There was a discussion a bit ago about how turbines don't like to fly low and this can be a problem in headwinds. I offer a specific example of this with this flight:

http://flightaware.com/live/flight/N305 ... /KCDW/KEVV

This was the worst headwind situation I can recall in my 7 years of MU2 operation as far as strength and distance I had to go.

Headwinds were roughly this average for the flight:

5,000: 55 knots
10,000: 75 knots
15,000: 85 knots
20,000: 115 knots
25,000: 130 knots

I flew the route in 3:11 for a block great circle ground speed of 200 knots.

I filed and started at FL180 (which was 18,500 ft due to high pressure). True airspeed was 300 knots, 92 GPH, ground speed was 194 knots. I decided to try lower based on the fact I was getting some light chop which suggests I was in a slip zone between air moving at different speeds, and also because XM winds loft suggested lower was less wind.

At 16,000 ft, true airspeed was 299 knots, 98 GPH, ground speed increased to 215 knots, air smoothed out. To cruise near 100 GPH is VERY rare for me perhaps only the second time I can recall, but in this case I gained 11% ground speed for 6.5% more fuel, and cut flight time down, so that was beneficial. I did not try lower feeling the winds would not improve that much. Also, I was running right at Vmo (250 KIAS), so my true airspeed would start to go lower as well.

I landed with 75 gallons left, easily an hour's worth at reduced throttle. Had the weather been hard IFR, I would have likely made a fuel stop (but then it wouldn't be such a big high, 30.66 inches, and thus would have had less headwind most likely). As it was, the weather was crystal clear and nice.

It was 290 gallons total. Using contract fuel, this was about $1K in fuel. While I can normally go about 1200 nm in still air, my range was reduced to about 650 nm under these conditions.

The take away here is that strong headwinds cause more fuel usage and reduced range, more so in a turbine than a piston. The turbine CAN fly low, nothing wrong with that, just burns more fuel, so the preference is to fly high when able.

As I was lamenting my situation, I thought back to the time I was considering buying a 421. The lowest practical IFR altitude for that route would have been 8,000 ft, about a 70 knot head wind. At 8,000 ft, the 421 cruises at about 190 KTAS, so the ground speed would have been 120 knots. That is 5:40 travel time accounting for the routing and climb/descent phases. That would use about 225 gallons 100LL leaving about an hour's worth if you had the 262 gallons capacity. That's $1100 in gas for the 421 plus 2.3 hours more operation of the machine and lost human time.

In other words, even in the worst situation, the turbine did better for time and fuel cost. Getting a 200 knot block time in roughly 100 knot headwinds is good. You buy a fast airplane for the headwind days, not the tailwinds!

Had I been going the other way, flight time would have been 1:30, FL270, 68 GPH, 410 knots ground speed, 120 gallons fuel. Whee!

Taken as a round trip, block speed of 270 knots, fuel 410 gallons, $1500, 4:41 total flight time. Still air comparison would be: 273 knots, 350 gallons, $1225, 4:40 total flight time. The still air numbers are not that different because of the altitude choices made in the wind.

Mike C.

Mike, great post. Will be chatting with Steven Scates today about that very thing.

He was bucking some serious headwinds the other day in the 200, groundspeed down to almost 100knots!!!! That's insane.

That's a very good example in our previous discussion on this topic Mike. Thanks much for posting. I will offer a slight counter regarding others who live in the flat lands like I do where there are practical IFR altitudes available as low at 3-4K ft. In fact on a recent trip in the Seneca I flew eastbound at 9K and came back westbound at 4K to duck underneath the 50kt headwinds. As I recall the headwind at 4K was only 10kt in comparison.

In the Pilatus I routinely fly Atlanta to Denver (1000NM) at 16.5K'. Headwinds last week averaged 65 knots at this altitude. I can make the trip non stop in 5-5.5 hours on about 350 gallons JetA. Fill up at APA for under $3.00 per gallon.

Last week I landed in Great Bend KS. instead of APA for fuel. It's not as far of a flight but it allows me to taker more cheap fuel as I also have to buy once I get to the ski resorts.

Didn't quite understand that since KAPA fuel is cheaper than KGBD and KAPA allows you to tanker more fuel to KEGE by being closer. You originally filed to go to KAPA and then diverted to KGBD, why divert to more expensive fuel if you had the range?

With 65 knot headwinds, no way I can make PDK to APA (1045 nm) non stop.

Mike C.

APA looks cheaper but add in the $100 lav service and $50 GPU and it ends up more expensive. GBD has $15 lav service and free GPU.

I need to buy 100 gallons when I land in Aspen. This means I can only buy 200 gallons in APA to be able to buy 100 in Aspen. If I land at GBD I can filler-up then burn 100 getting to Aspen from there. Therefore, I can buy more cheap fuel.

This trip I diverted just to see what GBD was like. GBD is non towered so much easier and faster in and out than APA. I was the only plane on the ramp at GBD. Service was fast and first class. Friendly people. I will use them again.

In the summer I make it non stop to Aspen. Of course coming back east I'm hauling ass at FL270 during 350PPH so it all works out.

Here's GBD. Yes, the runway and ramp were all ice.

Jason, what do you use the GPU for in the PC12?

Anybody else feel like there's too many dudes in that photo? C'mon Jason. You've got better ones than that...

I ran into that same headwind last week coming back from Orlando.

3:29 from New Braunfels, TX (near San Antonio) non-stop at FL250 to Kissimmee. Then nearly twice that time coming back at 10,000'.

Sure was fun with the tailwind though.

Issue I have is that white stuff. Only white stuff I like to see is three inches of foam after a double overhead set has passed.

That being said, frigging Pacific is damn cold.

Today is a rare day that I decided to leave the C-421 in the barn and take the airlines. I hate every minute of running my CC on delta.com today, but I believe it's the better part of valor given the challenges with the weather and airplane capabilities.
(The plane in the Foreflght screen shot is the Delta flight that I'm sitting in)This would have been doable in a TP. You would have to fly high today to avoid the icing. Non stop Burlington VT--Nashville TN in the 262 gal equipped 421 isn't an option today. A fuel stop isn't really a good option as I would likely get some ice in the descent and require de-icing on the ground etc., plus most of the region is hard IFR.
The icing pireps are mostly in the teens, so I would need to stay in The Flightlevels where it's colder. This trip would have been doable non stop at or below 16000 today.
Ground speed today would be ~130kts...brutal by my current standards. A fast TP would do the job, ideally a RVSM bird to top all the weather. But non RVSM should be fine as the tops are in the low to mid 20's along the route.

Icing at FL230:

So not bad. You don't need RVSM to escape icing. It is either something you can fly over or under, it can't be from 15,000 to FL280, the conditions to form ice can't have that much vertical extent, or if they do, it is of such limited lateral extent you can fly around it.


I can do it, but it is close. Flight planner says FL240, 3:50 flight time, 293 true cruise, 212 typical ground speed in cruise, 286 gallons (leaving 80 gallons reserve).

The TP goes up and down much faster, so getting through icing layers is not that big a deal, and with 1400 HP, it can carry more ice if you have to. Also, the additional speed causes a temperature rise which makes icing less likely to start with.

I've seen pictures of MU2s carrying enormous amounts of icing, but I have never had more than 3/8" in my 7 years of flying it, not really enough to even have needed the icing equipment.

Winter headwinds, particularly in the northeast US, are really annoying. They get winds from Canada, from the Midwest US, and up from the coast. Seems like everything blows towards New England.

Mike C.

To turn it on.

GPU allows me to power up all avionics and use GPU power to start the PT6. GPU allows for cooler starts. Otherwise half of the avionics are powered up when I go to engine start and after engine start everything powers up. All single pilot sized jets a TP's use GPU.

I don't like to bring sand to the beach.

Having an airplane is nice....... "Hey Jason, fly me out and you can stay at my house"

To turn it on.

GPU allows me to power up all avionics and use GPU power to start the PT6. GPU allows for cooler starts. Otherwise half of the avionics are powered up when I go to engine start and after engine start everything powers up. All single pilot sized jets a TP's use GPU.