Coordinate that turn to final

Topics related to accidents, incidents & over due aircraft should be placed in this forum.

Moderators: sky's the limit, sepia, Sulako, lilfssister, North Shore

photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

According to your correspondent, this was a commercial flight. Gulfstreams are GA, so are Boeing business jets. Not sure what GA has to do with it being ok to mis-manage your fuel system.

And this is not a hanging. The pilot learned a cheap lesson about the C172 fuel system. Let’s all get the benefit and do the same.
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
User avatar
rookiepilot
Rank 11
Rank 11
Posts: 4403
Joined: Sat Apr 01, 2017 3:50 pm

Re: Coordinate that turn to final

Post by rookiepilot »

photofly wrote: Sun Jul 08, 2018 6:51 pm According to your correspondent, this was a professional flight. Gulfstreams are GA, so are Boeing business jets. Not sure what GA has to do with not managing your fuel system right being ok.
deleted.
---------- ADS -----------
 
Last edited by rookiepilot on Mon Jul 09, 2018 7:23 am, edited 1 time in total.
Big Pistons Forever
Top Poster
Top Poster
Posts: 5861
Joined: Wed Feb 18, 2004 7:17 pm
Location: West Coast

Re: Coordinate that turn to final

Post by Big Pistons Forever »

I think this thread generated a good discussion. I bet many persons who read it learned something they did not know about high wing Cessna fuel systems, maybe even someone who flies a C182RG :wink:
---------- ADS -----------
 
digits_
Top Poster
Top Poster
Posts: 5931
Joined: Mon Feb 14, 2011 2:26 am

Re: Coordinate that turn to final

Post by digits_ »

photofly wrote: Sun Jul 08, 2018 6:40 pm I know why I think the engine stopped: because the “professional” pilot starved it of fuel.

Why do *you* think the engine stopped? how could he or she have screwed it up? Give me your hypothesis.
It is possible that the pilot flew with the fuel tank selector not in the both position, and/or with an empty tank in an uncoordinated attitude for a prolonged period of time.
The reason for the wrong fuel tank selector position could be a wrongfully labeled or otherwise faulty selector. Or pilot error.

This does not mean that running a tank dry in a C172 is illegal, dumb or otherwise bad airmanship. You just need to be able to handle the situation and research it if you are planning on doing so.

I see some references to my remark about a commercial flight, and noticed I didn't really explain why I mentioned that. If it was indeed a commercial flight, it would be reasonable to assume the pilot has spent a lot of time in this plane, flying similar flights, and should thus be familiar with the fuel consumption, tank contents etc. This just to add that in such a situation, running a tank dry as a technique to have a better estimate of fuel left on the plane, is not irresponsible.

On a side note: even if one tank is dry, and even if you run on the other tank only, if the air is smooth and you only do smooth manouvers, there's no reason why the plane shouldn't be able to land without issues. Obviously not allowed by Cessna, and a really bad idea to try -and this is not an invitation or encouragement to actually try that-, but a crash/engine out scenario is not the only possible outcome. In most cases, probably nothing would happen.

@photofly: thank you for the pictures. Take a look at this experiment if you have time: http://www.sumpthis.com/cessna150andces ... 24x768.htm
It is about a 150 (and a metal tank), but the principle should be the same. It shows that on earlier models, a fuel drain is not necessarily placed at the lowest spot in the tank. In later models this has been fixed by adding a bunch of fuel drains on the somewhat newer 172s. It shows that there can be a significant amount of fluid (they use water in the example) in the tank before it gets picked up by the engine pickup or fuel drains. Unusable fuel can be inaccessible during "normal" straight and level flight. It's great if your plane can use all that fuel, but it is not a guarantee, and it is definitely not the case for all airplane models.
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

Once again, you miss the point.

I’ll try again.

1.Fuel planning is based on useable fuel.

2. The amount of fuel you can drain from a tank until it’s dry is not equal to the useable fuel in the tank. In most models of Cessna 172 it’s 2 gallons more than your useable fuel. In other planes it might be a different amount, but it’s still not the same as your useable fuel.

3. Running a tank dry doesn’t inform you about your useable fuel, and therefore doesn’t assist you with fuel management.

4. Cessna explicitly warns against running a tank dry for fuel management purposes. The aircraft manufacturer says it’s not accurate.


In this case the pilot starved the engine of fuel: it would be entirely unreasonable to assume that he or she was familiar with the fuel system, or he or she would not have allowed that to happen.
The crash/engine out scenario is not the only possible outcome.
That makes it all ok then...?
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

This does not mean that running a tank dry in a C172 is illegal, dumb or otherwise bad airmanship. You just need to be able to handle the situation and research it if you are planning on doing so.
I’d prefer to use a technique that doesn’t require me to handle a power failure on short final!
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
digits_
Top Poster
Top Poster
Posts: 5931
Joined: Mon Feb 14, 2011 2:26 am

Re: Coordinate that turn to final

Post by digits_ »

photofly wrote: Tue Jul 10, 2018 3:15 am Once again, you miss the point.

I’ll try again.

1.Fuel planning is based on useable fuel.

2. The amount of fuel you can drain from a tank until it’s dry is not equal to the useable fuel in the tank. In most models of Cessna 172 it’s 2 gallons more than your useable fuel. In other planes it might be a different amount, but it’s still not the same as your useable fuel.

3. Running a tank dry doesn’t inform you about your useable fuel, and therefore doesn’t assist you with fuel management.

4. Cessna explicitly warns against running a tank dry for fuel management purposes. The aircraft manufacturer says it’s not accurate.
1. Agreed
2. Sort of, you might not be able to drain all the fuel out of it. But yes, if you could, everything you drain out of it would be usually bigger than the usable fuel
3. I accept your premise but I reject your conclusion. Worst case scenario, you'll have a calculation that is off by the unusable fuel left in the tank. You don't know if the first tank burned the usable fuel, or not. So in the other tank, you could have [remaining time according to fuel burn on left tank] - [whatever the unusable fuel is for that tank] left. So an uncertainty of 2 USG in this example. This is still more accurate than training to read the fuel gauges on most vintage C172.
4. Agreed, but neither are the fuel gauges in most small planes.
photofly wrote: Tue Jul 10, 2018 3:28 am In this case the pilot starved the engine of fuel: it would be entirely unreasonable to assume that he or she was familiar with the fuel system, or he or she would not have allowed that to happen.
*IF* it was his fault, he could be extremely familiar with the system yet have forgotton to select BOTH tanks. There is not enough info in the CADOR to explain exactly what happened.
photofly wrote: Tue Jul 10, 2018 3:28 am
The crash/engine out scenario is not the only possible outcome.
That makes it all ok then...?
No, it merely indicates that is likely that there is another factor to this incident. It's not just landing with one dry tank, there has to be something else: uncoordinated flight, turbulence, possibly lack of knowledge, etc.
photofly wrote: Tue Jul 10, 2018 3:28 am
This does not mean that running a tank dry in a C172 is illegal, dumb or otherwise bad airmanship. You just need to be able to handle the situation and research it if you are planning on doing so.
I’d prefer to use a technique that doesn’t require me to handle a power failure on short final!
Yes, good point, because I clearly said I prefer engine failures on final.

People ground loop tailwheel airplane in crosswind occasionally. Does that mean that crosswind or tailwheel planes are dangerous or irresponsible and should be avoided? No, only that you need to be able to handle it by training and/or research before you attempt such a thing. Just like running a tank dry.
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

If I thought that running a tank dry was a useful thing to do in cruise in a 172 (I don’t) then I’d make sure to switch the tanks to BOTH for long enough to refill the dry tank with a few gallons before landing.

Landing with an empty tank is dumb. it shouldn’t have to be “handled”, it’s avoidable.
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
digits_
Top Poster
Top Poster
Posts: 5931
Joined: Mon Feb 14, 2011 2:26 am

Re: Coordinate that turn to final

Post by digits_ »

photofly wrote: Tue Jul 10, 2018 9:06 am If I thought that running a tank dry was a useful thing to do in cruise in a 172 (I don’t) then I’d make sure to switch the tanks to BOTH for long enough to refill the dry tank with a few gallons before landing.
Yes, that would be a consequence from landing with a fuel selector in BOTH and not flying uncoordinated for more than 30 seconds. If you do that, the empty tank would most likely not be completely empty anymore, although that's not necessarily guaranteed.

photofly wrote: Tue Jul 10, 2018 9:06 am Landing with an empty tank is dumb. it shouldn’t have to be “handled”, it’s avoidable.
I never said landing with an empty tank needs to be handled. Running a tank dry needs to be "handled": know how long the engine could possibly quit, so be high enough to deal with it, don't fly uncoordinated and follow the checklist: tanks BOTH for landing. I even think most checklist call for it on downwind/5 miles out? Oh, and check if your airplane type actually allows that, I think there are some types that don't deal with empty fuel tanks very well.
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
User avatar
HiFlyChick
Rank 5
Rank 5
Posts: 386
Joined: Fri Aug 06, 2010 8:27 am

Re: Coordinate that turn to final

Post by HiFlyChick »

To the OP:
Where did this narrative of this incident come from? I just searched the CADORS by region and by operator name and can't find anything
---------- ADS -----------
 
TT1900
Rank 3
Rank 3
Posts: 153
Joined: Tue May 15, 2018 8:19 pm

Re: Coordinate that turn to final

Post by TT1900 »

photofly wrote: Tue Jul 10, 2018 9:06 am it shouldn’t have to be “handled”, it’s avoidable.
That’s true for any number of things in aviation. People make mistakes then need to work their way out of bad situations they’ve put themselves in. 99% of the time it all works out but every now and then someone gets bit, sometimes hard. If you’re telling me it’s never happened to you then I’ve learned one of two things: a- you’re incredibly inexperienced or b- you could benefit from an enema.

Acting like you’re above this is ridiculous. Jumping to conclusions about the pilot and his actions based on such limited information is foolish. There are normally a confluence of factors in an accident, hence why it often takes professional investigators significant time to reach a reasonable conclusion.

I truly hope it isn’t, but one day it could be you. I’m sure you’d appreciate the benefit of the doubt if it is.
---------- ADS -----------
 
photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

I’ve made many equally silly mistakes as this pilot, without doubt. And learned a cheap lesson from each one. I’m not really interested in what the pilot did wrong from a personal point of view, except we should all make sure not to land with an empty tank in a 172. From that point of view, the thread title is stunningly inappropriate.
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
User avatar
PilotDAR
Rank 11
Rank 11
Posts: 4053
Joined: Sun Sep 30, 2012 6:46 pm
Location: Near CNJ4 Orillia, Ontario

Re: Coordinate that turn to final

Post by PilotDAR »

we should all make sure not to land with an empty tank in a 172
As a matter of good practice, in common situations, yes.

There are rare times when fuel tank selections take on more importance. Twice, I have had fuel loss from an improperly fitted flush fuel cap (one 177RG, one P206). In both cases, noting an abnormal fuel consumption/loss, I figured out the problem, and managed fuel. The first thing I did was to switch to the draining tank, to get the most benefit of what was left, before it disappeared, and isolate the other tank. Then, once dry, I changed to the other tank to prevent crossfeeding what fuel I had left (moot in the P206 - no "both"). I was certain to assure that the tank with fuel was on the high wing, with coordinated turns, while maneuvering. I viewed this as an emergency fuel management procedure, necessary, but unwise in normal flying.

Understand your fuel system, and learn to optimize its function. And, fly your plane coordinated, unless there's a reason to slip it!
---------- ADS -----------
 
pelmet
Top Poster
Top Poster
Posts: 7138
Joined: Tue Jun 14, 2005 2:48 pm

Re: Coordinate that turn to final

Post by pelmet »

photofly wrote: Thu Jul 12, 2018 7:50 pm the thread title is stunningly inappropriate.
Actually, I find the title quite appropriate. It brings up a good discussion about the potential consequences of uncoordinated flight at lower levels of fuel quantities in fuel tanks even if there was more to the story in this particular incident.
---------- ADS -----------
 
photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

It's a bit like heading a discussion of the sinking of the Titanic with "don't sail to New York in winter."
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
pelmet
Top Poster
Top Poster
Posts: 7138
Joined: Tue Jun 14, 2005 2:48 pm

Re: Coordinate that turn to final

Post by pelmet »

photofly wrote: Sun Jul 15, 2018 7:46 am It's a bit like heading a discussion of the sinking of the Titanic with "don't sail to New York in winter."
A meaningless statement. The thread has had some good discussion about the title of the topic.....the critical importance of being in coordinated flight when fuel quantities are extremely low.

The only thing that is stunning is your assumptions of what the pilot did as if they are fact when in fact, it is based on no evidence. Which is unlike myself that started off with the statement...."Of course, the exact details of this accident are unknown but...…" and then discussed about the thread title.

By the way...the Titanic sank in the spring of 1912.
---------- ADS -----------
 
photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

As I said, I don’t really care what this particular individual pilot did or didn’t do, except that he or she landed with one dry tank. Which is a terrible idea because it can easily lead to an engine stoppage. To the extent they failed to prevent that, they suck. let’s all try not to suck: let’s all try to have some fuel in both tanks, and be feeding fuel from both tanks, when we land a 172.

The fact that the Titanic actually sank in Springtime makes this thread even more like one titled “Lessons from the RMS Titanic: Don’t sail to New York in winter.”
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
TT1900
Rank 3
Rank 3
Posts: 153
Joined: Tue May 15, 2018 8:19 pm

Re: Coordinate that turn to final

Post by TT1900 »

photofly wrote: Sun Jul 15, 2018 10:27 am As I said, I don’t really care what this particular individual pilot did or didn’t do, except that he or she landed with one dry tank.
How do you know it was “dry”? Weren’t you part of a big thing about usable/unusable/measureable fuel? I’ll admit, I know nothing of Cessna fuel systems other than what you posted. Seems like it could have been reading empty with up to 2gal remaining that would still be feeding. So I ask again, how do you know it was dry? (Hint: You don’t).

You don’t care what the pilot did or didn’t do to get to the point where he binned an aircraft for the most horrendously simple (paraphrasing you) error going? You’re not curious about what led to his actions/inactions leading up to the event, assuming it was within his control? Screw learning how to address root error, just don’t make the mistake and the mistake won’t happen. Fantastic philosophy......SMH.
---------- ADS -----------
 
C.W.E.
Rank (9)
Rank (9)
Posts: 1262
Joined: Mon Dec 18, 2017 2:22 pm

Re: Coordinate that turn to final

Post by C.W.E. »

Screw learning how to address root error,
So tell us all about addressing root error, it sure sounds interesting.
---------- ADS -----------
 
photofly
Top Poster
Top Poster
Posts: 11306
Joined: Tue Jan 18, 2011 4:47 pm
Location: Hangry and crankypated

Re: Coordinate that turn to final

Post by photofly »

TT1900 wrote: Sun Jul 15, 2018 1:15 pm
photofly wrote: Sun Jul 15, 2018 10:27 am As I said, I don’t really care what this particular individual pilot did or didn’t do, except that he or she landed with one dry tank.
How do you know it was “dry”? Weren’t you part of a big thing about usable/unusable/measureable fuel? I’ll admit, I know nothing of Cessna fuel systems other than what you posted. Seems like it could have been reading empty with up to 2gal remaining that would still be feeding. So I ask again, how do you know it was dry? (Hint: You don’t).
There are two possible explanations:

Either the fuel selector was not on BOTH at the time of landing, which contravenes the operation procedures in the POH and the mandatory placards in front of the pilot. (Note that the pilot did not report that he or she failed to follow the mandatory procedure, so let’s take them at their word.)

Or, alternatively, one tank was completely dry and the selector valve was set to both so late in the landing procedure that the empty tank didn’t have time to refil from the partially full tank. For sure, with only 5 gallons in the “full” tank, it won’t cross feed very fast.

If there had been the two gallons of “unusable” fuel in the left tank, and 20 litres of usable fuel in the right, the engine would not have quit.

We will never find out exactly the sequence of errors that pooched this flight. Never. Let’s instead learn not to empty a tank, and remind ourselves, if we need to, to make sure the fuel selector valve is set to BOTH as the manufacturer demands.

I’m curious to know what anyone else thinks the root error is. Perhaps the pilot should have had more rest, or not eaten the prawn cocktail for lunch.
---------- ADS -----------
 
DId you hear the one about the jurisprudence fetishist? He got off on a technicality.
Post Reply

Return to “Accidents, Incidents & Overdue Aircraft”