totter

Do you plan on using a larger battery, say a Gill G-6381? They way about 70-80 pounds each. When they converted the DHC-3 single otter to a turbine they moved the battery firewall forward and actually added a second battery, wired in parallel, to keep the airframe in CG. It also makes for really good starts. With -34s we get 20-22% at spool-up just on batteries.

So true. You're only allowed to keep the prop at 2750 for one minute before you have to pull it back.

I know what you mean. We have quite a few operators here that have 185s, seaplanes, with the 3-bladed prop. They are the loudest aircraft in the harbor on take-off. They are louder than the Turbine Otters and the 2-bladed Beavers.

I was tits backwards on this one. Not thinking of recent improvements and technology to props. Not that many DZs use one, but with the Beaver going from the 2 bladed Hamilton Standard to a 3 bladed Hartzell you lost a little in take-off/climb but it is much, much quietter.

Other way around. Two blades are better for climb, 3 are better for cruise and noise.

It's a shame that Transport Canada is the way it is. (The same can sometimes be said about the FAA). Going the reverse route and bringing an aircraft into the states is so much easier. As far as data in the AFM (Pilot's Handbook), the FAA considers this Approved Data. So if the AFM states that you can install an additional seat belt you do not need any further approval. We operate all Viking aircraft (deHavilland). When we imported 2 DHC-3s from Canada we had no issues with previously installed equipment. The FAA saw it as a Canadian built aircraft with the equipment installed in Canada. Good to Go. We just sold a DHC-3T to an operator in B.C. Aeroflite, in Vancover, is having difficulty with TC due to US STCs that were installed here, but not certified in Canada. Basically in the US the FAA will standardize a Canadian STC if all the data is complete and the I's are dotted and Ts are crossed. To go the opposite direction and have a US STC approved in Canada, TC wants you to go through the whole process from the beginning. Go Figure.

Not certified yet. The Garrett conversion will have better high altitude/ hot & heavy performance than the -42A being that the Garrett is de-rated from 1200 HP. The PT6A-42A will be using all of its 850 HP. Blackhawk should have gone with the PT6A-45R @ 1200 HP.

You are devoted to Garretts, I'm devoted to Pratts, so you're right that we can debate the pros and cons forever. We do both agree, though, that alot depends on proper maintenance and use (for both engines). No one, on this thread or the other thread, has knocked the -12 conversion on the whole. A bigger engine IS exactly what the Caravan needed to make it truely the aircraft it should have been from the start. Everyone is just skeptical with the use of the Garrett for skydiving. You're not going to change peoples minds overnight, only time will. And I hope that time does prove us wrong. I'll always be a Pratt lover, though.

Tom. I've seen results of a -114A & a -27 shedding its PT blades. All contained within the Exhaust Duct. I've seen a -27 shed its CT Blades, puncture the burner can and Exhaust Duct, but stay within the cowling. I've seen a -6 chunk all its turbine blades, puncture through the case, exit through the cowling and dent the side of the fuselage. And then there's the case of the Super -2, at Perris I believe, chunking its turbine blades and actually penetrating the fuselage. -2s, -6s & -10s. The 2s & 6s were on a Skyvan and the -10s were on a B100. Maybe a should be more specific. A Garrett needs to be rigged "By The Book". There is no room for fudge facture. The angles between the FCU and the Prop Pitch Control need to be exact on the linkage. The Feathering Valve needs to be rigged correctly and the Beta Tube needs to be set correctly to give the correct Flight Idle Blade Angle.

Bobby, One thing you have to remember, the TPE331-12 is a realitively new engine to the world of skydiving. When people talk about Garretts going boom, they are referring to the -2, Super 2, -5 and -6s. All these engines can be hot started, over torqued, over temped and negative torqued if the systems is not working properly. Garretts also fail in a more spectactular way, (i.e. Un-contained). That's more rememberable than just a loud boom or a bang. And as I've stated before Garretts are less forgiving then a PT6. You can miss rig a PT6 and it will work just fine. The aircraft may fly poorly, but the engine will not be damaged. Now if you miss rig a Garrett you can do some real damage to the engine and aircraft. Time will tell. The SRL feature on the -12 will keep most pilots from doing something stupid and the fact that the engine is de-rated 300 hp will help.

I watched it every day, PT6A-34 Single Otter/TPE331-12 Caravan. Before the operator started flying out of the airport he kept the aircraft on our ramp. So, I have had the opportunity to watch this Caravan take-off multiple times. It still takes 3 times the distance for the Caravan to get on step then our -34 powered Otters. This has nothing to do with the engine, though. It's the Caravan wing design. Once the Caravan was airborne then it won hands down. It does haul ass in the air. But this, compared to the Otter is because of wing design. Plus, the turbine otter is limited to 134 knot IAS. Airframe limitation. The stock Caravan is no comparison to the Garrett Caravan. The PT6 Caravan would easily eat up a mile of water to get on step.

You like that one. I was waiting to see how long it would take for someone to catch that. Actually shaft bow happens because the shaft has few bearings to support it in relation to its length. It can happen to any 331 regardless of age. Anyone who has listened to a Casa or Skyvan start and heard a distinctive little pop right after light off, that's due to shaft bow. The Garrett was the logical choice for the Caravan. The PT6A-114A is under powered for the aircraft and with all other PT6 models having dual exhaust going to the Garrett makes sense. A local operator here uses the first Texas Turbines conversion on amphibs. I still stand by my ideals of the PT6 being a better engine. The PT6 is just more forgiving to pilot mistakes and for lack of a better term, maintenance malpratice. The SRL on the -12, though, does take a lot of pilot error out of play.

There are -20 out there, because of all the operators who are converting. The biggest issue is maintenance costs. Not your typical inspection cost, but Overhaul & Hot Sections. There are still shops out there that support the -20 for overhauls and hots, but that number is slowly shrinking. Plus, add in there that Pratt & Whitney does not support the engine anymore, (i.e. New Parts) and that sends the cost of parts way up. You can pick up a decent -20 for $60,000 - $80,000, but come the first Hot Section that you need parts and the HSI will cost around $20K-$40K. Overhauls will cost 2-3 times as much as what the engine was purchased at.

The weight would work in your favor. The HC-B3TN Prop, as on the -100, -200 Otters with the -20 is 112 pounds. So the PT6/Prop combo would be lighter. Sorry for the miscalculation. I was thinking prop with paddle blades which th -20 would not be able to turn. How would the balance work out, though? The moment for the engine, (i.e. the engine mounts), would be 2-3 feet farther forward.

You are correct with the weight if your are replacing an IO-540 or a TIO-54O. The PT6 and prop combo would be less. If it is replacing an IO-520 then the PT6/prop combo would be alittle more.

If there was a demand for this type of aircraft, why aren't there more of the Allison powered Soloy 206s flying? The Allison puts out just as much horsepower. What type of prop would you use? The standard 3-bladed Hartzell barely has enough prop clearance on a King Air. Also, have you given thought to Weight & Balance. A -20 fully rigged weighs 340 pounds + 180 for the prop. This is more than a 206 with an IO-520 - IO-540. For an aircraft that already requires full UP Elevator to keep it off the nose wheel at landing this could pose a problem.

WE HAVE A WINNER!! This statement hits the nail right on the head. I've worked on and maintained both PT6s and Garretts. Both are excellent engines. I've seen a PT6, couple hundred hours out of the shop shread it's PT Blades. I've seen a PT6 go 8,000 hours with out an overhaul with nothing more than a Hot Section look-see and fuel nozzle changes. I've also seen Garretts with the same tack record. My Garrett experience is on TPE331-2, -6 & -10s. I've seen the -2s run quite long with no issues. I've seen -6s chunk metal after 2000 hours. Also -10(i.e. Casa) fail. -10s have a Single Red Line feature, just like the -12s. It all comes down to PROPER MAINTAINENCE. My experience has shown that a PT6 is more forgiving to lack of adequite maintenance and pilot awareness to trends. Make sure that on the Garrett the Fuel Nozzles are changed regularly, in-situ inspections are carried out and that the pilot knows the trends of the engine. The -12 will last long time then.

The TPE-331 is a good, strong engine. Just hope, though, that the aircraft owner does not decide that he/she can skip a Hot Section Inspection. That's when all hell breaks loose, literally.

After looking at the form USPA needs to add one more line for A&P mechanic's name and Certification number. Not all inspections require an IA's signature. A 100 Hour Inspection, Manufacture's Program (i.e. Twin Otter EMMA) and AAIP can be signed off and the aircraft returned to service by an A&P mechanic. No IA needed.

Unfortunately you are another victim of Skyride. SORRY

I remember one time we did a Fly Away load and I had to go back and close the door with a Pilot's Bail-out rig on. I was alittle nervous then since my intentions were not to jump.

Don't kick the handle!!!! I've forgotting how many times I had to fix that handle because some jumper was too lazy to bend over, so they just kicked the handle to release the latch.

Yes, Teflon.

The Casa door is hydraulic and is operated by the Co-pilot. The jumpers have no control of the door. The Skyvan door, on the other hand is opened and closed by the jumpers. The Skyvan actually has a two piece door. A large door section, that is hinged at the rear of the aircraft and a small forward door. Depending on the mod type of the door the door sections are either connected or seperate. On the aircraft that have seperate door pieces the small forward door is removed. This leaves a gap of about 18" that you have to lean across to unlatch the door. Plus, the door is quite heavey. Bungee cords are used to help support the weight of the door and make it easier to lift. To open the door you must lean across the gap, unlatch the door using the handle, then grab the bottom of the door, raise it all the way up and re-latch it in the up position. Door commands are given by lights, just like other aircraft.