Return versus Diversion

[G-CIVA 62]

Yawn,

 

No slander here pal, don't pull the military card either mate, I was also in the military - for over 24 years - chewed plenty of dirt in the two sand boxes & lots of places in between thanks.

 

Since you don't have the grace to include your age in your profile we don't have a clue how old you are.

 

Me I am 48, & retired, absolutely no real world commercial flying experience, go fact check that.

 

Peace & love.

 

Per Mare Per Terram

[skelsey 765]

Hi Wilhelm,

 

 

 

Look in the "Landing" chapter in the FCTM. 

 

Thank you for the reference, which is genuinely much appreciated -- had you directed us there in the first place then perhaps we might have had a more constructive discussion over the last few pages!

 

It provides an interesting read, but I would argue that it does not quite address or nullify the point that I have made. I agree that if you can take off from a runway you should in most cases be able to land back on it.

 

However, that is quite a leap to saying that you can land the aircraft at MTOW in 7,000ft, or that an immediate overweight landing is always the best or most appropriate course of action.

 

I found, incidentally, the source (I presume) for your MTOW/just over 7000ft claim -- a Boeing Aero article from 2007? Again, an interesting insight, but...

 

That just over 7,000ft, as I am sure you are aware, is completely unfactored -- i.e. test pilot, maximum braking, who cares if you can use the aeroplane again afterwards territory. As I mentioned before, if you are on fire and the nearest runway available is 7,100ft long, then that is a much better option than dumping fuel or going down in flames.

 

However, my argument would be that it would be sensible to apply the normal landing distance factors (and, indeed, Boeing do mention this in the Aero article). If you add the usual 15% then you are up over 8100ft assuming a maximum effort stop.

I admit that I may be guilty of imprecise language in my reference to brake energy limitations -- whilst Vmbe itself may not necessarily be a problem, brake/tyre temperature and fuse plug issues may well be and I cannot see how the QRH figures in this regard can somehow become invalid. As such, I would still argue that if you want to land the B747-400 at/near MTOW, and you don't want to trash the tyres, you will clearly want somewhat more runway available than that necessary for a maximum effort stop. How much more? Well, surely the QRH autobrake/brake energy tables would be a sensible place to start...

 

As I have said before -- I am not disputing that in some cases where time is of the absolute essence, a massively overweight immediate landing would be the best option. What I am disputing is that that would be a proportionate response to the sort of incident we have been discussing (i.e. not even strictly an engine failure but an engine shutdown). That is what I had hoped (and still hope) we might be able to have a sensible discussion about.

 

 

 

You and Simon have slander and belittled me while I have tried to add some real world insight into commercial flying.

 

I'm sorry Wilhelm, but that is absolutely not the case. Nowhere have I 'slandered' or 'belittled' you, and I apologise if that is the impression you have had because it has certainly not been my intention. All I have done is state my view and backed it up with facts, quotes and FCOM/QRH references. I have not questioned your experience or credentials, simply asked for references and/or guidance to point me (and others) in the right direction to find the information or do the relevant calculations. On the contrary, it is you whose main argument has been "how many hours do you have?" rather than providing actual data or references.

 

Anyway, back on topic -- I look forward to hearing your views on the merits of an immediate overweight landing as outlined above.