Sub-zero gas sumping

Discussion in 'Flight Following' started by labbadabba, Jan 1, 2018.

  1. labbadabba

    labbadabba Pattern Altitude

    Joined:
    Aug 12, 2014
    Messages:
    1,899
    Location:
    Lawrence, KS
    Display Name:

    Display name:
    labbadabba
    If there is residual water settling into to sump in sub-zero temps, will it freeze?

    I could see this being an issue if so...
     
  2. Zeldman

    Zeldman Final Approach

    Joined:
    Jun 13, 2014
    Messages:
    7,923
    Location:
    NM or the emergency room...
    Display Name:

    Display name:
    Billy
  3. Katamarino

    Katamarino Line Up and Wait

    Joined:
    Dec 14, 2011
    Messages:
    610
    Location:
    Basra, Iraq
    Display Name:

    Display name:
    Katamarino
    No problem. It's colder at altitude so it'll stay frozen in place and not cause any trouble.

    Just don't fly south.
     
    alaskazimm likes this.
  4. labbadabba

    labbadabba Pattern Altitude

    Joined:
    Aug 12, 2014
    Messages:
    1,899
    Location:
    Lawrence, KS
    Display Name:

    Display name:
    labbadabba
    So, if we're not using an alcohol-based fuel treatment, how cold is too cold to check the sumps? The idea of clogging the gascolator with slush doesn't appeal to me but neither does the idea of jamming the drains open due to ice in the sump.
     
  5. Zeldman

    Zeldman Final Approach

    Joined:
    Jun 13, 2014
    Messages:
    7,923
    Location:
    NM or the emergency room...
    Display Name:

    Display name:
    Billy
    When it is cold enough to freeze water, I won't sump. If there is a problem, it will show itself during the warm up and run up.

    Don't ask me how I learned to not sump when everything is frozen.....
     
    alaskazimm likes this.
  6. Stewartb

    Stewartb En-Route

    Joined:
    Nov 21, 2014
    Messages:
    4,387
    Location:
    Anchorage, AK
    Display Name:

    Display name:
    stewartb
    Water freezes at 32* F. That's a pretty good threshold for sumping/not sumping. My quick drains are frozen solid from October until April.
     
    alaskazimm likes this.
  7. labbadabba

    labbadabba Pattern Altitude

    Joined:
    Aug 12, 2014
    Messages:
    1,899
    Location:
    Lawrence, KS
    Display Name:

    Display name:
    labbadabba
    I mean, duh, water freezes below 32*. I did my initial training at KHPN and live in KS where we definitely have winter and I've not heard this from my CFIs. We always just checked the sumps as normal. The only real cold-weather consideration was cold engine start procs.

    What you're saying makes total sense, but just trying to figure out with the myriad of CFIs I've had over the years, I've not once had one tell me not to sump the gas below 32*.
     
  8. flyingron

    flyingron Touchdown! Greaser!

    Joined:
    Jul 31, 2007
    Messages:
    14,480
    Location:
    Catawba, NC
    Display Name:

    Display name:
    FlyingRon
    Pure water freezes at 32. The freezing point is depressed in proportion to the molecular weight of the solute. I've seen people try to work quick drains in colder weather only to find that the freeze while open.

    Frankly, I'm happy to have a heated hangar now.
     
  9. Zeldman

    Zeldman Final Approach

    Joined:
    Jun 13, 2014
    Messages:
    7,923
    Location:
    NM or the emergency room...
    Display Name:

    Display name:
    Billy
    Lack of experience on the instructors? I never had an instructor tell me not to sump below 32 degrees, not until I went to Alaska.
     
  10. Sinistar

    Sinistar Line Up and Wait

    Joined:
    Sep 9, 2016
    Messages:
    687
    Display Name:

    Display name:
    Brad
    This whole topic has me concerned too. I have yet to meet someone at the airport or a CFI who was like "Don't sump that tank!!!!...its below freezing." And we're the nut jobs who want to fly when its like -10F. Yet many here are quite adamant and have actual experience with this.

    So lets say we bypass sumping the tanks and the lowest level sump under the engine. What are the odds the engine would run during warm up, run-up and taxi but fail on take off due to water in the fuel? Can isopropyl be added? Will it wreck fuel bladders? Do the North Korean's get Netflix? ...too damn many questions for a newbie pilot :eek:

    :mad: ...that really is the answer though.
     
    labbadabba likes this.
  11. kgruber

    kgruber En-Route

    Joined:
    Jan 3, 2007
    Messages:
    3,390
    Location:
    Eastern Washington
    Display Name:

    Display name:
    Skywag
    Remember to put the EPA fast response team on "speed dial" if you want to sump below freezing.
     
    Sinistar likes this.
  12. Zeldman

    Zeldman Final Approach

    Joined:
    Jun 13, 2014
    Messages:
    7,923
    Location:
    NM or the emergency room...
    Display Name:

    Display name:
    Billy
    And how do you know what would happen if we sumped at below freezing temps..??? :lol::lol::lol:
     
    Sinistar likes this.
  13. Half Fast

    Half Fast Pattern Altitude

    Joined:
    May 7, 2016
    Messages:
    1,701
    Location:
    Central Florida
    Display Name:

    Display name:
    Half Fast
    Just use your cigarette lighter to warm up the quick drain for a moment...
     
    Zeldman, charheep, Sinistar and 2 others like this.
  14. Sinistar

    Sinistar Line Up and Wait

    Joined:
    Sep 9, 2016
    Messages:
    687
    Display Name:

    Display name:
    Brad
    So here's one for ya....if all goes well I will do my PPL checkride sometime soon this winter. It will most likely be somewhere between 5F..20F. Do I sump or not when the DPE is monitoring the pre-flight?????????????????????????
     
  15. mscard88

    mscard88 Touchdown! Greaser!

    Joined:
    Oct 1, 2015
    Messages:
    19,639
    Location:
    Alabama
    Display Name:

    Display name:
    Mark
    Gawd NO! :eek: Just in case someone does try that, DON'T! :D
     
  16. Stewartb

    Stewartb En-Route

    Joined:
    Nov 21, 2014
    Messages:
    4,387
    Location:
    Anchorage, AK
    Display Name:

    Display name:
    stewartb
    If you do happen to have a brain fart and have a quick drain stick and drip? A blow dryer works to thaw the ice and allow the drain to seal. That's a pirep. We learn from our mistakes. ;)
     
  17. Ravioli

    Ravioli En-Route

    Joined:
    Dec 1, 2014
    Messages:
    4,701
    Location:
    Fort Worth
    Display Name:

    Display name:
    Pasta Man
    I don't recall being "monitored." I'm pretty sure I did the whole preflight and gathered up all the logbooks prior to his arrival. After the oral was completed he said "let's go fly" (which is secret code for "you're about to be a pilot") and when we got to the plane he asked a couple of questions about what I had done for preflight but he didn't have me re-do it.
     
  18. Shopshirt

    Shopshirt Pre-takeoff checklist

    Joined:
    Oct 5, 2015
    Messages:
    238
    Display Name:

    Display name:
    Shopshirt
    Ha! So True! Sometimes the sarcasm gets lost in translation.
     
    mscard88 likes this.
  19. mscard88

    mscard88 Touchdown! Greaser!

    Joined:
    Oct 1, 2015
    Messages:
    19,639
    Location:
    Alabama
    Display Name:

    Display name:
    Mark
    From my experience they do watch and ask questions as one preflights. Be able to explain what you are checking and for what. Know which antenna does what, stuff like that.
     
  20. Skip Miller

    Skip Miller En-Route PoA Supporter

    Joined:
    Feb 22, 2005
    Messages:
    4,473
    Location:
    New York City
    Display Name:

    Display name:
    Skip Miller
    Thats a no-go too! Hair dryer motors like vacuum motors, will light off the fuel vapors! -Skip
     
  21. Stewartb

    Stewartb En-Route

    Joined:
    Nov 21, 2014
    Messages:
    4,387
    Location:
    Anchorage, AK
    Display Name:

    Display name:
    stewartb
    Blow dryers blow the fumes the other way. Like I said....pirep.
     
  22. Ravioli

    Ravioli En-Route

    Joined:
    Dec 1, 2014
    Messages:
    4,701
    Location:
    Fort Worth
    Display Name:

    Display name:
    Pasta Man
    Interesting. So the message to @Sinistar is to talk with your CFI about how your DPE will be doing things. They'll be able to answer much better than SGOTI.
     
  23. mscard88

    mscard88 Touchdown! Greaser!

    Joined:
    Oct 1, 2015
    Messages:
    19,639
    Location:
    Alabama
    Display Name:

    Display name:
    Mark
    SGOTI?

    It depends on individual DPEs also. But I imagine even if they're not out with a student watching the preflight, they're somewhere else watching, maybe while enjoying a cup of coffee. :D
     
  24. Scott@KTYR

    Scott@KTYR Pattern Altitude

    Joined:
    Oct 12, 2013
    Messages:
    1,587
    Display Name:

    Display name:
    Scott@KTYR
    If he want you to do a pre-flight then Yes Sump.
    But most of the time you pre-flight before he gets there.

    Good Luck with your test!!!
     
  25. PPC1052

    PPC1052 En-Route

    Joined:
    Feb 2, 2012
    Messages:
    3,764
    Display Name:

    Display name:
    PPC
    Some Guy On The Internet
     
    mscard88 likes this.
  26. Half Fast

    Half Fast Pattern Altitude

    Joined:
    May 7, 2016
    Messages:
    1,701
    Location:
    Central Florida
    Display Name:

    Display name:
    Half Fast

    Sarcasm? :dunno:
     
  27. Zeldman

    Zeldman Final Approach

    Joined:
    Jun 13, 2014
    Messages:
    7,923
    Location:
    NM or the emergency room...
    Display Name:

    Display name:
    Billy
    And suck air in from the other end, but yes, I have seen mechanics in Alaska use a heat gun on fuel sumps in a closed hanger.....but I only watched them for a second before I felt a strong need to go outside and look at the stars.....:loco::lol:
     
  28. Half Fast

    Half Fast Pattern Altitude

    Joined:
    May 7, 2016
    Messages:
    1,701
    Location:
    Central Florida
    Display Name:

    Display name:
    Half Fast

    Just have a pilot breathe on it. The hot air should thaw it in no time... :)
     
    Skyrys62, mscard88 and Zeldman like this.
  29. Stewartb

    Stewartb En-Route

    Joined:
    Nov 21, 2014
    Messages:
    4,387
    Location:
    Anchorage, AK
    Display Name:

    Display name:
    stewartb
    Who has a hangar? No freeze problems in those heated spaces. I park outside and preheat (or blow dry) using a generator. Anyone here ever use a Red Dragon pre-heater? Literally a propane flame thrower with a 12v fan to blow the air into the cowl. Guys use those all the time. Me? I watched a Red Dragon start my Cessna on fire once. Never again. A blow dryer to thaw a quick drain? That's pretty simple to do safely.
     
    Last edited: Jan 4, 2018
  30. paflyer

    paflyer Final Approach

    Joined:
    Jul 26, 2010
    Messages:
    6,598
    Location:
    PA
    Display Name:

    Display name:
    PAFlyer
    Sure, run a cheap, sparky motor in close vicinity of gasoline fumes. Kaboom!!!
     
  31. paflyer

    paflyer Final Approach

    Joined:
    Jul 26, 2010
    Messages:
    6,598
    Location:
    PA
    Display Name:

    Display name:
    PAFlyer
  32. Stewartb

    Stewartb En-Route

    Joined:
    Nov 21, 2014
    Messages:
    4,387
    Location:
    Anchorage, AK
    Display Name:

    Display name:
    stewartb
    When you live long enough where crap freezes up? You find ways to deal with it. Me? I don't touch my sumps in cold weather. Isopropyl in the fuel works better. But if I need to apply heat..... ;) 790C4CDA-02FA-4CBD-80B8-F09218574C4C.jpeg
     
  33. labbadabba

    labbadabba Pattern Altitude

    Joined:
    Aug 12, 2014
    Messages:
    1,899
    Location:
    Lawrence, KS
    Display Name:

    Display name:
    labbadabba
    So, back to the topic.

    If water is frozen inside the sumps, does that pose an operational hazard? Or will it simply remain frozen? Could slushy water end up in the gascolator or fuel lines and cause problems?
     
  34. Stewartb

    Stewartb En-Route

    Joined:
    Nov 21, 2014
    Messages:
    4,387
    Location:
    Anchorage, AK
    Display Name:

    Display name:
    stewartb
    It should stay frozen. It usually starts as ice crystals in the fuel and settles out into a layer of rime ice around the sump. In some cases you may get some ice in the finger screens and even into the strainer. I've never had fuel restriction myself but once you see it? Isopropyl sounds like a really good idea. Unless you do a good enough engine compartment preheat to warm the strainer that might be better left alone, too. There was another thread about it about a week ago with some good info and less BS.
     
  35. nrpetersen

    nrpetersen Pre-takeoff checklist

    Joined:
    Jan 4, 2013
    Messages:
    324
    Location:
    Minnetonka MN
    Display Name:

    Display name:
    nrpetersen
    A frozen quick drain suggests that there was water in the fuel that had melted for whatever reason & migrated to a quick drain location. If the initial a/c tank water was in the form of dissolved water in delivered fuel that was chilled, a small amount of isopropyl alcohol should keep it in solution so that it will pass thru the gascolator screen.

    If the water simply leaks in through crappy fuel tank filler seals that's another case and the amount of water that could be present is much greater. If that water freezes next to a quick drain, it probably won't plug the gascolator. I don't want to go there except to fix the filler seals ASAP.

    Each case may be different. Our case (described in another thread) the gascolator definitely plugged with ice crystals forcing the failed takeoff. In that case the airplane had been stored in an unheated -20 degF hangar yet the quick drains were free. After the incident, in cooler weather we started adding a few tablespoons full of isopropyl alcohol after every refueling. Sometimes we would get a few drops of liquid alcohol/water out the quick drains nut otherwise we never experienced frozen ones.

    To me, iced quick drains suggest the need for a review of alcohol additive procedures. It doesn't normally take a lot, unless you have leaky caps or are pumping in water.

    The very best is to cool the fuel as much as possible before filtering and adding it to an airplane. Q - stewartb from AK, are you fueling from an overhead/exposed tank?
     
  36. mscard88

    mscard88 Touchdown! Greaser!

    Joined:
    Oct 1, 2015
    Messages:
    19,639
    Location:
    Alabama
    Display Name:

    Display name:
    Mark
    FTFY
     
  37. Stewartb

    Stewartb En-Route

    Joined:
    Nov 21, 2014
    Messages:
    4,387
    Location:
    Anchorage, AK
    Display Name:

    Display name:
    stewartb
    I carry a 100 gallon avgas tank in my pickup. My own tank is double filtered. The bulk tank where I buy fuel is above ground and double filtered. It doesn’t rain much in Alaska in winter plus I use wing covers so no water gets to my fillers yet I ALWAYS have ice in the quick drains. I explained why in the other thread. That’s why I use 12 oz of isopropyl fuel deicer per 10 gallons of fuel for winter ops and occasionally in the warmer seasons, too.
     
    nrpetersen likes this.
  38. charheep

    charheep Pre-takeoff checklist

    Joined:
    Feb 5, 2013
    Messages:
    465
    Location:
    Aurora, IL
    Display Name:

    Display name:
    charheep
    What happens if you dont sump and take the plane to somewhere warm? Some planes with tip tanks could easily take off from say Chicago which is -5 right now, and not stop until Texas-type place. Would the ice melt upon descent and cause issues, or would it be used as the fuel is being drained during flight?
     
  39. nrpetersen

    nrpetersen Pre-takeoff checklist

    Joined:
    Jan 4, 2013
    Messages:
    324
    Location:
    Minnetonka MN
    Display Name:

    Display name:
    nrpetersen
    I think It depends on the temperature history of the fuel. If it was refined & delivered to the FBO always above say freezing, put in your tank & flown at -5 degF, moisture in the fuel will come out as snow crystals which could at some point plug your gascolator screens. A few gurgles of isopropyl alcohol added before flight would keep the ice crystals in liquid solution where they would successfully pass thru your gascolator.

    All bets are off if the fuel cap seals on your tanks previously allowed rainwater to leak in. And if the FBO has water in the bottom of his tanks the fuel will become saturated with water at that temperature. My contention is that the fuel/water system will behave like a small weather system, precipitating water, ice or ice crystals as it is chilled.

    This all assumes there is no water or frost accumulation from atmospheric breathing into the fuel vents. At cold temperatures (less than 32 degF) the amount of water present (i.e. the absolute humidity) in air is very small, and there is little opportunity for it to condense inside your tank.

    Later - liquid water doesn't create my type of problem as a small amount will pass through the engine with only a burp. It is ice crystals that permit a minute amount of ice to plug a gascolator and stop the show. Note the pictures from the FAA of the collapsed fuel filter from the Bonanza in my article referred to in the other postings. By the time the picture was taken, engine heat had melted the evidence.
     
    Last edited: Jan 5, 2018
  40. nrpetersen

    nrpetersen Pre-takeoff checklist

    Joined:
    Jan 4, 2013
    Messages:
    324
    Location:
    Minnetonka MN
    Display Name:

    Display name:
    nrpetersen
    (THX for bstewart's posting.) I wonder though, where his water that freezes in his quick drains is coming from? He is using what I think of as a massive amount of isopropyl alcohol.