Lou- How do those switches work and why are there only two of them?
Was not sure if they set take-off trim or had something to do with the engines since they are on the throttle quadrant.
Not sure about the initial design thoughts as far as there being 2. I guess 2 is better than 1 for redundancy. 4 would be overkill. While I don't really look at them when I push them, I've always assumed I've been pushing the one on the left (I sit in the left seat) with my right middle finger. From the right seat maybe it's more intuitive to hit the right one. Anyway, all you have to do is push one of them. Either switch activates TOGA (Take Off Go Around) depending on your situation. All 4 engines go to TOGA thrust. It's interesting to note that once you lower the flaps prior to taxi out, GA is armed. Pushing those buttons while taxiing would give full takeoff power. So for a normal takeoff, we push the power up manually to 70% N1 (747-400) or 45% N1 (747-8), then push the TOGA buttons. The EEC (Electronic Engine Control) then advances power to the predetermined takeoff power setting. The autothrottles go into "HOLD" around 65 kts IAS. At that point, the autothrottle is held, allowing you to move the thrust if you desire. For instance, if you want more power, you just push the levers forward. The autothrottle won't pull them back. Also for a rejected takeoff. Just pull them back. But if you reject below that speed, you must disengage the autothrottles, otherwise the autothrottles will push the power back up. Takeoffs with strong headwinds can cause the autothrottle to go into HOLD before reaching the desired takeoff power due to 65kts IAS being reached quite quickly. This rarely happens, but I have seen it a few times. On approach, when flaps are out, the GA mode is armed. Pushing those buttons will cause the AP and autothrottles to go into Go Around mode. Pitch is commanded initially to around 12 degrees. Autothrottle pushes power up to maintain approx 2000 fpm climb. If you push the button again, you'll get full GA power. Pushing those buttons in cruise has no effect. I hope this explanation helps. Simply put, we push them for takeoff, or for go around. Otherwise we don't touch them.
Trimming is done with electic trim on the yoke. While it's hard to see in that pic, you will notice 2 RED guarded switches and 2 black switches next to them. The black switches are an alternate stabilizer trim. We never use them. The RED guarded switches are the stabilizer trim cutout switches. One for each system (Hydrallic 2 and 3). In a stabilizer trim runaway, you use these switches to cutoff the trim motors. Haven't used these either....
Lou- Thanks, a lot more complicated than the fighters I flew, but I can see the advantages when you want a lot of things to happen quickly, like on a go-around.
Lou -- Is this (circled in red) a throttles lock / hold mechanism, or something else ? Image Unavailable, Please Login
That switch is the autothrottle disconnect. There's one on the other side of the throttle quadrant too. The throttle hold function is an internal function of the autothrottles. There's no way to turn it on or off. You can always override the autothrottles by just pushing or pulling and holding them where you want them. Also, even when the autothrottles are disconnected, they are still active for low speed protection.
Crud, all we had was a throttle friction adjustment in the F-111. Everything was manual. A few other things much more complicated, for weapons release and target designation, but the basic flight controls and engine controls were pretty simple. Like you would expect from something from the 60s, except the wings could swing.
Even for those of us who will never be in a pilot's seat on a jumbo jet, this is the most interesting and informative thread on the entire site. Thank you, Lou.
A buddy of mine (RIP) flew the 727 for years as an ATP. In his later years, he retired from the airline world and finished up his career as a private corporate pilot --- flying mostly Lears and the larger Gulfstreams. He always described the 727 as "a big Learjet" alluding to how quick and maneuverable it was compared to other jetliners .
New NAC -8F sitting outside the paint hangar today (Boeing Everett plant). Will it join the fleet directly or go sit in the desert with the 2 (3?) others?
I think it'll sadly be heading to the desert. I believe NCA will take the next delivery in the fall. Looks like 2 400's will be heading there too. Most likely August or Sept. They will be due for "C" checks and it's better just to park them I guess. NCA's fleet plans keep changing, but right now it's for 10 aircraft. Currently there are 7 400's and 5 -8's online. I believe airplanes are just sitting on the ramp in Narita. Sad to see. Hopefully things pick up. West coast flying has been pretty full with loads of 250,000 to 300,000 lbs!
Any chance of getting the keys to one of the ones sitting around in Narita ??? I've got 120 hrs SEL now...what could possibly go wrong ???
Lou- Great thread. Have learned a lot about a subject, airliners, about which I know very little. Except as pax.
Lou, your Cargolux colleagues had some nice cargo last week out of Milano. Pic by a friend of mine. Image Unavailable, Please Login
Also had "snakes on a plane" recently..... Noticed amongst the tuna and chocolate churros we had some reptiles onboard. They were in the lower aft cargo compartment, set to 21 C. I believe it was 4Kg worth of them. Chocolate Churros? Hard to believe those are flown over! Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
OP, nice thread, didn't realize Fchat even had an aviation section. Just got to fly a -8 for the first time after a year at my current carrier. Somehow finagled 4 legs this month which is pretty much unheard of in the long haul world. Compared to the 400, the -8 seems more responsive or at least lighter in roll and pitch.
Great pictures Nate! Do the -400 and -8 share a common type rating? And if I may, a question for the airline pilots - which school of thought do airline pilots generally stick with, attitude for airspeed; power for ROD, or attitude for ROD; power for airspeed?
Yes, common type. Just did some 'differences' training for the -8 and a line check and good to go. Ask three pilots about pitch vs power for airspeed and you'll get three different answers. My answer has always been, as long as you have power available; pitch for altitude and power for airspeed. Of course changing one affects the other, but the initial action by the pilot should be based on that relationship. Not sure why I can't get pics to embed?
In Japan, they are common type rating as well. Just differences training. They do fly a bit differently (see the beginning of this thread). I fly the -8 probably 90% of the time now. I did fly a 400 the other day. It had been almost 2 months. Larger aircraft have a lot of inertia. Pitching for airspeed would take too long. Also, just 1 degree of pitch change makes a fairly large glidepath change when flying at say 160 kts vs 70 kts. So it's pitch for glidepath, power for airspeed. That's how the autopilot flies an ILS. Nate, you Polar/Atlas, or Atlas? I used to work for Polar, but that was 15 years ago! Classics back then.
