Jump to content

A new AVWeb video...


Recommended Posts

I found this new AVWeb video worth watching. Two Mooneys are featured in it... sadly one was a fatal crash (discussed earlier I'm sure). Good reminders of what to do. Every. Single. Time.

EDIT: to add this - I personally don't have any issue with raising the gear early, as it could (should) help with climb performance.  If I need to get the gear down, it does so quickly...and if I'm too low for that then I've got bigger issues than worrying about a GU landing.  Just my thoughts though...not advice.

 

  • Like 9
Link to comment
Share on other sites

18 minutes ago, Ross Taylor said:

EDIT: to add this - I personally don't have any issue with raising the gear early, as it could (should) help with climb performance.  If I need to get the gear down, it does so quickly...and if I'm to low for that then I've got bigger issues than worrying about a GU landing.  Just my thoughts though...not advice.

Yes! I couldn't agree more.

  • Like 3
Link to comment
Share on other sites

I always sump the tanks but I have a question I've been pondering. If I were to get fuel from a contaminated source, how long would it take to be apparent during sumping? If I fill up and immediately sump the tanks, would I see water contamination if it were present or would I need to wait a little while for it to settle down? How long would it take to settle?

I have never found any evidence of water in my fuel. Not in my Mooney or my previously owned Cessna 152. 

 

 

Link to comment
Share on other sites

I always sump the tanks but I have a question I've been pondering. If I were to get fuel from a contaminated source, how long would it take to be apparent during sumping? If I fill up and immediately sump the tanks, would I see water contamination if it were present or would I need to wait a little while for it to settle down? How long would it take to settle?
I have never found any evidence of water in my fuel. Not in my Mooney or my previously owned Cessna 152. 
 
 

Next time u sump, pour a little water in to see what happens.

For me, I’ll fuel up then push the plane back and out of the way, then sump. #1 I get out of the way in case someone else rolls in for fuel, and #2 I feel the motion of pushing the plane would help any water make its way to the lowest part of the tanks. Should be plenty of time, I don’t see a need to wait longer than that.
  • Like 2
Link to comment
Share on other sites


Next time u sump, pour a little water in to see what happens.

For me, I’ll fuel up then push the plane back and out of the way, then sump. #1 I get out of the way in case someone else rolls in for fuel, and #2 I feel the motion of pushing the plane would help any water make its way to the lowest part of the tanks. Should be plenty of time, I don’t see a need to wait longer than that.

Better yet, put some avgas in a glass jar, add a little water, shake it a few times, watch what happens, use a gats jar to separate water from gas, remeasure the water, is it the same?
  • Like 1
Link to comment
Share on other sites

There's also the potential for water bubbles to get stuck along the bottoms of the ribs where the weep holes are.   If you shake the wingtips vigorously for a bit you may dislodge some from there so it can make its way down to the sump.  

 

  • Like 1
Link to comment
Share on other sites

Water will go immediately towards the drain... no waiting required...

 

Now... getting all the water to get to the drain... That may take more time...

Water is more dense than fuel by far... so it wants to go towards the drain...

It wants to ball up into spheres when it can... it may get stuck behind ribs and things....

 

So...

Shaking the plane, and bumping around will help things settle....

 

There is a lot of room lower than the drain For water to collect... so you might see water drops that keep showing up after you have drained what seems to be everything...
 

The POH has explanations for dry gas or alcohol use to get rid of moisture that hangs out lower than the drain...

The most common source of lots of Mooney water in tanks... rain water.  We have two O-rings per fuel cap... know them both...   if you have a mild steal (rustable) piece of sheet metal that the cap fits into... check for how rusty it is... it can rust all the way through and allow a gallon of water into the tanks in one rain storm...

 

PP thoughts only...

Best regards,

-a-

  • Like 1
Link to comment
Share on other sites

I echo what @carusoam writes.   Last summer while flying from AL to CO a line of convection formed from Texas to Wisconsin.  There was no way I was going to go around it or get through it.  I diverted to a smaller airport in OK and wound up staying the night.  When I left, I asked the FBO to top off the tanks.  It poured rain that night.  Rainwater even got in the pitot tube it rained so hard with big wind gusts. 

On my walk around during preflight the next morning I noticed that one of the gas caps had rainwater pooled on top, and the other one didn't.  Next, I sumped the tanks agressively looking for water.   I'm not kidding it took 17 cups to get all the water out of that tank that had no water pooled on the gas cap.   I've got the blue gaskets and ordinarily don't get water in the tanks from rain.  The cap wasn't put on correctly by whomever filled the plane.

  • Like 2
Link to comment
Share on other sites

7 hours ago, 0TreeLemur said:

I echo what @carusoam writes.   Last summer while flying from AL to CO a line of convection formed from Texas to Wisconsin.  There was no way I was going to go around it or get through it.  I diverted to a smaller airport in OK and wound up staying the night.  When I left, I asked the FBO to top off the tanks.  It poured rain that night.  Rainwater even got in the pitot tube it rained so hard with big wind gusts. 

On my walk around during preflight the next morning I noticed that one of the gas caps had rainwater pooled on top, and the other one didn't.  Next, I sumped the tanks agressively looking for water.   I'm not kidding it took 17 cups to get all the water out of that tank that had no water pooled on the gas cap.   I've got the blue gaskets and ordinarily don't get water in the tanks from rain.  The cap wasn't put on correctly by whomever filled the plane.

Always check your own caps regardless of who puts them on....and regularly replace “both” o rings for each cap.(at least every other year)

  • Like 2
Link to comment
Share on other sites

3 hours ago, larrynimmo said:

Always check your own caps regardless of who puts them on....and regularly replace “both” o rings for each cap.(at least every other year)

Checking the fuel caps is part of every pre-flight inspection.  That is how I spotted the difference in the water that was ponded around the perimeter.  Also important is ensuring that the caps are installed correctly.  Sometimes the caps in Mooneys don't seat properly even when they clamp tight.   I like to give my caps a jiggle before pushing the dog down to make sure they are fully seated.

I have the blue flourosilicone o-rings.  At annual this year they took them off and put rubber ones on.    I inspected them and had them put them back on.  They have a lifetime much longer than 1 year.  They looked like new as they were only two years old.

 

  • Like 2
Link to comment
Share on other sites

On 7/2/2020 at 12:33 PM, ReconMax said:

I always sump the tanks but I have a question I've been pondering. If I were to get fuel from a contaminated source, how long would it take to be apparent during sumping? If I fill up and immediately sump the tanks, would I see water contamination if it were present or would I need to wait a little while for it to settle down? How long would it take to settle?

I have never found any evidence of water in my fuel. Not in my Mooney or my previously owned Cessna 152. 

I’ve been pondering a similar question...how much water would cause a problem?  8 gal/hr is about 30.2 L/ hr (in sensible units); this is ~8.2 ml/sec .  How long will it take to cause a problem?  My sample cup is only ~30 ml; if I have 10 ml of water, will it cause complete stoppage?  Should we be slumping more than 10-20 ml?

  • Like 1
Link to comment
Share on other sites

On 7/2/2020 at 2:33 PM, ReconMax said:

I always sump the tanks but I have a question I've been pondering. If I were to get fuel from a contaminated source, how long would it take to be apparent during sumping? If I fill up and immediately sump the tanks, would I see water contamination if it were present or would I need to wait a little while for it to settle down? How long would it take to settle?

I have never found any evidence of water in my fuel. Not in my Mooney or my previously owned Cessna 152. 

 

 

The only time I have found water in my fuel was in my old 152 which was parked outside.  The first sample was about half water, next sample some drops, next sample clean, shook the wing which resulted in more drops for the next ~2 sumps, finally a few more clean sumps.  No issues on runup or takeoff.   I feel like it was rainwater, not contaminated fuel.

  • Like 1
Link to comment
Share on other sites

The only time I've had water in the tanks was from incorrect fuel cap installation. In my E, it is possible to get the cap on and fastened, and it looks properly installed from a glance, when in face the cap's top is not parallel to the adjacent wing skin.

My practice after finding this is to install the cap, and then run my finger around the circumference once. You will quickly feel whether the cap is askew or not.

And yes that was a great video. Mr. Bertorelli has done a lot for GA and I appreciate his style and humor. Particularly the video about pattern sizes, and CFI's who wear stripes on their shoulders :)

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

19 hours ago, Comet said:

I’ve been pondering a similar question...how much water would cause a problem?  8 gal/hr is about 30.2 L/ hr (in sensible units); this is ~8.2 ml/sec .  How long will it take to cause a problem?  My sample cup is only ~30 ml; if I have 10 ml of water, will it cause complete stoppage?  Should we be slumping more than 10-20 ml?

You ask a good question that prompted me to study this issue a bit.   In my readings of NTSB accident reports where water in the fuel system was a contributing factor it is an insidious problem and some makes and models are more prone to problems than others.   Articles that I've read written by folks who fortunately survived this problem most often report that the engine doesn't sputter, it just stops.  From a fluid mechanics standpoint, the worst case occurs when the water-fuel interface is just below the intake strainer and the strainer is located near the aft end of the tank.  In this case the engine runs great on runup and taxi.  However the acceleration of the takeoff roll will cause the water to accumulate in the back of the tank and submerges the strainer.  In this condition, only water is being sucked into the fuel system.  After t/o the acceleration diminishes, but now the aircraft is climbing with a significant nose-up attitude and water remains in the aft portion of the tank and continues to flow into the intake- and at a low altitude, the engine stops.  The entire fuel system is full of water and there is insufficient time to clear it and re-start.   Sadly, it often takes more time than the t/o roll for the engine to stop.

 

  • Like 2
Link to comment
Share on other sites

On 7/2/2020 at 2:33 PM, ReconMax said:

I always sump the tanks but I have a question I've been pondering. If I were to get fuel from a contaminated source, how long would it take to be apparent during sumping? If I fill up and immediately sump the tanks, would I see water contamination if it were present or would I need to wait a little while for it to settle down? How long would it take to settle?

I have never found any evidence of water in my fuel. Not in my Mooney or my previously owned Cessna 152. 

 

 

I believe you need at least 15 minute settling time. 

  • Like 1
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.