You will note that 126 kts has been selected in the speed window on this Kittyhawk 737. My question is, presuming this to be either v1 or vr why has this speed been selected, I thought the pilot rotated the aircraft by visual reference to the speed bugs etc, and engaged AT for climbout, say 230 kts. Or is this something to do with the TOGA settings. Pardon my ignorance.
Jetlagged From United Kingdom, joined Jan 2005, 2462 posts, RR: 17 Reply 1, posted (7 years 11 months 1 week 3 days 2 hours ago) and read 1800 times:
For takeoff, the speed window would be set to V2 or V2+10, depending on airline SOP. V1 and Vr would be set using the smaller white bugs, manually positioned around the ASI bezel. In the photo they are at about 112 and 114, which makes sense relative to the speed bug. They may be set around one speed (113) as V1 and Vr could be the same value. The other white bugs are set to flap retraction speeds (about 143 and 243).
The speed bug (salmon bug) slaved to the speed window selection is clearly visible in the F/O's ASI, but not so visible in the Captain's due to the angle of view.
The speed window selects the required airspeed for the AFCS. During climb, the ATS is controlling engine N1, not airspeed, which is controlled by aircraft pitch angle. In level flight the ATS controls airspeed. In VNAV the FMC commands airspeed, but the crew can intervene.
The glass isn't half empty, or half full, it's twice as big as it needs to be.
XFSUgimpLB41X From United States of America, joined Aug 2000, 3996 posts, RR: 36 Reply 2, posted (7 years 11 months 1 week 2 days 19 hours ago) and read 1705 times:
From the speed bug configuration on the airspeed indicator.... it looks like its V2+10 thats bugged..
Meister808 From United States of America, joined Jan 2000, 972 posts, RR: 1 Reply 4, posted (7 years 11 months 1 week 2 days 7 hours ago) and read 1598 times:
Here's my question... how usual is it to see 45-46 KIAS sitting at the holdshort line? I know that they may be feeling some winds(but hopefully not too much, because the nose is pointed downwind based on landing traffic), and I know that the Airspeed Indicator doesn't need to be accurate below flying speeds(what is the rule on that, because I don't know, and probably should), but 46 knots is a pretty significant error for sitting still, I think.
-Meister
Twin Cessna 812 Victor, Minneapolis Center, we observe your operation in the immediate vicinity of extreme precipitation
Jetlagged From United Kingdom, joined Jan 2005, 2462 posts, RR: 17 Reply 5, posted (7 years 11 months 5 days 23 hours ago) and read 1417 times:
ASI's do not read very low airspeeds because the pitot static system lacks accuracy below 60 knots. IAS will be badly affected by crosswinds and gusts and will not be much use. I believe the IAS digital counters probably have a minimum endstop at the value indicated to stop them bouncing around uselessly.
The main ASI pointers are also on their endstops, just below the 60 knot mark. You'll notice the standby ASI is sitting on its minimum mark too.
Above 60 knots the speed indication is much more accurate and less affected by crosswinds. All the crew need to note is that the indication is increasing towards the first speed call at 80 knots.
For taxiing there's a groundspeed readout on EFIS, which does read down to zero.
The glass isn't half empty, or half full, it's twice as big as it needs to be.
Wing From Turkey, joined Oct 2000, 1552 posts, RR: 24 Reply 6, posted (7 years 11 months 5 days 22 hours ago) and read 1394 times:
Quoting Meister808 (Reply 4): Here's my question... how usual is it to see 45-46 KIAS sitting at the holdshort line? I know that they may be feeling some winds(but hopefully not too much, because the nose is pointed downwind based on landing traffic),
It has nothing with the winds,45 is the lowest speed that the ASI shows,it comes alive after that speed.
Meister808 From United States of America, joined Jan 2000, 972 posts, RR: 1 Reply 7, posted (7 years 11 months 2 days 12 hours ago) and read 1204 times:
That answers my question perfectly. I'm used to flying airplanes where 45 kts. is still usable to fly with.
-Meister
Twin Cessna 812 Victor, Minneapolis Center, we observe your operation in the immediate vicinity of extreme precipitation
Sprout5199 From United States of America, joined Feb 2005, 1783 posts, RR: 2 Reply 9, posted (7 years 10 months 3 weeks 5 days 21 hours ago) and read 991 times:
Quoting Zeekiel (Reply 8): Do some airlines have the PNF call "Airspeed Alive" when the IAS starts moving?
I say that to myself(maybe out loud also?) when I fly (c-152). just one of those mental checks I do.
Wing From Turkey, joined Oct 2000, 1552 posts, RR: 24 Reply 10, posted (7 years 10 months 3 weeks 5 days 20 hours ago) and read 995 times:
Quoting Zeekiel (Reply 8): Do some airlines have the PNF call "Airspeed Alive" when the IAS starts moving?
We don't have a call of "airspeed alive" in our SOP, I cant comment on the other airlines since I dont know.100 kts is the speed check call that we do.
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