trim setting during approach/landing

[PHXMD-11 86]

Do you know wheter , let's say 4.3 , is used in reality sometimes as well or whether the PMDG units are the same as the ones in realtiy?

 

It depends on the situation. One degree of trim may be needed in one situation but may be completely different in the next situation.

 

thrust controlls descent rate and pitch controls the speed but only up to the point when reaching the glideslope. Then the principle chnages.

 

Because when you're following a -3 degree glideslope, you don't want a 1,000 fpm descent. What do you think will happen in that situation at 100 feet AGL?

 

During approach and landing, the nose will pitch up and down to maintain a constant rate of descent to follow the glideslope. The thrust will then take over to control your speed.

[scandinavian13 5,192]

The principle of pitch for speed, throttle for rate still applies. The issue is that when you're fine tuning that for landing, pitch changes more immediately affect rate than speed does. If you set up a stable approach early on, this should not be an issue, however.

[kevinh 409]

Flying the glideslope is rather like being in VNAV PATH. In that mode, the autopilot uses pitch to maintain the desired path, therefore power is used to control speed. If flightpath is not constrained then pitch is a better controller of speed.

[BlueStar 323]

The principle of pitch for speed, throttle for rate still applies

 

Next time you're setting at the end of the runway about to take off start moving your yoke back and forth and let me know when you reach flying speed. :smile2:

 

Billy Bluestar

[acko52 13]

If your at the end of the runway and havent taken off your in big trouble.

sorry couldnt resist

Jeff

[N520AT 3]

On my airplane, when I do a flight, I look at the trim position indicator one time per leg. Before start when I set the trims for takeoff. That's it.

 

I trim to relieve control pressure. I fly the airplane with the yoke and trim when needed to keep my arms from getting tired.

 

The idea of setting the trim for landing makes no sense and at all and I've never heard anything like it.

[martybuzz 2]

I hand flew a 747-400 from Sydney to Melbourne (Australia) with no autopilot engaged (in the Qantas Sim). The only time I looked at the trim indicator was as part of the take off check list. Never looked at it again, just trimmed to keep controls neutral. If you can let go of the yoke and the aircraft goes where you want it to go, then it's in trim.

 

I then did an engine out after V1, but before Vr. After lift off, the rudder trim was used a lot, but wound back for the approach because assymetric thrust disappears when the throttles are closed.

 

Remember, fly the aircraft before anything else. As it goes, Aviate, navigate, communicate.

 

Buzz.

[Rations 102]

Was that in a full-motion simulator? It must have been quite challenging to follow the route precisely, especially at cruise and at cruise speed. With the B747, I engage autopilot at around 10000 ft and disengage it when aligned with the localizer, and I know I do a lot more manual flying than most B747 pilots do.

 

I wonder how many times real-world commercial aviation pilots fly legs completely manually in large jets such as the A330, A340, A380, B747, B777, etc during their careers.

[kevinh 409]

Not many unless the autopilot fails in which case there's little choice. Sydney to Melbourne isn't that long a leg though.

[PHXMD-11 86]

completely manually in large jets such as the A330, A340, A380, B747, B777

 

ATL-JNB or EWR-SIN? I don't think any pilot can do that.

[Rations 102]

Obviously not, but I was referring to shorter flights (even A320 and B737 flights) around one to two hours long, such as the routes I mentioned.

 

I wonder why some commercial aviation pilots like to engage autopilot at very low altitudes (less than 1000 ft in normal traffic and weather conditions) after takeoff. Is it mainly due to economics (attempting to save fuel in order to receive more salary bonuses) or is it just done to provide greater comfort to the passengers and reduce pilot workload? I find that with the flight director, I am able to maintain smooth flight with the B747 without making large corrections like I see in many real-world videos. Also, with two pilots, I do not think that workload would be an enormous issue if the aircraft was flown manually until flaps were fully retracted. With the autothrottle and flight director, workload is already drastically reduced.

[martybuzz 2]

Was that in a full-motion simulator? It must have been quite challenging to follow the route precisely, especially at cruise and at cruise speed. With the B747, I engage autopilot at around 10000 ft and disengage it when aligned with the localizer, and I know I do a lot more manual flying than most B747 pilots do.

 

I wonder how many times real-world commercial aviation pilots fly legs completely manually in large jets such as the A330, A340, A380, B747, B777, etc during their careers.

 

This is the story I posted about my Sim session a couple of years ago http://forum.avsim.net/topic/293112-two-hours-in-a-real-744-sim/#entry1811146

 

The Capatain mentioned had an IRS Failure (not exactly sure what the actual system is called) a couple of months ago on an A380. Manual flight from Singapore to Sydney. They took it in turns (10 minutes each) to fly the aircraft.

[Rations 102]

Wow—did they really complete the trip without diverting to another airport? While that seems weird considering the possible danger involving an IRS failure (is it legal or safe to operate a large aircraft like that on GPS alone?), it is nice that they were able to practice their manual flight skills and not rely completely on technology for once. It would be interesting to compare the fuel usage of that flight with that of a regular, extensively automated flight.

 

I enjoyed reading about your B747 full-motion simulator experience. I hope I get to do something like that in the future. I once did a flight experience program with an A320 fixed-base simulator in Singapore, but the immersion factor was not as great, because there was no camera shake upon touchdown!

[PHXMD-11 86]

engage autopilot at very low altitudes

 

Fly in/out of New York or Chicago during the early morning or early evening. Four eyes are better than two. TCAS does not relieve the flight crew of ensuring that aircraft in the vicinity are maintaining separation.

[Rations 102]

In some cases, it is of course understandable, but in other cases, wouldn't one find it boring to take off, engage autopilot under 1000 ft, and then monitor the systems for a few hours before descent and landing?

 

While four eyes are certainly better than two, the eyes of the pilot not flying are aided by ATC, the pilots in the surrounding area, who are hopefully paying attention, and TCAS (as you mentioned), which I believe is generally quite safe.