Help with Flight Technique
 

Hi,

Im a first officer on the B737NG (800/900ER). I had a question on landing during bumpy conditions on a hot summer day. WIth the A/P and A/T engaged, the thrust levers keep jumping around, then push forward and then come back to compensate, which makes for a pretty crappy ride. Now I need some advice. Is it better to click it off, maintain a constant thrust setting, what would you recommend? Thanks!

In your situation, and you will face this a lot during summer, especially at the famous holiday resorts, Speed Off, adjust thrust to 59-61% depending on weight (30 degr flaps), disconnect the AP and fly your attitude.
Works charming.

As Nightrider said maintain an average constant thrust setting, fly manually and dont overcontrol which would lead to pilot induced oscillations. In general i have found that manual flying by far beats automatics in bumpy conditions. Especially as we can anticipate whats coming.

Thanks, you guys. Ill try that on tomorrows trip.

On your last "crappy" ride did not the Captain give some helpful hints?

Believe it or not, some Caprtains don't, preferring instead (it seems) to announce loudly...'didn't they teach you anything during line training?

This is most unhelpful to new folks.:ugh:

Exactly!!!! We have quite a few of those at my company!!! The landings kinda work out ok, after going back on forth on the thrust levers but im noticing that im landing a tad long and I gotta pop max reverse and/or stomp on the brakes.

Some of the more experienced skippers in my company say to set the power and live with the speed (within reason). The 738 has crap speed control in bumby conditions.

One of life's great pleasures is then seeing them make a complete balls of it on the return leg.

Disconnect A/P A/T and scan your attitude, speed, VSI constantly. Correct by 2 - 4 % N1 but don't be shy on the thrust if you go significantly below Vfly a good quick burst of 10 - 15 % and then quickly back to your reference setting will help you a lot. If you find yourself to be 10 kts fast, be careful with too big a reduction, never below 40 - 42%. But the scan and small corrections will most of the time keep speed and attitude fairly stable. If you anticipate up or downdraft just before touchdown, ie coming from the sea to land or passing a forrest/road etc on short final think in advance what you wanna do - Do I need more thrust, should the attitude increase etc.
Check the wind on your display against reported wind, - will it turn 60 degrees the last 500 ft?
A good landing starts with a stabilized approach.

Safe landings buddy.

If you intend to hand fly a circuit or approach then switch off the autothrottle completely just like the instructions in the FCTM.

Thats bad, very bad advice.

Deselect speed. Thats it.

This will leave the AT in armed mode, so u still have the protections from it.

I would say deselect or completely switch off AT according to company SOP. There are good reasons for both types of operation and you have to be aware that keeping it in ARM (speed deselect) can surprise you at times.

We allways had the deselect speed (ARM) SOP and it works in many cases, but especially in bumpy conditions many of us preferred to switch it off completely to prevent AT intervention at the wrong time.

To avoid confusion.....A/T to off. That is per FCTM Boeing 737.

As a matter of fact, this confusion is only present due to bad or insufficient training. If a pilot understands the A/T and the Speed Off function there will be exactly the protection available which may be needed in a situation with varying speed such as the one we are talking about here.
If the A/T speed function jumps out of ARM and applies thrust, the thrust is for sure required to get back to bug-speed.
Surprises, as mentioned above, will only happen to underspeed situations, and I assume this is not a speed anyone should operate at in moderate thermal or gusty conditions.