LSAS
I'm rather curious because for the third time in three days someone has asked me about LSAS. I'm not the ultimate authority so bear with me kindly. I did not even know that there was a "book". At the time that Douglas transitioned from the DC10 to the MD11 there was an air of decay hanging all around their enterprise. As 411A can tell you the better engineered big trijet was the TriStar but the demise of R-R didn't help! Douglas took what seemed to be the simpler aerodynamic option for the "straight-thru" engine no 2 but at a structural penalty and some would say a thrust line penalty too. Be those as they may they had a few problems with the boat-tail drag and that cost them development time and money. So you may say that the straight through design was a "bought bunny" when it came to MD11. The DC10 was I believe a "peaky airfoil" and the MD11 I think is first generation supercritical. Yet mindful of their own parlous financial affairs and how nearly the B747 had cost Boeing the farm they put their money on the trijet. They could squeeze more out of the 10 and the longed for 12 might not be a pipedream if only the 11 could sell. What they had to do was cut down on drag, the wing airfoil was I believe pretty good, they were wedded to three nacelles, the fuselage length was a pretty much given so all they could do was look at the tail. Not much could they do with the fin as it had the dual job of being part of the engine support structure. So they cut down on elevator area and hence elevator authority. Now you could do that then but I seriously wonder that FAA would be as accommodating now. That is a personal view so no takers please. To win the FAA round they used two approaches: firstly LSAS which is not a nice to have, whatever will they think of next device but a necessity to counteract the loss of elevator authority. Next along the line they could argue that having a hot engine right there was handy for ice prevention and that therefore the traditional ideas on elevator area could be relaxed. It is interesting to note that when Boeing acquired the marque they quickly saw to it that MD11 operators saw attractive incentives to move on to a twinjet of their own making. Without going into the reason why many aircraft become converted to freighters the MD11 if it really was that goldarn good was unfairly discontinued. I'd say the MD11 requires respect, its tendency to PIO is noted and specific traing is given. It is not a bland machine and many have argued that its delights, and it has many, do not outweight its vices. What interests me is the sudden appearance of interest in an aircraft that will bite hard if mishandled, is a bit controversial accident wise in landing when elevator authority, pitch and PIO can rebder the aircraft geography in a quick space of time. When it hits hard, it does seem to self dismantle but I think that all the mory gory pictures are of aircraft with "history" before the ensuing "geography". In nmy view LSAS was made necessary by Douglas having to make more fuel efficient a design that already had enough shortcomings. Personally I have no great gripes about the MD11 but I take the point expressed so often that whenever extra special care and training is necessary it is a pointer to underlying design issues. Regarding Airbus similarity, there is a certain nodding similarity in the Honeywell but that is about it. This ain't a fly-by-wire aircraft or an earl Airbus either. Really intrigued by the upsurge in interest though. Three times in as many days and I know of no-one hiring. Coincidence?