CTSW Cruise Speed

[okent]

I plan for 121 knots True at 5400rpm and 6 gallons per hour.

Usually fly at 4500 or 5500 MSL

 

[CTDan]

I can’t wait for Tom to work mine over... I showed 106kts(ish) on the way home from PA @just under 5500RPM.... Prior to the storm passing I was down to 78 knots across the ground for quite a while  

The next day, after the storm had passed I got a little push (going West) & had ground speeds in the 1-teens. Another 10 or 15 knots of TAS would have been nice. 

[GrassStripFlyBoy]

I wonder how much a well waxed airplane contributes to airspeed in CT, other general aviation birds have "a couple knots" as common thought, but in CT what might this mean.  My SW runs in the mid teens and I'm never pushing it to 5500, generally 5350 to perhaps 5400.  I do keep it slick, wipe down post every flight, with a hit of wax at least on the leading edges.

Last Saturday with the 45-50 temps, at 2k MSL, I was indicating 120N and even seeing 121-122 on occasion, around 5450 RPM.

Non tundra gear, as I believe Andy is as well?  That could be a factor as well.

[FlyingMonkey]

1 hour ago, GrassStripFlyBoy said:

Non tundra gear, as I believe Andy is as well?  That could be a factor as well.

Correct.  I think the smaller and lighter gear is good for 3-5kt.  I think prop pitch is the biggest factor that can be changed that has a large effect.  When I first got my airplane it would not go faster than 108kt WOT, and the prop was factory pitched very, very coarse.  IIRC I flattened it 1.5° and immediately gained over 10kt.  Most of the CTSWs (I don't know about the LS) came from the factory with a way over-coarse prop.

[AGLyme]

After every trip I review my speed on FlightAware.com.  Simple to use, just plug in your N# up top and within a few easy clicks each speed variation and height variation are measured.

I Def picked up about 4 knots after prop re-pitch.  

[Ed Cesnalis]

In 2007 my CT with a warp drive was faster than the others at the CT flyin.   That was all about prop pitch and being early to understand best speed is at 5,500 rpm and wot.

Today I have a faster CT and I attribute the 128kt TAS mostly to the Sensinitch prop,  I dont think more efficient props come into play much until you optimize the pitch first.

I don't think the Tundra gear cost much, my opinion there.

Now that I have a fuel flow meter I am much more prone to throttle back some.  The last 5 kts in speed seem to cost an additional 1 1/2 gph.

[johnnyjr]

26 minutes ago, Ed Cesnalis said:

In 2007 my CT with a warp drive was faster than the others at the CT flyin.   That was all about prop pitch and being early to understand best speed is at 5,500 rpm and wot.

Today I have a faster CT and I attribute the 128kt TAS mostly to the Sensinitch prop,  I dont think more efficient props come into play much until you optimize the pitch first.

I don't think the Tundra gear cost much, my opinion there.

Now that I have a fuel flow meter I am much more prone to throttle back some.  The last 5 kts in speed seem to cost an additional 1 1/2 gph.

Ed are you running the 2 blade Sensinitch prop?

[FlyingMonkey]

1 hour ago, Ed Cesnalis said:

Now that I have a fuel flow meter I am much more prone to throttle back some.  The last 5 kts in speed seem to cost an additional 1 1/2 gph.

Definitely true.  I don't have a fuel flow meter, it's the one instrument I want but don't have (yet).  I used to do long cross country trips at 5400rpm, and sometimes I still do if I'm in a hurry, but 5300rpm seems to be the sweet spot for me.  Above that I will get more speed, but the noise, heat, and fuel burn go up a lot faster than the TAS.

[sandpiper]

6 hours ago, GrassStripFlyBoy said:

I wonder how much a well waxed airplane contributes to airspeed in CT, other general aviation birds have "a couple knots" as common thought, but in CT what might this mean.  My SW runs in the mid teens and I'm never pushing it to 5500, generally 5350 to perhaps 5400.  I do keep it slick, wipe down post every flight, with a hit of wax at least on the leading edges.

Last Saturday with the 45-50 temps, at 2k MSL, I was indicating 120N and even seeing 121-122 on occasion, around 5450 RPM.

Non tundra gear, as I believe Andy is as well?  That could be a factor as well.

I had a C-206 for about 20 years. Living in Alaska very few were fortunate enough to have a hangar. The majority of planes reside outside and could get pretty dirty. Especially in Anchorage with all that was almost constantly in the air.

Every 3-4 years years I would not only wash the plane and scrub the belly but also polish it with a power buffer. A lot of work but it seemed to pick up 2 - 3 knots. Maybe that was all in my head after all that work?

[FlyingMonkey]

There is a guy locally that will do a ceramic paint coating on airplanes, like you see people put on their nice cars.  I have considered it (if only to make cleaning bugs off easier!), but it's a hard $1000 to swallow.

[Ed Cesnalis]

6 hours ago, johnnyjr said:

Ed are you running the 2 blade Sensinitch prop?

3 blade

[gogogo888]

I went flying today, used wash wax all to "wash" the leading edge of the wings, windshield, cowling and props before going up.

It was around 34 degree at 3,800 ft MSL, it was a bit gusty and bumpy, here are the airspeed:

5080 rpm shows 111 kt burns 4.9 gph

5310 rpm shows 117 kt burn 5.6 gph

5520 rpm shows 124 kt burn 6.2 gph

I only have the fuel burn for the following 2 rpms, forgot to toggle the D120 back to show airspeed.

4,750 rpm burn 4.4 gph

4,340rpm burn 3.4 gph

--Edit--

All the above are Indicated airspeed.

[okent]

True airspeed?

[sandpiper]

On 10/27/2020 at 12:51 PM, FlyingMonkey said:

There is a guy locally that will do a ceramic paint coating on airplanes, like you see people put on their nice cars.  I have considered it (if only to make cleaning bugs off easier!), but it's a hard $1000 to swallow.

Why not do it yourself?

[FlyingMonkey]

25 minutes ago, sandpiper said:

Why not do it yourself?

I know it's a possibility, but haven't researched it.  Time is an issue as well.

[AGLyme]

17 hours ago, gogogo888 said:

5520 rpm shows 124 kt burn 6.2 gph

I'd like to see a panel photo... I did that speed yesterda (TAS), but with an (effective) 6 knots tailwind... 

[gogogo888]

55 minutes ago, AGLyme said:

I'd like to see a panel photo... I did that speed yesterda (TAS), but with an (effective) 6 knots tailwind... 

I’m using e-props, the 5500 rpm is my WOT. I was flying on a bumpy day with a cross wind of about 20kt.
 

[AGLyme]

Good stuff.

[Madhatter]

My e-prop does about the same. Are you ELSA? Flight Design USA called me a few months ago and asked me for my documented analysis I did a while ago on the E-prop. They were trying to get blanket approval fro Germany.  Someone requested an approval.

[gogogo888]

1 hour ago, Madhatter said:

My e-prop does about the same. Are you ELSA? Flight Design USA called me a few months ago and asked me for my documented analysis I did a while ago on the E-prop. They were trying to get blanket approval fro Germany.  Someone requested an approval.

I'm SLSA, I was the one asked for approval few months ago. They granted it and I'm very happy with the e-prop.

[Madhatter]

It's great it worked out for you. A lot of people questioned my data but you confirmed it.

[gogogo888]

12 minutes ago, Madhatter said:

It's great it worked out for you. A lot of people questioned my data but you confirmed it.

It wasnt easy to get all the blades to pitch 5,500 rpm. It took me 3-4 adjustment to get there. But once it gets there, the plane performs extremely well comparing to the factory props.