Running a tank dry in flight

[jetdriven]

Again, ran the RESERVE tanks dry, and starved the engines inadvertently.  The reserve tanks were found empty, and the selectors were positioned to reserve.  The pilot also lost control of the aircraft.  

simple.    fuel.     mismanagement.   

http://www.avweb.com/news/safety/183014-1.html

So keep looking.  I would like to see a documented event where the pilot had fuel onboard the aircraft, switched to it, and could not get the engine to restart.  Since that is such a common fear oft repeated on here.  

The aircraft must be demonstrated to the FAA for certification to run a tank out, interrupting the fuel flow, and then be able to restart it on another tank.

Quote: 201-FLYER

Points To Ponder

 

 

Aircraft Systems

 

Anyone attempting to fly this P-40 should first get a thorough checkout on its systems and quirks.

 

 

Older airplanes do not follow modern certification rules on switch positions or operation of their systems. For example, fuel systems can be incredibly complex on even small, single-engine airplanes. Flying without first doing one’s homework and fully understanding the airplane's systems is too often fatal. Even a devoted warbird pilot such as Jeff Ethell apparently made his final error with a fuel system of the P-38, running a tank dry under conditions in which he could not restart the engine. [EDITOR'S NOTE: AVweb includes the NTSB's final report on the Jeff Ethell P-38 crash.] Before you get in, know how to get at all the fuel in the airplane, where any return fuel from a fuel-injected engine goes so you don’t overfill a tank (early Bonanzas return fuel to the left tank, Cessna 310s return fuel to the mains only), and how to shut off all of the fuel to the engine(s) should you desire. Does the fuel selector handle function by pointing the long or short end at the detent? Is the electrical system 12- or 24-volt? Does it matter? Why? How does it work in an emergency? How much oil does the engine hold? What is the minimum amount?

 

 

The older the airplane, the more likely the systems are to have a design philosophy which is unfamiliar and probably counterintuitive to you. It is wise to have a good working knowledge of the systems when something goes south in flight rather than to try and puzzle things out under stress.

[jetdriven]

well if the fuel selector was selected ot an empty tank, and the doubt of fuel being in the other tank suggests the NTSB is right, fuel mismanagement.     I am looking for a case where the fuel is available and the engine would not relight.

Quote: 201-FLYER

Sorry....you asked the question and I thought I was answering it

According to the article...The report also raises the question of if she followed the proper procedure for restarting an engine in flight when a tank runs dry.

 

 

[carusoam]

JetD,

 

Call me crazy, but I think you have made some good points.

 

(1) Mooneys are designed to run a tank dry.

(2) it is a good practice to have remaining fuel in one tank.

(3) pilots that fly hundreds of hours per year have a higher comfort level

(4) pilots that fly less than 100 hours per year may be less comfortable

(5) fuel in one tank can lead to mistaken fuel exhaustion 

(6) verifying the fuel system operation of each plane is good

(7) paying somebody to do this for you is not the same as going yourself

 

There is nothing wrong or illegal about running a tank dry.  Some people are uncomfortable with it, and may avoid it like flying at night.

 

Fortunately, our systems are simple.  There is only one choice.  If fuel doesn't come out of one side, turn the selector to the other side.  Fly on....we all have experience with the fuel selector on most every flight.

 

I like the fact that we discuss differing opinions.  It helps me make more informed decisions.

 

I most appreciate the thought process of the high timers, pros (military and commercial) and CFIs.  What is obvious to you, may not be so obvious to the newbie just getting started....many of us are in between......

 

Thanks again.

 

Best regards,

 

-a-

[orangemtl]

Quote: carusoam

 

JetD,

 

Call me crazy, but I think you have made some good points.

 

(1) Mooneys are designed to run a tank dry.

(2) it is a good practice to have remaining fuel in one tank.

(3) pilots that fly hundreds of hours per year have a higher comfort level

(4) pilots that fly less than 100 hours per year may be less comfortable

(5) fuel in one tank can lead to mistaken fuel exhaustion 

(6) verifying the fuel system operation of each plane is good

(7) paying somebody to do this for you is not the same as going yourself

 

There is nothing wrong or illegal about running a tank dry.  Some people are uncomfortable with it, and may avoid it like flying at night.

 

Fortunately, our systems are simple.  There is only one choice.  If fuel doesn't come out of one side, turn the selector to the other side.  Fly on....we all have experience with the fuel selector on most every flight.

 

I like the fact that we discuss differing opinions.  It helps me make more informed decisions.

 

I most appreciate the thought process of the high timers, pros (military and commercial) and CFIs.  What is obvious to you, may not be so obvious to the newbie just getting started....many of us are in between......

 

Thanks again.

 

Best regards,

 

-a-

 

[fantom]

Good points, all....

Just thinking that lots of less experienced pilots, and probably some experienced ones, don't know the proper way to restart their engine in the air. It's in the POH.

[jetdriven]

runnig a tank dry is not "outside the envelope" it  is a normal SOP.

I would suggest doing it once with a CFII on board, and at 12k feet over your home airport.  At least you can view the symptoms of fuel starvation and train yourself to act if you detect it. And how to relight it without overspeeding your prop or overboosting your engine.  There are procedures int the manual which shouldn't be attempted the first time anywhere near the ground.   You know the fuel pump can fail its the same symptoms.  Many pilots are startled and cannot respond properly.   That can save your life.

[Shadrach]

Quote: orangemtl

Yes.

The entire thread, if nothing else establishes that there's not necessarily a single answer to a single question.  Ask me about treating early stage prostate cancer and I'll give you FIVE, equally valid answers. Depends upon the setting.

If you're a CFI, or have 3000 hours at the yoke, or fly professionally: many things are possible, or doable.  I work 'outside the envelope' in my day job all the time, because I've done it for 24 years.  If I flew every day for decades, or did it professionally, many many things come as second nature.

But, I'm 51 and with luck will fly 100-200 hours per year, and will likely have to hang it up at 70 after perhaps 2500 hours total in the air. And my risk tolerance is slightly different than when I learned to fly at 28.  SO: While I was mildly facetious about 'paying the man' to gauge my tank volume, I still firmly believe that for most low timers, the risk:benefit ratio is not appealing for "Hey, what happens when I empty this tank?" After all, nobody ever crashed from keeping too much fuel reserve.

[fantom]

Quote: Shadrach

[John Pleisse]

I cannot ever think of a time or practical reason to run a tank dry. It serves absolutely no purpose and assumes some risk. Sediment clog, vapor lock, engine not restarting. Why do it?

[jetdriven]

All those "risks" have been addressed, and they are not risks.  They do not exist.

I'm still waiting for some concrete proof of some incident where someone ran a tank out, and switched to the other tank, followed the POH, and it did not restart.

 

Just one.

[fantom]

Quote: jetdriven

All those "risks" have been addressed, and they are not risks.  They do not exist.

I'm still waiting for some concrete proof of some incident where someone ran a tank out, and switched to the other tank, followed the POH, and it did not restart.

 

Just one.

[jetdriven]

I'm asking someone to put some facts or data  forth instead of feelings, old wives tales, and misinformation..  They have no place in a professional cockpit.

[Hank]

Quote: N4352H

I cannot ever think of a time or practical reason to run a tank dry. It serves absolutely no purpose and assumes some risk. Sediment clog, vapor lock, engine not restarting. Why do it?

[Hank]

Quote: fantom

Just thinking that lots of less experienced pilots, and probably some experienced ones, don't know the proper way to restart their engine in the air. It's in the POH.

[Shadrach]

As Hank says, to actually see the inside of the tank and the fuel system on the whole would eliminate the concerns of a blockage to most. The sump is located ~2" below the fuel pick up. The gascolator screen is the next line of defence and would require a considerable amount of junk to block off fuel. If you're running with a tank that is so full of junk as to have a clogging concerns, you're flying a very poorly maintained AC or your ex wife is trying to kill you. Either way, your craft is un-airworthy and you have bigger problems then when you switch tanks...

[fantom]

Quote: jetdriven

I'm asking someone to put some facts or data  forth instead of feelings, old wives tales, and misinformation..  They have no place in a professional cockpit.

[jetdriven]

Yes Hank those old books are pretty poor.  Not much substance. You might try finding a copy of a 1976 M20C POH I bet there is some much more meaningful information in that. 

 

 

[orangemtl]

Performing the process with a CFI on hand is an excellent suggestion. When next I start working with mine (IFR training time, once I hit >200 hours), I plan to do this. Great recommendation.

Neither is it irresponsible to perform the process with adult supervision, nor to avoid low tanks.  Some people hang glide because it's perfectly safe. Others avoid expressways bvecasue they're dangerous. Both are correct within their own frame of reference. As one of the posters notes in his identifier, "A man's got to know his limitations..." Signing off.

[John Pleisse]

So I just read all 8 pages of this entire thread (includ. my engine out in St. Augustine). Somebody explain to me the benifits of intentionally running a tank dry. Never mind if you are afraid of it, whether or not an engine restart is a SOP, airlines and military do it..etc..............what is the benefit? How does it make flying a Mooney better and safer?

[jetdriven]

the benefit is

1. you can calibrate your fuel tank capacity and your totalizer.  Or if you have no totalizer, you know exactly how long the engine has ran from that tank, by carefully setting power and timing the tanks.  Doing so allows you accurately estimate your fuel burn and your time remaining in the other tank.

2. You can extend the range of your aircraft safely. You use all the fuel on one side, and maybe get a couple free gallons of unusable fuel as well.  10 gallons is a reasonable reserve, but fuel guages arent accurate and they will not accurately account for what fuel is in which tank.  if it is in one tank you know how much you got, and even better, its all in one place.  No hoping there is 6 gallons in the left it might actually be 3.   10 gallons (EDIT: in Lycoming 360) reserve both sides is a waste of utility (ours only holds 57 gallons).  We can only take 37 gallons wth 4 in our 201, and if you are going to fly further than 300 miles, you need to manage fuel carefully.   You can also plan your tank to run empty near top of descent, then one fuel tank change then and you are done with the system. Messing with the fuel selector at low altitude (or on the ground) can get you killed.  Most engine failures are fuel related.  

 

So thats the best represntation I can give, I think Ross and Ward are better than me with words perhaps they can add some.

[John Pleisse]

You have bladders Byron?

[jetdriven]

yes.  not having that extra ten gallons is sometimes a hassle.

[aviatoreb]

Quote: jetdriven

... Messing with the fuel selector at low altitude (or on the ground) can get you killed.  Most engine failures are fuel related.  

[jetdriven]

Basically, yes you have it right.

  I have seen people, on the runup checklist, switch "fuel - fullest tank" then do a 1 minute runup, then ready to go.  Switching tanks on the ground before you sample it adequately can introduce water into the system precisely when its worst, right after takeoff.   For that reason, I always start, taxi and runup on the same tank.  If it runs ten minutes plus runup you have used all the fuel in the line and some of the tank, verifying fuel quality . Now if I were really paranoid i might start and taxi on one tank, then runup on the other, but it better be a nice long runup.

I wouldn't run one tank dry and the other full.    Use it and switch tanks as you see fit.  Liquid aileron trim. For a 2-3 hour flight who cares, they are both half full.  But if you are trying to maximize range of the aircraft make sure your last 12-15 gallons are in one place.  It doesnt happen very often, but it is a good technique, IMO.

[WardHolbrook]

Quote: jetdriven

the benefit is

1. you can calibrate your fuel tank capacity and your totalizer.  Or if you have no totalizer, you know exactly how long the engine has ran from that tank, by carefully setting power and timing the tanks.  Doing so allows you accurately estimate your fuel burn and your time remaining in the other tank.

2. You can extend the range of your aircraft safely. You use all the fuel on one side, and maybe get a couple free gallons of unusable fuel as well.  10 gallons is a reasonable reserve, but fuel guages arent accurate and they will not accurately account for what fuel is in which tank.  if it is in one tank you know how much you got, and even better, its all in one place.  No hoping there is 6 gallons in the left it might actually be 3.   10 gallons reserve both sides is a waste of utility (ours only holds 57 gallons).  We can only take 37 gallons wth 4 in our 201, and if you are going to fly further than 300 miles, you need to manage fuel carefully.   You can also plan your tank to run empty near top of descent, then one fuel tank change then and you are done with the system. Messing with the fuel selector at low altitude (or on the ground) can get you killed.  Most engine failures are fuel related.  

 

So thats the best represntation I can give, I think Ross and Ward are better than me with words perhaps they can add some.