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sgreen91

Go Around Issue

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I'm trying to find what I'm doing wrong on the go around procedure.

 

I've been simulating this for about 4 hours and it always bust the go around altitude by 500-1000 feet.

I'm practicing at KLAX rwy 25R.  Missed approach altitude is 2000 feet.

 

My procedure is as follows:

 

Hit TOGA

Flaps 20

Positive rate of climb Gear Up verify MA altitude set

400 feet verify LNAV

At 1500 feet acceleration altitude the aircraft firewalls the throttles to achieve flaps up speed which bust the MA Altitude.

 

I'm not hitting the TOGA button a second time for full throttle so I'm not understanding what I'm doing wrong.

I've read the FCTM and tried to follow but at Acc Alt if firewalls the throttles.  It goes back out of full once at flaps up speed.

 

Thanks in advance if you can help me out.

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Exactly.  That 2000 ft missed approach altitude is important too because of the VFR corridor above the airport extending North to South.  You need to reduce your power as soon as it is safe to do so instead of being configured for a climb thousands of feet higher.

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So in that case probably best to use speed intervention to achieve a slower speed rather than going straight to flaps up as it seems levelling out here is more important than immediate acceleration and flap retraction. is that fair Dan?

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This was discussed in length in another post. There's a particular blog where a 777 pilot speaks about go around and acceleration and meeting requirements for turns required in the missed approach procedure where a smaller radius turn may be required to conform to the missed approach track and you achieve this by preventing the aircraft from acceleration, and also possibility of busting altitudes when the engines accelerate when the speed bug jumps up. From what i remember reading, and from what I understood, there's a certain point during the climb to the missed approach altitude, given the rate of climb among other parameters where the aircraft will calculate a level off path and if there is a big enough thrust change during this level off path it can cause an overshoot. Anyway long story short the procedure they use at his company is after pressing the toga switch, increase the MCP speed by 1 kt until you level off, I have tried it and it works well but i prefer to just change the speed upwards to the Flaps 20 manoeuvring speed. Making this speed change, even by 1 kt will prevent the autopilot from increasing speed automatically and reduce the likelihood of a massive overshoot in our desktop sims

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after pressing the toga switch, increase the MCP speed by 1 kt until you level off,

 

That's pretty clever, thanks for sharing that. However, even with that technique (I like setting F20 too) the 1000-1500 ft climb in missed approach mode is pretty tight and don't expect to have time to clean up the wings before reaching 2000 when you are light.

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That's pretty clever, thanks for sharing that. However, even with that technique (I like setting F20 too) the 1000-1500 ft climb in missed approach mode is pretty tight and don't expect to have time to clean up the wings before reaching 2000 when you are light.

 

True, it was also said that the autopilot cannot perform miracles and there will be situations, such as what you described where you have no choice but to turn off the automatics and take over.

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Yup, top priority in flying is always first fly the airplane.

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