance and has not yet identified a specific root cause, Schaefer said. The events were reported as “physiological events with hypoxia-like symptoms,” she noted.

The Air Force uses the single-engine T-6 turboprop as a basic trainer for all student pilots. From the T-6, students choose one of three advanced training tracks based on their class standing. Future fighter/bomber pilots next train in the T-38 Talon; pilots on the airlift/tanker track fly the T-1A Jayhawk; and helicopter/tilt-rotor trainees fly the TH-1H Huey.

In addition to Vance, student pilots also train in the T-6 at Randolph AFB, Texas; Moody AFB, Georgia; Columbus AFB, Mississippi; Laughlin AFB, Texas; and Sheppard AFB, Texas.

Since the grounding, Vance AFB has partnered with Air Education and Training Command, 19th Air Force and medical, functional and industry experts to determine the cause of the incidents. That effort has included reviewing procedures for physiological events, providing refresher physiological training, background briefs and Q&A with T-6 instructor pilots, Schaefer said. 

“Following the operational pause, we anticipate that flying operations at Vance Air Force Base will continue as usual, with added awareness and training concerning physiological events and the life-support equipment onboard the T-6 designed to protect pilot safety and ensure continued safety of flight,” Schaefer said.

The T-6 incidents come as a spate of hypoxia-like cockpit incidents plague the Air Force and U.S. Navy fleets. Both the Air Force and Navy grounded fleets this year: the Navy’s T-45 Goshawk trainers and the Air Force’s F-35Asat Luke AFB, Arizona, the service’s premier F-35 training base. Similar incidents are also on the rise in the Navy’s F/A-18 Hornet and EA-18G Growler fleets.

[LiquidSky]

Interesting that only 1 of the many basis flying the T6 is having major OBOGS issues (to my knowledge). Though majority of the Laughlin T6 fleet was grounded this week for other reasons. 

[FishBowl]

Just now, LiquidSky said:

Interesting that only 1 of the many basis flying the T6 is having major OBOGS issues (to my knowledge). Though majority of the Laughlin T6 fleet was grounded this week for other reasons. 

I was wondering about that. I didn’t know if it was related, but I know all the T-6s here were told to RTB for mx reasons. 

[MooseAg03]

Should have bought this instead: https://en.m.wikipedia.org/wiki/Fairchild_T-46#

What was the Laughlin maintenance issue?

[FishBowl]

22 minutes ago, MooseAg03 said:

Should have bought this instead: https://en.m.wikipedia.org/wiki/Fairchild_T-46#

What was the Laughlin maintenance issue?

I can find out tomorrow. They have us grads sitting RSU until we PCS.

[YoungnDumb]

They're sending some of the KEND studs to Columbus to finish up.  My guess is that since it's isolated to a base that it's something MX related.

[LiquidSky]

Saw today that the T6 got a new boldface for physis due to this.

[nunya]

Handgrips - Raise, Triggers - Squeeze?

[xcraftllc]

I sure hope the T-X uses LOX. I haven't heard of any issues recently on any aircraft that uses it.

[LiquidSky]

2 hours ago, nunya said:

Handgrips - Raise, Triggers - Squeeze?

Got it passed along from a buddy,

OBOGS Failure/Physiological Symptoms

GREEN RING - PULL (AS REQUIRED)(BOTH) 

DESCENT BELOW 10,000 FEET MSL - INITIATE

DISCONNECT MAIN OXYGEN SUPPLY HOSE FROM CRU-60/P

 

Will be interested to see down the line what the ultimate cause of all this is with OBOGS systems.

[HU&W]

21 hours ago, LiquidSky said:

Got it passed along from a buddy,

OBOGS Failure/Physiological Symptoms

GREEN RING - PULL (AS REQUIRED)(BOTH) 

DESCENT BELOW 10,000 FEET MSL - INITIATE

DISCONNECT MAIN OXYGEN SUPPLY HOSE FROM CRU-60/P

 

Will be interested to see down the line what the ultimate cause of all this is with OBOGS systems.

That's a lot of writing, and quite a bit of detail for a BF.  Surprised it's not a little more student(and hypoxia)-proof...

GREEN RING - PULL

DESCENT - INITIATE

OXYGEN HOSE - DISCONNECT

[hindsight2020]

The last line is legalese so Stanley doesn't default to disconnecting the mask hose at the CRU-60, as opposed to the airplane hose at the CRU-60. Big difference in outcome of course.

But yeah, that's gonna be a lotta sit-downs during stand-up and procedural phase tests lol.

Edited December 6, 2017 by hindsight2020

[Homestar]

23 hours ago, LiquidSky said:

Got it passed along from a buddy,

OBOGS Failure/Physiological Symptoms

GREEN RING - PULL (AS REQUIRED)(BOTH) 

DESCENT BELOW 10,000 FEET MSL - INITIATE

DISCONNECT MAIN OXYGEN SUPPLY HOSE FROM CRU-60/P

 

Will be interested to see down the line what the ultimate cause of all this is with OBOGS systems.

Geez lots of opportunities to Q3 that boldface novel 

[Duck]

4 hours ago, hindsight2020 said:

But yeah, that's gonna be a lotta sit-downs during stand-up and procedural phase tests lol.

Are bases allowing instructors to sit people down during stand ups? What happens if it hurts their feelings? It’s not like they are gonna wash out these days! Ugh.

[matmacwc]

On 12/4/2017 at 4:35 PM, xcraftllc said:

I sure hope the T-X uses LOX. I haven't heard of any issues recently on any aircraft that uses it.

I’ve had LOX all leak out in 30 minutes once, but then again, I’ve had way more OBOGS issues

[HossHarris]

We had a lox bottle blow the front end off a 38 at Tyndall ....

look for the report, lots of good pictures. 

(Not common....lox is good)

Edited December 6, 2017 by HossHarris

[Heavywanabe]

23 hours ago, hindsight2020 said:

The last line is legalese so Stanley doesn't default to disconnecting the mask hose at the CRU-60, as opposed to the airplane hose at the CRU-60. Big difference in outcome of course.

But yeah, that's gonna be a lotta sit-downs during stand-up and procedural phase tests lol.

That's exactly why. 

Also they said the above will change again shortly. Looks like it was a quick response to get it back up and the pipeline moving again. 

[tk1313]

There's a hyperoxia theory going around... Thought it was interesting. 

[LiquidSky]

2 minutes ago, tk1313 said:

There's a hyperoxia theory going around... Thought it was interesting. 

That doesn't make sense. Saw the fcif today and it came with specific direction that old procedure of gangloading was ineffective due to potential contaminants/toxins in the OBOGS. The emergency O2 it specifies is the only guaranteed source of pure 100% O2 hence the new boldface to pull green ring for hypoxia rather than gangloading. 

[jazzdude]

That doesn't make sense. Saw the fcif today and it came with specific direction that old procedure of gangloading was ineffective due to potential contaminants/toxins in the OBOGS. The emergency O2 it specifies is the only guaranteed source of pure 100% O2 hence the new boldface to pull green ring for hypoxia rather than gangloading. 

Hypemic or histotoxic hypoxia both would make sense- contaminated air from OBOGS could block oxygen absorption, resulting in hypoxia. Think along the lines of carbon monoxide poisoning. Which would make pulling the green ring instead of gangloading make sense (actual 100% O2 from a seperate system), and if they suspect that the normal oxygen supply from OBOGS is providing contaminated air, gangloading would only make the hypoxia worse by increasing the amount of contaminants the crew is exposed to. And rather than have the crew try to figure out what kind of hypoxia they are experiencing, just go for your known good supply of oxygen all the time and figure it out later.

[Boomer6]

23 hours ago, Duck said:

Are bases allowing instructors to sit people down during stand ups? What happens if it hurts their feelings? It’s not like they are gonna wash out these days! Ugh.

Can't speak to T-6s but the sit downs are few and far between in 38s. Dude we can't sit post solo kids, no one cares about EPs, we have the timeline to worry about... 

1 hour ago, jazzdude said:

3 hours ago, LiquidSky said:

 

Hypemic or histotoxic hypoxia both would make sense- contaminated air from OBOGS could block oxygen absorption, resulting in hypoxia. Think along the lines of carbon monoxide poisoning. Which would make pulling the green ring instead of gangloading make sense (actual 100% O2 from a seperate system), and if they suspect that the normal oxygen supply from OBOGS is providing contaminated air, gangloading would only make the hypoxia worse by increasing the amount of contaminants the crew is exposed to. And rather than have the crew try to figure out what kind of hypoxia they are experiencing, just go for your known good supply of oxygen all the time and figure it out later.

Shack. Scary shit. 

 

Edited December 7, 2017 by Boomer6

[jazzdude]

Are bases allowing instructors to sit people down during stand ups? What happens if it hurts their feelings? It’s not like they are gonna wash out these days! Ugh.

When I was an IP, the common USEM technique (that I didn't agree with) was to sit people down on standup if they deserved it, but if they had 2 Stan failures (EPQ or stand up) in a row, to give them an open book boldface quiz that their buddies could check to reset their failures and prevent triggering pro-cap or other consequences. EPQ retakes were generally the same test again, but after you remediated and were told what the right answers were.

[flyusaf83]

Is Vance the only base with grounded T6s?

[Laxer69]

 

2 hours ago, flyusaf83 said:

Is Vance the only base with grounded T6s?

Affirm

[YoungnDumb]

Had another one yesterday.  Also, they're flying weekends with "volunteers" now.