DLMD-11 From , joined Dec 1969, posts, RR:
Reply 2, posted (14 years 11 months 4 weeks 1 day 2 hours ago) and read 1928 times:
Fly By Wire means that, instead of having physical connections (via hydraulic pipes) between the control yoke and the surfaces, the control unit merely generates computer signals, (like a joystick) which then go thru a computer on the airplane, which then sends an electrical signal to motors etc. on the wing to extend something or retract something such as the ailerons. This is basically it, but even on Airbus FBW aircraft, there is still physical back-up connections to surfaces such as the rudder should all computers onboard fail.
Narrowbody means the aircraft has one aisle (eg. a 757 or A320)
Widebody means that the aircraft has two aisles (eg. 767s and upward)
Anything as wide as / wider than a 767 is widebody I suppose you could say - anything narrower is narrowbody.
A Turboprop engine is a jet engine with a propellor stuck on the front - obviously the prop is geared down in terms of speed from the speed of the main jet shaft - but effectively a Turboprop is a jet with a propellor on the front.
Mach-1 is roughly 760 miles per hour AIRSPEED - AT SEA LEVEL - which is approximately 1200km/h.
Mason From United States of America, joined Jun 1999, 749 posts, RR: 1
Reply 3, posted (14 years 11 months 4 weeks 1 day 2 hours ago) and read 1915 times:
"Fly-by-wire" refers to aircraft that use computers insted of actual linkage to the control surfaces. In other words, the computers move the control surfaces instead of actual cables, or hydrauloc systems. Aircraft that are equipped with this include the A320, A330, A340, and B777. A wide body aircraft is one with two aisles, as opposed to one. And, a turboprop uses a jet engine to drive the prop, but the prop provides the power for the aircraft. The advantage of a turboprop is a much smaller jet engine can be used, since the prop powers the aircraft, and not solely the exhause gasses, although the exhaust gases do provide some power.
NKP S2 From United States of America, joined Dec 1999, 1714 posts, RR: 5
Reply 4, posted (14 years 11 months 4 weeks 1 day 2 hours ago) and read 1904 times:
To put a finer point on FBW,the difference is not what actuates a control surface,but how. Everyone says "cables move the surface" in non FBW,but that's an oversimplification,unless you are referring to DC9/Md80 ailerons and elevators. On a non-FBW a/c that has hydraulically actuated control surfaces,the cable controls a metering valve that will command an actuator to move..proportional to the input by the cable. The hydraulics do the "work",not the cable. FBW,dispenses with the manually operated metering valve and uses an EHSV (elecro-hydraulic servo valve). Basically an elecrically operated metering valve which ports pressure to the actuator,so the actuator moves the surface. The amount of pressure ported by the EHSV is proportional to the amount of voltage sent to it,varied by the control yoke (or whatever) in the cockpit. Advantages include lighter weight,dispensing with the packaging of complex cable runs,as well as others I'm sure. Non-FBW works very well also,I might add.
Mark152 From , joined Dec 1969, posts, RR:
Reply 6, posted (14 years 11 months 4 weeks 1 day ago) and read 1894 times:
Remember that the speed of sound in air decreases with height above the ground (the air density decreases as you go higher). Therefore you must remember that the mach speed of an aircraft varies with altitude even if it is travelling with the same airspeed.
Bbinchi From , joined Dec 1969, posts, RR:
Reply 8, posted (14 years 11 months 4 weeks 22 hours ago) and read 1884 times:
Perhaps this will make it easier to understand:
A DC8 is configured just like a 707, 727, 737, 757, 319, 320...with one aisle running down the center of the cabin. It has many rows of seats and each row is split into two sections with the aisle as the dividing line between sections.
For example, when standing in the Coach cabin and facing the cockpit, you would have for Row 1 (left to right):
seats A,B,C then the aisle and then seats D,E,F.
Of course, this pattern is repeated for every row in the cabin.
A wide-body aircraft, such as the DC10, MD11, L-1011, 767, 747, 777, 300, 310, 330, 340 has two aisles running the length of the cabin. The aisles split each row of seats into three sections. For example, on an American Airlines DC10 or MD11 in Coach:
From left to right (facing the cockpit) you would have in Row 1:
seats A,B then an aisle, then seats C,D,E,F,G then another aisle then seats H,J.