Reduced Power to Increase Range in Vintage Mooney?

[Seanhoya]

Ladies and Gents,

 

Has anyone ever tried to follow the endurance tables in the back of the POH with a normally aspirated Mooney?

 

I am just wondering if the aircraft really can remain aloft for eight hours on reduced power.  I am interested in flying from Miami to Port-au-Prince nonstop, but would have to follow the endurance charts to do so (about 680 nm).  I normally fly at 22" MP and 2400 RPM, but I thought there might be some people out there who have stretched their range by using the tables and flying at 18" MP and 2400 RPM, or some other economy setting.  I have only 52 gallons of gas and fly with a normally aspirated O-360 in my 1968 Mooney M20G.

 

Any advice is greatly appreciated.

 

Sean

[mike_elliott]

While he had extended tanks, Jonathan Paul flew his E model non stop from San Diego to Savannah a couple of years ago. 1900 RPM, 13K, WOT. LOP at 6 GPH

[N201MKTurbo]

Just blow a couple hundred bucks in gas and do a test flight some Saturday and see how your plane does. Over dry land of course.

[Seanhoya]

Sorry, WOT? Does that have to do with power setting?

And yes - I plan to do some tests (over land in a known area!)

[N201MKTurbo]

WOT = Wide Open Throttle

[Oscar Avalle]

Ladies and Gents, Has anyone ever tried to follow the endurance tables in the back of the POH with a normally aspirated Mooney? I am just wondering if the aircraft really can remain aloft for eight hours on reduced power. I am interested in flying from Miami to Port-au-Prince nonstop, but would have to follow the endurance charts to do so (about 680 nm). I normally fly at 22" MP and 2400 RPM, but I thought there might be some people out there who have stretched their range by using the tables and flying at 18" MP and 2400 RPM, or some other economy setting. I have only 52 gallons of gas and fly with a normally aspirated O-360 in my 1968 Mooney M20G. Any advice is greatly appreciated. Sean

I flew my M20c from key west to Guatemala City. Could I have done it using the long range endurance power settings? May be, but I preferred to have gas in the tanks just in case of bad weather or any other contingency. So I decided to get a 23 gallons ferry tank. This buys you a lot of sanity and if needed you can always revert to the technic.

[Seth]

It can be done as long as the math works out.  Figure out your range.  I personally would want some extra gas and for that distance over weather, however, again, it can probably be done.  Just make sure to bring some portable bathroom device.

 

-Seth

[ahe]

I have flown my M20A (49 gal. tank) 700NM with reduced power - 18 mp/2200 rpm. I had approximately an hour left in tank when i landed. 
 

But if there is headwind it would likely be more economical to fly with higher power settings.

 

Best regards

[jetdriven]

Conventional wisdom was to fly at max range speed and add 1/2 the headwind component to that. However, I am hearing rumors that is still a bit fast for max range. Fwiw we did 800 miles on 39.4 gallons at 128-130 KTAS (120 indicated) in a M20J. It took 6:01 to fly it. I would bet a M20C would come real close to that at around 120 KTAS.

[DrBill]

I find that over 8000 ft I'm at WOT (wide open throttle) trying to get to 24in at 2400 rpm.  I think around 11K, i'm down to around 20 inches (maybe less).  Fuel flow is 8gph.  TAS about 140kts.

with 54 gal tanks, 10 gal reserve, that's 44 gal  would give you 5 hrs cruise (4 gal for the climb).

5 hr at 130 (conservative) is 650nm range. 

 

How much range do you need ?

BILL

[carusoam]

A fuel totalizer and FF indicator are modern tools of the trade... Like having a GPS...

Best regards,

-a-

[Mooneyjet]

Get your self a monroy long range tank, it's got to be the biggests speed mod for a vintage mooney that will have an advantage of passing lots of high performance singles and twins..

[N201MKTurbo]

About a month ago I flew from KRDM to KCHD non stop. I planned on a fuel stop, but when I got there it looked like I could get home with 45 minuets of fuel left. When I got home I topped it off and actually had 54 minuets of fuel left. That was an 849 Kmile leg.

That was flown at 15500 28.5 in 2400 RPM 9.3 GPH LOP 175 TAS 190 GS.

I love my Mooney....

[Seanhoya]

Bill - the problem is that the distance is about 680 NM - which is right outside of my comfort level.  I cruise at around 134 kts at 22" and 2400 RPM.  500-550 NM is fine (Which would take about 3.5-4 hours), but 680 NM is a bit out of my comfort zone over water with few diverts.

 

-a- - I have thought about a fuel flow indicator - any recommendations?

 

Mooneyjet Dude -  How would the Monroy extended range tanks improve my performance?  The reason that I haven't gotten extended range tanks is that I still have wet wings that are sealed well.  I attribute my success to the fact that I always shut down with full fuel.  But taking off with full fuel reduces my already low climb rate with a normally aspirated O-360 - this is why the G model wasn't so popular.  So if I get extended range tanks, I am going to have to keep them full, which is more weight that I really don't need on a regular basis.

 

N201MKTurbo Guy - You the man.  But I don't have fuel injection or a turbo...  If I fly at altitude with WOT, I can lean until engine roughness - this probably will be at peak EGT, but at low power levels, it won't matter (If I am at 8000', I probably am only producing about 21" MP).  But a carburetor is just not as precise as fuel injection, and especially not as good as Gami injectors.

 

It is my sense that most people don't stretch fuel by flying at reduced power - but this was the norm when the airplane was originally produced - wasn't it?  We now have the luxury of fuel flow indicators and engine monitors to ensure peak performance.  But then again, I think that we are losing far fewer aircraft....

 

Thanks for your input.

 

Sean

[Z W]

You can reduce power to extend range.  In my C model I could reduce power to about 6 GPH and still cruise about 110-120 kts.  I used that setting for cross-country flights building foggle time for my IFR rating.  Endurance at that setting, with 52 gallon tanks, was about 8.6 hours, with a theoretical range of 946 miles, no reserve, no wind.  Your heavier G, with the same engine, will probably do just a little worse than that, on either speed or fuel burn (but with more legroom in the back).

 

I would not even think about trying a trip like you are describing without a fuel flow gauge I trust, some very large margins for unexpected headwinds, a life raft, and a personal locator beacon.  Even then, I think I would buy a removable ferry tank like Oscar did.  Flying is no fun when you aren't 100% sure the flight will have a positive outcome.

 

Most endurance fliers also wait for the right weather pattern, e.g. a nice tailwind, that may make it a non-event.  But if you are going to do this flight more than once, you won't want to wait two weeks for weather, and you're going to want some more gas on board.

 

The Monroy tanks are a nice feature, but for their cost, you could probably sell your G and buy a J or K that can easily do 1000 NM and would fit this mission better.

[AmigOne]

I have made the trip to the Dominican Republic and beyond several times in a variety of airplanes but never in a Mooney. If I'm going to Punta Cana from SE Florida, maybe about the same distance than PoP I will stop in Exuma,cheap fuel, quick turnaround and no landing fees. You still need the general dec and customs forms but if you have them ready it takes no time. This fuel stop will allow me to arrive at the DR with plenty of fuel. If one does not want to stop at Exuma I believe that in most single engine airplanes with regular tanks then one should make a fuel stop at Puerto Plata for peace of mind. And this stop takes a long time. From Providenciales to Puerto Plata is about 100 miles over water and after that you'll be crossing many mountains before you get to PoP. And also weather, in a Cessna 206 had to shoot an approach in low IFR at Punta Cana, good thing that I didn't want to stretch my fuel (I had departed from Stewart, Fl). The last thing I would want to do is to arrive at PoP with minimum fuel.

[Hector]

If you don't have a fuel totalizer like a simple JPI 450, I would consider that a MUST if you are going to attempt this. At least with one you will know exactly how much fuel remaining you have at all times (mine is accurate to within a gallon). I have stretched my legs on several occasions but only because I felt very comfortable knowing exactly how much fuel I had. The JPI will couple with a GPS (even a Garmin portable) and it will constantly let you know how much fuel you need to get to your destination and how much fuel reserve you will have when you get there based on current fuel flow and ground speed. Even with a fuel totalizer, that is still a long flight over water and I would want to make sure call the conditions are just right before I tried it. I would sure look into a ferry tank just for piece of mind.

[Hector]

I flew my M20c from key west to Guatemala City. Could I have done it using the long range endurance power settings? May be, but I preferred to have gas in the tanks just in case of bad weather or any other contingency. So I decided to get a 23 gallons ferry tank. This buys you a lot of sanity and if needed you can always revert to the technic.

Oscar, can you provide some details on you ferry tank. Where did you purchased it, how is it installed, and approx cost if possible. I might be interested in that option. Thanks.

[Oscar Avalle]

Oscar, can you provide some details on you ferry tank. Where did you purchased it, how is it installed, and approx cost if possible. I might be interested in that option. Thanks.

 

Hector,

I bought the 23 gallon ferry tank at Turtle pac (http://www.turtlepac.com/en/photo-gallery/aircraft-ferry-tanks.html). Not cheap (about 2K) but extremely well build and reliable. It comes with a small electric pump to transfer fuel from the ferry to the mains. This gave me about 2 hrs in addition to what i already had, in total about 72 gallons. I flew Key west to Guatemala (MGGT) in about 6 hours and arrived with a decent reserve.

[schule]

Might try to message TestWest from this forum about techniques revolving around Carson's Speed.  Then go flying to find the speed and power settings required to cruise there.  Remember to add extra fuel for reserves.  620NM straight from Miami Executive to MTPP.  Considering the best route is not a straight shot over open water and Cuba, you might be better off routing over the Bahamas.

 

-Mark

[mike_elliott]

Bill - the problem is that the distance is about 680 NM - which is right outside of my comfort level.  I cruise at around 134 kts at 22" and 2400 RPM.  500-550 NM is fine (Which would take about 3.5-4 hours), but 680 NM is a bit out of my comfort zone over water with few diverts.

 

-a- - I have thought about a fuel flow indicator - any recommendations?

 

Mooneyjet Dude -  How would the Monroy extended range tanks improve my performance?  The reason that I haven't gotten extended range tanks is that I still have wet wings that are sealed well.  I attribute my success to the fact that I always shut down with full fuel.  But taking off with full fuel reduces my already low climb rate with a normally aspirated O-360 - this is why the G model wasn't so popular.  So if I get extended range tanks, I am going to have to keep them full, which is more weight that I really don't need on a regular basis.

 

N201MKTurbo Guy - You the man.  But I don't have fuel injection or a turbo...  If I fly at altitude with WOT, I can lean until engine roughness - this probably will be at peak EGT, but at low power levels, it won't matter (If I am at 8000', I probably am only producing about 21" MP).  But a carburetor is just not as precise as fuel injection, and especially not as good as Gami injectors.

 

It is my sense that most people don't stretch fuel by flying at reduced power - but this was the norm when the airplane was originally produced - wasn't it?  We now have the luxury of fuel flow indicators and engine monitors to ensure peak performance.  But then again, I think that we are losing far fewer aircraft....

 

Thanks for your input.

 

Sean

Sean,

In 2000, Yury Avrutin flew his stock C mooney to Berlin from Caldwell, NJ. and back for the Berlin air show.I asked him at Oshkosh what he did to prepare his plane for the trip besides change the oil, his response was "I didn't even do that" I bought a GPS with a European database that I could return within 30 days"

Anyway, Yury is no longer with us, but my real point is that by reducing RPM, flying high at low power settings, you can get quite a bit of range out of your 52 gal. G model.

 

Sometime, Google "the Viking route" by Yury, very interesting read, albeit his risk tolerance is far more than what I would consider sane.

[Hector]

Oscar, can you provide some details on you ferry tank. Where did you purchased it, how is it installed, and approx cost if possible. I might be interested in that option. Thanks. Hector, I bought the 23 gallon ferry tank at Turtle pac (http://www.turtlepac.com/en/photo-gallery/aircraft-ferry-tanks.html). Not cheap (about 2K) but extremely well build and reliable. It comes with a small electric pump to transfer fuel from the ferry to the mains. This gave me about 2 hrs in addition to what i already had, in total about 72 gallons. I flew Key west to Guatemala (MGGT) in about 6 hours and arrived with a decent reserve.

Thanks Oscar. That is actually not a bad price and the extra fuel buys a lot more piece of mind. Just curious, where is the fuel in the ferry tank pumped into the mains?

[pinerunner]

Check out this web site.

 

 

http://jonathanpaul.org/pdf/LongRangeFlight.pdf

 

He does it in an E model using 18 in 1700 RPM 5.7 GPH 122 KT. He stayed up for longer than you'd need. This article really aroused my curiosity though I haven't seriously tried it yet. Learning to take care of lavatory needs gives me pause but maybe I should hurry up and get that over with BEFORE upgrading my interior.

 

While nice modern gadgets would make it easier you could figure out your fuel flow by filling both tanks, climbing and setting up cruise conditions on one tank, switching to the other, full, tank, running it, noting time carefully,  then going to the first tank to finish the flight and getting the gallons off the pump when you fill back up. The author recommends you actually run one tank dry to be sure all is going as planned. Doing that over the ocean should supply your adrenaline needs very nicely. No need to take up skydiving! I imagine you've got GPS so you'll be right on top of exactly where you are. You've also, got some alternates in the Bahama's and Bimini along the way.

 

Has anyone done this sort of thing? There must be some stories out there.

 

[Seanhoya]

Pinerunner - thanks for the article - that is really interesting, and thanks to everyone for the valuable information.  

 

In regards to the ferry tank, I am not familiar with the process - don't I need a 337 and/or field approval every time I install it and/or remove it?

 

The big issue for me is that I should be able to save 2-3 hours by flying non-stop, but I intend to take a route over the Bahamas - not a straight-line flight.  

[mike_elliott]

Sean,

I also believe Wayne Smith flew his G model to Port-au-Prince a few years ago when he went there to help for the earthquake disaster. If you would like, PM me and I will put you in touch with him. What I don't know is whether he flew non stop or not.