diablopilot 2 #26 October 19, 2009 Quote 900-shp Honeywell TPE-331-12JR powerplant. Oh look a flying grenade. I just don't see it. At a minimum of 750,000 for a used Caravan, and a 500,000 upgrade, using a power plant that has been shown to have a lot worse survivability in the skydiving environment than the reliable PT-6, I can think of a few more places I'd put 1.3 million.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
fishejas 0 #27 October 20, 2009 I am the ONLY DZ pilot flying the ONLY Honeywell powered Grand Caravan. The aircraft engine is derated at 900 HP down from 1100 HP. This engine is powering the CASA 212-400. Honeywell engines are mroe reliable and have an in-flight shutdown rate LOWER that and PT-6 ever made. If you wonder what the ENTIRE AVIATION INDUSTRY thinks of Honeywell VS Pratt read this http://texasturbines.com/ttpress/AIN_2009.pdf I challange any twin otter to keep up and do it on 15 gallons per load like I do. Jason Quote Share this post Link to post Share on other sites
diablopilot 2 #28 October 20, 2009 It still doesn't change the fact it is a direct shaft driven propeller, which when put into the environment of repeated heating and cooling from constant high power climb, power off descents, and multiple shut downs and starts it just won't have the longevity of the PT-6. Time will tell.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
fishejas 0 #29 October 20, 2009 the overhaul time for a pt-6 is generally 3-4000 hours. The overhaul for a Honeywell is 5-7000 hours. Do you think the FAA asks for nothing when they approve TBO's? The temp difference between Climb and Descent is 200 degress C. Time isnt going to tell. The Honeywell 331 engine has 11 BILLION flight hours. It also has a LOWER failure rate than PT-6 engine. I am sorry if you dont understand numbers and FACTS. Anyone know what kind of engine is on the USAF and CBP Preditor aircarft. Its a TPE-331. We are not taking about a new engine here. IT been around since the 70's. Quote Share this post Link to post Share on other sites
pilotdave 0 #30 October 20, 2009 Quote IT been around since the 70's. How do you know? You've only been around since the 80s! How's it going? Where ya headed for the winter? Dave Quote Share this post Link to post Share on other sites
diablopilot 2 #31 October 20, 2009 And it still has seen relativly few hours in the skydiving environment compared to the PT-6.---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
totter 2 #32 October 20, 2009 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. Quote Share this post Link to post Share on other sites
fishejas 0 #33 October 20, 2009 Hey dave you have to come fly this things its a rocket! no plans for witner yet. Having this engine in skydiving has nothing to do with it. The engine has been in skydiving on skyvans, porters, casa's and lots of others. the fact is you hav nothing to base your opinion on except for what others have mislead you with. THe term garret grenade comes form the first 731 TURBINE engines not the 331 TURBOPROP. It is rumored at Honeywell the they are going to a 5000 hour overhaul with no hot-section for the new -12 engines. Diablo? are you a mechanic? even a pilot? Experience with aircraft than jsut riding in them and shooting your mouth off? Quote Share this post Link to post Share on other sites
billvon 2,991 #34 October 20, 2009 > THe term garret grenade comes form the first 731 TURBINE engines not >the 331 TURBOPROP. The 331's seem to do the hand-grenade thing with some regularity when used on Skyvans. Quote Share this post Link to post Share on other sites
pilotdave 0 #35 October 20, 2009 QuoteHey dave you have to come fly this things its a rocket! no plans for witner yet. I know a little airport on your way home where you can stop for cheap fuel... Dave Quote Share this post Link to post Share on other sites
wolfriverjoe 1,523 #36 October 20, 2009 Quote> THe term garret grenade comes form the first 731 TURBINE engines not >the 331 TURBOPROP. The 331's seem to do the hand-grenade thing with some regularity when used on Skyvans. Like at Summerfest?"There are NO situations which do not call for a French Maid outfit." Lucky McSwervy "~ya don't GET old by being weak & stupid!" - Airtwardo Quote Share this post Link to post Share on other sites
captain1976 0 #37 October 20, 2009 I agree, this engine has already proven its worth and I would rather have it than a PT6. With 5K the projected Hot Section look see and 7K TBO, it might prove to be the most cost effective powerplant out there.. Its just the damn initial cost, but with most of these birds out there today its gonna take a lot of tandems to pay for 'em.You live more in the few minutes of skydiving than many people live in their lifetime Quote Share this post Link to post Share on other sites
diablopilot 2 #38 October 20, 2009 I am a pilot, and while I started an A&P program, I decided that career path wasn't for me. Unlike many skydivers I' have made it a passion of mine to learn all I can about the aircraft I ride and fly. As for my personal experience, I've seen 3 Garrets "grenade", all on Skyvans, and I have yet to personally see a PT-6 do so. From my research PT-6s tend to loose an accessory drive, or gear box, where as the 4 Garrets I've seen all cause extensive damage to the aircraft OUTSIDE of the engine casing as the lunched parts, including damage to one pick up truck on the ground. It was later purchased by the DZ to appease the owners and became a great "bad spot" truck.Garrets with their shaft drives are a great high altitude "cruise" power plant, but when it comes to up and down, rugged use, the PT-6 still rules. Look at the aircraft it's on, Otter, Twin Otter, Caravan, King Air, PAC750, Turbine Porter (most). I'm sure the "SuperVan" is a beast and hauls ass well, I'm just doubting it's longevity, and value. Time MAY prove me wrong. ---------------------------------------------- You're not as good as you think you are. Seriously. Quote Share this post Link to post Share on other sites
RMURRAY 1 #39 October 20, 2009 I am no aircraft mechanic or pilot but jason pointed this out in the other thread.... "The engine has autostart and a torque/Temp limiter which is helps the pilot not to over stress the Engine. Skyvans do not have this. Thats why they go boom. Bad pilots not the engine." Quote Share this post Link to post Share on other sites
fishejas 0 #40 October 20, 2009 they skyvans thats have had engine issues were ragged out pieces of shit with spotty engine maint. at best. That is a problem with any aircraft engine. if you dont take care of it it goes boom. all of those cases the pilot was not following the limitations of the engine. after a while the engine went. Call Paul Fayard and ask him which engine is better in the long haul. He operates both pt6 and garrets. you have had learned bad, misleading information and you personal experiences are clouded by the fact you jsut dont understand how engines are designed and work. The fact the you think that skydiving turbines are ran hard up and idled down is wrong. just because you arent adding fuel doesnt mean that the engine is doing anything but 99% RPM Cheeers Quote Share this post Link to post Share on other sites
hackish 8 #41 October 21, 2009 I build car engines for a living, not turbines but I'm still interested because I've never heard anything good about the garrett engines even though I've had excellent luck with garrett turbochargers... What about having to hand turn the prop while the engine cools down so the shaft doesn't warp? Is there truth to this? I've never seen a twin otter pilot out doing this as his bird cools down... -Michael Quote Share this post Link to post Share on other sites
RMURRAY 1 #42 October 21, 2009 yes, to me it looks like spinning the prop by hand for half a minute or so on cool down is part of the procedure. what gets to me is that some people cannot look at the current facts/data and change their mindset. read the article that jason posted a link above - those are current users of the engine. Quote Share this post Link to post Share on other sites
davelepka 4 #43 October 21, 2009 Quotewhat gets to me is that some people cannot look at the current facts/data and change their mindset. read the article that jason posted a link above - those are current users of the engine Those people could say the same thing about you. The fact is that several Skyvans have had engines let go in spectacular fashion. You could argue that those planes were old, and the maintenece was probably sub-par, but every Otter in skydiving is also old, and the maintenece issue on the Skyvans is just speculation. Granted the new generation of Honeywell engines may be great performers, but I'm going to bet the every single one of them is in 'corporate duty' flying people or cargo on scheduled runs. Much more of their time beign spent in cruise at altitude as compare to climbing or descending. Also, I got the vibe from that article that the operators they surveyed were all professional operators who probably have a regular maintenence program, or fly under 135 where they have to have a program in place. The truth is that the Pratt engines are the ones that have proven themselves in jumpships for many years. You can't just ignore that track record, and the trust that it builds among jumpers. The Honeywell may be a great engine, but only time will tell if it's great for skydiving. It's like this - when you want a video camera to jump with, Sony is the only choice. Every other brand has VERY high failure rate in freefall, while the Sonys seems be almost indestructable. That's not to say that a Cannon, or a JVC isn't a good camera for filming things in the ground, and they might even be better then a Sony for that job. But for right now, if you're taking a camera into freefall, take a Sony. Quote Share this post Link to post Share on other sites
pchapman 279 #44 October 21, 2009 Quotewhat gets to me is that some people cannot look at the current facts/data and change their mindset. But there wasn't much info available to work at convincing people. Whatever the actual truth, you at least actually posted some information (I think from Jason in an older thread) about WHY to believe the new Garrett's may be good, something that is specific about why the Garrett on the Caravan may do better than what people have observed for Skyvans. (e.g., better automation / limiting) Quote Share this post Link to post Share on other sites
kallend 2,026 #45 October 21, 2009 QuoteI am no aircraft mechanic or pilot but jason pointed this out in the other thread.... "The engine has autostart and a torque/Temp limiter which is helps the pilot not to over stress the Engine. Skyvans do not have this. Thats why they go boom. Bad pilots not the engine." "Blame the pilot", the mantra of the aviation industry. The only engine I've seen "grenade" was on a Skyvan, and I've probably made 100x more jumps from Otters than from Skyvans.... The only sure way to survive a canopy collision is not to have one. Quote Share this post Link to post Share on other sites
totter 2 #46 October 21, 2009 QuoteThat is a problem with any aircraft engine. if you dont take care of it it goes boom. 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. Quote Share this post Link to post Share on other sites
Supervan900 0 #47 November 1, 2009 QuoteQuoteI am no aircraft mechanic or pilot but jason pointed this out in the other thread.... "The engine has autostart and a torque/Temp limiter which is helps the pilot not to over stress the Engine. Skyvans do not have this. Thats why they go boom. Bad pilots not the engine." "Blame the pilot", the mantra of the aviation industry. The only engine I've seen "grenade" was on a Skyvan, and I've probably made 100x more jumps from Otters than from Skyvans. When talking about engine failures, it is always funny how people can remember that a Garrett blew up on a Skyvan and put a few holes in the airplane, but forget about the PT6 on the Twin Otter in Missouri that blew up and people were killed. Check out the NTSB website: http://www.ntsb.gov/publictn/2008/AAR0803.pdf And another recent skydiving PT6 engine failure: http://aviation-safety.net/database/record.php?id=20080601-0 The fact is all engines can fail and their reliability is heavily dependent on the operator and the maintenance. Here is another great educational report for those that have time to read it (36 pages), but it explains things that damage turbine engines: http://www.atsb.gov.au/publications/investigation_reports/2005/AAIR/pdf/aair200507077_002.pdf Quote Share this post Link to post Share on other sites
billvon 2,991 #48 November 1, 2009 > it is always funny how people can remember that a Garrett blew up on a >Skyvan and put a few holes in the airplane, but forget about the PT6 on >the Twin Otter in Missouri that blew up and people were killed. Any engine can fail, especially when they are not maintained to manufacturer's recommendations. In my experience, in the skydiving environment, Garretts fail a lot more often than P+W's. Doesn't mean they are bad engines, just means that in the skydiving environment, they may not be the most reliable choice. Quote Share this post Link to post Share on other sites
totter 2 #49 November 2, 2009 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. Quote Share this post Link to post Share on other sites
RMURRAY 1 #50 November 2, 2009 Jason Fisher just left today...it worked flawlessly at parachute school of toronto this summer. Quote Share this post Link to post Share on other sites
