Differences between jets & turboprop for regional ops

[Rwy in Sight]

I am trying to understand the differences between a jet and a turboprop operation. Fuel consumption and speed are two that I can think of but I am sure there are more.

May I make appeal to the collective wisdom of PPRUNE about the differences regarding perfomance, turn around time (and daily use), severe weather operations between the two aircraft and any other aspect that you like to point out.

Many thanks in advance,

Rwy in Sight

[windriver]

Customer resistance to aircraft with propellers may be a factor on some routes.

[AircraftOperations]

Luggage/Baggage/Cargo payload or capacity might be better on something like a Q400 compared to a ERJ 145.

Runway lengths would also make a difference for some short fields where you can use STOL prop aircraft.

[Mad (Flt) Scientist]

May I make appeal to the collective wisdom of PPRUNE about the differences regarding perfomance, turn around time (and daily use), severe weather operations between the two aircraft and any other aspect that you like to point out.

Very crudely:

TP has slower max and cruise speeds, lower max and cruise altitudes, shorter takeoff and landing requirements, possibly better Xwind capability, and are generally smaller aircraft. TP also has generally better fuel burn.

Turn around time should be similar all other things being equal (but since the prop is smaller usually can turn round the load faster).

Both are equally good (or bad) in poor weather but jet may have more chance to get over the top of it.

Conventional wisdom is that all the above favour TP on shorter, thinner routes, especially to smaller airfields. Jets win out on longer routes especially to/from hubs.

[chornedsnorkack]

TP has slower max and cruise speeds,

Makes sense, since the propeller tips are exposed and therefore get transonic at high speeds - they lose efficiency and also get loud. Mind you, this is equally applicable to propeller planes with infernal combustion engines.
But TP can be pretty fast yet still efficient. Tu-114 and Tu-95 are somewhat slower than B-52 or B-707, but they have a rather good range. Tu-95 is indeed loud.
And of course a jet can be slow. See Cri-cri twinjet, or Yak-40, or Virgin Global Flyer. But a jet tends to lose efficiency at slow speeds - too much fuel goes to moving the jet rather than the plane. Turboprops are better - if you want a slow turboprop, you just make a bigger propeller with lower rpm and gearbox with a bigger gear ratio. No wonder Yak-40 is the Fuel Destroyer. On the other hand, Global Flyer does achieve a rather impressive range.

lower max and cruise altitudes,

Because of lower ratio between cruise and takeoff TAS, correct?

shorter takeoff and landing requirements,

Because of lower takeoff IAS?

shorter takeoff and landing requirements, possibly better Xwind capability

How do turboprops achieve higher slip angle?

and are generally smaller aircraft.

Generally. On the other hand, compare Tu-114 with Yak-40. Or even ATR-72 with ERJ-135.

[Mad (Flt) Scientist]

One big answer to a lot of those is wing sweep. Since jets are relatively more efficient at higher speeds it makes more design sense to sweep a jet's wing. (Only TP counterexample I can think of is the Tu95). Swept wings are generally worse for low speed/high lift perf (i.e. takeoff and landing) and swept wings really don't like high sideslip angles.

[chornedsnorkack]

How do swept-wing STOL turbojets like MD C-17 handle in strong crosswinds?

[OverRun]

There is a dividing line between regional jets and turboprops, which is determined by both revenue and costs. Revenues are determined by a combination of passenger numbers and average fares. The circumstances of some operations means the revenue generated per trip cannot cover the cost of a regional jet. Regional jets are larger, burn more fuel, have higher maintenance costs, may in certain airlines have higher flight crew charges, have higher weight related user charges in certain circumstances and have higher finance or leasing costs.

Turboprops provide a lower cost alternative to regional jets, and are the only alternative for airlines with particular operating and economic circumstances. The two extremes of regional jet and turboprop operations are US regional carriers operating regional jets at main US hub airports and carriers in mountainous and other remote regions where passenger numbers and revenues are low, and operating conditions prevent operations as efficient as in the large US market.

Besides basic unit and trip costs, there are other physical and airline operating constraints which prevent the operation of regional jets. These are limitations posed by short runways, pilot scope clauses preventing the operation of regional jets over certain sizes or in particular numbers, and factors preventing high enough levels of aircraft utilisation. These pilot scope clauses are well documented in the USA, but they also exist in Europe. Many believe that SAS Commuter, which had a lot of Q400s until very recently, may have only selected the type to appease its pilot unions. Many other airlines have scope clauses limiting jet numbers.

[Kiwiguy]

... Or you could sling 300 seats in an Antonov An-70, operate 2000 nautical miles from an 800 metre dirt strip at jet speeds and confound everyone ha ha

[PAPI-74]

TP's can keep high speed in the descent for longer. We can stay at 265kts to 6 miles if reqd with a high rate of descent while the jets are back to 210 miles behind. I normally keep it intil 3 miles to the LOC and intercept at 220kts, depending on the approach and the angle to the LOC (no point going through if the controller is unaware of your groundspeed).
This means on a short route (1hr-1hr20) TP's are only a few mins slower, if at all than Jets, yes a little louder in the cabin, but for 1hr who cares.....
In the cruise our TAS is around 330kts.
And with smaller cabins, the pax have less boarding times and baggage reclaim time.
I still fancy flying a biz jet though....I think.