Jump to content

Recommended Posts

2 hours ago, jetdriven said:

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.

 

IMG_2263.jpg

IMG_9786.JPG.1a78227809c112c9cff949e259a48e37.JPG

Thanks for posting your side by side experience. I too have great admiration for Beech products. I think the V35B is one of the finest singles ever produced.  Across all models the basic design does so many things well that there’s little reason to pad its attributes. They are reasonably efficient, but Walter still had to contend with the laws of physics. The Bo has a slightly higher Cd than the 201, but what’s more is that it has 23% greater flat plate area. As you said it’s not physically possible for the one airframe to be as efficient as the other, yet people that are smart enough to know better often ignore this reality.  Ken should get a pass during honeymoon, it’s easy to become a little gaga in a new relationship.:wub:

Link to comment
Share on other sites

8 hours ago, Shadrach said:

As you said it’s not physically possible for the one airframe to be as efficient as the other, yet people that are smart enough to know better often ignore this reality.  Ken should get a pass during honeymoon, it’s easy to become a little gaga in a new relationship.:wub:

I never claimed a Bonanza is as efficient as a Mooney. I've owned four Mooneys and have taught in almost all Mooney models; I know them well. I planned to get back into a Mooney when I went back to a single but a great opportunity arose on a Bonanza so I went with it. I am surprised as to how efficient the Bonanza really is though, not what I expected and not what most believe, I think.

  • Like 1
Link to comment
Share on other sites

24 minutes ago, KLRDMD said:

I never claimed a Bonanza is as efficient as a Mooney. I've owned four Mooneys and have taught in almost all Mooney models; I know them well. I planned to get back into a Mooney when I went back to a single but a great opportunity arose on a Bonanza so I went with it. I am surprised as to how efficient the Bonanza really is though, not what I expected and not what most believe, I think.

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

17-20 NMPG is significantly more efficient than 11-13 NMPG.   It may not be the way some wish it were, but that math doesnt care.

here is the log sheet from the KISM-KAXH trip. It was 43.8 gallons and 6.4 hobbs hours Flying time was around 6.1.  Again, this was done at 2700' into an average headwind with the throttle pulled back. Not the most efficient way to fly but stronger headwinds aloft forced it.

 

 

IMG_2835.jpg

Edited by jetdriven
  • Like 2
Link to comment
Share on other sites

On 1/17/2019 at 9:39 AM, smccray said:

Looks like an 830.  You can make those adjustments yourself if you choose as it's not primary.

It is an 830 and I went into it yesterday to change the redline in the MP and change OAT to ºC. Half of the values entered were wrong. They're all correct now. There is a choice to set %HP by default (can be changed during flight) to ROP or LOP. It was sent to ROP, now set to LOP. It also had the wrong factor for LOP (13.7 versus 14.9) so that's fixed. Apparently the 830 was set up for a turbocharged engine. I reset a bunch other settings, the alarm limit was set to 450º for CHTs, I reset it to 400º, the oil temp low value was set to 90º, the POH calls for 100º so that's now correct, I entered the TTAF and TACH time (I set TACH to SMOH) to actual versus since the JPI was installed. The 830 is properly set up now :D

  • Like 2
Link to comment
Share on other sites

Reading this thread made me get out my notebook.  I’ve had my Debonair for 7 years now and have many notes on airspeed and fuel flow.  I also have done a 3 way gps true airspeed calc and compared it to my airspeed indicator.  The gps calculated out to 156knts true, the airspeed came out at 154 knots true.  I’d call that a wash as I was flying, and writing at the same time.

I have the lower compression 225hp engine that is not as efficient as the higher hp v tails.

i generally cruise at 150 knots at slightly under 12gph.  That’s just slightly lop.  I can do 160, but that’s pretty much down low and very rich.  

But I can burn Mogas.  Currently 90 octain cost $2.66 vs $3.69 for 100ll.  

So to cruise at 150 Knt.

12 gph 100ll cost $44.28 per hour.  Mogas cost $31.92 per hour.

8.7 gal of 100ll cost $32.  

So my Debonair using Mogas is also pretty efficient cost wise.  Granted on longer trips it’s not available.  And come overhaul time it will be hard not to opt for a 260hp plus engine for the extra speed.   

 

  • Like 4
Link to comment
Share on other sites

3 hours ago, bradp said:

I want to know where to get LL for 3.69 :-) first 

I filled up on $3.59 about 2 weeks ago in a "free trip" to KRME just south of us here in KPTD.  By taking on about 75gal it was cheaper to fly there and get the cheap fuel than to fill up at the pump on the field.  ...except note - its -18F right now outside as I sip my coffee by the fire.

Link to comment
Share on other sites

Just now, Marauder said:

Can you repeat that latter value from July 23rd 2018? emoji1787.png

 

Exactly!! I couldn't agree more. And the primary reason we bought a house in Denver on Saturday. 

We haven't spent July in Texas in about four years and every August I send the Mooney in for annual. It's just too miserable to fly.

  • Like 1
Link to comment
Share on other sites

On 1/18/2019 at 12:26 PM, KLRDMD said:

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.

 

On 1/18/2019 at 12:36 PM, 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.

I had the airplane weighed today. The true empty weight is 2186 lb which gives 1114 lb useful load and the true empty CG is 77.8. So I gained about 30 lb of useful load and the empty CG is just over 1" further aft which makes it absolutely perfect !

  • Like 2
Link to comment
Share on other sites

2 hours ago, bradp said:

Ken how does the CG change on a long flight - say burning full to 20 gal reserve? 

Attached is a W&B for a flight I'll do next week. Taking off with full fuel and 40 lb under gross with four people and weekend baggage, burning 50 gallons of fuel for the trip. All weights at all times are safely within the W&B envelope.

W&B.pdf

Edited by KLRDMD
Link to comment
Share on other sites

2 hours ago, bradp said:

Ken how does the CG change on a long flight - say burning full to 20 gal reserve? 

Here's another W&B for the same flight but if I added 40 more pounds to the baggage area (worst case scenario) to put me right at gross weight and full fuel for takeoff and landing with 20 gallons remaining. It is still within the W&B envelope and all 1,114 lb of useful load on this airplane is actually usable.

W&B.pdf

Edited by KLRDMD
Link to comment
Share on other sites

I probably should have mine weighed.  No idea if it’s ever actually been on a scale.  My CG is 78.8 and useful load is 1086.  And I’ve flown it at gross many times with no problems.  I do have to watch the weight in the baggage area.  

of coarse I live at sea level.  I could gain 300# of usful by adding tip tanks, but it’s not worth the expense for me.  I believe they just Change the category , utility to normal.

 

Link to comment
Share on other sites

9 minutes ago, dmc said:

I probably should have mine weighed.  No idea if it’s ever actually been on a scale.  My CG is 78.8 and useful load is 1086.  And I’ve flown it at gross many times with no problems.  I do have to watch the weight in the baggage area.  of coarse I live at sea level.  I could gain 300# of usful by adding tip tanks, but it’s not worth the expense for me.  I believe they just Change the category , utility to normal.

My mechanic told me before we started yesterday that he had never weighed an airplane that gained useful load. There's a first for everything :D

Link to comment
Share on other sites

What's interesting to me is the rough performance numbers are somewhat similar to my F model in ROP cruise. My full fuel payload is 675lbs with a range of 820nm with 1 hr of reserve at 150kts. I didn't bother to account for fuel burn in the climb which might dscrease the delta. Nevertheless, not a huge price to be paid for the additional fuel burn. What genuinely surprises me is that you're getting 8% more speed and only paying a 15% penalty to do it in an aircraft with roughly 23% more flat plate area.

Link to comment
Share on other sites

4 minutes ago, Shadrach said:

What's interesting to me is the rough performance numbers are somewhat similar to my F model in ROP cruise. My full fuel payload is 675lbs with a range of 820nm with 1 hr of reserve at 150kts. I didn't bother to account for fuel burn in the climb which might dscrease the delta. Nevertheless, not a huge price to be paid for the additional fuel burn. What genuinely surprises me is that you're getting 8% more speed and only paying a 15% penalty to do it in an aircraft with roughly 23% more flat plate area.

I'm sure if I pulled the power back to 150 KTAS the fuel flow would be much less but are you getting 170 KTAS in your F model at 12.5 GPH ?

1:2 seems fairly consistent. Every 1% increase in speed takes a 2% increase in fuel. In my 231 every 3% increase in speed cost 6% more fuel.

That extra useful load of 75 lb that the Bonanza has over an F or 225 lb increase I had over my 231 really makes a difference for some people, me included.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.