Cheyenne 400 VS King Air 200

[cheyflyer]

An interesting review of the Piper 400LS - The website was shut down, so here's the cached version from google.com:

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http://64.233.161.104/search?q=cache:3hjFlvB80D4J:www.fliteguide.co.za/Imperial_Aviation/Full_aircraft_reports/FR_piper_cheyenne_pg2.htm+%22cheyenne+400LS%22+%22imperial+bank%22&hl=en



Excerpts:
The result is astonishing. The 400LS will out climb most small to medium business jets. In terms of hard numbers, it has a maximum true airspeed of 360 knots and will cruise at over 40,000 feet at 340 knots for nearly seven hours. It will accomplish this seating nine people in stretch-out comfort and at less than half the fuel burn of a Citation II. . . .

During the pre-flight walk about it is clear this is a Piper and not a Beechcraft product. PHO's age is beginning to show in the general fit of the panels and particularly on the fibreglass mouldings, which were beginning to craze. The heavily over-engineered solidity of Beech products seems to be lacking, most obviously when looking at the access panels which appear to be loose fitting. . . .


The huge power of this Piper has made this not just a hot rod special of limited utility but an aircraft of immense practical use. It is capable of taking as many people as a Citation I a far greater distance at a similar speed. The owner says that on a Lanseria to Luanda leg, the aircraft can carry more payload than a King Air 200. With 2,000lbs of fuel for four hours there is still capacity for another 2,200 lbs of passengers. Typical fuel burn at a high cruise level is 400lbs (60 US gallons) an hour - half that of a comparable Citation. With total useable fuel of 570 gallons, the aircraft can comfortably make Johannesburg to Mauritius non-stop. . . .

I have been operating the III for a couple months now and have been researching the 400LS for one of the bosses who wants one bad. From what I have found 2000 pounds fuel is not 4 hours. More like 2 and some change. I think it would be an awesome airplane to fly and kinda wish we would get one but, the things I have learned is 1. RVSM is a must and 2. heaven forbid should you need prop MX. Blades run about 20K each if you ding one. RVSM is runnng about 125K. I think the shear size, power, and weight of the Garrets help with the CG problems the III has, which yes, IS a problem in the III. I have heard from several KA200 guys that getting it out of CG is almost impossible. And the 7 hours mentoned in the above article, well maybe so, but with no people. From what I saw, plan on about 1000 NM with full passengers, or about 3 hours or so.

I have found this by asking around. Check with Cheyenne Air Service Center in PA or Columbia Air Service in CT, they seem to be the resident experts on Cheyennes.

 

[knelson]

Pilot's airplane

I flew a 400LS for about a year and a half (4-500 hrs) and absolutely loved the thing. That's cause I wasn't paying the MX bills. It was not like it was real MX intensive, just that there was no great support network and we were practically charting new territory every time line maintenance was required. Also, that was prior to DRVSM and I had no experience taking one through that process. The long-short of it is this-talk to a lot of people who have operated them, and then when it is all said and done, just let them keep the plane and you live vicariously through them. I think the 400LS had a pretty decent shot at being a pretty great plane. The only thing that stood in the way of that is the brand name. Yet another product Piper doesn't support. Go for a ride, remember it, buy a King Air.


knelson

 

[mzaharis]

I had found that article because I had gotten my PPL at the Piper dealer in DSM (Des Moines Flying Service), and that airplane was the ultimate propeller lust object for me at the time. Still is, but it sounds like it's also a lot of trouble if you actually have to own and maintain one.

 

[jeb]

Cheyenne vs 200

I have a friend who flew the 400 for about a year, great preformer. Downside they are no longer in production, he waited six weeks for a replacement fuel cell. It seemed to be pretty maintenance intensive. If I remember right most of the 400's were sent overseas. If you are getting an airplane for business you better get something thats dependable.

 

[Thedude]

Why would you want a turbo prop that is RVSM qualified. If you are operating at 28,000 and above, you are either in the wrong aircraft for your mission or you don't understand the performance curve of a turboprop.

 

[bigD]

Why would you want a turbo prop that is RVSM qualified. If you are operating at 28,000 and above, you are either in the wrong aircraft for your mission or you don't understand the performance curve of a turboprop.

I think in the case of the 400LS - the fuel burns get pretty reasonable in the mid 30's. I've heard numbers like 340 knots on 500 pounds per hour up there. That's pretty impressive, given that I burn that much gas on 80 fewer knots in the 20's.

 

[THE Flying Ace]

In the old Citation II, we are lucky to do 340 kts in the mid-thirties and we are burning double what the 400LS is burning.

 

[FlyFlyFly]

you don't understand the performance curve of a turboprop

From the numbers I have seen, the airplane doesn't have a good understanding of the performance curve you reference either.

Maybe you could sit it down and calmly explain things to it...

 

[Thedude]

I think in the case of the 400LS - the fuel burns get pretty reasonable in the mid 30's. I've heard numbers like 340 knots on 500 pounds per hour up there. That's pretty impressive, given that I burn that much gas on 80 fewer knots in the 20's.

340 TAS ?? That seems a little high

Have you looked at the specfic fuel consumption...just because your fuel flow goes down doesn't mean that you are getting the most bang for the buck. I dont know a lot about the K-Mart King Air but I understand it has Garretts. I have many hrs in the TPE-331-12 and I can defintly tell you your power available curve really drops off after about 18,000'. So unless you are looking for max endurance you should stay in the mid teens. Same goes with the King Air.
I am trying to find the performance curves for the SA-227 and the BE-200 in my library but it is all in boxes right now

 

[bigD]

340 TAS ?? That seems a little high

That's what was told to me by a guy that flies one, but he could have been BS'ing me - I dunno. I don't have any personal experience with the 400LS, I was just relaying a data point from someone who would know.

 

[Thedude]

I found my old BE-200 manual right off the bat. And luckily it already has the TAS curve and the range curve already calculated.

if you look at the cruise speed chart you will see tha the TAS curve is linear until 14,000 @ 284 TAS then it does a small regressive curve and peaks at 23,500 at 286 TAS.
14,000 wil give you a range of about 1120 NM @ 281 TAS
23,500 will give you a range of about 1380 NM @ 286 TAS
35,000 will give you a range of about 1900 NM @ 259 TAS

Assuming no wind, the best opearting altitude would then be 23,500 for best dist. vs time. Remember you also have to look at time to climb, descend and stage length. Typical length for a turboprop are 1.5 hrs and shorter or about 500 NM. If you are operating more than 500 nm its actually cheaper to switch to a jet.


I did a couple of quick calculation of a flight for 500NM
At 35,000 its 2:03 with a burn of 1021
At 18,000 its 1:50 with a burn of 1364
a slightly higher fuel burn at 18,000 but the stage length is very long for a T'prop

 

[jasonwb]

Why would you want a turbo prop that is RVSM qualified. If you are operating at 28,000 and above, you are either in the wrong aircraft for your mission or you don't understand the performance curve of a turboprop.

for the most part this is true, but the King Air 300 is one of the few TP's that is a great performer in the low 30's. it will true 300 kts at almost every altitude you choose to fly at. the TAS really doesnt bleed off until you get to around FL320 and up and your fuel flow is significantly lower in the 30's.

jb

 

[CL604DRVR]

for the most part this is true, but the King Air 300 is one of the few TP's that is a great performer in the low 30's. it will true 300 kts at almost every altitude you choose to fly at. the TAS really doesnt bleed off until you get to around FL320 and up and your fuel flow is significantly lower in the 30's.

jb

I agree with that. I used to get 290 true 600pph @ 350 in my King Air 350.

 

[cvsfly]

I found my old BE-200 manual right off the bat. And luckily it already has the TAS curve and the range curve already calculated.

if you look at the cruise speed chart you will see tha the TAS curve is linear until 14,000 @ 284 TAS then it does a small regressive curve and peaks at 23,500 at 286 TAS.
14,000 wil give you a range of about 1120 NM @ 281 TAS
23,500 will give you a range of about 1380 NM @ 286 TAS
35,000 will give you a range of about 1900 NM @ 259 TAS

Assuming no wind, the best opearting altitude would then be 23,500 for best dist. vs time. Remember you also have to look at time to climb, descend and stage length. Typical length for a turboprop are 1.5 hrs and shorter or about 500 NM. If you are operating more than 500 nm its actually cheaper to switch to a jet.


I did a couple of quick calculation of a flight for 500NM
At 35,000 its 2:03 with a burn of 1021
At 18,000 its 1:50 with a burn of 1364
a slightly higher fuel burn at 18,000 but the stage length is very long for a T'prop

Operating a B200 with -42 engines book calls for normal cruise at 1700 rpm, ISA - TAS peaks at 22,000 at 281 K and flow at 674 lbs. At 18 k TAS is still 280 and burn at 746. This all based at 11,000 lbs. This the table on Page 5-55 vs chart on pg 5-60 which gives slightly higher speeds. The table is pretty much on the mark in our experience. Of course we hardly ever see ISA or standard lapse rates. We normally pull 2050-2100'-lbs until we get 750 ITT (vs 800 max) (using these numbers we usually temp out around 16 -18k) and try to get to 24,000 going and 25,000 (typically :15 - 17 min un obstucted climb) coming home depending on winds and get 270 kts in summer and 275 in winter with about 600 - 650 lbs/hr. Good rule of thumb for altitude vs stage length for us is - distance x 100 = altitude up to ideal of 250 nm = altitude of 25000'. Less if expecting STARS or SIDS that keep the TPs down low anyway.

 

[Thedude]

for the most part this is true, but the King Air 300 is one of the few TP's that is a great performer in the low 30's. it will true 300 kts at almost every altitude you choose to fly at. the TAS really doesnt bleed off until you get to around FL320 and up and your fuel flow is significantly lower in the 30's.

jb

I have never flown a BE-300 but i think that is the same as the B-1900? If it is I have a hard time belieing that it will hold 300 TAS up till the 30's. The reason I say that is, I used to race a 1900 against a Metro (me) and the metro would usually win.

Then again it might be because the BE-300 weighs considerably less than the 1900. There are a few T'props that do defy the conventioanl t'prop performance such as the Saab 2000. Mainly because that have plenty of SHP available.

Then again I haven't flown a t'prop since '99 and the rules for jet performance are a little different.

Doing a cruise climb has to be one of biggest peeves that people don't do. They aim for something around Vy and never condsider the additional mileage they could have covered if they would climb at a higher airspeed. As a general rule for t'props, I never went abve 18-20 range unless the winds were really cranking. You just loose to much time in the climb and TAS vs what you save in fuel flow.

Like I said before, most guys just don't understand the power curves for a T'prop and its mainly because they have never been taught to look at such items and compute the climb and descent profile.