Intrersting fuel management issue

[Big Pistons Forever]

The original post said the aircraft had 2 crew and 6 pax plus presumably some luggage and full fuel. The last Ho I flew would be significantly over gross with that load if you were using segmented weights.......

Its a Chieftain... With full fuel and 8 people it would be right on max gross. With an up gross and some lighter passengers plus bags it still might be doable.

But hey... go big or go home... right?

a/c empty (guess) 4700
8 pax (guess) 1600
fuel 1092
=7392
Upgross is 7368. The cheiftain I fly has a empty weight of 4900 so I'm betting that theirs is lighter. Either way.. hard numbers to work with.

If you are using segmented weights the only way to get 1600 lbs with 8 people is if they are all women. If they are all men then the weight would be 1876 lbs. You may be do a bit better with actual weights but looking at the average size of the folks getting on a Ho flying in the sticks I doubt it, and we have not even talked about baggage.

With the new rules I do not see how you can on any average run plan on 2 crew plus 6 pax and still carry full fuel unless you are not interested in following the rules, which maybe is a clue as to how and why this incident played out.........

[AOW]

Using segmented weights appropriate for a chieftain, I get 4 males and 4 females is 1576 lbs (winter weights). If one or more of the pax were children, then that number gets even lower. 7 males and 1 child works out to 1587 lbs. so 1600 is not an unreasonable estimate!

If you factor in baggage, they probably had better have had 2-3 kids, but it is theoretically possible to have been under gross.

8 males = 1876? That would mean 234.5 lbs per person. That is much higher than the segmented weights should give you. For a chieftain, type certified for 9 pax, you should be using 178 lbs per female, and 216 lbs per male (6 pounds less in the summer).

[Big Pistons Forever]

From TC Advisory circular 703-004

Appendix A segmented weights for passengers aged 12 years and older (in pounds)
Maximum Certificated Passenger Seating Capacity WINTER
Pax No.- Pax weight
1 – 4: Use actual weights; volunteered weights; or estimated weights. (as described in this document)
......5: 202lbs female 242lbs male
6 – 8: 198lbs female 237lbs male
9 – 11: 191lbs female 229lbs male

4 females + 4 males = 1680 lbs again with no bags

8 males = 1832 lbs

Sorry but I find it doubtful that if you put that aircraft on the scales it would have been undergross

[rum-runner]

From TC Advisory circular 703-004

Appendix A segmented weights for passengers aged 12 years and older (in pounds)
Maximum Certificated Passenger Seating Capacity WINTER
Pax No.- Pax weight
1 – 4: Use actual weights; volunteered weights; or estimated weights. (as described in this document)
......5: 202lbs female 242lbs male
6 – 8: 198lbs female 237lbs male
9 – 11: 191lbs female 229lbs male

4 females + 4 males = 1680 lbs again with no bags

8 males = 1832 lbs

Sorry but I find it doubtful that if you put that aircraft on the scales it would have been undergross

What does being over or under gross have to do with not paying attention to the fuel selector position?
You girls are arguing about something that you have no facts for. i.e you have no idea of the age or sex of passengers and no idea of what they had for luggage. SO......

[human garbage]

The summary in the original post doesn't state how the crossfeed came to be open, or if the crew checked the position of it.
I don't remember at all what the linkage between the control and the valve looks like on any of the PA31s. Given the age of all of these airframes though, it wouldn't surprise me at all if some kind of wear, stiffness or other deterioration of the system or markings contributed to the error.

Its a turn handle in a detent shroud. Has to be lifted up to be turned to crossfeed. I imagine it was made that way because its in a prime position to be swept by a foot as your getting in (bottom of the pedestal). I've never seen one move without deliberate action in other words.

It pretty common to have a cross feed check on a Navajo checklist. Where I used to fly, we would turn it on, activate one of the electric boost pumps, and verify that both sides of the fuel pressure gauge increased, turn crossfeed off and check that the pressure boost was now only on the side with the pump active. Perhaps SOP was the same and they forgot to turn it off. Only a guess.

The crappy thing about the Ho is if the the gauges are off, there is no good way to check fuel level due to the shape of the bladder tanks. Dipstick wouldn't show dick if you were below 3/4 full on the inboards, and about 5/8 full on the outs. Why I hated the super poor gauges on those things. Give me a C206 anyday... The gauges are still crap but at least you can check physically with a stick.

As for the imbalance, I would say it would be noticeable. Granted as another pointed out, the inboards not so much as the outs. Fly with that type of imbalance in the outboards and you would be at 1/4-1/2 of the aileron trim from center. BTDT when I ran the fuel dry at an airport and had to ferry 30nm to fill up properly. I always filled the inboards first due to POH limitations on turns and TO/Landing so I've never had that issue with the ins...

I used to run tons of scheds on the Ho. Six (normal) people and reasonable baggage would take you right to gross on a VG equipped example. I can't say without exact numbers in the case at hand, but it would have been really close either way. The only way we got seven on was if it was almost all females or a child was in the mix.

Glad this situation had a safe ending though! That is all that counts. Live to learn.

[flyinthebug]

From TC Advisory circular 703-004

Appendix A segmented weights for passengers aged 12 years and older (in pounds)
Maximum Certificated Passenger Seating Capacity WINTER
Pax No.- Pax weight
1 – 4: Use actual weights; volunteered weights; or estimated weights. (as described in this document)
......5: 202lbs female 242lbs male
6 – 8: 198lbs female 237lbs male
9 – 11: 191lbs female 229lbs male

4 females + 4 males = 1680 lbs again with no bags

8 males = 1832 lbs

Sorry but I find it doubtful that if you put that aircraft on the scales it would have been undergross

What does being over or under gross have to do with not paying attention to the fuel selector position?
You girls are arguing about something that you have no facts for. i.e you have no idea of the age or sex of passengers and no idea of what they had for luggage. SO......

Agreed! Also, who is to say they used segmented weights? We (and all operators) have the right to weigh each pax if they are willing to do so...so maybe they had some slim men and small women on board. I regularly flew 8 in a Cheiftain as long as they were skinny and/or majority of women. You aren't forced to use segmented weight as long as the pax are willing to be weighed. Like rum . said, what does any of this have to do with a cross feed issue?

Fly safe.

[iflyforpie]

We've been using actual weights for a couple years now... I don't know about on a plane as big as a Chieftain but we can't use segmented weights on our aircraft anymore.

What it has to do with this issue is the lack of airmanship--if the aircraft was over gross. Lots of times, overweight and insufficient fuel or poorly managed fuel go hand in hand... and in an accident the overweight configuration would be a 'finding due to risk' and highlight the type of company culture that allowed a fuel management issue to happen (lack of training, lack of oversight, pressure, etc).

[vstrom]

...so maybe they had some slim men and small women on board. I regularly flew 8 in a Cheiftain as long as they were skinny and/or majority of women.

Fly safe.

Obviously you've never flown outta ThePas before.

[flyinthebug]

...so maybe they had some slim men and small women on board. I regularly flew 8 in a Cheiftain as long as they were skinny and/or majority of women.

Fly safe.

Obviously you've never flown outta ThePas before.

lol, yes...and several places north of there too.

[Big Pistons Forever]

What it has to do with this issue is the lack of airmanship--if the aircraft was over gross. Lots of times, overweight and insufficient fuel or poorly managed fuel go hand in hand... and in an accident the overweight configuration would be a 'finding due to risk' and highlight the type of company culture that allowed a fuel management issue to happen (lack of training, lack of oversight, pressure, etc).

Exactly that was the point I was trying to make

[flyinthebug]

What it has to do with this issue is the lack of airmanship--if the aircraft was over gross. Lots of times, overweight and insufficient fuel or poorly managed fuel go hand in hand... and in an accident the overweight configuration would be a 'finding due to risk' and highlight the type of company culture that allowed a fuel management issue to happen (lack of training, lack of oversight, pressure, etc).

Exactly that was the point I was trying to make

I see the point you are (both) trying to make...but we lack too much information to make the assumptions that the plane was over gross. Nor do we know what the company culture is like there? I realize you and iflyforpie are just speculating and we all do it...but the reason I pointed out that the flight could have used actual weights vs. segmented, was that they very well could have been well under gross.

I think its far too early to hang the crew with these type of comments until we know more about the entire situation. I also think it is irresponsible to correlate poor fuel management, with suggesting they also "naturally" must have also been overweight.

We do know they missed a checklist item. Why? What led up to them missing that? What are their SOPs? We should find these things out before grouping poor fuel management (which is true just based on the fact that it happened, and it did take them a while to figure out what was wrong) and, flying over gross.

Nothing personal guys, I just don't agree with blaming the crew before we find out the "ifs" of the story.

Fly safe.

[AOW]

From TC Advisory circular 703-004

Appendix A segmented weights for passengers aged 12 years and older (in pounds)
Maximum Certificated Passenger Seating Capacity WINTER
Pax No.- Pax weight
1 – 4: Use actual weights; volunteered weights; or estimated weights. (as described in this document)
......5: 202lbs female 242lbs male
6 – 8: 198lbs female 237lbs male
9 – 11: 191lbs female 229lbs male

4 females + 4 males = 1680 lbs again with no bags

8 males = 1832 lbs

Sorry but I find it doubtful that if you put that aircraft on the scales it would have been undergross

Those weights include 13 lbs of carry on baggage. The last few navajos I've looked in didn't have provisions for carry on, so that's where my 178/216 numbers come from. Same AC, or perhaps the updated version that includes certificated seating capacity of up to 25.

[LousyFisherman]

Snip....
After Landing in -------- it was determined that the fuel indication disparity was a fuel indication problem and fuel levels were never physically checked.
Snip.....

What does not checking the fuel AFTER AN INDICATION OF A PROBLEM have to do with the size of the load?

Blatant incompetence if they were amateurs. Negligence if they were supposed to be "professionals". The pilots in question are lucky it was not criminal negligence.

IMHO
LF

[pelmet]

After Landing in -------- it was determined that the fuel indication disparity was a fuel indication problem and fuel levels were never physically checked.

What does not checking the fuel AFTER AN INDICATION OF A PROBLEM have to do with the size of the load?

Blatant incompetence if they were amateurs. Negligence if they were supposed to be "professionals". The pilots in question are lucky it was not criminal negligence.

IMHO
LF

I have to admit, that was what caught my attention the most when I initially read the report. But I am not sure how easy it is on this type.