Patmack T-6A Comments

[CAL to T-1A]

I'm was the AF T-6 program manager (brain) that Patmack refers to in his thoughts on the T-6A.

I wish we had T-6's here, but the last word we got was not until 2008ish give or take a few. They've started a new program to try and extend the life of the current 34C's by limiting the G loading. There's a number of birds that are now limited to 2.5+. The story we got from someone, was that the reason we arn't taking them yet, was that the AF brain that was behind helping Raytheon put this thing together decided "all our AF bases have 10K+ runways, why worry about having a reversable pitch prop?" So no beta range, thus the Navy can't use it because all our outlying fields are 3500' or less, and the T-6 requires a 5K' runway. The guys at Sherman have gotten it waived down to 4K'....

The Navy bought an aircraft (T-6A) that requires a 5,000 feet long runway to perform a touch and go and can be waived to 4,000 feet. The Navy plan was to extend the runways at their training fields. The Navy realized well after deciding to purchase the T-6A that real estate prices and environmental law changes would prohibit them from completing their planned runway extensions.

The reason the Navy isn't training pilots with T-6As is that they prefer to spend their money on boats. The 46 T-6As they have on order are all Congressional adds not requested by the Navy.

The start of student pilot training for the Navy will be in July 2009 at Whiting unless the Navy decides to buy boats instead!!!!

 

[CAL to T-1A]

I've got pretty thick skin .... so no harm, no foul.

I'm not sure how they will handle the issue. There is a large call from the Navy side for anti-skid breaks and that should help some. Most likely between now and then there will be a split between Navy and AF T-6s. The Navy version will be more expensive with a life raft, anti-skid, TCAS and maybe beta.

 

[Spur]

So no TCAS on AF T-6s? No anti-skid either?? Are there any safety systems we didn't deem too expensive? I guess we would have bought the old tweet ejection seats if they were still available.

And how did 5000' end up as the minimum r/w length? Seems like an awful lot of runway a turboprop with the kind of performance the T-6 has.

 

[HueyPilot]

T-6 TCAS

Last I heard the AF T-6 had TCAS. That was one of the bugs they were working out at Randolph prior to achieving IOC. As for the others, dunno.

 

[phroggdaddy]

T-6

Cal,

Common perception is that the Navy bought the Texan with Beta and that the AF paid to have it removed. Any truth?

 

[Tweetdrvr]

Huey,

The T-6 has a system called NACWS Naval Anti Collision Warning system. It needs inputs from ground radar and transponders to display aircraft with range and bearing info. Without ground radar inputs, you just get a bell warning and text message that there is traffic somewhere out there.

Funny thing is the new digital ASRs and Center Radar systems that the FAA is upgrading to don't work very well with the NACWS.

Also it doesn't display on the VVI/VSI with constant info, it is buried beneath another one of the liquid crystal engine displays and you have to actively think about it using it and squeeze the trigger on the stick to change the display.

At Randolph they instruct using it to clear and to try to consciously think about using it. At Laughlin since we got the new RAPCON, it doesn't work worth anything. San Antonio approach is about to upgrade their radar system, so then the PIT guys will see that this thing is not the Holy Grail that everyone thinks it is now.

 

[CAL to T-1A]

Tweet Driver has the correct situation on TCAS. T-6A has NACWS like the T-34C. FAA is updating radar making NACWS even less usuable than now. AF leadership doesn't require TCAS because our MOAs are under constant radar control. I disagree, but since I'm only an O-4.... I lose.

Beta was taken off the aircraft at the start. Raytheon was required to make an aircraft that could safely perform a touch and go in 5,000 feet. They did so and that aircraft did not include beta.

In hindsight, the Navy should have realized the prohibitive cost to extend their runways and forced the T-6A touch and go requirement to their existing runway lengths.

The Navy still has the chance to get beta, if we ever go away from a single configuration for the T-6A.

 

[CAL to T-1A]

I failed to respond to Spur's comments

So no TCAS on AF T-6s? No anti-skid either?? Are there any safety systems we didn't deem too expensive? I guess we would have bought the old tweet ejection seats if they were still available.

NACWS was a compromise. We didn't know that the FAA would update the radar and make the system oboselete.

Why would taxpayers want me to spend an extra $300k per airplane to put beta on an aircraft that would only be used on 5,000 foot long runways?

As for your safety system comments.... We have an anti-collision system (NACWS), excellent ejection seats, beefed up leading edges, beefed up canopy, presurization, GPS, an air conditioner that keeps you cool in the summer at Laughlin, burns fuel at 1/3 the rate of the T-37, etc.

Before making your final judgement on the sucess of the T-6A talk with those thay fly it. I think you'll find they say its a great aircraft and a great training system.

 

[Talon]

I'm one of those guys that trained in the T-6 at Moody. I can tell you it was a lot of fun.

NACWS = TRASH. We didn't really use it. I can't tell you how many times in our MOA the thing would go off in the middle of a loop for no reason at all. It would call traffic within 500', causing much concern. Query MOA monitor and their scope is clear. We can't see anybody anywhere. Nothing. Oh, and then there were plenty of times I got within a mile or so of traffic (fully aware of it ahead of time) and the darn thing didn't squawk a bit. We totally ignore it in the pattern because it's totally useless there too.

BRAKES ... uhh... well, I can see that being a problem for Navy guys. At Moody we were told to never use the brakes unless we had to. Reason being they decided to use T-38 tires (so we were told) for standardization purposes, which blew out left and right if you honked on the brakes. Had an IP do that to me once. Of course all the maintainers looked at me like I was an idiot when they saw the gaping hole in the tire. Couldn't exactly just point at my IP and run though.

BETA RANGE. I really don't understand the big deal with this. I'm in TC-12s right now and BETA is simply 0 forward thrust, not reverse thrust. When you pull the throttle to idle in the T-6 you feel that huge prop turn into a giant speedbrake if you're doing anything over 40 kts or so as it is. I don't see why it would be a problem (assuming you have good brakes and tires on that puppy) to just pull it to idle and stop. Now if you're talking about full reverse, then that's a different story.
I guess I can see that you have to have a pretty good safety margin for student error.

Not that it'll ever happen or anything, but if the Navy were to ever consider converting to the Air Force way of doing pattern work then they could cut down their number of outlying fields to about 25% of what they have now. I'm amazed at how much in the way of resources it takes to do pattern work in the Navy. If they cut it down, then they could spend the money saved on better, longer runways and equipment. Just my opinion though. I'm sure the Navy has reasons for doing things they way they do.

Overall, it's a lot of fun to fly and I've heard stories from a few instructors who say they've been in some situations with students where, had it not been for the immediate torque available (as opposed to the Tweet), they would've ejected.
Anybody I've ever talked to that's flown both the T-6 and the tweet would pick the T-6 every time without a second thought.
I just feel a bit odd about becoming a USAF pilot who has never flown and may never fly a Jet aircraft. (except for a few incentive rides, but that doesn't count, right?) I may never know what it's like to just push the throttle up and not have to worry about rudder.

 

[Spur]

Im not saying the T-37 is a better airplane, just that the T-6 doesn't quite meet my expectations. The avionics look great, the ejection seat is great, and the performance is great. But that is to be expected.

As far as safety goes, there are some negatives. First, although the PT-6 is a very reliable engine, I still think 2 is safer than 1. Especially one that takes so long to airstart and develop usable power (ref RAFB accident). Also, one thing that really puzzles me is how everyone keeps touting the lack of onboard O2 storage as a benefit. I've heard it refered to as safer and allowing for a quicker turn. Well, it takes about 10sec to fill a tweet with O2, and you can still breathe if you lose your engine.

As far as the AC system, I have talked with some Del Rio drivers who said it is better than the tweets, but not that much better... Maybe that was before the mod though.

TCAS-- How many safety reports have you read about T-37s having close calls with VFR civilian traffic? How many tweet drivers have had such an experience? Well, after mine I distinctly remember thinking that once we get the T-6 that we'll be much safer because surely it's gonna have TCAS. I remember thinking the same thing about anti-skid after a stud got me in a hydoplane skid on a wet runway. I wouldn't buy a car without anti-skid, and its much more critical in a airplane than a car.

Its been nearly 50 years since the tweet first flew, and the AF has been looking for a replacement for almost 20 years. Maybe my expectations were too high, but I figured after waiting all this time for a replacement it would have been a little better.

Still looking forward to the transition---just not as eagerly...

 

[TheRealStory]

Ok,

I hate to jump into the fray here, but here it goes.

I fly the T-6 as a reserve IP and fly a big jet as my other job. So that is from where my prospective comes. The T-6 is way better than the T-37(And I am not busting anybodys plane here but I mean way better). It produces a much better product(according to the T-38 and T-1 IPs that call to give us input). The only complaints we get are from the 38 IPs that say the studs don't watch the gas enough(T-6 has plenty) and they have trouble staying in the area at first(because no GPS). I have not heard of a T-6 stud washing out of a 38.

As far as the AC is concerned the ones in Del Rio might not have been moded last summer(the upgrade makes a big difference). The NACWS is a piece of junk. I turn it off in the pattern because it goes off too much and the stories are true of it going off in the area in the top of a loop with nobody there(happen to me more than once) and I cannot tell you how many times I have seen traffic but nothing on the NACWS. Hands down TACS is a better product, but I do not know the cost differecnce between the two systems.

The non reversable prop could be an issue on short fields(3000 or less) but I think the numbers could be worked for this thing to do 5000 foot ops for the Navy. The no anti-skid must have been a cost issue as well because if a stud jumps on the brakes as he is turning above 40kts he might blow a tire. Would be nice to have. Just like the second engine. However, the Air Force has more single engine figther(F-16s) than any other model. I know they put more of those in the dirt but the numbers don't lie they are alot of them out there. Also, the JSF is also going to be a single motor as well.

In closing all the issues about what we all would have liked on this jet(or prop if that is what you want to call it) propably came down to the almighty buck. The changes that I see going forward are 1.) An inverted oil tank(about 1 qt would do) 2.) Anti skid brakes(with those and new performance data the Navy might not need the Beta) and 3.) The NACWS replace with TCAS.

For what is worth.

 

[Spur]

By definition the BETA range is essentially reverse thrust.

Not to pick nits, but Beta refers to the condition on a constant speed propeller where the prop pitch is directly controlled by the throttle position. In the Alpha range, the pitch is controlled by the prop governer. It is certainly possible to have forward thrust in the beta range, and well as drag in the alpha range, depending on airspeed.

I agree with TheRealStory that probably the best bet for the Navy (and the AF) is to forget about beta and go with the anti-skid.

I guess first they would have to weigh the cost of installing anti-skid vs the cost of repairing the x number of T-6s that will be damaged/destroyed in ground mishaps preventable by anti-skid.

 

[CAL to T-1A]

TheRealStory hit the nail on the head. All of the decisions are made with a trade off being cost. With a joint Navy/AF aircraft there was zero chance that the aircraft would have more than one motor. The T-6A is already significantly more expensive to operate than the T-34C. Another motor would make it more exepensive.

All aircraft delivered to Laughlin have the new air conditioner.

Fixes I forsee that will happen on the T-6:
1) improved oil system for motor
2) cockpit improvements to iclude storage space & lighting
3) TCAS 1, TCAS 2 won't work because of antenna grounding problem

Working the program was a learning experience for trying to purchase a plane that meets the mission requirements and stay within a very limited budget.

 

[Spur]

Working the program was a learning experience for trying to purchase a plane that meets the mission requirements and stay within a very limited budget.

Yeah, I guess it was a Clinton era project.... thanks again Billary

 

[HueyPilot]

On a side note:

Patmack....

Have you seen an Air Force pattern?

Essentially, it's an overhead pattern. You call initial, break where the RSU tells you (or approach end if nothing is said), and there are no crosswind/base legs. 180 deg. turns just like the Navy patterns.

Once you're on the go from a touch-n-go or go-around, you pull closed to a tight (inside) downwind, or enter the outside downwind to enter initial again. I don't know exactly what the Navy flies pattern-wise, but having flown into plenty of NAS's, it doesn't seem too much different.

 

[BMD]

texan

The Texan is definitely a joint (read compromise) trainer but it beats the hell out of the weenie (T-34). After a two hour hop, my a$$ isn't sore, I haven't sweated through my bag, and I'm happy knowing that crew canopy cords harness crouch dive pull isn't my only means of getting out of the plane.

 

[Spur]

Re: Re: texan

by your definition of Beta, then the Garrets on an MU-2 (and I'm sure other a/c with the same engines) are always in Beta.

Well, I'm not familiar with the MU-2, but I doubt that it or any other turboprop flies in beta. It would require way to much pilot workload and probably wouldnt work anyway. There are so many issues which make it unfeasable I wouldn't know where to start explaining them. Instead let me take a hack at explaining the Alpha/Beta ranges again.

1. Alpha: Propeller pitch is selected by the prop governer. When you move the throttle forward, it schedules increased fuel flow (or TIT, or torque which in turn increase FF). The increase in FF causes the RPM to begin to increase. The prop governer (either electric or hydraulic) senses the increase in RPM and increases pitch to maintain desired RPM. During a climb, the RPM will also begin to increase due to increased TAS and reduced air density, and the prop governer will increase prop pitch to maintain RPM even without a change in throttle position.

2. Beta: The prop governer is bypassed and prop pitch is DIRECTLY controlled by throttle position. Whatever throttle angle you set will have the same prop pitch regardless of altitude, airspeed, temp etc... RPM will vary considerably with different environmental conditions. This is why beta range RPMs are much wider than alpha range RPMs.

Sorry about starting this off-thread discussion.

 

[Spur]

Patmack.
You are correct in saying that when you push the throttles forward in flight, you get an increase in blade angle (and vice-versa), but it is the prop governer that determines that blade angle, not thottle postion.

Let me give you an example. Lets say on takeoff, you set t/o power which happens to be at 85 deg Throttle Angle (TA). You are at sea level standard day and your prop pitch happens to be 35 deg. Now after level off at FL250, you set cruise power and it happens to be at 85 deg TA again. Your prop pitch WILL NOT be 35 deg, but much higher, say 50 deg. This is because the prop governer has increased the pitch to maintain constant RPM. The increased TAS and reduced air density require a higher blade angle to maintain the same RPM. This is operation in the Alpha range. If your TA set your prop pitch, you would have to constantly be pushing the throttles more and more forward during the climb to increase the blade angle. And you couldnt set idle at high alt/TAS or your prop would overspeed.

Now lets say you land at sea level and use 1/2 reverse (say 5 deg TA) and get -10 deg prop pitch. On the next leg you land at 6000' MSL and use 1/2 reverse again. You will again get -10 deg prop pitch because you are in beta, the prop governer is bypassed and your TA selects the exact prop pitch.

Hopefully that clears it up.

 

[Hugh Jorgan]

Re: On a side note:

Patmack....

Have you seen an Air Force pattern?

Essentially, it's an overhead pattern. You call initial, break where the RSU tells you (or approach end if nothing is said), and there are no crosswind/base legs. 180 deg. turns just like the Navy patterns.

Once you're on the go from a touch-n-go or go-around, you pull closed to a tight (inside) downwind, or enter the outside downwind to enter initial again. I don't know exactly what the Navy flies pattern-wise, but having flown into plenty of NAS's, it doesn't seem too much different.

No comparison.

 

[Talon]

Alright, since we're talking about the AF/Navy pattern, let me throw my 2 cents back in:

I have flown both AF and Navy UPT patterns. No comparison as in they're totally different, yes. What T-34/T-44/TC-12s do is completely boring and as far from carrier ops as you can get. Buzzing around a closed pattern with your gear hanging at 120-140 kts, no more than 30 degrees bank, no more than 3-5 aircraft in the pattern--not very exciting or very challenging at all. Air force UPT pattern is at 200kts, up to 90 bank (legally) and up to 12 aircraft in the pattern. Huge difference in challenge and excitement to me, personally. Not to mention the radio clutter that the Air Force UPT pattern avoids by cutting down to the bare minimums. It drove me nuts trying to get a word in edgewise in Navy patterns because of all the back and forth comms with each pass.

Oh well. That's just my opinion.
My whole original point was this: if the Navy could find a way to cut down on the tremendous amounts of resources it spends on its outlying field (personnel, mx, etc.) it could use it towards buying and maintaining aircraft, improving runways, etc. Air Force UPT pattern can fit 2-4 times as many aircraft in the pattern as an example of doing it differently and more efficiently. (Money wise) The only downside, which never seemed to be a problem, was that you don't get as many touch-n-gos per sortie. But then, that wasn't even always the case. You can pull closed if the pattern isn't busy and get just as many if not more (because of the higher speeds) in a short amount of time.
It's all good. I just thought it was more fun anyways.

Remember, we're not talking about T-45s and all the unique stuff they do. That's a whole different ballgame. But to say that the T-34 pattern is dynamic and predicated by what happens on carriers is just not true from what I've seen. Unless the guys at P'cola/Whiting do something different from Corpus.

Not starting a war or anything, just asking questions, that's all.