S35

[KLRDMD]

The S35 Bonanza seems to have decent efficiency.

8,500 ft cruise, 48ºF OAT, full MP (21.8" Hg), 2400 RPM and 11.5 GPH. All CHTs under 300ºF. According to my calculations that provided a TAS of 162+ knots and 13.4 NMPG.

I'm not sure any Mooney model would do much better. Have I mentioned that I'm really liking this airplane ??

[Niko182]

31 minutes ago, KLRDMD said:

LOP, percent power is determined exclusively by fuel flow. MP and RPM are totally irrelevant.

Nvm. Ignore what I said then. I always thought the JPI calculated power by MP and RPM

[KLRDMD]

6 minutes ago, Niko182 said:

Nvm. Ignore what I said then. I always thought the JPI calculated power by MP and RPM

I'm sure it does, but that's ROP, not LOP. Except for climb, I never fly ROP.

[jetdriven]

7 hours ago, KLRDMD said:

The S35 Bonanza seems to have decent efficiency.

8,500 ft cruise, 48ºF OAT, full MP (21.8" Hg), 2400 RPM and 11.5 GPH. All CHTs under 300ºF. According to my calculations that provided a TAS of 162+ knots and 13.4 NMPG.

I'm not sure any Mooney model would do much better. Have I mentioned that I'm really liking this airplane ??

Nah. My J will only get around 17 NMPG at that altitude and speed (30%) or 21 NMPG low and slower (60%).  Beech airplanes have a lot of things but comparable efficiency is not one of those. 

Edited January 18, 2019 by jetdriven

[0TreeLemur]

On 1/15/2019 at 4:39 PM, Hank said:

I've figured it out--Ken's purpose is to upgrade as many GA planes as possible, and release them back to the market! Thanks for what you do for the rest of us, Ken.  

As an owner of one of @KLRDMD's former aircraft, I agree.  He knows how to pick them.

[KLRDMD]

1 hour ago, Fred_2O said:

As an owner of one of @KLRDMD's former aircraft, I agree.  He knows how to pick them.

You sir, have the distinct honor and privilege of owning my very first Mooney.

[KLRDMD]

8 hours ago, jetdriven said:

15 hours ago, KLRDMD said:

The S35 Bonanza seems to have decent efficiency. 8,500 ft cruise, 48ºF OAT, full MP (21.8" Hg), 2400 RPM and 11.5 GPH. All CHTs under 300ºF. According to my calculations that provided a TAS of 162+ knots and 13.4 NMPG. I'm not sure any Mooney model would do much better. Have I mentioned that I'm really liking this airplane ??

 

8 hours ago, jetdriven said:

Nah. My J will only get around 17 NMPG at that altitude and speed (30%) or 21 NMPG low and slower (60%).  Beech airplanes have a lot of things but comparable efficiency is not one of those. 

Either it is time for education or you're just seeing if you can get away with this statement. The only reason I mentioned 13.4 NMPG is since it was displayed on the JPI when I took the photo. Surely you know that NMPG is based exclusively on fuel flow and ground speed for the one flight in question and for the instant the time is recorded. Note on the MX20 my ground speed was 153 knots. I had a 9 knot headwind component based on my calculated 162 KTAS. With a fuel flow of 11.5 GPH, that provides my NMPG. Your contention of 17 NMPG assumes that, in level flight at 8,500 ft you're getting 170 knots on 10 GPH. With a tailwind maybe but I haven't seen a J model Mooney that gets 170 KTAS on 10 GPH at 8,500 ft. Likewise your 21 NMPG says you are getting 210 knots on 10 GPH. I call bullshit on that unless you're in a significant descent or have a monster tailwind. There wasn't a J model made that would do 210 KTAS on 10 GPH.

The 162 KTAS on 11.5 GPH (14 NMPG) isn't that far off of a typical "real world" J model Mooney that does 155 KTAS on 10.5 GPH (14.7).

 

[smccray]

I don't have any independent information but I've always taken the drag coefficients from this site: http://www.mooneyland.com/why-mooney/

Parasite Drag Coefficients & Flat Plat Area

Aircraft CDP Flat Plate
Area (sq. ft.)
Mooney 201 0.017 2.81
Beech Bonanza 0.019 3.47
Piper Arrow 0.027 4.64
Cessna 182 0.031 5.27
Beech Sierra 0.034 5.02
Piper Warrior 0.034 5.83
Cessna 172 0.036 6.25
Cessna 152 0.038 6.14
Beech Skipper 0.049 6.36
Piper Tomahawk 0.054 6.64

The article references a V35, the S is the same body but a little older and lighter.  Nevertheless, the drag coefficients of the two planes are very close.  I suspect the Mooney is a little more efficient, but in real world flying with antennas, dirt, etc. on the airframes I have always said that they're pretty close in the real world.  It's certainly possible that there are planes that different from the numbers here, but they're both incredible airplanes.

It's also notable that the 201 is using a 4 cylinder lycoming vs. the 6 cylinder continental.  I believe that contributes to the lower overall cost per mile traveled for the 201.  The 201 is also cheaper to buy, and likely cheaper to maintain over the ownership term.

[KLRDMD]

On 1/15/2019 at 9:37 AM, KLRDMD said:

It will not surprise anyone on this site that knows me that I have a different airplane. This is #16. I change airplanes as my needs change.

This prompted me to go back and review what I've owned, in order.

1967 Piper Cherokee 140 (with 180 HP upgrade, C/S prop and S-Tec 50 A/P). That was a nice first airplane and it is still in Tucson owned by the same person I sold it to

1967 "C" Mooney now owned by someone on MS

1978 Cessna 152 (bought ¼ share to allow my CFI to have his own airplane to instruct in, sold my share to him after a couple of years when he could afford it)

2001 Cirrus SR-22

1991 "M" Mooney Bravo (known ice)

1981 Seneca III

1967 "F" Mooney (Ray-Jay turbo)

1969 Beechcraft B55 Baron (Colemill President)

1959 Cessna 182

1966 Twin Comanche

1992 Lancair 235 (EXP 320 engine at 200 HP)

1974 Cessna P337

1974 Cessna 182

1985 "K" Mooney 231

1964 Beechcraft B55

1965 Beechcraft S35

 

[KLRDMD]

5 minutes ago, bluehighwayflyer said:

Those of us who have been here since the beginning of MooneySpace remember Ken buying his Ray-Jay'd  F from another member here.  It has been interesting watching him buy and sell airplanes over the years since.  His experience totally undermines the notion that it is hard to find good airplanes.

There's a good chance we're seeing the end of an era for a couple of reasons:

1) While not imminent, I am looking toward retirement. An airplane is a business asset for me. The Bonanza is an airplane I can afford to keep in retirement if I choose, the Baron would have been difficult to justify. Retirement may be a year or two away or it may be a decade yet. I've always said I'll quit when it is no longer fun. Parts of what I do have become no longer fun and since I've been able to reduce those parts significantly I continue to work. But someday . . .

2) Tax law changed. From my accountant: "Beginning Jan 1, 2018, due to the new tax law, like-kind exchanges are limited only to Real Estate. So, exchanges of airplanes will no longer qualify for tax deferral under IRC Sec 1031. In some cases, the loss of like-kind treatment will be offset by the ability to claim 100 percent bonus depreciation with respect to the replacement aircraft. The bonus depreciation is available only if the new airplane is used predominantly for qualified business use."

My airplane is almost exclusively for business use but I see the writing on the wall.

[KSMooniac]

A good J model will do 150 KTAS all day long on 8.5 GPH...yielding 17.6 NMPG. A very reasonable combo of useful speed and fuel economy.

Sent from my LG-US996 using Tapatalk

[KLRDMD]

Just now, KSMooniac said:

A good J model will do 150 KTAS all day long on 8.5 GPH...yielding 17.6 NMPG. A very reasonable combo of useful speed and fuel economy.

Good to know. I'll have to slow the Bonanza down to 150 KTAS once and see how close I can get to that fuel flow.

Efficiency drops significantly at higher airspeeds and even though I'm generally not in a great hurry, I'm also generally not willing to fly as slowly as 150 KTAS. 160 KTAS is pretty much my lower threshold for speed that I can live with.

[gsxrpilot]

My Mooney will do 195 TAS on 9.5 gph for a NMPG over 20!

But I gotta be way up in the flight levels to do that  So not practical for flights under about 3 hours.

[KSMooniac]

Good to know. I'll have to slow the Bonanza down to 150 KTAS once and see how close I can get to that fuel flow.
Efficiency drops significantly at higher airspeeds and even though I'm generally not in a great hurry, I'm also generally not willing to fly as slowly as 150 KTAS. 160 KTAS is pretty much my lower threshold for speed that I can live with.

Agree with you 100%. There are a few exceptional J models with some careful rigging and drag reduction that will exceed 160 KTAS on 10 GPH (LOP), but they're rare. I'd love to know what a V-Tail fuel flow is for 150-155 KTAS, and how sensitive it is to CG location.

Sent from my LG-US996 using Tapatalk

[KLRDMD]

1 hour ago, gsxrpilot said:

My Mooney will do 195 TAS on 9.5 gph for a NMPG over 20! But I gotta be way up in the flight levels to do that  So not practical for flights under about 3 hours.

That's excellent !

[KLRDMD]

11 hours ago, jetdriven said:

My J will only get around 17 NMPG at that altitude and speed.

 

1 hour ago, KSMooniac said:

A good J model will do 150 KTAS all day long on 8.5 GPH...yielding 17.6 NMPG. A very reasonable combo of useful speed and fuel economy.

The original quote, as you see was that this J model would get 17 NMPG at the same altitude and speed. That is, 162 KTAS at 8,500 ft. That means 9.5 GPH. I doubt that claim. Bob Kromer in his MAPA article was able to get 162 KTAS but at 7,000 ft, not 8,500 ft and at 50º ROP.  While not explicitly stated 50º ROP at 7,000 ft in an IO-360 is much more than 9.5 GPH.

I'm not saying a Bonanza of any flavor is as efficient as a similar Mooney but it surprised me that the Bonanza is as efficient as it is.

[Niko182]

To be fair, no where did @jetdriven state tha the J would do 210 knots. They stated at slower speed the could get 21NMPG. 145 at 7 gallons an hour LOP, sounds very realistic for the faster J's out there.145/7 is 20.7.

 

5 minutes ago, KLRDMD said:

 

The original quote, as you see was that this J model would get 17 NMPG at the same altitude and speed. That is, 162 KTAS at 8,500 ft. That means 9.5 GPH. I doubt that claim. Bob Kromer in his MAPA article was able to get 162 KTAS but at 7,000 ft, not 8,500 ft and at 50º ROP.  While not explicitly stated 50º ROP at 7,000 ft in an IO-360 is much more than 9.5 GPH.

I'm not saying a Bonanza of any flavor is as efficient as a similar Mooney but it surprised me that the Bonanza is as efficient as it is.

No where in his original quote did he say at the same speed.

[KLRDMD]

1 minute ago, Niko182 said:

No where in his original quote did he say at the same speed.

"My J will only get around 17 NMPG at that altitude and speed. . ."

[Niko182]

1 minute ago, KLRDMD said:

"My J will only get around 17 NMPG at that altitude and speed. . ."

21 NMPG low and slower 

[KLRDMD]

2 hours ago, KSMooniac said:

I'd love to know what a V-Tail fuel flow is for 150-155 KTAS, and how sensitive it is to CG location.

Next week I'm flying to Vegas so will gather some data at 10,500 ft. V-Tails vary, of course but the empty CG of mine is 76.7 which is excellent so loading out the rear of the envelope isn't a real concern as it is with some. Personally, I wouldn't buy a V-Tail with a CG greater than about 78.5.

[smccray]

4 minutes ago, KLRDMD said:

V-Tails vary, of course but the empty CG of mine is 76.7

If I were in your shoes I would weigh that airplane.  A CG that far forward in a V Tail is a surprise unless there's something specific to that plane (e.g. TN system).  My new bird is being weighed right now.  I don't like the prospect of loosing useful load, but the useful load is already lost- it's the paperwork.  My useful load didn't make any sense, but we'll see what the scales say. 

Reports are that Beech aircraft are very sensitive to the rear CG limits.  I don't have any first hand knowledge, but it's cheap insurance.

[smccray]

lol- just received the new W&B via email.  Gained 20 lbs vs. 50 lbs calculated, and CG move back 2" vs 1" via calculation.  Useful load is 1,357 LBS, or 913 lbs with full main tanks (74 gallons of fuel).  

[kris_adams]

Nice looking S Ken.  I've always loved the Vtails too

[KLRDMD]

2 hours ago, smccray said:

If I were in your shoes I would weigh that airplane.  A CG that far forward in a V Tail is a surprise unless there's something specific to that plane (e.g. TN system).  My new bird is being weighed right now.  I don't like the prospect of loosing useful load, but the useful load is already lost- it's the paperwork.  My useful load didn't make any sense, but we'll see what the scales say.  Reports are that Beech aircraft are very sensitive to the rear CG limits.  I don't have any first hand knowledge, but it's cheap insurance.

Weighing is already planned and if the CG is accurate, remove some of the lead weight in the nose.

[jetdriven]

12 hours ago, KLRDMD said:

Either it is time for education or you're just seeing if you can get away with this statement. The only reason I mentioned 13.4 NMPG is since it was displayed on the JPI when I took the photo. Surely you know that NMPG is based exclusively on fuel flow and ground speed for the one flight in question and for the instant the time is recorded. Note on the MX20 my ground speed was 153 knots. I had a 9 knot headwind component based on my calculated 162 KTAS. With a fuel flow of 11.5 GPH, that provides my NMPG. Your contention of 17 NMPG assumes that, in level flight at 8,500 ft you're getting 170 knots on 10 GPH. With a tailwind maybe but I haven't seen a J model Mooney that gets 170 KTAS on 10 GPH at 8,500 ft. Likewise your 21 NMPG says you are getting 210 knots on 10 GPH. I call bullshit on that unless you're in a significant descent or have a monster tailwind. There wasn't a J model made that would do 210 KTAS on 10 GPH.

The 162 KTAS on 11.5 GPH (14 NMPG) isn't that far off of a typical "real world" J model Mooney that does 155 KTAS on 10.5 GPH (14.7).

Your first post shows 148 KIAS, 9000' IALT,  30.35" ALT setting, and 14.2 GPH. At the standard -3 temp, that's 168 KTAS and 11.8 NMPG. ( You do realize the Beech ASI reads 2 KT high, right?) FWIW my race setting is 172 KTAS and ~15 GPH. but this is 95% power ROP at 1000' DA.

I never said 170 KTAS at 10 GPH. But I can do 162 KTAS at 9.5-9.6 GPH.  Its a noisy 2600 RPM but its there.  At long range cruise it will touch 21 NMPG. Yes thats 120 KTAS 5.7 GPH. 

And here's some real world data for you. KISM to KAXH. Coastlined it.  6:03 flight time, 2300', about half was a few knots of headwind, and total burnoff was 39.8 Gallons. And i refilled it myself till fuel was spilling over the wing. Thats 780NM and 39.8 gallons. Average net headwind.  19.59 NMPG. 

Beech airplanes are known for stellar build quality, roominess, superior seating position, larger windows, outstanding control harmony, more useful load, and outrageous spare parts bills. However, fuel efficiency is one of the tradeoffs. I'd pay good money to see a S35 Bonanza fly KISM, KTLH, KAXH on a 39.8 Gallon burnoff.  It physically isnt possible.  Or lets put it this way, and I've done this before with my wife flying the S35 Bonanza, at every speed, the M20J has a lower FF rate. We were comparing real time info on the radio. Side by side in formation. Photo proof below.   At max S35 cruise of 172 KTAS, yes, we're both matched at 16 GPH. But at 160kt, 150kt, 140kt, 130kt, we were always significantly less. Especially at 90 KIAS. 4 GPH.   An IO520 just cant do it.

Enjoy your Bonzana. I love them. I like Beechtalk more than here. Its a great community. But again, don't tell Mooney pilots your plane offers all the things I mentioned above along with lower trip burn or higher NMPG.

 

Edited January 19, 2019 by jetdriven