Eff Oh,
I will try to fill in the blanks here. I think you don't give me enough credit here...
Now, correct me if I'm wrong:
Before the pilots left their origin (i.e. preparing the FMC prior to taxi out) they typed into FMC the ZFW for the flight in question. This data is a constant for the flight in question (if the pax and cargo didn't jump out the window lol). The 767 has sensors that "sniff" the amount of fuel in the tanks. Also, if one disagrees with the calculated fuel (found in PERF INIT), one can manually enter the assumed right value.
Now, with this information, the FMC is able to make up the Gross Weight, which simply equals the ZFW + fuel. This weight changes as the flight progresses as the CALC fuel diminshes ... At least in the Honeywell FMC that I'm very familiar with, the Approach page does contain the Approach speeds that are calculated from those very figures. So, to answer your question: I wouldn't have to calculate anything. Please tell me what's amiss here ...
Secondly, if I faced the situation that I had no speed information available through the FMC, I would check what our current calculated GW is and estimate an app speed probably a little above the "right one". Would you say that for a 767 with, say, 20klbs of fuel left with a ZFW of ~ 250 klbs a Flap 30 speed of 135-140 would be so far OFF that it would actually CRASH the plane upon touchdown. I would think that some kind of rough estimation would be enough, IF in the rare case there was something wrong and an app-speed couldn't be read from the CDU. I'd like to add that I would always go for a bit higher estimation for the APP speed, and if it would regardless of that end up too slow, the situation wouldn't go unnoticed as the plane would start to pitch over 5 degrees ANU early in the approach. I'm not blind you know...
Secondly, what is there to explain about the flaps? The 767 (and 757) even has Vfe speeds for every setting beside the flap indicator gauge. Also, in the Pegasus-type EADI the red flap- speed zones are clearly visible in the speed tape.
Well, I'll write some detailed information to be more specific.
I'd make sure that I was ~ 5000ft 20-30 miles out, just to be on the safe side. Then I would gradually slow down and would lower the flaps on schedule. The schedule is this, and I would slow down to below Vfe speed before lowering the corr. setting:
flaps 1, 250 IAS
flaps 5, 230 IAS
flaps 15, 210 IAS
flaps 20, 210 IAS
flaps 25, 180 IAS
flaps 30, 170 IAS
I would lower the gear once the G/S came alive, and I assume that I would do this (to be on the safe side) already 10 miles out.
As for the max speed for gear extension in the 763, it's 270 IAS (primary system, same speed for retraction) and if I had to resort to alternative system, it's 250 IAS. So I _really_ don't think I would mess that up.
As for the profile; are you referring to VNAV or ILS profile? Probably to the G/S as I wouldn't be using VNAV for descent. Too much error possibilities, I would just do it with V/S mode and SPD mode in MCP. And YES, I know how to read the ILS indicators in EADI and EHSI
. After reading my first post, do you really have to ask??
As far as I know, standard B767/757 (excluding the B764) AFDS does NOT activate all channels above 1500 AGL automatically. The 777 and next gen 767-400 AFDS does this, but for the rest of the clan, I would have to press the other two APs on to get LAND3. Of course, if one channel was "busted"
I could also land it with LAND2 which is similar to LAND3, only difference being less redundancy. I'm not arguing with you on your company's 757 AFDS. If it has the automatic activation of all three channels above 1500 AGL, so be it. I didn't know that the older gen 757/767 had this feature.
To comment on the "would I have the balls to do it". I can only say that yes I would. I think I would do ANYTHING to get me and others safely on the ground. Airline pilots are not gods. I agree that you have a big responsibility, a REALLY big responsibility over the PAX, yourself and the aircraft itself. But you are still humans. So are we wannabees and also the rest of us humans.
I have been in engine failure situations three times in a single engine aircraft with my dad (once at night in the middle of nowhere). Each time we held the act together and managed to get the crippled bird back to terra firma in one solid piece. In short, I would TRY to do my best, and if I failed... that would be too bad. As simple as that. I'd like to add that I'm not a stupid teenager with too much time in my hands. I'm 23 and one year to go till I get my M.Sc in electronics. Just so you don't think that I'm an 8-year-old flying with my dad in cessnas once a year and reading too much pilot-magazines
lol...
Feel free to bombard me some more, I'm delighted that someone took this perspective to this
).
cheers,
Tero