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Guest air miles

737NG Speedbugs......

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Guest air miles

hello everyone,I wonder if someone can tell me what is the white speedbug line that appears to the right of the airspeed tape just after take-off until flaps are retractedIs it the recommended inital climb speed ?????It also appears on final below 2500' RA until touchdown....hmmmmI just can't work it out.:-hmmm ThanksJonGCLPP.s. Where can I get this advanced tutorial I keep reading about by the learned Mr. Metzinger?

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Hi Jon,The only line I know you can be referring to is the amber line that appears as the airplane accelerates. As the amber line gets longer, there is a red line that appears as the speed continues to increase. I think the amber area is the flap retraction speed and you do not want to use the flaps in the red operating range. As you retract the flaps, the amber line is no longer there but as the plane accelerates, the amber line comes down the airspeed tape and you retract to flaps to the next setting. Someone correct me if I'm not correct. This does not indicate the recommended initial climb speed. To determine the climb speed, first determine the V1, VR, and V2 speeds either using the FMC or the Take-Off chart in the Take-Off performance manual. You'll find this manual by clicking Start, Programs, PMDG Simulations, and 737 Flight Manuals. There is one thing that bothers me about this chart. The maximun gross weight of the 737-700 is 153,000 pounds but in the chart under 737-700, the weight is listed as 180,000 pounds and the V speeds seems to be too low to me. Has anyone noticed this? Here's how you perform the climb after take-off: Once you have determined the the V2 speed, enter this speed into the speed select on the MCP. Arm the auto-throttles by swithing it on and turn on the flight director or FD. Of course, you'll set the flaps and prepare the airplane for take-off. I usuall use flaps 10. Advance the throttles to 40% N1 and when the engines stabilizes, activate the TO/GA mode. Either click the screw at the left of the MCP or pressing the keys Ctrl+Shift+G will activate the TO/GA. After passing V1, you are committed to take-off. At VR, you rotate at a rate of 2.5 degrees per second to about 15 degrees nose up. Using the flight bar, put the magenta line right on it and follow it. This will give a speed of V2+20 knots. At 800ft, I think is what the manual says, push the nose over and allow the plane to accelerate. At this time you'll see the amber line, I think you were referring to, and start retracting the flaps. Hope this helpsKen.

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Guest tmetzinger

>It also appears on final below 2500' RA until>touchdown....hmmmm>I just can't work it out.:-hmmm >On Departure, the white bug is v2+ 15On approach, it's VRef+15

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Guest glenb

Thanks Tim. I have been wondering about that also.

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Hi Tim,I read the posts about the white bug on the PFD, to the right of the airspeed tape. What white bug is everyone referring to? I haven't noticed a white bug. Does it only come up when the FMC has been executed? I tried a flight yesterday to see if I see the white bug but I never saw one.Thanks, Ken.

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Guest air miles

Thank you Mr.T for clearing that up for me. Now I know their values, why are they there? Are they to remind the pilot the minimum initial climb airspeed ( before lowering the nose to accelerate to flap retraction speeds)calculated by the FMCI can't find any mention of them in the PMDG documentation.I have been treating them as such and I aint stalled my BMI Baby yet. yet.I find this forum very useful.JonGCLP

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Guest frankathl

"On Departure, the white bug is v2+ 15On approach, it's VRef+15"Hi Tim,According to the AOM:V2+15 (white)Displayed for takeoff.Removed when either of the following occurs:

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Guest tomahawk_pa38

Ken,I have problems with this too. In spite of some very useful replies and another look at the excellent 'Geezer Guide', I still stall.In other threads it says not to engage the a/p until well established in the climb (2 or 3000 ft). However I have found that my MCP speed doesn't jump to VR + 20 until I hit the a/p button to on. If I don't do this straight after gear up, I stall. I watched the MCP very carefully yesterday and the speed didn't change whatever I pressed unless I hit the a/p button. Help !many thanks

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Dave,Can you enlighten the rest of us with some screenshots of what's happening. I'm sure it's something simple we can pinpoint once we see how you are set-up. Zoom panel shot would be best.What are your weights?F/D mode on, pitch to keep V2+20, MCP speed window shows V2 BUT F/D will guide for V2+20!Hope it helps,


Mats Johansson
PMDG Flight Test Dept
Boeing777_Banner_BetaTeam.jpg

| Asus Z270-A | Intel i5-7600K @ 4.8 GHz OC/H2O | nVidia Geforce GTX 1070 8GB OC/O2|

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Guest canyonblue737

>Thank you Mr.T for clearing that up for me. Now I know their>values, why are they there? Are they to remind the pilot the>minimum initial climb airspeed ( before lowering the nose to>accelerate to flap retraction speeds)calculated by the FMC>I can't find any mention of them in the PMDG documentation.>>I have been treating them as such and I aint stalled my BMI>Baby yet. >yet.>>I find this forum very useful.>>Jon>GCLPwe use them as minimum speed required before first flap retraction. normal speed however is v2 + 20. in the event of a go-around the vref + 15 white bug is used for the min speed required for second flap retraction (the 1st being the initial flap retraction for go-around.)lets take the following examples:during flap 5 takeoff... retract to flaps 1 when at v2+20 but no less than v2+15 (white bug). during flap 40 landing... retract to flaps 15 immediately and then retract to flaps 5 at vref+20 but no less than vref+15 (white bug).hope this helps.

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Guest tomahawk_pa38

Mats,Sorry about the delay but here's a bit more info. I've got some screen shots but am having a problem getting them below the limit, if you have an email address I

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Guest frankathl

Hi Dave,45 knots is the default setting on the MACH/Airspeed Indicator when the aircraft is not moving. That is, the instrument does not register airspeed until 45 knots is reached(note that the pointer will not move until above 60 knots).BR,Frankhttp://forums.avsim.net/user_files/111714.zip

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Dave,Frank gave you a good explanation on the speed tape and machmeter readings.>5. I rotate when instructed, the a/p is off speed, is 153kts


Mats Johansson
PMDG Flight Test Dept
Boeing777_Banner_BetaTeam.jpg

| Asus Z270-A | Intel i5-7600K @ 4.8 GHz OC/H2O | nVidia Geforce GTX 1070 8GB OC/O2|

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