Classic British Flight Sim

Always a good starting point eh Rob

Garry

Tonks wrote:
VAT... DM was correct. That would be used uf for some reason we had to land straight away and could not dump fuel.

This brings up an interesting point I think. If both options are available, is it better to dump fuel (which is obviously costs money for the wasted fuel) or land overweight (which I imagine costs more through excess stress on the aeroplane and therefore possible extra maintenance or shorter life, and more importantly (but probably not to the company operating the aeroplane) is more dangerous), because I can imagine most operators, being the penny-pinchers that they are, will have some sort of calculation for this to work out how they can lose the least money possible. Presumably if the aircraft was overweight by a large amount then it would be unsafe to attempt a landing before dumping fuel (if possible) and so fuel dumping would make more sense. But if the aircraft was only slightly overweight for landing then chances are there would be negligible extra stress on it and therefore it might not be worth wasting fuel by dumping. How overweight do you need to be before it makes more sense to dump fuel? And does anyone else (particularly GA pilots I would imagine, who directly pay for their fuel themselves) hate to see that precious fuel wasted?

The age old question - when to dump fuel...

As Tonks says, it's not a simple question and is definitely correct in stating that money is never a factor, safety is the only factor.

The dump thing is important too, although I would note here that there is only one manufcaturer who builds aircraft that are unable to dump its fuel - Airbus. Embraer, Bombardier (Canadair/DeHavilland Canada), Boeing, and ATR are all equipped with fuel dump capability as are all of the Russian designs.

The reasoning for Airbus not to provide fuel dump on most of its aircraft (A32x series, A300 series) typically don't carry enough fuel to make dumping fuel an issue. They are sufficiently strong to land at the heaviest normal landing weight and not destroy the aircraft, so Airbus felt it easier to just eliminate the dump system and save a little weight. There have been a few times and a few situations when it probably would have been nice to have a fuel dump capability on those aircraft, but typically it's not an issue.

Pete. Read the whole post please. I didn't say without caveat that no Airbus has fuel dump capability.

Also, the 737 does have fuel dump capability, airlines can choose to leave it off though (and many have). It's the same with the 757 and 767. I've seen aircraft with and without dump tubes on them and some with dump tubes that have been inactivated via a modification to the aircraft that removed the fuel dump valves and plugged the upstream end of the dump lines. Airbus does not offer the A32x series or the A300-600 with fuel dump capability. UPS and FedEx both wanted fuel dump on their A300s but Airbus refused to install the system on the "new build" aircraft, in fact, if you look at the FedEx Airbuses, you'll see the blanked over dump tubes on the aft flap fairing. UPS only has a stub where the tube is on the older aircraft.

Ummm Chris

MD80 has no dump capability either

Leif

Lief, I was speaking of current build aircraft. ("...who builds aircraft...")

Thanks Tonks.

Tonks wrote: I have to say that cost does not come into it!

Tonks

Very glad to hear that.

Going back to Viscount Cornbank's point about high speed tyres, EAA's particular problem was that Nairobi is about 5900 feet AMSL. Thus the actual rolling speed , particularly at daytime temperatures, was close to 190 kts ( I haven't actually got my computer out but it's about that) and the tyre limitations are very important , particularly in the case of a Rejected takeoff close to V1

Absolutely fascinating. I could read posts like this all day.

Thanks for all that info Tonks, you really help to bring it all alive. However, I reserve most gratitiude to DM for including the chinagraph in his models. I'd never get airborne if I had to work it all out for myself :roll: Should be compulsory in all FS models!

Ian