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Turbofan powered aircraft are more efficient per passenger-mile at higher altitudes than turboprop power aircraft at lower altitude, but it takes time and fuel to get to those altitudes. Turboprop only generally has an efficiency advantage on hops too short to allow turbofan aircraft to get to their efficient altitude. And yes, the mix is different today than it was 20 or 30 years ago because today's turbofans are considerably more fuel efficient than they used to be. On an unrelated note, Dominion Power has had their helicopter(s) out checking for storm damage after Hurricane Irene. This guy flew from tower to tower and hovered ROCK-steady for about a minute at a time at each, then came back an hour later in the opposite direction, and did it again. Was impressive just how precisely he held the hovers. 
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Sep 10, 2011 20:06
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Public perception for turboprop aircraft is also abysmal. If you've ever taken a regional hop, you're guaranteed to hear at least one person complaining that they '...have to get in THAT?! Is that SAFE?!' even if its a gorgeous new Saab 2000 or something. The public perception is so bad that it had a hand in killing the propfan off, despite its advantages. Also: 
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Sep 10, 2011 20:26
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Cygni posted:Public perception for turboprop aircraft is also abysmal. If you've ever taken a regional hop, you're guaranteed to hear at least one person complaining that they '...have to get in THAT?! Is that SAFE?!' even if its a gorgeous new Saab 2000 or something. I would imagine that at least some of this is rooted in a prop = reciprocating engine = OLD AS BALLS perception.
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Sep 10, 2011 20:48
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slidebite posted:
On shorter trips, less than 350 miles or so, the speed advantage of the pure jet is virtually negated; both aircraft would arrive within a couple of minutes of each other, especially if we're talking about a Dash 8 Q400, which is fairly quick as turboprops go. With the fuel economy advantage of the turboprop, it makes a lot of sense to fly them on short flights.
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Sep 10, 2011 21:16
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Cygni posted:
is this from one of those hurricane planes?
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Sep 11, 2011 00:44
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Naw, Precision Air ATR-72.
Cygni fucked around with this message at 00:55 on Sep 11, 2011 |
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Sep 11, 2011 00:53
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I don't care how much more comfortable they are, I hate the look of planes with the wing spar above or below the fuselage. Those ATRs look great until you realize that the spar is hidden in the clouds and it really looks like a hunchback in person. The old Fairchild Merlins - those were some good looking planes. Too bad they were slightly smaller in diameter than e people crammed inside 
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Sep 11, 2011 01:03
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 That's how you do a high wing. 
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Sep 11, 2011 02:12
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Cygni posted:Naw, Precision Air ATR-72. Ah, the ATR 42/72. The planes so unrelentingly terrible in icing the advice to operators was "stop using them in cold places".
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Sep 11, 2011 04:21
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slidebite posted:^^ I guess in the big picture, slow does make a difference all around if the cycles are cut that much. Range is 2522 km on the series 400, at roughly 667 mph - 3.78 hours total travel time at max range with the Q400. With an Embraer E-Jet of similar size, it;s 2.83 hours airborne time. You would have to offer me, as the customer, a proportionate discount to take the Q400 and I like prop planes. That discount would eat in to whatever margin you'd make on fuel savings (aside from Grover's point that turbofan aircraft are efficient at altitude and speed) and a rival airline offering the same route with a turbofan aircraft would probably eat you alive. Turboprops really only make sense on sub 300 mi routes, or routes that are slightly longer but very thin, as you can typically have a decreased load factor on a turboprop and still make money.
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Sep 11, 2011 11:26
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Epic Fail Guy posted:Ah, the ATR 42/72. The planes so unrelentingly terrible in icing the advice to operators was "stop using them in cold places". One of our undergrad MechEng projects was designing a bleed-air anti-icing system. Our unofficial conclusion in the literature research phase was: "Don't get on ATR planes". drat thing has icing problems in the caribbean.
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Sep 11, 2011 16:21
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AlexanderCA posted:One of our undergrad MechEng projects was designing a bleed-air anti-icing system. Well to be fair, it's cold enough to ice at altitude no matter where you are in the world. I've flown on ATRs a lot and yeah I'd rather not do it much more.
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Sep 11, 2011 17:10
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Epic Fail Guy posted:Ah, the ATR 42/72. The planes so unrelentingly terrible in icing the advice to operators was "stop using them in cold places". Interesting. I've flown ATR 42s & 72s several times in Finland -gulp.
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Sep 11, 2011 18:26
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KYOON GRIFFEY JR posted:Well to be fair, it's cold enough to ice at altitude no matter where you are in the world. Is it humid enough to ice at altitude, or is it only problematic if you bring your water with you (i.e. condensation or dew on the airframe)
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Sep 11, 2011 18:36
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BonzoESC posted:Is it humid enough to ice at altitude, or is it only problematic if you bring your water with you (i.e. condensation or dew on the airframe) It's when you fly through visible moisture that you really need to worry about icing. So any clouds will do.
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Sep 11, 2011 18:54
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Epic Fail Guy posted:Ah, the ATR 42/72. The planes so unrelentingly terrible in icing the advice to operators was "stop using them in cold places". First Air operates ATR-42s in the Arctic; from what I hear, they are completely satisfied with the performance of the ATR in that environment. KYOON GRIFFEY JR posted:Range is 2522 km on the series 400, at roughly 667 mph - 3.78 hours total travel time at max range with the Q400. With an Embraer E-Jet of similar size, it;s 2.83 hours airborne time. Comparing an E-Jet (specifically, the E-170) to a Dash 8 is like comparing a Porsche Cayman to a 1/2 ton pickup because they both have two seats. The Dash is designed specifically for flying lots of short trips out of small, somewhat austere airports, whereas the E-Jets are optimised with much longer flights in mind. On the ground, the Dash will turn around faster than the E-170 (enough that it can offset any speed advantage the E-170 will have on flights within that 350 mile radius I mentioned earlier). The Dash also burns a LOT less fuel per block hour than the E-170 does; typical fuel burn for a 350 mile flight in the Dash 8 is about 3500 pounds, whereas the E-170 would burn about 4500 pounds, while only arriving about 5 minutes earlier. There are a lot of other factors that I haven't considered in this comparison; I guess my point is that a straight-up comparison doesn't really do justice to either aircraft.
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Sep 12, 2011 00:20
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The little turboprops are great for short distances. I fly a ~300km trip quite often, about half the time in ATRs (or perhaps Dash 8s, they look the same to me) and the other half in 737s and over such a short period you hardly notice the slower speeds.
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Sep 12, 2011 00:34
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I flew this today.  Bonanza! on Flickr  Untitled by austinwalden, on Flickr
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Sep 12, 2011 02:58
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Thank god you're not a doctor, Captain Apollo.
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Sep 12, 2011 03:05
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Something tells me that turboprops need more maintenance than actual jets need. You've got a rather serious gearbox, and pitch control mechanisms. And I can't imagine that one of the massive bypass turbofans that are common now are all that far behind on fuel economy.
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Sep 12, 2011 03:27
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Turboprops need like 1/10th the maintenance of turbofans.
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Sep 12, 2011 03:29
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ApathyGifted posted:Thank god you're not a doctor, Captain Apollo. I've always wondered, does PhD count in this instance?
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Sep 12, 2011 03:36
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Cygni posted:Turboprops need like 1/10th the maintenance of turbofans. That doesn't make any sense to me at all. Care to explain?
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Sep 12, 2011 04:23
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Nerobro posted:And I can't imagine that one of the massive bypass turbofans that are common now are all that far behind on fuel economy. On an large plane sure. On a small plane things are different.
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Sep 12, 2011 04:41
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Cygni posted:Turboprops need like 1/10th the maintenance of turbofans. Not quite that good, but a turboprop engine will need less maintenance (both in terms of man-hours and dollars) than a turbofan engine of equivalent power. Partly because a turboprop is a more efficient propulsion unit than a turbofan is (which allows for simpler designs and fewer/smaller parts), but mostly because the components just aren't all that complicated - reduction gearboxes and propeller controls, in all honesty, hardly require any maintenance other than occasional inspections and oil changes. dissss posted:On an large plane sure. For an equivalent power level, a turboprop engine will always have better specific fuel consumption than a turbofan engine. This is because the turbofan needs to accelerate a smaller amount of air to a higher velocity than the turboprop does to generate a similar amount of thrust. As the energy needed to accelerate air increases with the square of the change in velocity, an engine that can accelerate more air will always be more efficient. That's why the bypass ratio of modern turbofans has gone up dramatically with every subsequent generation. Even still, the best bypass ratio in a turbofan engine today is about 12:1, whereas the equivalent bypass ratio of a typical turboprop is around 30:1. MrChips fucked around with this message at 05:19 on Sep 12, 2011 |
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Sep 12, 2011 05:16
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Captain Apollo posted:I flew this today. Bonanzas are just all-around classy airplanes.
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Sep 12, 2011 05:34
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On turboprop chat, jump plane wise I like riding in planes equipped with PT6A's, not terribly noisy and are workhorses. The Garretts that are used on Short Bros. Skyvans are some seriously noisy mother fuckers with not the best record.
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Sep 12, 2011 06:08
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Captain Apollo posted:I've always wondered, does PhD count in this instance? PhD's don't get paid enough/have too many student loans, so you're safe. Edit: JD's are hosed, though.
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Sep 12, 2011 06:13
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Alaska/Horizon Air has some turboprops they use for flights from SEA to Spokane and Yakima. I had some "interesting" experiences flying to Yakima on them. Oh, when I was camping over in Eastern Washington a few weeks ago, some school apparently caught fire and they dispatched a helicopter to pull water out of the lake we were on to put it out. I can probably post some pictures if anyone is interested.
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Sep 12, 2011 09:34
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MikeyTsi posted:Alaska/Horizon Air has some turboprops they use for flights from SEA to Spokane and Yakima. I had some "interesting" experiences flying to Yakima on them. Yes please!
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Sep 12, 2011 11:16
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grover posted:On an unrelated note, Dominion Power has had their helicopter(s) out checking for storm damage after Hurricane Irene. This guy flew from tower to tower and hovered ROCK-steady for about a minute at a time at each, then came back an hour later in the opposite direction, and did it again. Was impressive just how precisely he held the hovers. This reminded me of watching those crazy bastards do some tree trimming around power lines. I don't get to see them come around here too often but when they did I had to stop what I was doing and watch. It went pretty much like this: https://www.youtube.com/watch?v=UsNb4scGfbg
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Sep 12, 2011 19:31
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MikeyTsi posted:Alaska/Horizon Air has some turboprops they use for flights from SEA to Spokane and Yakima. I had some "interesting" experiences flying to Yakima on them. There is nothing inherently bad about turboprops. They are used frequently here in the northeast, as our cities are pretty close together. You're not going to save any time using a CRJ or junglebus to go from ALB to EWR. In fact, i'd rather ride in a Dash 8 than a CRJ or junglebus, actually. The Dash is descended from one of the nastiest bush planes ever, the Twin Otter.
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Sep 12, 2011 20:22
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Epic Fail Guy posted:There is nothing inherently bad about turboprops. They are used frequently here in the northeast, as our cities are pretty close together. And I hate when I get a ticket that puts me on one of them, because they don't have the crosswind tolerances. Having your flight home from Nashville be one of *two* flights that are being canceled because of the storm outside when all the 737s and A320s are still taking off nonstop sucks a wet goat.
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Sep 12, 2011 20:50
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Q400s are fine, after they've had their gear recall work done! https://www.youtube.com/watch?v=Tu89SIBDizQ
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Sep 12, 2011 20:52
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Phanatic posted:And I hate when I get a ticket that puts me on one of them, because they don't have the crosswind tolerances. Having your flight home from Nashville be one of *two* flights that are being canceled because of the storm outside when all the 737s and A320s are still taking off nonstop sucks a wet goat. The maximum crosswind component on an A320 is exactly 1 knot higher than a Q400.
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Sep 12, 2011 23:08
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Epic Fail Guy posted:The maximum crosswind component on an A320 is exactly 1 knot higher than a Q400. I live on a hill overlooking an extremely windy airport and the ATRs and Dash-8s are still coming and going in the same windy conditions 737s and A320s are
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Sep 13, 2011 01:12
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Epic Fail Guy posted:There is nothing inherently bad about turboprops. They are used frequently here in the northeast, as our cities are pretty close together. You're not going to save any time using a CRJ or junglebus to go from ALB to EWR. I don't dispute that, it's just Yakima is so close that any delay results in a "might has well have loving driven", and since it goes over the Cascades, the flights can sometimes REALLY suck.
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Sep 13, 2011 02:38
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Alaska/Horizon is also really weird about their Q400 routes. They simply don't fly them in Alaska. There is absolutely no reason most of the routes in-state couldn't use them. Off the top of my head, the Petersburg-Wrangell flight has got to cost them a ton of money using 737s instead of turboprops. You do not need a plane that big to fly 32 miles between two poor towns of less than 3,000 people.
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Sep 13, 2011 03:50
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So I just finished up reading Fate is the Hunter by Ernest Gann. Anyone interested in a mini-let's read on it in here? Not sure how familiar everyone is with it...if everyone's already read it then I won't bother but if you haven't read it there are a lot of really interesting/harrowing stories from the early days of commercial aviation, spanning from the early days in the '30s through spanning the globe with Air Transport Command during WWII and then finishing out in the post WWII boom.
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Sep 13, 2011 15:37
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Christ 222 5 star reviews? Ordered from amazon I'm curious to read it.
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Sep 13, 2011 16:02
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