Ditching - how to do it

[ExSp33db1rd]

.......The bad news is you may be 7 or 8 hours into the trip when you hit the no go mark and have to turn around and fly another 5 or 6 hours back.......

That's the optimistic view - what happens when you are WAY beyond your PNR - at which point everything was on plan - and now have no option but to continue into unforecast increasing headwind.

Splash.

Never had to do it, only ever flown that route at 35,000 +ft or so with 4 engines and more fuel than one could possibly need, i.e. flt. plan plus diversion plus 10% plus a bit for Mum - just in case.

Way to go.

The only time one has too much fuel is when one is on fire.

Not that he had any choice of course, he would doubtless have tanked up to the maximum.

I've just sold a final 10 litres of Avgas to a guy setting off from Northern New Zealand to Norfolk Island (part way to Oz. ) he insisted on absolutely full tanks to the last drop.

I knew another guy who flew up to the very top of NZ, illegally landed in a field and stashed away a couple of cans of fuel under the hedge, then flew back to the Customs airfield of departure for the night, some 45 minutes away. Next morning he cleared Customs, flew to his field again and topped off his tanks with his stash before also setting off across the Tasman to Aus.

But that's another story !

[Big Pistons Forever]

Originally Posted by ExSp33db1rd

That's the optimistic view - what happens when you are WAY beyond your PNR - at which point everything was on plan - and now have no option but to continue into unforecast increasing headwind.

That is what reserve fuel is for. The bottom line is as you are approaching the PNR you have to have your planned reserve fuel at destination. If you don't because the head wind component have not decreased as forecast then you have to turn around. This only works with a weather pattern that gives you strong headwinds to start but which are forecast to diminish throughout the trip.

You would have to be out of your mind to takeoff with a forecast increasing headwind along your route of flight.

[ExSp33db1rd]

You would have to be out of your mind to takeoff with a forecast increasing headwind..........

Agreed, but I did say .......

......unforecast increasing headwind.

and what about the " bit for Mum " do you keep it to the end, or use it enroute ?

One of our guys was approaching New York and was advised of a 45 minute hold, and experience was that such delays usually lengthen, so had he continued he would, eventually, have still been airborne in the hold below the minimum reserve fuel required, so diverted to Boston, where the weather was worse, but manageable. Arriving Boston the weather had deteriorated below limits. Had he continued to New York he would, most likely, have by then landed without trouble - but been "illegal"; he has now no alternate fuel left, having used it diverting, and almost used his 'bit for Mum' and has nowhere to go - but he had done everything 'by the book' and was 'legal'. - but nearly dead. Eventually ATC managed to get him into a Military airfield nearby.

Don't pick me up on detail, many moons ago, can't remember all the figures, but the point is that despite ones' best efforts Murphy is always with us.

[moreflaps]

Damn only 13 miles short! Could he have glided in if he had kept high while he had fuel?

Cheers

[IO540]

I dont get why a flight into a forecast reducing headwind is smarter than a flight into a forecast increasing headwind.

A wind forecast is only a forecast.

Anytime the general weather pattern shows a significant wind relative to ones range, one needs lots of reserve.

I am sure this pilot had lots of reserve, but evidently not enough - unless something else happened e.g. A fuel system problem.

[Big Pistons Forever]

Originally Posted by IO540

I dont get why a flight into a forecast reducing headwind is smarter than a flight into a forecast increasing headwind.

If you have to turn around prior to the PNR, would you rather have a large and likely increasing tailwind or a small and likely decreasing tailwind ?

[IO540]

If you have to turn around prior to the PNR, would you rather have a large and likely increasing tailwind or a small and likely decreasing tailwind ?

I would take a view of the overall wx pattern. There is no simple answer. The way you pose the question has no practical meaning.

The accuracy of a forecast varies widely according to the weather. So e.g. The light winds prevailing within a large area of one or multiple high pressure zones are basically unforecastable. They may all be within 10kt but nobody can tell which way it will go and at what altitude. Same with a region of multiple (but weak) lows. If you have an aggressive frontal system OTOH then the situation is better defined but the winds along a route are much more sensitive to timing because the whole lot is likely to be moving at some speed, and forecasters routinely get the speed wrong i.e they forecast the wx ok but for the wrong time.

For me, the only way is to disregard tailwind (unless there are so many alternates along the route that it is moot) and take the worst case headwind as constantly present.

In the TB20, this policy makes Crete easily reachable from the UK with one fuel stop somewhere nice. If one took tailwind into account one could do all kinds of things and possibly LGST would be reachable nonstop (1450nm) but none of the alternates have avgas so if you screw up.... Not all that different to this ferry flight really except there was not just no avgas but no runway too.

But then i dont ferry to Hawaii

[GWYN]

Ray Clamback anyone??

[Big Pistons Forever]

Originally Posted by IO540

. The way you pose the question has no practical meaning.

Actually the way you are posing the questions has no practical meaning.

The bottom line is simple. Ferrying aircraft across the Pacific is not something private pilots do. Virtually all of theses flights are done by professional ferry pilots. A PPL like yourself would find it almost impossible to get insurance for the trip.

Obviously the preferred situation is a weather pattern that will produce light winds, preferably from behind you, for the entire route, thus being in the position that you will be fat on fuel right from the the time the wheels leave the ground. However this is unlikely to occur at this time of the year.

It is simply unrealistic for a ferry pilot to wait for these conditions as it may mean a delay of multiple weeks. The alternate is to launch into the forecast reducing headwind with the turn back option kept open by a careful monitoring of the flight progress. Most of the time this works out fine and by the time you get to the PNR you have enough fuel to continue with adequate reserves. Occasionally the wind Gods do not cooperate and you have to turn around which obviously sucks big time.

Very Very occasionally the pilot gets it wrong and thereby makes the news along with a a lot of speculation by folks who do not have the specific knowledge and experience of trans oceanic flying to be credible when criticizing the decisions of a pilot.............

[IO540]

professional ferry pilots.

How do you define that?

A PPL like yourself would find it almost impossible to get insurance for the trip.

FWIW, I am not a PPL

when criticizing the decisions of a pilot

Criticizing when?

If I was going to criticise Mr Mellor's decisions (which I know nothing about) I would first get the historical forecasts and actuals for his route, and post them here. Then it could be discussed properly. I haven't done that, so... but neither has anybody else. (I have done that in some other accident cases which were discussed here).

So, over to you, BPF. As you clearly are a "professional" pilot, your contribution to knowledge in this area would be enlightening (seriously). Let's see the weather for the route, and how would you plan it.

[Big Pistons Forever]

Originally Posted by IO540

I wonder if he had a GPS-linked fuel totaliser.

If not, that's a very brave pilot, relying on the gauges in that old heap and the POH figures.

Rather sounds like a "criticism" to me
but maybe I am just a sensitive soul

Fuel totalizers are only as good as the "K" factor set and the condition of the transducer. If you fly only one aircraft, over time you can really dial it in, and they will give amazingly accurate results. But if I am in flying a strange aircraft I look at what the totalizer tells me with a very jaundiced eye. Only after several legs where I have been able to compare the fuel uplift values with the totalizer will I believe what it is telling me, and this of course requires filling the tank to the brim which may not be possible on every leg.

Bottom line: The presence or absence of a fuel totalizer is only one very small factor in a successful (or not) trans oceanic flight .........

[IO540]

I know a ferry pilot who never does USA-Europe jobs unless he can pick the plane up well inland before the US coast, so he gets a chance to suss it, over some hundreds of miles over land, before heading out to Greenland. So he can see the oil consumption, etc. Apparently a significant % of ferry jobs which start right at the US coast are cases where a previous ferry pilot abandoned the plane because he didn't like something about it

100% right about checking a fuel totaliser. Again, this could be done over a single tank fillup. I know quite a number of pilots with totalisers and would bet that half of them do not use them because they don't know how to, or because nobody ever set the K-factor so the thing is 10-20% off.

[Big Pistons Forever]

Originally Posted by IO540

100% right about checking a fuel totaliser. Again, this could be done over a single tank fillup .

I would argue one fill up is not enough. I have twice seen intermittent transducers. The totalizer would work great on some flights, but under count on others. The bad news is when totalizers lie they will almost always say you have more fuel than the actual amount in the tanks

[IO540]

The totalizer would work great on some flights, but under count on others.

If you keep half an eye on the systems, you should spot that.

The way one normally works is that you level off in cruise, set up the engine etc, and look at the appropriate GPS page to see the computed FOB at the loaded destination. On most flights, this figure changes suprisingly little through the flight. Tailwind improves it of course, and headwind degrades it. But the nearer you are to destination, the less difference the wind makes, obviously.

If you have a sticky transducer, which is possible but is extremely unlikely to be thoroughly sticky on some flights and perfectly OK on others, you will see wild fluctuations in the computed LFOB (landing fuel on board) figure. Not to mention wild fluctuations in the current flow rate indicated on both the flow instrument and the GPS page.

Some notes here and here

[Big Pistons Forever]

Originally Posted by IO540

If you keep half an eye on the systems, you should spot that.

Some notes here and here

You do have a gift for stating the obvious

As for your assertion that you can't have a intermittent fuel transducer......well all I can say is that is exactly what I saw. It was right on on some flights and 10 to 25 % off on others with no wild fluctuations of fuel flow or gallons remaining. A replacement fuel totalizer for stupid dollars instantly and permanently fixed the problem. The other failure was a wiring issue and it was as you say pretty obvious. I guess the moral of the story is when dealing with GA systems "never say it can never happen"

Thanks for posting your notes on fuel totalizer systems, I learned some stuff I did not know about the unit

[ExSp33db1rd]

The bad news is when totalizers lie they will almost always say you have more fuel than the actual amount in the tanks

.......with GA systems "never say it can never happen"

...and not only GA.

Murphy is always with us.

The only time to believe fuel system 'gauges' is when the say 'empty' !!

[Jetblu]

Fuel totalizers are not by any means your get out of jail free card for fuel management. I have seen many errors with them.

Maybe, it was the fuel totalizer that gave the pilot incorrect information here ??

Anyway, the thread was about ditching. It was a perfect ditching by a very experienced pilot whom I guess is grateful that it was a Cessna 310 and not a leaky TB20 It was most certainly not a gps approach on autoland