Why are some aircraft still powered by propellers?
Dave Reid
I was lazy and didn't check -you are of course 100% right and it was a DHC 7 , four engines for 40 odd pax and a very impressive airplane too.
Belonged to Henson Airlines and flew as Allegheny Commuter which through the convolutions of the US Airline industry is now American Airlines.
I was lazy and didn't check -you are of course 100% right and it was a DHC 7 , four engines for 40 odd pax and a very impressive airplane too.
Belonged to Henson Airlines and flew as Allegheny Commuter which through the convolutions of the US Airline industry is now American Airlines.
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The turboprops are also the controllers friend when it comes to speed versatility. Generally they can keep ATC spacing speeds for longer and later and decelerate much more quickly. At a place like London City for example it was always easier to put the turboprop ahead of the turbojet which wanted to slow down earlier. Conversely if you stuffed a turboprop up too tight behind a turbojet it could disc-up the props and give you minimum safe approach speed in seconds. If a turbojet is stuffed-up too tight behind a turboprop the prop can more readily minimise runway occupancy and make the first exit.
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point of order.
there is not a single aircraft in the world powered by a propeller.
they are powered by the engine that drives the propeller.
there is not a single aircraft in the world powered by a propeller.
they are powered by the engine that drives the propeller.
Talkdownman - indeed, a turboprop can brake rather quickly. On occasion, this catches (inexperienced?) controllers out cold though. On approach, us getting a bit close to the preceding jet for his liking, the director once had us (flying a DH8-300) "Reduce now to minimum approach speed". Well, if this is what he wants, this is what he gets: a reduction from 160ish to about 105 kIAS within an instant.
Followed about 15 seconds later by the polite question if we would mind speeding up again a little bit for the benefit of the succeding traffic...
Followed about 15 seconds later by the polite question if we would mind speeding up again a little bit for the benefit of the succeding traffic...
Last edited by Tu.114; 16th Jun 2013 at 12:15.
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I recall riding the RHS of a DHC6 into LGW one morning with a screaming headwind, it seemed like it took forever and a day just to fly across the staff car park, asked if we could expedite a quick exit at "Charlie" we expedited an even quicker exit at "Bravo".
The DHC7 was even more fun, in crosswind conditions they'd land across St. Mawgan's 300' wide runway.
The DHC7 was even more fun, in crosswind conditions they'd land across St. Mawgan's 300' wide runway.
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Of course, the biggest advantage (as a pax) with a prop or turboprop aircraft is that you can tell that the engine is working.
Best flight I ever had was in a DH89B, four wings, two piston engines, one take-off and five landings! 
Best flight I ever had was in a DH89B, four wings, two piston engines, one take-off and five landings!
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I remember my first ever flight on a prop aircraft. My family and myself were flying Humberside to Toronto via Schipol. We were on a Shorts 360 Air UK and then Canadian Pacific DC10.
Having traveled extensively in Europe I can say that I prefer the jets to props any day. Although I do have fond memories of the Shorts 360 and the F27
Having traveled extensively in Europe I can say that I prefer the jets to props any day. Although I do have fond memories of the Shorts 360 and the F27
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At LHR the Brymon Dash 7 simply wanted to know whereabouts to vacate and invariably touched down in the 'block' containing the turn-off. On 09L this usually had to be Block 9 with one behind over the numbers, but when it was quiet it would fly the length of the runway touching down as close to the stand as possible. (I recall a lady slightly over-cooked it one day and just came to a halt at the 09L stop-end for 19/27...I believe a bit of beta sorted it out)
Wasn't there a DC9 derivative that had an "open rotor" fitted (port side?) for testing at one point? The point being that I've always thought that the fan of a jet could be referred to as a "shrouded propeller" if you're willing to strech a point.
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It was called the UDF - Unducted Fan. Noisy, but saved a lot of fuel. Unfortunately the development was an oil crisis child and coincided with massively reducing oil prices which killed it off. For now. It will come back.
There is basically no way of increasing efficiency without increasing the fan size of fanjets. We're almost at the limit today with the Trents and the GEnx - the airplane makers have to incorporate bigger and bigger fan casings under the wings, increasing the landing gear height and adding structural weight and in the future it will become impractical to encase that big fan. So the unducted fan - basically a glorified turboprop - will come back.
Moving lost of air slower is always more efficient than moving less volume faster. So the bigger you can make a fan, the more efficient it will be.
There is basically no way of increasing efficiency without increasing the fan size of fanjets. We're almost at the limit today with the Trents and the GEnx - the airplane makers have to incorporate bigger and bigger fan casings under the wings, increasing the landing gear height and adding structural weight and in the future it will become impractical to encase that big fan. So the unducted fan - basically a glorified turboprop - will come back.
Moving lost of air slower is always more efficient than moving less volume faster. So the bigger you can make a fan, the more efficient it will be.
