Safety The Human-Engine Interface Many problems, one easy solution BY JAMES ALBRIGHT
[email protected] y first piece of aircraft auto- you to engage the autothrottles for autothrottles had a role to play leading SAICLE/GETTY IMAGES mation was a flight director in takeoff and then simply forget about up to the scene of the accident. Four fol- the Northrop T-38. It was pure them until after landing. And, I must low — each with an autothrottle prob- magic: Two mechanical needles admit, sometimes I forget about them. lem. Let’s see if we can come up with a Mcame into view, one for course and an- But these days, I mostly don’t trust solution. other for glidepath, and you simply flew them during the climb because with the airplane so as to center them. Over the wrong mode of the autopilot they Case Study: Gulfstream the next few years the crossbars turned can result in a stall. Oh yes, I don’t trust GIV, G-GMAC to vee bars, but there was nothing them en route because changing envi- earthshaking until one of my airplanes ronmental conditions can leave us short Problem: There has been a divergence of allowed us to couple those bars to the of thrust. And then there is the descent. opinion in the Gulfstream world on the autopilot. Now, that was neat. And don’t get me started about the ap- proper way to engage and disengage Then came an autothrottle system proach phase! OK, OK. I guess I just the autothrottles. There are two sets of that was good for an ILS approach and don’t trust them.