Legalities of flying with a collapsed strut?

Discussion in 'Flight Following' started by Rgbeard, Apr 2, 2021.

  1. Rgbeard

    Rgbeard Pattern Altitude

    Joined:
    Aug 26, 2017
    Messages:
    2,195
    Location:
    Phoenix, AZ and Ensenada, Mexico

    Display name:
    rgbeard
    When I flew back to Phoenix from San Diego on Wednesday, I saw a trail of oil accompany me to the parking spot, and saw that I blew a seal on my right main oleo strut.

    I certainly don’t intend on flying the airplane until it’s repaired. Parts have been ordered and I’m getting together with my mechanic on Monday to resolve.

    However this turned into a conversation between my wife and I and I don’t really know the answer? I understand it’s not a good idea. But is it legal to fly the airplane?
     
  2. luvflyin

    luvflyin Touchdown! Greaser!

    Joined:
    May 8, 2015
    Messages:
    11,020
    Location:
    Vancouver, WA

    Display name:
    Luvflyin
    Yes. FAR 91.7. You be the one what gets to decide if it’s airworthy or not. If you decide wrong you may have some splainin’ to do under 91.13. Probably sumpin else somewhere says more about it. I say let the juice out of the other one and go for it.:fingerwag:
     
    Last edited: Apr 2, 2021
  3. Timbeck2

    Timbeck2 Final Approach

    Joined:
    Nov 4, 2015
    Messages:
    8,194
    Location:
    Vail, Arizona

    Display name:
    Timbeck2
    Rusty is the strut completely collapsed? I had the same situation several years ago but noticed it leaking (slow drip) after landing on a breakfast run. I skipped breakfast and flew it back before it completely collapsed. It’s a judgment call. Do I fly it and possibly make it a lot worse on the next landing or do I try to have it fixed here? Personally I wouldn’t fly it until it was fixed if the hydraulic fluid was gushing out and or the strut was collapsed
     
  4. Bellanca_Pilot

    Bellanca_Pilot Pre-Flight

    Joined:
    Aug 29, 2010
    Messages:
    82
    Location:
    Georgetown, Texas

    Display name:
    Dewey
    Doesn’t it sit on a spring?


    Sent from my iPhone using Tapatalk
     
  5. denverpilot

    denverpilot Tied Down PoA Supporter

    Joined:
    Nov 8, 2009
    Messages:
    55,441
    Location:
    Denver, CO

    Display name:
    DenverPilot
    Judgement call based on aircraft type and what metal is going to take the punishment of a hard landing with no strut pressure.

    Often the components that would be damaged if even an accidental hard landing back at home base, are unobtainium or waaaaaaay more money than getting it fixed away from home and the hassles involved.

    Something to ponder. Big bucks vs little bucks.
     
  6. Bell206

    Bell206 En-Route

    Joined:
    Oct 6, 2017
    Messages:
    4,533

    Display name:
    Bell206
    Legal = ferry permit. But as mentioned, landing with a collapsed strut can set you up for possible strut damage and landing control issues.
     
  7. Rgbeard

    Rgbeard Pattern Altitude

    Joined:
    Aug 26, 2017
    Messages:
    2,195
    Location:
    Phoenix, AZ and Ensenada, Mexico

    Display name:
    rgbeard
    Thanks for the answers.

    just to be doubly doubly clear, this was only an academic issue. I’m certainly not flying the aircraft.

    9CA87E9C-FB1F-4877-A052-B1566C0ABFDB.jpeg

    sigh. I give up on properly oriented photos
     
    denverpilot likes this.
  8. GRG55

    GRG55 Final Approach Gone West

    Joined:
    Dec 29, 2015
    Messages:
    9,307

    Display name:
    Aztec Flyer
    No. MIL-H-5606 hydraulic fluid with nitrogen gas pressure (although I've seen some mechanics use air on the smaller, lighter Cherokees). It's similar to a gas shock absorber on a car.
    Fortunately the Piper oleo isn't a very complicated assembly, and the seal kits don't cost half the price of the airplane.
     
  9. NordicDave

    NordicDave Pattern Altitude

    Joined:
    Oct 31, 2015
    Messages:
    2,271
    Location:
    Monterey County

    Display name:
    NordicDave
    Oleo rebuilt kits are under $50, assuming the issue is seals and scrappers. Biggest mistake people make is only replacing the lower seals which are cheaper and easier to access. The upper seal requires more disassembly. Not unusual to see log book entries for “strut rebuild”, only to find the upper seals completely flat spotted and useless. Eg. not changed since plane was born.
     
  10. RyanB

    RyanB Administrator Management Council Member PoA Supporter

    Joined:
    Jul 21, 2010
    Messages:
    13,661
    Location:
    Chattanooga, TN

    Display name:
    Ryan
    Yeah the seal kit is peanuts, it’s much more labor intensive than anything.
     
  11. Matthew Rogers

    Matthew Rogers Ejection Handle Pulled

    Joined:
    Dec 1, 2017
    Messages:
    1,235

    Display name:
    Matt R
    I use a special blend of nitrogen and oxygen with a little argon to round it out.
     
    TCABM, Todd82, Daleandee and 9 others like this.
  12. GRG55

    GRG55 Final Approach Gone West

    Joined:
    Dec 29, 2015
    Messages:
    9,307

    Display name:
    Aztec Flyer
    Why?
     
  13. Matthew Rogers

    Matthew Rogers Ejection Handle Pulled

    Joined:
    Dec 1, 2017
    Messages:
    1,235

    Display name:
    Matt R
    Because it is called “air” and it is free.
     
  14. GRG55

    GRG55 Final Approach Gone West

    Joined:
    Dec 29, 2015
    Messages:
    9,307

    Display name:
    Aztec Flyer
    By airplane standards the labor to properly rebuild a Piper oleo is quite reasonable. I agree with @NordicDave that it's false economy not to rebuild it completely while you have it apart. It's a messy job working under the wing, but it's not complicated.
     
    NordicDave likes this.
  15. GRG55

    GRG55 Final Approach Gone West

    Joined:
    Dec 29, 2015
    Messages:
    9,307

    Display name:
    Aztec Flyer
    LOL As I said in my original post I've seen some mechanics use air on the smaller, lighter Cherokees. It's not a good idea on the heavier planes, such as the OP's Lance, and I certainly won't use air for the oleos on my Aztec.

    Also, there's NOTHING that is free in aviation, other than the advice one receives on this forum.
     
    RyanB and Tarheelpilot like this.
  16. MauleSkinner

    MauleSkinner Final Approach

    Joined:
    Oct 25, 2005
    Messages:
    9,897
    Location:
    Wichita, KS

    Display name:
    MauleSkinner
    Keep in mind that the strut normally needs to be fully extended to fit in the wheel well properly, and strut pressure is a major factor in that. If you were to fly it, I’d definitely leave the gear down.
     
    Jim K, Rgbeard, GRG55 and 2 others like this.
  17. Dan Thomas

    Dan Thomas Final Approach

    Joined:
    Jun 16, 2008
    Messages:
    7,826

    Display name:
    Dan Thomas
    And it will contain more water than argon, too. It's only free for a limited time.
     
    GRG55, Tarheelpilot and RyanB like this.
  18. unsafervguy

    unsafervguy Pattern Altitude

    Joined:
    Aug 16, 2011
    Messages:
    2,183
    Location:
    Sw florida

    Display name:
    bob
    to end the academic discussion, have you priced that casting lately?
     
  19. AA5Bman

    AA5Bman Line Up and Wait

    Joined:
    Jun 14, 2009
    Messages:
    615

    Display name:
    He who ironically no longer flies an AA5B
    Ehh, I may or may not have done it.

    My mechanic said it was safe, I asked was it smart? He said, basically, can you make one landing on a giant paved runway without putting it down on the nose wheel?

    I may or may not have flown it to him for repair.
     
  20. NealRomeoGolf

    NealRomeoGolf En-Route

    Joined:
    Apr 12, 2016
    Messages:
    2,826
    Location:
    Illinois

    Display name:
    NRG
    Rusty it must be PA32 strut collapsing week. Mine collapsed too....just as it went into annual. That was kinda convenient.
     
  21. GRG55

    GRG55 Final Approach Gone West

    Joined:
    Dec 29, 2015
    Messages:
    9,307

    Display name:
    Aztec Flyer
    How long has it been since all you folks have replaced the seals, O-rings and put fresh hydraulic fluid in your struts?

    @NRG when they pull open the strut if the fluid looks and smells bad, you'll know its overdue.
     
  22. NealRomeoGolf

    NealRomeoGolf En-Route

    Joined:
    Apr 12, 2016
    Messages:
    2,826
    Location:
    Illinois

    Display name:
    NRG
    I'd have to look at the books. I've only owned it 9 months.
     
  23. GRG55

    GRG55 Final Approach Gone West

    Joined:
    Dec 29, 2015
    Messages:
    9,307

    Display name:
    Aztec Flyer
    Depending on what you find in the books and what your shop finds when they open it up, you may want to consider doing all 3 - or one each year over the next 3 annuals to spread the cost out.
     
  24. ktup-flyer

    ktup-flyer En-Route

    Joined:
    Jun 28, 2012
    Messages:
    3,978
    Location:
    Tupelo, MS

    Display name:
    ktup-flyer
    If you go to edit and rotate it 360º on your phone before you upload, it will upload in the correct orientation. Annoying, but it works.
     
  25. NealRomeoGolf

    NealRomeoGolf En-Route

    Joined:
    Apr 12, 2016
    Messages:
    2,826
    Location:
    Illinois

    Display name:
    NRG
    We are doing all 3. Ordered parts yesterday.
     
    GRG55 and Ghery like this.
  26. Ghery

    Ghery Touchdown! Greaser!

    Joined:
    Feb 25, 2005
    Messages:
    10,600
    Location:
    Olympia, Washington

    Display name:
    Ghery Pettit
    That depends on where the air came from. In Arizona I'd be surprised in the summer if it contained any water at all. I don't call that state Aridzona for nothing. :p
     
  27. Rgbeard

    Rgbeard Pattern Altitude

    Joined:
    Aug 26, 2017
    Messages:
    2,195
    Location:
    Phoenix, AZ and Ensenada, Mexico

    Display name:
    rgbeard
    Believe it or not, I definitely have to check my air compressor's drain regularly and still get a good dose of water from it.

    It's currently 92 here, and 20% humidity if my weather station is to be believed.
     
  28. Stan Cooper

    Stan Cooper Pattern Altitude PoA Supporter

    Joined:
    Aug 29, 2017
    Messages:
    1,789
    Location:
    Santa Rosa, CA

    Display name:
    Stan Cooper
    A little off topic, but years ago at a Cessna Pilots Association fly-in to First Flight at Kitty Hawk one of the attendees had a collapsed nose wheel oleo strut on his 182. Another attendee who was an A&P used a length of radiator hose and slit it open so it would fit over the strut and held it in place with four hose clamps. It was a pretty clever way to get the 182 home without a prop strike or worse.

    Legal? I dunno.
     
    Huckster79 and Mtns2Skies like this.
  29. Dan Thomas

    Dan Thomas Final Approach

    Joined:
    Jun 16, 2008
    Messages:
    7,826

    Display name:
    Dan Thomas
    Yup. A good explanation here: https://www.thecompressedairblog.com/why-is-compressed-air-wet

    There's always some water vapor, even in the desert. The compressor tank will accumulate it more slowly, but it will still accumulate. The bigger danger is water accumulating in low spots in the shop's plumbing and hoses, especially in low spots, during high air usage when the lines and hoses cool the still-warm compressed air and the water condenses out of it. Once it gets high enough in a low spot to start blocking airflow it will blast out of that hose and contaminate whatever you're doing with it, whether it's air tools or spray painting or an oleo strut. In one place I used to have to stop everything and go around and stick an open quick-coupler fitting in each air chuck and let air and water blast out, working my way downstream, and the hoses were last. I'd have water all over the floor. And that was in a fairly dry climate and with regular tank draining.
     
    GRG55 likes this.
  30. Bell206

    Bell206 En-Route

    Joined:
    Oct 6, 2017
    Messages:
    4,533

    Display name:
    Bell206
    Have seen a number of bush planes with added hose bumper guards on the nose. It's there as added protection for landing off airport. Whether to use it as a band-aid to get one home....
    On the bush planes it's usually installed as a minor with an entry.
     
    Stan Cooper likes this.
  31. GRG55

    GRG55 Final Approach Gone West

    Joined:
    Dec 29, 2015
    Messages:
    9,307

    Display name:
    Aztec Flyer
    You'd probably be surprised. ;)
    Rusty's correct.

    The relationship between temperature and maximum moisture content is not linear. If you want dry air you'll have better success in Colorado in the winter than in Phoenix in the summer.

    Phoenix, AZ has an average daily high temperature of 103.6 deg in July and an average relative humidity that same month of 31%. Maximum moisture content at 104 deg F (40 C) is 51.1 grams/cubic meter, or 15.8 grams/cubic meter actual water content at 31% relative humidity.

    That's about the same mass of water in the air as a 70 deg F day at 85% relative humidity, and almost 25% more water content than a foggy 60 deg F day.
     
    Last edited: Apr 3, 2021
    denverpilot and Spring Ford like this.
  32. Tarheelpilot

    Tarheelpilot Final Approach

    Joined:
    Dec 5, 2010
    Messages:
    5,422
    Location:
    North Carolina once again.

    Display name:
    Tarheelpilot
    Yeah. Shop air in a strut is not a good idea.
     
  33. Matthew Rogers

    Matthew Rogers Ejection Handle Pulled

    Joined:
    Dec 1, 2017
    Messages:
    1,235

    Display name:
    Matt R
    Well, I just used a hand pump, so no accumulated water in the lines or tank. I did so at 40 degrees and let's say 50% humidity (because I don't remember knowing that value). A total of 1.1664 g of water was present per pound of air on that day. Factor in the volume of the strut (adjusted for pressure and temperature) and I get 20-50 milligrams grams of moisture (water vapor) in the strut. A rounding error in my book.
     
  34. Zeldman

    Zeldman Touchdown! Greaser!

    Joined:
    Jun 13, 2014
    Messages:
    14,042
    Location:
    high desert NM

    Display name:
    Billy
    I have never taken off with anything broken/not right on the plane.

    But I sure have landed with a few that somehow became broken in flight....
     
    Huckster79, Palmpilot, Ted and 3 others like this.
  35. denverpilot

    denverpilot Tied Down PoA Supporter

    Joined:
    Nov 8, 2009
    Messages:
    55,441
    Location:
    Denver, CO

    Display name:
    DenverPilot
    I’m always shocked when I go places that wet towels don’t dry themselves just by hanging them up for an hour. LOL.
     
  36. Silvaire

    Silvaire En-Route

    Joined:
    Oct 10, 2012
    Messages:
    4,132

    Display name:
    Silvaire
    Yes and let's be clear that 200 psi doesn't mean that you've put 200 pounds of air in your strut. Historically over the past 70 years or so I'd say that probably 95% of the GA Pipers and Cessnas have been flying around with "shop air" in their struts but nowadays even Les Schwab will try to convince you that you need nitrogen in your car tires.
     
  37. denverpilot

    denverpilot Tied Down PoA Supporter

    Joined:
    Nov 8, 2009
    Messages:
    55,441
    Location:
    Denver, CO

    Display name:
    DenverPilot
    I love the car nitrogen guys. They always say the oxygen molecules are small enough they escape through the tire.

    To which one answers, “Cool. So if I keep filling with air the tire will slowly make it all nitrogen inside as it leaks out the oxygen!”

    Freaking idiots.
     
    Dan Thomas and jsstevens like this.
  38. jsstevens

    jsstevens Final Approach PoA Supporter

    Joined:
    May 18, 2007
    Messages:
    6,055

    Display name:
    jsstevens
    Osmosis. I love it!

    The version I heard was oxygen reacts with the inside of the tire and ages it. Not sure what's happening to the outside...
     
    denverpilot and Palmpilot like this.
  39. GaryM

    GaryM Line Up and Wait

    Joined:
    Apr 16, 2020
    Messages:
    912
    Location:
    New Jersey (KMMU)

    Display name:
    Gary M
    Outside where they are exposed to both oxygen AND sunlight? Nevermind that, just pay us the upcharge for the nitrogen fills! In a few years when you are replacing your cracked, worn-out tires, you'll be amazed at how good they look on the inside!
     
    jsstevens likes this.
  40. Zeldman

    Zeldman Touchdown! Greaser!

    Joined:
    Jun 13, 2014
    Messages:
    14,042
    Location:
    high desert NM

    Display name:
    Billy
    I used nitrogen in the race car tires.

    Because the nitrogen does not get as hot as oxygenated air then expand when it gets hot, then raising the tire pressure.

    Because the increasing tire pressure can throw off the suspension set up thereby slowing the car down and/or making it hard to handle through the turns.

    I use nitrogen in the truck and trailer tires to keep the heat down in the tires when loaded and at highway speeds.

    Heat eventually breaks down tires.