November 30, 20169 yr Pretty much everything is inhibited during the takeoff roll with (mainly) the exception of the fire bell. Even that is inhibited after V1. Except the failure occurred prior to reaching V1, and he RTO'd before reaching V1. Tom Cain Thanks Tom My Youtube Videos! http://www.youtube.com/user/tf51d
November 30, 20169 yr Commercial Member Except the failure occurred prior to reaching V1, and he RTO'd before reaching V1. I believe he meant that "the fire bell is even inhibited after V1." Regardless, they're inhibited from 80 knots through either 20 seconds after rotation, or 400' RA. I know this first hand from being in a sim with a sadistic instructor. Was headed down the runway and after V1 all I heard was "pop" and an engine de-spooling. Glanced down at the EICAS in the rotation to confirm I'd lost what I thought I'd lost matched the pedal I was pressing on and kept on going while I dialed in some rudder trim. Carried on smiling and feeling accomplished, which was probably the reason I then heard "pop" again a few seconds later... Kyle Rodgers
November 30, 20169 yr Except the failure occurred prior to reaching V1, and he RTO'd before reaching V1. Tom Cain That's why he said most everything is inhibited during takeoff roll. ~William Genovese~
November 30, 20169 yr LOL...instructors and their "dial a disaster":...they're all the same sadistic animal.
November 30, 20169 yr This video is from a training simulator, granted it's a 777 but it still shows EICAS warnings on engine failure after 80kts but before V1. Tom Cain Thanks Tom My Youtube Videos! http://www.youtube.com/user/tf51d
November 30, 20169 yr Commercial Member granted it's a 777 That's a 777. This is a 747. EDIT for clarification - from the 747 FCOM: "ENG FAIL" EICAS Message Message is inhibited whenever on ground, through liftoff. Kyle Rodgers
November 30, 20169 yr That's a 777. This is a 747. EDIT for clarification - from the 747 FCOM: "ENG FAIL" EICAS Message Message is inhibited whenever on ground, through liftoff. Even after the pilot RTo's and comes to a complete stop to diagnose the situation? Tom Cain Thanks Tom My Youtube Videos! http://www.youtube.com/user/tf51d
November 30, 20169 yr Hi Tom, Even after the pilot RTo's and comes to a complete stop to diagnose the situation? The ENG FAIL EICAS is inhibited on the ground (inhibit ends at liftoff), so yes. Of course, in a real engine failure there would probably be some other messages that would result in EICAS Caution messages. If this were the case, above 80kts the message would appear on the EICAS, but the audio beeper and the Master Caution lights are suppressed until the inhibit ends (800R or 75kts during the RTO for Master Cautions). I know this first hand from being in a sim with a sadistic instructor. Ah, good old "TRI fingers"... Simon Kelsey
November 30, 20169 yr Why did Boeing choose to inhibit the engine fail warning on the takeoff roll? To avoid distraction? I mean, I know the yawing motion and n1 spooling down on the EICAS are instant indicators but would it not be better for instant crew awareness than ENG FAIL on the EICAS screen? A
November 30, 20169 yr Why did Boeing choose Boeing doesn't come up with these decisions in a vacuum but does convene many committees and panels to dig into minutiae of alarm messages. I've seen a little of this in an industrial setting where experts and operators spend days going over the alarm logic for a single processing unit, you are just second guessing them unless they publish the reasons or you were there. The Boeing groups are comprised of company and client representatives, and sometimes regulators. It is very detailed work. Dan Downs KCRP
December 1, 20169 yr As mentioned above, it wasn't the most popular option (and is regularly U/S) but BA have it (on their B777s and B767s as as well) and so do a couple of other operators mentioned above. It is a very simple and straightforward unit, however. Its purpose is to enable takeoffs in lower visibility that would otherwise be possible. Broadly, the minimum RVR for takeoff for a Category D aircraft like the B747 is 150m (under EASA rules). Using an 'electronic guidance aid' brings this down to 100m, and this is where the PVD comes in (an HUD would also count for aircraft so equipped). The PVD is only operational on the ground (and only unshutters when it has a valid tuned localizer signal and the aircraft heading is within 45 degrees of the runway centreline). The "barber pole" simply rotates in the direction of the centreline, and the faster it rotates the further from the centreline you are. Just apply rudder in the direction the pole is rotating to regain the centreline... That's about all there is to it! An example of the PVD value as an instrument is the Singapore Flight 006 accident. The PVD did not unshutter because the crew lined up on the wrong (closed) runway at CKS. The FO mentioned the PVD unshuttered and the observer commented it needs to be 45 degrees from centerline- HINT! The Captain dismissed it because he had a visual of the runway he felt adequate. Unfortunately ignoring this simple cue cost 83 lives. Joe Colao
December 1, 20169 yr Commercial Member Why did Boeing choose to inhibit the engine fail warning on the takeoff roll? To avoid distraction? I mean, I know the yawing motion and n1 spooling down on the EICAS are instant indicators but would it not be better for instant crew awareness than ENG FAIL on the EICAS screen? To avoid distraction (I believe this is expressly stated in the FCOM). You'll have yaw, you'll have an audible cue, and you'll be looking at the engine display to determine what is going on. You're already aware that something is up. The EICAS displaying a message of "SOMETHING IS WRONG" isn't going to help you identify anything useful in a high workload situation. Having a horn blaring away about a situation you're already aware of will only add unnecessary stress. You have the info you need. Anything more is either going to distract or add stress. Kyle Rodgers
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