Love is in the air

A comment was received  on ‘An impossible dream’ concerning the A380 discussed in chapter 1 (pages 6-9) and is here answered. The original comment is printed below. For more comments go to posting June 9, 2009, below.

Thank you for your comments – they are sincerely and very much appreciated.

First, let me say that the book is not in any way intended to be about the Airbus A380 – an airplane and engineering marvel that I greatly admire.  But it is an aircraft that paved the way for composed aircraft, and that is the reason that I included a small section in the book on the A380.

With regards to your specific comments:

I do not fully understand your comment about equivalent passengers. The only purpose of civil aircraft is transporting passengers, their luggage, and cargo.. So it is that small difference in weight between MTOW with and without passengers and luggage that has to make the money. I can’t see how to express that as a percentage – but I will give it some thought.

I do mention in the book:

“What has surfaced is that the A380 is lower on fuel than expected and everybody who has seen the aircraft at take-off or landing has been surprised by the silence of the aircraft – more than 6db below a 747-400 on takeoff and up to 3.7db quieter on arrival. Compared with the 747-400, the A380 requires 17 per cent less runway than the Boeing 747-400 to take off and 11 per cent less to land and cruises at a 4000ft higher initial cruise altitude, a 20 knot lower approach speed and 1100 nautical miles more range ³⁸⁴⁾.”

Aerodynamics do play an important role here, but the main savings indicated above are achieved because of the powerplants. This is an important aspect when considering all composite aircraft where savings on fuel and noise are also (probably only) achieved because of the powerplants.  Which means these advantages can also be recognized with aluminum aircraft. The A380 proves that suburb aerodynamics can be achieved with aluminum-constructed wings.

I am a bit surprised – to be honest – about the giant plane/problems issue. This is definitely not intended to be misleading in any way. The book mentions that the composite structure was a success, as you noted in your comment. It is, however, difficult to deny that the past and present issues with the A380 are largely caused by the enormous scaling, especially with regards to the present issues of ramp-up.  The problems with the wiring would not have been the major issue that it was, and would have been far easier to solve, on a smaller and more traditionally sized aircraft.  It was the size of the A380 that exacerbated the wiring problem to begin with, and then made it such a herculean task to resolve.

The book is not intended to generate scandal; however, it details what I believe to be scandalous behavior with regards to certain issues, but is nowhere cited as such. This does not involve the A380 as a structure, but all-composite aircraft. My only interest is safety, and too many lives have been lost in the past because of ignorance – as discussed in chapter 2.  I see the same patterns being repeated in the industry that cause problems in the past with certain aircraft, and which resulted in unnecessary loss of lives.

I assume that you did read the version on the web. When you download the sections as PDF on ’sex and showers’ you will see that these are in small print – and as such are intended to be ‘entertaining’, but with an underlying message/warning. It appears my humor does not come through here and I will give ‘the obvious joke’ some thought and possibly revise the pitch of the message. Regardless, I appreciate the remark and perspective, but find here a comment – in small print – I received from another source:

You piece about the Singapore  A380 reminds me of a story we heard at the RR Heritage Trust in a lecture by a retired Concorde Captain (presumably they are all retired now?) from BA on his experiences. (He was also relative of a family member who held the World’s Air Speed Record with the Supermarine 6B in the 1930’s – with the Rolls- Royce ‘R’ Engine – the engine which held every World Record  - Air, Land and Water from 1930 until 1939 when record breaking was interrupted – this fact not widely reported).

I digress, – at Mach 2.0 somewhere over the Atlantic en route from  JFK to LHR his reverie was interrupted by the Purser to report that inappropriate behaviour was taking place in the forward toilet with a request for guidance. Were both sexes involved? – Yes. Were both of an appropriate age? – yes. Are other passengers complaining? – No. Is there a queue for the  other facilities? – no. Well let them finish and when they emerge present the lady involved with a bottle of Champagne and invite  her to join me on the flight deck for the landing at LHR. After landing, during which no comment about previous behaviour was made the lady thanked the Captain profusely with ‘Thank You ,Captain for the ride of my life’. Apparently the cpouple had met in the departure lounge with some time before departure and had then found themselves in seats A1 and A2!

Having said that, I am a bit disappointed that you blame Emirates for the stupidity, as only Airbus is to blame – really scandalous, to use your terminology - as I have no doubt that their sales reps overruled sound engineering principles.  This was bound to happen. The ‘fiction’ as I wrote it is not the true version since the plane was apparently on a test flight when it happened. I took the liberty to write it this way (in small print). But looking at it now the first paragraph of this small print section should be ‘large print’. (I wonder whether somebody is going to react on the story of Fred in chapter 3.)

You are correct with regards to AA587. Discussing this very sensitive issue with people closely involved, I’ve since decided on a compromise.

Again, thanks again for your comments and insights.  I would appreciate more of the same.

Best regards,

Hans.

ORIGINAL COMMENT

I’m not qualified to comment on the engineering aspects, but I think some other sections could be improved:

“The target weight had been exceeded by some 5,500 kg (~12,000 lbs) – the equivalent of 55 passengers – regardless enormous effort, but the composed structure was a success and still saves considerable weight – it would have been impossible to fly the A380 without composites”

Comparing the weight to equivalent passengers is useless. Extra weight primarily causes problems for cargo and range. Especially if the MTOW is raised, range will be the only problem. It is also worth mentioning that in this case Airbus delivered on fuel burn *despite* being overweight, even if your point is about composites – not every aspect needs to succeed at exactly 100%.

This should be kept in mind for future models as well: despite being above target weight on the XWB, Airbus already reduced engine thrust requirements once, and then raised them to be either the same or still lower depending on model. This means that low speed aerodynamics are overperforming. The same may apply to the 787, especially if some of that extra weight has been put into a more aerodynamically efficient structure.

I would compare weights in %. 5500 kg means nothing to me given the size of the aircraft, and the other aircraft aren’t even the same size as each other, let alone the A380.

The wiring problem is indeed interesting, but your title should make it clear that the problem wasn’t with the aircraft itself, let alone composites (”A380 – a giant airplane causing giant problems” – MISLEADING given your book’s topic).

Your description of the other problems borders on scandal seeking: “However, soon the A380 disappointed the world at large. In a shock announcement Singapore Airlines warned that when you have the privilege to share one of the private cabins in front of the plane provided with airborne double bed with your secretary, inappropriate activity is not allowed for.”

Disappointed the world at large? Really? Because one airline says you’re not allowed to have sex in its luxurious beds? Come on. Not only is being too silent a simple “problem” that can be remedied in future models, but everyone will just get around it by having sex quietly. Turn this paragraph into an (more?) obvious joke and it’ll be good.

The shower incident is more interesting, but it was Emirates who were stupid enough to want showers. Even if Airbus custom designed the system itself and failed, that’s still unrelated to the success of the A380 program or composites. Besides, how does this support the point you’re making? The cabin section was flooded of all things, but the aircraft still landed safely and needed relatively little maintenance based on the downtime. Seems to me that’s a good thing!

(Had the aircraft crashed due to the nude muslim woman hindering male help, by the way, that would be an excellent Darwin award candidate .

Your comment about AA587 is downright stupid: “The structure fulfilled its duty because the vertical tail has been loaded above ultimate, i.e. outside the certified load envelope, but it might be speculated how a structure out of aluminium reinforced composite would have behaved.” Quite obviously imho, a different material would have had a different weight, but still be designed to 150% in order to minimize it and also failed. If you have more insight into this than I do, explain what you mean.

The A300 doesn’t have flight envelope protection anyway, making this argument pointless