Stories from FL280...

[eagl]

OBOGS uses engine bleed air to force oxygen through a molecular sieve.  It basically enriches oxygen content in air using bleed air pressure.  The enriched air is fed to the pilot through a fairly conventional regulator.  Large aircraft with OBOGS will use it to feed O2 to a pressure reservoir where its used on demand and also as a backup O2 supply if the motor or OBOGS fails.  In the T-6, there is no backup system or reservoir so if it quits, its done.  Not only that, there is no direct readout on the quality of the air you're getting, other than an "idiot light" that illuminates if any one of a number of self-tests fail.  It's sort of like a check engine light that could light up if you're either low on windshield washer fluid or about to have total brake failure.  So there's not a lot of trust there and I think most people try to forget that they're using it because like it or not there's nothing we can do about it.  And it does seem to work well most of the time, and it doesn't require expensive liquid or high pressure oxygen servicing.  You're just breathing bleed air, and what could possibly go wrong with that?

Also, it can sometimes expel "zeolite dust" into the system, which the pilot gets to breathe.  Nobody knows what zeolite dust is, other than sometimes OBOGS makes you breathe it.

And any contamination that enters the air intake or turbine compressor could end up getting partially burned and then sent through the OBOGS system, with unpredictable results.

In the T-6, the ejection seat's emergency oxygen bottle is the backup system in case OBOGS fails at high altitude.  If that happens, the simplified version of the solution is to activate the emergency bottle which blows your mask right off your face and makes it impossible to talk, disconnect your oxygen hose from the aircraft, and make an emergency rapid descent to below 10k altitude.

[Serenity]

OBOGS uses engine bleed air to force oxygen through a molecular sieve.  It basically enriches oxygen content in air using bleed air pressure.  The enriched air is fed to the pilot through a fairly conventional regulator.  Large aircraft with OBOGS will use it to feed O2 to a pressure reservoir where its used on demand and also as a backup O2 supply if the motor or OBOGS fails.  In the T-6, there is no backup system or reservoir so if it quits, its done.  Not only that, there is no direct readout on the quality of the air you're getting, other than an "idiot light" that illuminates if any one of a number of self-tests fail.  It's sort of like a check engine light that could light up if you're either low on windshield washer fluid or about to have total brake failure.  So there's not a lot of trust there and I think most people try to forget that they're using it because like it or not there's nothing we can do about it.  And it does seem to work well most of the time, and it doesn't require expensive liquid or high pressure oxygen servicing.  You're just breathing bleed air, and what could possibly go wrong with that?

Also, it can sometimes expel "zeolite dust" into the system, which the pilot gets to breathe.  Nobody knows what zeolite dust is, other than sometimes OBOGS makes you breathe it.

And any contamination that enters the air intake or turbine compressor could end up getting partially burned and then sent through the OBOGS system, with unpredictable results.

In the T-6, the ejection seat's emergency oxygen bottle is the backup system in case OBOGS fails at high altitude.  If that happens, the simplified version of the solution is to activate the emergency bottle which blows your mask right off your face and makes it impossible to talk, disconnect your oxygen hose from the aircraft, and make an emergency rapid descent to below 10k altitude.

The only thing I'd add is that my nickname for Zeolyte Powder is Insta-cancer...

Onboard Oxygen Generator. Seren, when you get to Meredian let me know. You might still have Chuckles as your paddles.

I appreciate the vote of confidence! I'love find out for sure next week!

[TheBug]

Serenity and eagl, thanks for sharing!   

[eagl]

You're welcome

The T-6 is kind of like a lightweight P-51A...  Better power to weight if I recall correctly, but the wing is optimized for low to mid speed behavior and the fuselage with the huge canopy isn't shaped to reduce drag, so its slower.

[Serenity]

We're almost to bingo folks!

Wednesday night, I'm in the back seat for my instrument check. We get started, and I go to enter the flight plan into the FMS, and the data entry knob falls right off! I tell my IP, and he says "well, see if you can find it". So I shine the flashlight around looking all over trying to find the damned thing. "I don't see it anywhere" I say. "Keep looking, I'll go ahead and enter the plan for you". More looking, more negative reports, but he seems to want to press. Always looking for that X...

Well about the time I'm about to say "sir, we can't fly with FOD back here, we need to get a different plane", the master caution goes off. IAC1 is gone. Well, I knew I was due for an electronics failure. "Did you touch something back there?!" The IP says. "Uh, no?" I said "that's IAC1, that's up front with you". He starts checking his circuit beakers and I check mine just in case. Nothing on either end. About 30 seconds later, TCAS fails. "We just lost TCAS in the back" I said. "What?! But that doesn't make sense. IAC1 and TCAS are on different busses..." says the IP. "Sir, I vote we give up" I said. Just as the words leave my mouth, all three MFDs go dark...

[HL117]

We have visited the white sands of Gulf Shores, AL quite often in the early summer for several years now, we stay a week or so renting a house on the beach, doing nothing but chilling, many times while I sit in chair toes buried in sand I hear the drone of aircraft out over the water out past the oil rigs, never have I seen any of these aircraft myself but hear them, drives me crazy, think I have damaged my eyesight searching for the culprits, it is not the drone of aircraft traversing from point A to point B, it is the sound of aircraft doing maneuvers or so I think it is ............tell me I am not crazy and it is you and your fellow airmen practicing just beyond visual range from the beach 

[Serenity]

We have visited the white sands of Gulf Shores, AL quite often in the early summer for several years now, we stay a week or so renting a house on the beach, doing nothing but chilling, many times while I sit in chair toes buried in sand I hear the drone of aircraft out over the water out past the oil rigs, never have I seen any of these aircraft myself but hear them, drives me crazy, think I have damaged my eyesight searching for the culprits, it is not the drone of aircraft traversing from point A to point B, it is the sound of aircraft doing maneuvers or so I think it is ............tell me I am not crazy and it is you and your fellow airmen practicing just beyond visual range from the beach 

Could be south of you, but more likely it's north of you. Foley Alabama is what we call Area 1 and the South MOA. Just east of Foley is NOLF Barin, where students fly their first 4 flights. Slightly higher up (7k up to 26k) we do aerobatics.

[Maverick]

Serenity I think your call sign should be gremlin. Not like the ones in the movie, but the one in the old bugs bunny cartoon from WW 2 time frame. You are death on aircraft........ not  the other guys aircraft just on the one you are in.   

[Serenity]

Serenity I think your call sign should be gremlin. Not like the ones in the movie, but the one in the old bugs bunny cartoon from WW 2 time frame. You are death on aircraft........ not  the other guys aircraft just on the one you are in.   

No joke! My on wing (a helo guy) said he's gonna do everything he can to keep me away from rotary, because he knows if he flies with meach in the fleet, we're gonna die lol

[DaveBB]

Could all these problems be a result of corrosion?  Being in a warm, marine environment can cause very high rates of corrosion, especially for aluminum and copper.  Sodium chloride and magnesium chloride are probably the two biggest offenders as far as electrolytes go resulting from seawater.  Magnesium chloride especially, as it is hygroscopic. 

Or these planes could simply be old and used up.  I read "Black Aces High", a great book about VF-41 and their F-14s during the Serbian Air War.  On almost every single launch, a piece of equipment would fail on the aircraft.  The majority of the time it wasn't critical to the mission, sometimes it was...

[Bino]

Could all these problems be a result of corrosion?  Being in a warm, marine environment can cause very high rates of corrosion, especially for aluminum and copper.  Sodium chloride and magnesium chloride are probably the two biggest offenders as far as electrolytes go resulting from seawater.  Magnesium chloride especially, as it is hygroscopic. 

Or these planes could simply be old and used up.  I read "Black Aces High", a great book about VF-41 and their F-14s during the Serbian Air War.  On almost every single launch, a piece of equipment would fail on the aircraft.  The majority of the time it wasn't critical to the mission, sometimes it was...

One of my old college friends was a US Naval Aviator for nearly a decade, flying the Sikorsky SH-3 helo. His experience with the "Sea Pig" mirrored that of VF-41: some gadget or other failed on almost every flight.

Serenity & Eagl, thanks for posting. 

[eagl]

Could all these problems be a result of corrosion?  Being in a warm, marine environment can cause very high rates of corrosion, especially for aluminum and copper.  Sodium chloride and magnesium chloride are probably the two biggest offenders as far as electrolytes go resulting from seawater.  Magnesium chloride especially, as it is hygroscopic. 

Or these planes could simply be old and used up.  I read "Black Aces High", a great book about VF-41 and their F-14s during the Serbian Air War.  On almost every single launch, a piece of equipment would fail on the aircraft.  The majority of the time it wasn't critical to the mission, sometimes it was...

Corrosion is very possible.  The specifications for the T-6 permitted a lot of commercial off the shelf components to be adapted to the program.

As for old and used up... not hardly.  The Navy T-6s are almost new.  Even the oldest USAF T-6 is still a fraction of the age of the T-37 it replaced, same for the T-38s still in use.  The newness of the program and the desire to cut costs in design, production, and operations, are all huge factors for reliability.

[Serenity]

Could all these problems be a result of corrosion?  Being in a warm, marine environment can cause very high rates of corrosion, especially for aluminum and copper.  Sodium chloride and magnesium chloride are probably the two biggest offenders as far as electrolytes go resulting from seawater.  Magnesium chloride especially, as it is hygroscopic. 

Or these planes could simply be old and used up.  I read "Black Aces High", a great book about VF-41 and their F-14s during the Serbian Air War.  On almost every single launch, a piece of equipment would fail on the aircraft.  The majority of the time it wasn't critical to the mission, sometimes it was...

Well, for my instrument check ride last night, I had a great chat with the IP, who was a former Herc pilot for the Air Force, but had been a Navy Reserve IP for the last 13 years. We were discussing the T-6 versus the T-34C it replaced (She flew both, and had at LEAST 1,000 hours in the 34). Her comparison was this:

The T-6B is a GREAT airplane, but entirely wrong for it's job. The T-34 was a workhorse, bulletproof, and very forgiving. The T-6 is a diva. Too hot outside, and you have trouble starting. Too cold, and you have internal issues. It's got GREAT avionics, but because of that, the maintenance requirements are pretty extreme, (And trying to teach a student JUST learning instrument flight to balance the old needles with the FMS, and transition between the two is a pain in the neck). It's prone to blown tires, it CANNOT be landed in a crab under any circumstances, it's incredibly unforgiving at low speeds and in the pattern... (These are her statements, I have no basis for comparison).

When you have a plane that's THIS finicky, and have students with no idea what they're doing fly it 5 times a day, 7 days a week... things are GOING to break. And often. Which they do.

[eagl]

Give it a few years and even the crusty old Navy instructors will learn to love the T-6, and they'll come up with the tricks and techniques necessary to teach the students how to fly them without breaking them all the time.  It took Sheppard about 2 years to sort out most of the hassles with the T-6, even with the benefit of being able to look at how the other UPT bases and Randolph deal with the somewhat more fragile nature of the T-6. It'll never be as robust as the T-37 but with some attention to avoiding certain behaviors it can be effective while the incident rate drops and mission ready percentage climbs.  Even the T-37 had quirks that we all took for granted, but which were horrible before we figured them out.  There must be a couple dozen stall/spin fatalities in the T-37 history for example, and the mishap rate for that specific situation didn't drop until the USAF figured out a really GOOD stall/spin training program for both instructors and students.  And still, the last T-37 fatality that I know of was an IP at Laughlin who spun during a final turn go-around just a couple of years before they transitioned to the T-6.

The T-6 has far more overall performance than the T-37 so even though the regular USAF UPT bases don't take advantage of it, at least at Sheppard they've utilized the improved performance to move some basic formation and low-level training down to the T-6 from the T-38.  2-ship tactical formation and 2-ship low-level are great examples.  Not using that capability is a total waste of resources, but the USAF has worked itself into a situation where they can't get T-6 instructors who even know what 2-ship tactical is, let alone can teach it, so the capability is totally wasted and that training has to be done in the far more expensive T-38.  But the capability is there with the T-6, if we have the courage to actually use it.

In my deployment to Iraq standing up an Iraqi T-6 training squadron, we had the opportunity to teach some of these advanced techniques and even some tactical training using the high performance of the T-6.  Unfortunately at a critical time we had a squadron commander who was awesome at the administrative stuff we absolutely needed at the time but who was also a heavy driver who had never flown the T-6 or any sort of tactical maneuvering in any aircraft until he got his command in this T-6 squadron.  So the first advanced formation flight he went on with our Sheppard-trained instructors, he got scared and forbade us from doing that ever again.  Too bad, the Iraqis sure could have used that training and even though the CC couldn't do it himself, a third of his IPs were from Sheppard and we could have taken on that role as an advanced qualification.  Oh well.

The point is that yea the T-6 is a bit fragile especially compared to the T-37 in a primary training role, but once the IPs and maintainers get used to its quirks, the additional performance can open up some great training opportunities that offload some advanced stuff from the more expensive advanced trainer aircraft.  That's pure gold in terms of training program affordability since every single sortie moved from the T-38 (or hawk) to the T-6 probably saves somewhere around $3000-$5000.

[DaveBB]

Good insight from your IP.  That's a pretty dangerous combination right there.  Just for comparison, the chief test pilot for the Mig-25 was killed by an electronic instrument malfunction (fuel sensor) and getting too slow in the pattern.