Patmack T-6A Comments

[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.

 

[Hugh Jorgan]

I certainly agree with the difference in challenge between the two patterns. No war here, just observations. The very simple navy pattern teaches a student how to make a final turn, roll out in the groove and land. The Air Force pattern teaches a student how to fly an Air Force pattern. Having instructed in both patterns, I can't even begin to express the amount of frustration involved with trying work on a student's landings when they have to be a freaking lawyer in the process. Yes, the radios might be a bit more cluttered, but as a student in T-34's I got from 10-12 landings per sortie. As an IP in the AF command, I witnessed students mostly getting on the order of 5 or 6 landings per sortie...but got real good at figuring out when they could pull closed, when they had to go around the box or break out or do just about anything else other than land...on second thought, no they didn't.

Regarding the 90 degrees angle of bank limit...Sure it's necessary for the types of manuevers that must be done at certain times in the pattern, but in the short time I was at AETC, there were two fatal mishaps due to accerlerated stalls in the final turn.

I never really warmed up to the AF pattern for teaching, but it was a lot of fun to play around in without students.

 

[Spur]

As far as leaving the gear down in the pattern, I don't think throwing the handle up and down makes it all that much more exciting.

No, but pulling a 6 g closed from the offset sure does

 

[Tweetdrvr]

Can you imagine the abuse it would take (on top of what they get now) if you start putting the gear up and down on each plane 50-70 times a day more than what they get?

You would get a 1957 model T-37 with 20,000 hours at 1.35 per sortie that averages the 5-6 landings on each student ride as previously mentioned which works out to about 74,000 total landings (the mx dudes tell me they keep the actual numbers in the computer) and almost half of those were accrued during the pre solo hard landing phase of training.

So if a T-37 is worth $250K, that works out to $3.38 per landing. At $4Mil apiece a T-6 would have to survive long enough to reach 1.18 million landings to get the cost per landing to the same value. Whether you do it the Navy way with the gear hanging in the pattern or the AF way and raise it on each closed pattern, it won't survive that long.

 

[Kuma]

I've taught in both patterns also. Everyone has made accurate accounts of the patterns so far, but I'm not sure how Talon can make the statement that T-34 patterns are "as far from carrier ops as you can get". Sure, T-44 and C-12 patterns may be different, but they are training P-3 pilots and KC-130 pilots (and obviously they don't need ship board type training). I was given the opportunity to fly with the T-2C squadrons at Meridian for a month a couple of years ago and other than putting a "15 second in the groove" requirement and flying the ball on final, they were the same. Maybe a carrier aviation type pilot should give us the scoop here. Shipboard helicopter patterns are similar to the T-34 pattern also.

Naval pilots fly almost a constant airspeed, 30 AOB (other than the break) and refrain from aggressive changes of attitude in the pattern (training for the low vis environment that the sea gives us).

What no one has mentioned is the ASD...Average Sortie Duration. The Air Force has a 1.1-1.3 ASD and the Navy has a 2.0 ASD. It seems to me that both services are happy with the product after flight school/UPT so neither program is broken.

IMHO, after seeing both patterns and training philosophies up close and personal for a long time, I believe that the AF enhances pilots' SA by doing the complex AF pattern, while the Naval service enhances pilots' SA by doing EPs in the air. Two different ways of achieving the ultimate goal - an aviator who can think and fly at the same time.

 

[Hugh Jorgan]

What no one has mentioned is the ASD...Average Sortie Duration. The Air Force has a 1.1-1.3 ASD and the Navy has a 2.0 ASD. It seems to me that both services are happy with the product after flight school/UPT so neither program is broken.

IMHO, after seeing both patterns and training philosophies up close and personal for a long time, I believe that the AF enhances pilots' SA by doing the complex AF pattern, while the Naval service enhances pilots' SA by doing EPs in the air. Two different ways of achieving the ultimate goal - an aviator who can think and fly at the same time.

Fully Concur.

And if the tweet didn't run out of gas so fast, and you could spend more time in the pattern, I think you'd have the best of both worlds.

 

[BMD]

experience?

Talon should have started his post, "In my vast experience..."

 

[Talon]

Alright, alright,
I'm not experienced, I know. I thought that would be obvious by my mindless rantings anyway.
The stuff I said about carrier ops was based on conversations I've had with carrier guys about their pattern. I was intrigued by what I saw the T-45 guys doing and asked around about it. Seems to me like hanging around in the stack until it's your turn and then doing a break for a 3 mile straight-in (or thereabouts?) is considerably different from what the T-34s do. But that's just me. I don't know nothin' about nothin', I know. (seriously, no sarcasm) And then I know even less about what the rotorheads do. That's a whole different world to me.

I guess I'm just a little bitter about not zipping around at 200kts, 7gs in a little toy like the T-6 anymore. I didn't realize I was having fun at the time, but I was.

The EPs in the pattern do add an entirely different challenge, so yes, both ways of doing business get the job done in the end.
It's allll good!