Yes, but I find that I'm never at .35 since I always have a headwind or tailwind.

Using AOA for best range is subject to some errors. AOA is sometimes not perfectly calibrated in the low angles area. Also that does not correct for headwind/tailwind factors.

I don't know if any of the above is at or near 0.35 AOA, I would have to try it out.

The operations manual gives this chart (per altitude, this is FL410 and for my Citation V) for optimizing range based on setting N1 fan speed:

Ideally, you constantly adjust fan speed based on altitude, weight, and winds to get the most over the ground distance. Towards the end, your power goes down and your speed does too.

In a tailwind, you want to go slower airspeed and thus higher AOA. In a headwind, you want to go faster airspeed and thus lower AOA.

I have no idea why max fan speed is 104% and not renormalized to 100%, but that's the way legacy Citations are. And just to make it more confusing, max N2 is 96%.

Mike C.

From the theory section of studying for my ATP, best range is not as easy to calculate in a Jet as a piston. As Mike says there is headwind and tailwind issues, but also turbine engine efficiency is not a straight line like lean of peak piston power. So most jets will achieve max range somewhere above L/D. But you certainly want to fly faster into a headwind and faster when heavy. Still impressive to stretch the range in a turbine. Now throw in their cost of spinning the turbine, and the efficiency matrix gets complicated.

Seems to be a Pratt thing - my PT6s have max Ng of 104% also. I think it is 104% of some other engine’s certification numbers, but I have no idea why they certify and display it that way.

What? You have never given 110% at work?

Sierra gives a similar set of instructions for Citation 1 and Citation 2. I'll email you the full document.

I don't know any AOA indicator that is truly calibrated to an accuracy of 0.01 AOA, and that is worth 10 knots of wind correction per those instructions.

Cessna gives adjustments in N1 fan speeds for altitude, weight, and winds. Setting N1 is highly repeatable.

Mike C.

Do you know how you can "feel" if a outboard boat is on plane and trim the engine for minimum drag? It's just a feel but it's highly accurate because you can nail it within 1mph without looking at the speedo.

The same thing works for flying airplanes and gliders. The AOA gauge just helps you verify that your Citation is on plane.

My Widgeon flying boat is the most unique of them all, it truly combines the flying AOA with the hydrodynamic AOA and it's definitely not something I could write down; it's just a feel I have and also the sound of the water on the hull. The range is about 2 degrees on the water; mess this up and there's a violent porpoise.

So long story short; we all have the ability to feel drag in whatever machine we are operating.

In my Operating Manual, there are tables similar to what you posted above but they also include temperature as a variable. The output of the table is fuel/nm based on N1. So you can find the N1 setting with the lowest fuel per distance travelled. After my painful flight home from Savannah with a strong headwind a few years ago (before I knew better I flew the whole thing at LRC - we made it just fine but it took forever) I now use those charts to optimize in cruise. Plus it gives me something to do in cruise

Mike inspired me to do my longest flight to date in the 501. San Bernardino to KOMA/Omaha.

https://www.flightaware.com/live/flight ... /KSBD/KOMA



1141nm, 3.75hrs in the air/4.2hrs startup to shutdown. Flew AOA and reduced N1 as winds and weights permitted. 305kts average groundspeed and 272kts block. Block fuel burn of 102 gph. Took off with 3800lbs and landed with 950lbs. Considering it was day vmc, I would have felt comfortable continuing for another 30 minutes/150nm but gas was more expensive if I went any further east. Definitely confident that my 501 is a 4 hour/1200nm airplane and more if conditions permit.

Glad we have finally debunked the rumor that Citations burn 180 GPH!

Criss-crossing the country this week and had another long (great) flight yesterday.

https://www.flightaware.com/live/flight ... /KOKC/KSBD

Left Oklahoma City in 90 degree heat heading west and it never got below ISA +20 the entire trip. Small tailwind on the climb that quickly turned into no wind and then a steadily increasing headwind. By the time I was approaching hour 2 in the air it was 50-65kts on the nose.

I like to land with 1000# of gas, so I pulled it back to 99% N1 which got me 325kts TAS and just over 700pph for the remainder of the flight. Not exactly earth shattering groundspeeds, but I was able to easily accomplish 1000nm westbound with hot temps and unfavorable winds. Landed with 950# or well over an hour reserve.

5300nm of flying this week. Squawk free, above the weather, quiet, comfortable...this is the best plane I've ever owned and it's not even close.





The only gripe for the trip was during the descent. I was over Palm Springs descending at 225KIAS and LA Center told me that could cancel the speed restriction?

I had to key the mic and explain that was my normal descent speed.

Hah! Love seeing this


For those of you citation guys with 750s installed--is it easy/common to get fuel flow sent to the 750 for range calcs? And as a totalizer?

That's one of my favorite tools on longer range flights stretching out for range.

Can someone give me a ballpark cost to add 2 GTN750s to a 501? Or maybe I only need the 725s? Looks like they can be had for roughly 13k per box.
How bad is the install?

Hi Neema,

My plane was used by Jet Tech for the Garmin STC so it does have fuel flow. I do not know how common it is to have it. I also really like the Fuel Planning page on the 750 - I use it as a sanity check on longer flights to make sure my fuel planning was in the ballpark.

Of course it isn't very smart - it just takes your current fuel burn and groundspeed and divides into fuel available (which you have to type in at the beginning of the flight). We "gain" quite a bit of range on the descent so the "fuel remaining at destination" calc will always read low. But it's still a really great sanity check