Fuel additives

[aviatoreb]

Does anyone here use fuel additives to their tanks to prevent fuel line freezing?  How is that for a dog-days of August question?

If so, what do you use and when?  If not, then why not?

Just thinking forward to winter in my new to me turbo Mooney.  Here in the the far North of the USA, we sometimes get day time high temps in the minus teens, but often in the single digits - on the ground.  And of course colder at altitude.

[jetdriven]

the Mooney Service and Maintenance manual mentions anti-icing additives.  They are real strict as to what and how much. 

[aviatoreb]

Quote: jetdriven

the Mooney Service and Maintenance manual mentions anti-icing additives.  They are real strict as to what and how much. 

[carusoam]

EB,

 

Interesting question.  I do not use any fuel additives.  I mainly fly the NE region.  My tanks do not allow moisture in.  My M20C could not keep moisture out.  I have not had any moisture or ice issues with fuel.

 

On the other hand, I have cancelled two flights for having ice in the spinner.  Where was the prop pastie then???

 

-a-

 

[aviatoreb]

Quote: carusoam

 

EB,

 

Interesting question.  I do not use any fuel additives.  I mainly fly the NE region.  My tanks do not allow moisture in.  My M20C could not keep moisture out.  I have not had any moisture or ice issues with fuel.

 

On the other hand, I have cancelled two flights for having ice in the spinner.  Where was the prop pastie then???

 

-a-

 

 

[carusoam]

My M20C spent it's entire life out doors.  The fuel rings of older Mooney's were not made of stainless steel.  The fuel ring is what the cap mounts in.  What looked like constant light surface rust turned out to be a rusty crack that was a through hole.  It rusted from the inside out.

 

There was always a few drops of water to be sumped out.  Then for a few weeks there was more.  A lot of sumping.  When it was below freezing I was falsely comfortable that free water would not enter the fuel system.  This is not good flight planning....

 

I read about changing the fuel rings to SS.  Getting ready,  I bought new fuel caps from Lasar.   By the time I went to get the fuel rings changed,  I sold the plane.  It was time to invest heavily in that one or put the money in the next one....

 

Best regards.

 

-a-

[aviatoreb]

Quote: carusoam

 

I read about changing the fuel rings to SS.  Getting ready,  I bought new fuel caps from Lasar.   By the time I went to get the fuel rings changed,  I sold the plane.  It was time to invest heavily in that one or put the money in the next one....

 

-a-

 

[David Mazer]

I believe there is a small amount of water suspended in the fuel.  I also believe you need to be very cold for it to be a problem.  I have flown in -40 at altitude and not had a problem.  So, by very cold, I mean substantially less than that.  It seems unlikely you will encounter those temperatures even in upstate NY.  Alaska might be another story.

[triple8s]

My old bird would let water in if it sat out in lots of rain, but after I bought new "O" rings that went away. That being said after the water showed up I became paranoid about it. Although my plane now lives indoors in a heated/airconditioned hangar and rarely sets outside, when it does I have a routine which maybe silly to some but here is what I do. I carry a roll of clear packing tape and tape over the fuel caps. I tape over the crack around the door and also over the vent window too. I cant stand the thought of water getting in the cabin and rusting my tubing. I also bought a small dehumidifier that I leave running in the back floor once I get home. I was amazed at how much moisture is in the air. I also built an engine de humidifier. These can be bought but I made my own. It uses dessicant that can be baked back out when they turn pink.

 

[aviatoreb]

Quote: Mazerbase

I believe there is a small amount of water suspended in the fuel.  I also believe you need to be very cold for it to be a problem.  I have flown in -40 at altitude and not had a problem.  So, by very cold, I mean substantially less than that.  It seems unlikely you will encounter those temperatures even in upstate NY.  Alaska might be another story.

[jlunseth]

Bruce Yaeger recommends isopropyl in the talk he gives at the ppp.  I think the POH says how much, don't remember the numbers.  I have used it because I often fly in the Flight Levels and it is cold, even in the summer.  But I have also not used it on some trips because I didn't have any, and have never experienced a problem.  I think the coldest I have seen on the OAT gauge is a little lower than 26C, which would be about 15 dF.  But we sometimes get colder than 15 dF on the ground here in Mpls during the winter.  I definitely use isopropyl in the winter, but don't fly much, not because of the cold but because of the constant threat of icing.

[aviatoreb]

Quote: jlunseth

Bruce Yaeger recommends isopropyl in the talk he gives at the ppp. 

[Awful_Charlie]

I picked up a 25 litre drum (6USG ;-) of IPA which cost about the same per unit as AvGas (2EUR/litre) and sploshed in a couple of litres during the cold snap last winter.  The POH recommends a maximum of 1% by volume, but I've not had a problem with high altitude flight at -45C, so will probably use the remainder for ground de-icing.

Main problem with the very cold in the Bravo is that the heater isn't really up to the job when it gets below -30C or so, and ice starts to form on the inside of the screens.  I do know of two Aztec operators who have had significant fuel flow problems with icing, even with temps in the mid minus teens (deg C), so there is something airframe specific about the issue.

Ben

[David Mazer]

I was surprised that my cockpit remained comfortably warm and I was in shirt sleeves at -40.  Ground operations were very cold and the FBO in OH pulled my plane out of the hangar hours earlier than I requested but it started and ran fine.  Ignorant or stupid.  Either way, I never thought about adding anything for the potential of fuel icing.

[aviatoreb]

Quote: Mazerbase

I was surprised that my cockpit remained comfortably warm and I was in shirt sleeves at -40.  Ground operations were very cold and the FBO in OH pulled my plane out of the hangar hours earlier than I requested but it started and ran fine.  Ignorant or stupid.  Either way, I never thought about adding anything for the potential of fuel i

cing.

[David Mazer]

The plane had been in a hangar overnight and was taken out of the hangar a couple hours before I got there in -5 degree temps.  Maybe I should have pre-heated it but I don't do frigid starts very often here in FL.  I hope the one time didn't hurt and the engine has been overhauled since then so whatever it did is done and gone.

[aviatoreb]

Quote: Mazerbase

The plane had been in a hangar overnight and was taken out of the hangar a couple hours before I got there in -5 degree temps.  Maybe I should have pre-heated it but I don't do frigid starts very often here in FL.  I hope the one time didn't hurt and the engine has been overhauled since then so whatever it did is done and gone.

[jlunseth]

Quote: aviatoreb

Do you mean he recommends that as the additive of choice if you want to use additives?  Or he recommends that one should use additives and that is the one?

Do you mean -15F?  That sounds right for Mnpls.

[GeorgePerry]

Does anyone else use Alcor TCP?  I've heard from serveral different sources that it does a wonderful job of cutting down on lead deposits and keeping internal parts clean and free of lead.  I've used it for several years, but it's hard to measure a non-event.  I can say I've never had to aggressively lean the engine on deck to clear a fouled plug....so maybe it does work.

http://www.aircraftspruce.com/catalog/appages/alcortcp.php

[kortopates]

Thought I add my two cents to this discussion and reading.

Although I live in the Banana Belt of Southern California, we fly all winter over and into the Sierra's Mammoth airport to ski. I have never yet drained a drop of water from my tanks nor after nearly 10 years operational experience flying high in the winter did I yet have a miss from a passing ice crystal. However every year, I am tempted to add a little IPA prophylactically - but I never do. I guess I am waiting for a first sign of need. Ben is right in that different airframes have different susceptibility and the K’s have not had issue. Yet there were a couple of fuel icing events reported in early model TLS, both crossing the Sierra’s.

Definitely, IPA or Isopropyl Alcohol is the only approved additive for our Mooney per both your POH and Mooney SI M20-64, which limits it to quantities not to exceed 3% for the Continental’s and 1% by volume for Lycoming powered models*. It must of course be anhydrous IPA, not your drug store variety blended with water. Avoid other additives like Priest (EGME). (*BTW, for sake of completeness SI M20-64 actually states 3% for 231’s and 1% for all other models. But it was written in ’83 when the only Continental powered model was the 231, and thus before 252’s, Ovations etc)

The primary reason keeping me from adding IPA is that it will trash the rubber o-ring in your fuel system components. I know of one K owner that added it regularly every winter and then found it trashed all soft rubber parts in his fuel system after 4 years. I won’t hesitate to use it if I see any evidence of water in my fuel system, either from sumping or signs of missing at altitude. But I plan to remain extremely sensitive of its use because of its damaging long term effects on o-rings; just using it conservatively when warranted. Frankly, I probably would have been using it by now if I was a Bravo operator just because of past reported incidents.

BTW, its Bruce Jaeger, not Yaeger and he’s certainly seen a lot of this in MN and an excellent person to discuss directly with. I’d bet he would recommend adding a conservative amount each winter to be safer than sorry as jlunseth advises; rather than worry about babying those expensive fuel system o-rings as I do. Probably best to be safer than sorry. You can contact him directly through his website at http://www.jaegeraviation.com/ - he’s a very helpful guy.

Kudos though, for raising questions about this as a new turbo owner. Still, I think you’d benefit from hearing from someone with many years of Rocket experience. But so far you’ve heard from one Rocket owner is reporting no issues in very cold conditions.

BTW, +1 about the utility of engine heaters, even I use mine away from home whenever starting up below 32F.

[kortopates]

Quote: jlunseth

[thinwing]

hi Paul...good to finally meet you at TVL this weekend.I wonder how 1/3 % IPA could possibly degrade fuel system rubber components ???I remember when MTBE was an additive sold in all automotive fuels in California and elsewhere in the 90 s as a pollution control.I recall a lot of complaints and letters to the airresources board complaining of ruined carbs ,the mtbe ate the rubber in old carbs...I wonder if this is how rubber degradation from isoproanol alcohol in gasoline got started???I have used alcor tcp in a helicopter engine as a lead scavenger...plugs cleaner etc...not in the Mooney though due to expense...regards k p couch

[BorealOne]

I live and fly in cold places. For the few pennies maintaining 1% isopropyl in the fuel in the winter costs, I consider to be as cheap insurance. I trained with Bruce Jaeger in Feb in Willmar, and the mechanics there quickly confirmed the wisdom of doing so religiously. 

As to pre-heat, I've got the Tannis + a very cool rig called an Areothem - when it's really cold, I use them both - http://www.aerothermheaters.com/

[jetdriven]

I'm exactly with you Jim. No wonder ourt planes true within 1 knot of each other. I do use both ASL Camguard and Corrosion-X as well.

[rbridges]

Is isopropyl acohol a problem for fuel lines?  I guess you're adding smaller amounts than the 10% ethanol in gasoline, but it still crossed my mind.