Nr Fairy

1 - Original fuel planning calc error
2 - Error on calculating RPM/MP setting
3 - Didn't plan sufficient diversion fuel
4 - 'Reluctance to fill' due to operator's policy - he's the PIC, not them.
And 5) I would also be surprised if that house was his only possible landing place (although I don't know)

The only time I have needed to offload fuel was when I hired a Piper Arrow at Madison in the USA and had a very oversized passenger. I asked the renting company and they said "no-problem". It wasn't either... the fuel truck pulled up, a special nozzle was put into the tanks and I was asked how much avgas I wanted offloaded. I seemed like a routine job to them and took all of a couple of minutes.

Don't ask me if the avgas went into a separate tank on the fuel truck because I simply don't know, but the speed and efficiency suggested it was a routine operation. I've never seen it done in the UK, although to be fair I have never needed to ask.

Chuck

Yes its a valid point and indicates something not quite right somewhere.

However, consider the following (its not in the AIB report - just surmising).

Guy turns up at aircraft, sees the tech log, and guestimates there is about 30 USG residual fuel. This would be about 1/4 tanks. No point making an inspection, you can't see it when its that low, apparently (from the AIB report). However, he asks the refueller to put in his route fuel, 30USG each side, which would bring it up to about 3/4 tanks each side. Maybe a visual inspection will show fuel, but no telling how much - besides the refueller has just put in enough, hasn't he? Jump in the aircraft, throw the switches, look at the gauges, one says 3/4 - yep, OK. The other says full - "oh, there must have been more left over in that tank than I thought!"

How about the tanks on the return? Nothing said here in the AIB report. However, if an hours fuel had been used, the gauges would show 3/4 and 1/2 - plenty for the return flight of one hour. Plus, no point in a visual check, you can't see the fuel that low down, it seems.

After an hour's flight on the return, the tanks would be showing about 1/2 an 1/4.
From the AIB report, when arriving over Shoreham and performing his checks: "As he did so he noted that the fuel gauges indicated 'half full' for the left wing tanks and a 'quarter full' for the right tanks. Sounds about right doesn't it?

Then the engines quit, presumably because the tanks were empty! Now, the gauges are supposed to be accurate when empty - but they were reading 1/2 and 1/4 full - hey that's WAY out.

Now, if the aircraft landed without fuel there are two reasons, not enough fuel uplifted, or fuel leak en-route. Take a look at the AIB report. Does it even mention this second possibility? Does it even try to investigate this possibility? No! The only comment is "The left wing, outboard of the engine, was almost detached. The right wing was still attached, but the inboard section of the right wing fuel tank had been ruptured by an impact with a low concrete wall. There was little evidence of fuel at the site; some fuel had drained from the right wing down the wall, destroying a small amount of vegetation beneath. There was no evidence of fuel from the left wing."

A fuel leak is not even contemplated, researched or denied. There is no mention that a fuel gauge reading 1/2 or 1/4 for an empty tank is outside the tolerance error on the gauges.

No, either the pilot is lying, or he was genuinely caught out by gross errors in the gauges or there is more to this which has not been properly investigated.

Groundbound

There is no mention that a fuel gauge reading 1/2 or 1/4 for an empty tank is outside the tolerance error on the gauges.

Is this really a requirement? Most planes I trained in were at least that bad, and IIRC G-OMAR was a pretty old plane.

On the one hand people are going over these "details", on the other all this is standard practice in the business...

IO540
it has been my understanding that the only requirement for accuracy on fuel gauges is that they must be correct when reading zero. This, from an instructor.

I think I also remember someone saying this earlier on this forum, Genghis maybe?

Hence, if the tanks were dry the gauges should have indicated zero. If they didn't, then there would seem to be a problem.

Steps on Cessnas
 

All the C150 I have flown have had them

Only the areobat C152's have had them.

All C172's have had them

Lucky I am not a short arse and can still get my leg up high enough so can climb onto the spar with out the step (although this has cost me a pair of jeans splitting). Although normally I only do my first flight in that plane then I go by time after that.
MJ

OK, here is what I am driving at.

Pilot visually checks tanks, Cannot determine how much fuel there is.

Pilot checks fuel guage after getting in airplane and sees one tank indicating full. However he did not see the fuel tank full when he looked into it.

Anyone see something wrong here?

Live and Learn from this accident
 

The first thing to say, is thank the Gods and fate that nobody was killed.

If the flight had been “authorised” by someone other than the Commander, that someone showed a distinct lack of management come Airmanship skills in allowing the flight to depart with half-tanks, knowing, or ought reasonably to have known, the aircraft would arrive back O/H Shoreham with less than what HIS own FOB said it should arrive back with.
What “Authorisation” process did this chap employ – Mickey Mouse’s ?

That the PIC (even a PPL with very limited experience, never mind twin-time) did not ‘twig’ that having filled the machine to half-full (FOB intended at departure 60 US galls) yet in evidence noted after refuelling the Left Tank said “FULL” and the Right Tank said “3/4” - was not too bright for a man with a superior brain - regardless of previous tech log entries he may or not persued.

His intent was that the aircraft departed with HALF its FM quoted TOTAL fuel capacity (128 inc 5 unusable). It did not; even after taking note of the stupid wish of the Clubs management that he returns the aircraft with basically minimum fuel, that should have triggered a warning sign that something was amiss at this early stage ….
eg I’m departing with the aircraft indicating nearly FULL tanks……..how do I get back with basically minimum fuel using my 20 gal/hr Rule of Thumb for a round trip of 2 hrs (plus 2 mins) ?

It was never going to work if he was to please the idiot who “authorised” the flight.

What does this brain surgeon do in his theatre when an oxygen bottle says “FULL” knowing he’s been operating for 6 hours ?

AAIB Report excerpts with my comments in RED.

Ref : http://www.dft.gov.uk/stellent/group...ty_502314.hcsp

After refuelling the pilot noted that the fuel gauges indicated 'full' on the left and 'three quarters full' on the right.

As the aircraft passed through the Shoreham overhead, the pilot began a shallow left turn and started to carry out the Pre-Landing checks. As he did so he noted that the fuel gauges indicated 'half full' for the left wing tanks and a 'quarter full' for the right tanks.

Was that the one and only check he did of FOB ?

In the limited time available the pilot was unable to refer to the emergency checklist during the restart attempts and he cannot recall whether he selected the AUX fuel pump to HI in accordance with the checklist.

Flying solo and having an engine failure, there’s not much spare metal capacity to confirm by check-list your “Engine Failure” drills.

at about 400 feet and pointing directly at the airfield, the pilot realised that he would be unable to glide to the runway and he began looking for a suitable place to land.

It’s a bit late at 400 feet looking for a suitable place to make an emergency landing.

The total fuel capacity is 128 US gallons, with 5 US gallons unusable.

So if you want to depart with HALF tanks……..why accept the situation that tells you the machine is only a quarter of a tank away from MAX fuel load ?

Fuel planning
The evening before the flight the pilot had carried out his navigation planning using a computer based navigation planning aid.
The computer was programmed to assume zero wind for the route and a cruising true airspeed (TAS) of 154 kt with a fuel consumption of 25.5 US gallons per hour (GPH). The computer printout of the plan, which the pilot took with him on the flight, showed a total flight time for the return trip of 2 hrs and 2 minutes and a fuel burn of 52 gallons.
The pilot later stated that he did not rely on his computer programme for fuel calculations but used a 'rule of thumb' rate of fuel consumption of 20 US GPH which had been given to him by instructors during his type conversion training.

The PIC was certainly ‘let down’ by these “instructors” giving him duff gen which was NOT on the side of safety.

He was also aware that G-OMAR was occasionally used for charter flights and that in order to avoid potential weight problems the aircraft operator had an unwritten policy that the aircraft should not be returned with very high residual fuel loads.

As has been said by others, this policy should NEVER deter any PIC of what fuel HE wants over-head.

Accordingly, the pilot calculated he would need 40 US gallons for the 2 hour flight plus 10 US gallons reserve giving a total requirement of 50 US gallons. The pilot further stated that he was in the habit of converting the US gallon figure to Imperial gallons to provide an extra safety margin. Thus for this flight he planned to have 50 Imperial (60 US gallons) on board for the flight.

Fair enough. Having taken into account this logic, it is disappointing to know a mental process failed in further logic after the refuel operation.

Fuel uplift

The aircraft technical log indicates that 30 US gallons remained on board after the previous flight, but the pilot states that he based his uplift calculation on 30 Imperial gallons (36 US gallons) remaining.
To achieve his planned total fuel of 50 Imperial gallons (60 US gallons) the pilot calculated that he needed to load a further 20 Imperial gallons (24 US gallons); he therefore requested the refueller to load 45 litres (12 USG) in each wing tank.
The pilot was unable to explain why he had indicated in the aircraft technical log that he would uplift a total of 30 USG.

If there was 30 US on board already, he needed another 30 to make the FOB 60 he wanted, that is what he planned to depart with. No ?


the fuel gauges in the Seneca III provide a general indication of fuel on board but cannot be relied upon for fine tolerance readings.

“FULL” and “3/4” Full are not noted for being fine tolerance readings.

with an evenly balanced fuel load of 50% or less the fuel is carried only in the two inboard tanks and there is therefore no fuel to be seen in the outboard tank.

Having noted 30 galls before refuelling, and wanting to depart with HALF the full capacity of the machine, it was very unfortunate the PIC did not have a look to verify what the gauges were telling him after the refuel.
If they were in any way reliable (forget fine tolerance readings) he would have seen fuel in the tanks.

The aircraft technical log has a record of arrival fuel, fuel uplift and fuel on board for each flight.

The aircraft had last been filled with fuel two weeks before the accident flight and a total of fourteen flights had been made prior to the aircraft's departure from Shoreham on 2 April 2001.

I cannot believe, having read about this dumb “unwritten” charter flight restriction on returning the aircraft with low fuel states, this machine actually flew 14 flights and NEVER refuelled.
Who would hire this twin (any twin) for anything less than 30 minutes ? So let’s say we have 7 hours flying and using that erroneous Rule of Thumb of 20 gal/hr that’s 140 gallons burnt off……… more than the damn thing can carry. Some Operations department ! Or am I reading this wrong ?

PA 34 qualified pilots of the operating company questioned during the investigation were all aware that the unwritten, but generally widely used consumption figure of 20 USG per hour was applicable to the 55% power settings.

General Aviation Safety Sense Leaflet 1C 'Good Airmanship Guide', published by the CAA, recommends that the AFM fuel consumption figures should be increased by 20% to allow for in-service wear.

The owners who hired this machine out obviously do not subscribe to the above publication.

The Flying Order Book (FOB) for the aircraft operating company requires pilots to take account of the fuel burn for the entire route plus five per cent and carry additional fuel to allow a diversion to a nominated alternate from overhead destination plus a further 45 minutes reserve. A fuel plan calculated in accordance with the AFM and the FOB and using Lydd as an alternate for the return flight shows a total fuel required for the return flight of 73 USG.

Having “Authorised” this flight, what steps did this gent take to ensure his own FOB was being followed ? Very small ones !


Safety Sense Leaflet 1C 'Good Airmanship Guide' recommends that pilots should 'plan to land by the time the tanks(s) are down to the greater of 1/4 tank or 45 minutes, but do not rely solely on the gauges which may be unreliable'.
The Safety Sense leaflet's fuel planning advice applied to the pilot's calculated fuel burn would have given a total fuel required of 71 USG.

I have not read that the PIC intended to follow this good advice – or that he was even aware of it.

FUEL PLANNING.

The pilot based his fuel plan on a 'rule of thumb' provided to him during his type-conversion training.
However, the pilot planned to fly at 154 kt TAS which the AFM indicates requires 23.3 USG per hour.

The pilot calculated his reserve fuel by adding 10 USG to the fuel burn and by adding a further safety factor by converting the final figure into Imperial gallons.
He thus planned to carry a total of 60 USG compared to the 73 USG that would have been required if the flight had been planned in accordance with the AFM and the FOB.

Any “Authorising” Officer worth his salt would know 60 US gallons were not going to be enough for this trip. A terrible management failure. Slack is not the word.

The pilot's fuel plan gave him less fuel than either the FOB or CAA recommend.....

it appears that the fuel on board prior to refuelling was at or very close to the 30 USG shown in the aircraft technical log.

Does not explain how the machine flew 14 trips without a refuel along the way !


Conclusion

The fuel on board prior to departure from Shoreham was at least 54 US gallons.
The actual fuel burned during the flight was approximately 55 USG.
It is therefore possible, but perhaps unlikely, that both aircraft wing tanks emptied within a few seconds of each other.
It seems more likely that the fuel remaining on board when the aircraft arrived overhead Shoreham was very low with perhaps slightly more in the right tank than the left.
At 90 kt the windmill RPM would have been above the maximum for starter motor engagement and the pilot's attempts to restart with the electric starter motor would have had no effect.

A lesson for all.

Running out of fuel can be fatal.
Running short of common sense likewise. I hope owners and operators brush-up on their FOB’s and eradicate stupid and negligent items, and those who plan to be PIC take careful note of this accident and its catalogue of pitfalls and bear traps.

TG

ps Edit was me spelling colour the real way instead of color for the UBBCODE

Of course not, the tech log said there was plenty of fuel :D

TG
Agree with much of what you say but, unless I've misread Datcon's post, you've misunderstood a few points.
eg The aircraft was refuelled several times, but the tanks hadn't been filled for 14 flights. So the last time the actual qty of fuel on board was known for certain was 14 flights previously.
Also, when they were filled, the full quantity fuel on board (128 gals) was wrongly put in the Tech Log, not the usable fuel (123 gals) so everyone after that had been flying with 5 gals less than they thought. And that was before the rest of the errors crept in which made the true figure about 9 gals less than shown in the Tech Log.

I suspect that there was no visual inspection prior to refuelling, since the tech log suggested only about 1/4 tanks - which would not be visible (the AIB report doesn't mention a visual inspection, only checking the drains).

After refuelling, I suppose there was no visual inspection either - since he'd presumably seen it being fuelled with his desired amount.

Back in the cockpit, and the gauges show 4/4 and 3/4, and he thinks "gee, there must have been more fuel left over than I thought", but doesn't get out again to make a visual inspection - to what purpose? He has just seen his route fuel put in, and knows there is enough (ignoring his poor fuel planning and conversion errors) for the flight. Any extra is a bonus, and he doesn't want to bring it back with a lot of fuel - because of the local operators requirements.

Lets suppose he does get out and make a visual check, and sees the left tank is not full. What would he think? "Well, these fuel guages are notoriously inaccurate (just read this thread :)) - but I have put in enough route fuel, plus a half hour spare, so I'm all right."

Doesn't seem an unlikely scenario, and I'm sure a lot of other people would have done the same (excluding the poor fuel burn planning, diversion, and conversion error, of course :) ).

I still think that if the gauges showed 1/2 and 1/4 when the engines quit, as the pilot claims, then this is a serious fault, and merits more comment than has been given in the AIB report.

It doesn't mean that his planning was not at fault. However, without the conversion error, he would have made it back without an accident. Maybe the next pilot who didn't 'fill to the brim' would have had the accident? There had been 14 flights before where the aircraft had not been fuelled to the top. Perhaps they too made mistakes, but no-one is noticing, because they did not fall in someone's garden. Why has none of these previous pilots reported the severe discrepancy in the gauges - they must have noticed surely, since none of them were negligent?

I think the guy's fuel planing was poor, and it was the last link in the chain of events leading to an accident, but I still wouldn't say he was negligent.

groundbound

Why has none of these previous pilots reported the severe discrepancy in the gauges - they must have noticed surely, since none of them were negligent?

Because fuel gauges that barely work are standard in the 1970s general aviation fleet. I don't have my logbook handy but I have flown at least 10 different planes, PA28-161, PA28-181, PA38, C150 C152 and not one of them had gauges which bore more than a passing resemblance to what was actually in the tank. Only on a newish £200k plane have I seen accurate (capacitive sensor) gauges.

When flying with an instructor I didn't worry about the lack of physical checks, even when I knew it was marginal. Stupidly in retrospect, I assumed that HE would do a good forced landing and then I would have rubbed his nose in it. Except once when I knew there wasn't enough (but he thought there was), I refused to fly. But on my own, I used to always go to the pumps and fill right up (or to tabs if a PA28), even if only say 20L went in and I got told off for it afterwards.

Because of the duff gauges, nobody should use them for anything. One fills up with a physical check of some sort, and one uses a timer to change tanks en route (I used to use a cooking timer). The other reason to not rely on gauges is because it is awfully awkward to be flying along and have to stop at a pump when the gauge reads rather low (like one does in a car).

Negligent? That's a legal term, and evidently relying on others' log of operations isn't negligent. But it is pretty stupid. Or is it, when you are taught to do that, and nearly everyone does it? I don't know. I only know what I would not do.

This can go on for ever, because most operators are unable/unwilling to change their procedures They are certainly not going to fix their gauges :O

RTFQ
 

Heliport

Many thanks for sorting out my understanding of the 14 days nightmare, with the word "filled" being the operative word. It would explain things a bit better.

Does that aircraft's particular Tech Log state,
FOB includes "unusable". Or does it state clearly anywhere, "enter only usable fuel" or words to that effect ?

To me, FOB is exactly that..........pilots are expected to know what's "unusable".

Any PIC, on any aircraft, knows even with FULL tanks not all of it will be employable for powering the machine.

Cheers

TG

As an aside on the practicalities of checking fuel, in the R22 the CAA have MANDATED that a secondary method of fuel checking is available, other than the gauges.

For those who don't know, the R22 has one main fuel tank, on the left hand side just below the pylon. There is sometimes an optional aux tank on the right hand side, smaller in capacity. All up about 3 hours worth of fuel. You can see to the bottom of both tanks but there are no markings on the tank to provide any calibration to the naked eye.

There is also a low fuel light which gives about 5 minutes warning of fuel exhaustion.

Anyway - back to the point. The secondary aid is a calibrated piece of metal which is dipped into the tanks. It works well, and if you correlate with the gauges and the amount uplifted you should be OK. It seems that the Seneca, and lots of other types, don't have the ability to even do this, so why aren't we tackling the problem at source rather than blaming a pilot for running out of fuel when there's no easy, simple way to measure fuel contents at source ?

P.S. I preferred the wooden broomstick with marking on it that we used at Bankstown when I was learning to subdue helicopters - it stayed wet for a time after you took it out, and the markings were accurate !

IO540

I don't fundamentally disagree with you. I have been told repeatedly not to trust the fuel gauges - they are only accurate when reading zero - and then its too late!

If I take a C172 or PA28 for a ride, I always look at the fuel gauge and make a visual check of the wing tanks. I also try to check when it was last filled and the flight time since, but not every pilot enters the refuelling into the log book, so its no guarantee.

However, If I am going for a 1 hour jolly in the local area, and the fuel gauges show half tanks and I can see the fuel, I will probably not fill it up, on the (perhaps mistaken) belief that 1/2 tank indication may not be exact but it will not be close to empty, and there should be at least an hour's flight in it.

If I am making a trip, I always fill up before leaving, so I know what I've got.

I even invested in one of those dip stick thingy's which you calibrate yourself by filling the tanks and marking the calibration sheet. However, I left it in the aircraft and it disappeared, as did several of my fuel testers.

The bottom line is that though the fuel gauges are not exact, I am horrified at the thought that they could be wrong by such an order of magnitude as 1/2 tank, or around 30USG, in the case in point.

I rather like Nr Fairy's broomstick idea. If I leave it in the aircraft, nobody's going to steal it as its too old fashioned. :)

Groundbound,

In any C150/152 or 172, IGNORE the fuel gauges. I mean it!! On this thread somewhere I described how I took out a club C152 that was close to empty after I was told it had been filled after every flight. The gauges were showing over half full. I recently got a share in a C150. We filled it completely with fuel, and I was shown that one gauge showed three-quarters full and the other a quarter full! :eek: It made the point for me - you cannot rely on these things AT ALL! As far as I remember, they work by float thingies in the tank, and these can stick...in virtually any position. Hopefully someone will tell me if I'm remembering that wrong, but the bottom line is: IGNORE THE GAUGES!!! Work out your fuel by some other means, or fill up completely if weight and balance means you can.

Unusable fuel shouldn't be included in Tech Logs. Reading Datcon's post, that is also the CAA view.

Heliport the only fuel figure that should ever be written down anywhere is total fuel on board...as Tarten says it's the PIC's responsibility to know what proportion is deemed unusable.

GK430

I can only assume that because the taxi fuel is such a small amount in most 2 or 4 seat trainers a level of complacency comes into play.

My aircraft, an IO550 powered A36, has a EDM700 with fuel flow transducer/computer giving extremely accurate readings (+/- < 1lt) and I use on average about 2 liters from start to airborne. And yes I make allowance for that in fuel calcs.

While fuel gauges on light aircraft in general aren't great I find if I compare fuel gage readings AS CORRECTED BY THE FUEL CALIBRATION CARD and compare that to fuel remaining via the computer I can get pretty good results. Mind you my aircraft would be refuelled to full tanks on average every second or third flight thereby resetting the fuel computer to the programmed full tanks fuel total of 280 liters. A Baron I fly occasionally does not have the fuel computer but comparing corrected fuel gage readings to estimated FOB using realistic FFs and slightly buffering required reserves keeps that safe.

Chuck.

PS so your CAA are very much like our CASA...Cretins Against Sensible Avation.

I agree, ignore fuel gauges. However if they are accurate then they are handy for changing tanks over.

They aren't any good for anything else because one has to take care of fuel in the planning stage.

So you're saying that the figure written in the tech log should be total fuel, and that I should subtract unusable fuel before every flight when making my W&B calculations? And I should subtract unusable fuel when setting the fuel totaliser, which I expect to read zero when there's no usable fuel left?

Isn't it rather more straightforward to record usable fuel and treat unusable fuel as part of the basic aircraft, as is done on W&B sheets? That strikes me as less error prone, given what I've seen of pilots' arithmetic skills after flight.