short King Air trips

[prpjt]

Just wondering if anyone has already figured out the most efficient way to do really short trips. I'm flying a C90B, 80% of it's trips are about 70 miles. I've never done this short of leg on a regular basis. If anyone has some tips from past experience I'd like to hear about it, doesn't have to be King Air, just really short trips and turbine. I've pulled the power back, climbed higher, went lower, climbed faster, just to collect data and formulate the best profile for the trip. Thought I'd tap some of the experience out there. Thanks.

P.S. Any one regularly run the 90 at anything but 1900 rpm.

 

[cvsfly]

Flying the BE-200, I was taught a good rule of thumb for the altitude for a particular distance is to take X 100 and convert to an altitude/flight level up to the most efficient cruise altitude of the plane. I think this works well with most turbo-props/King Airs. I.E. for a 70 nm trip x 100 = 7000', 250nm = FL250 or close proximation, 400 = 40 = for the BE-200 it would be about FL250, for a C-90 - about 17,000 or FL 180. I also take into consideration the type of airspace I'm flying into. Flying to TEB from the south, they start you down to 11,000 in a turbo-prop at or before PXT - for 250nm trip it may only pay to go up to 18,000. I also consider "indian territory". Most of your Warrior's, Apache's, Aztec's, etc are down below 10,000' so even on short trips I try to get above them and it also usually keeps you out of the summertime haze layer. You can only get so efficient on those short trips - fuel burn is still going to be fairly high.

 

[cherokee]

Interesting way to choose cruise altitudes but don't understand part of what you wrote

"400 = 40 = for the BE-200 it would be about FL250, for a C-90 - about 17,000 or FL 180"

Not sure what this means and how the numbers change from the 200 to the 90.

 

[JetPilot500]

I've used that formula for most turbine airplanes I fly. It is a good place to start at least. Usually try to go at least 10,000' on short trips to say above the bug smashers. If you are light and/or it is cold outside, you climb faster so maybe go a little higher. On the other hand, if you are heavy and/or it is hot outside you won't climb as well so go a little lower.

Another rule of thumb is that you should spend 1/3 of your time climbing, 1/3 in cruise, and 1/3 in decent. Of course on the longer trips you'll cruise more than 1/3. So on a 30 minute trip, climb for 10 minutes, Cruise for 10 minutes then Descend for 10 minutes.

Altitude selection is more of an Art than a Science!

Hope that helps,
JetPilot500

 

[prpjt]

Thanks for the replies. I use the 10% rule and the 1/3 cruise climb dec rule. But I'm wondering if it would be more efficient / cost effective to climb like a bat out of Hll and decsend like a rock or if a faster speed in the climb and a powered descent would be more benificial(sp) on a short trip. Probably doesn't make a difference. After I get the data for a few months I'll post what is fastest or most fuel efficient for a short trip. Most fuel efficient is to pull the power back, but being a pole chaser I can't bring myself to do that each trip in the 90. By the way, I'm a number cruncher. And I don't know if it's cost effective if you consider engine reserves. We fly about 200 hrs a year. You guys are great. Thanks again for the replies.

 

[JetPilot500]

There are a lot of factors here.

Let the wind be your guide. If the higher you go the faster the tailwind, then climb like a bat out of hell to get up there and take advantage of it as soon as you can. Then decend by dropping like a rock at the last minute. If you have a big headwind at the cruise altitude, then make it a nice cruise climb...no need to get up there quickly. Start your decent early by pushing the nose over with the power up and decend on the barber pole.

Ok, so don't fly like a bat or a rock, keep it comfortable for your passengers. I'm sure they'd rather fly for 25 minutes in smooth comfort versus 23 minutes of fighter pilot flying.

Where you will really save time is on departure and approach. I've seen a lot of pilots slow down way too early, or fly B-52 patterns. That kind of stuff will eat up minutes fast. Land with a slight tailwind (less than 10 knots) if you can do a straight-in versus a full traffic pattern. Take a visual when ever possible. Go as fast as you can as long as you can (keep in mind safety and pax comfort). This will save you a lot of time.

We figure every minute in the air costs us $12 in the Citation. Might not sound like much, but if you can save 2 minutes every flight, and fly 300 flights per year, that adds up to $7200! I fly a Citation I and we routinely beat the block times of a Citation II in our charter fleet flying the same trips, and I think its how we fly versus how they fly.

I am not recommending you sacrifice safety. But a King Air or a light Biz Jet can be flown very safely at its limits. If you are new to the airplane, take your time and get comfortable first. When the weather is Crap, sloooooow down, and take whatever time you need to be safe. But if it's VFR and it usually is, get the plane on the ground as quick as you can.

Good Luck,
JetPilot500