Can someone explain why these are the common mistakes made on final approach...

 

Pitching for speed or Power for height – this is a basic prop pilot error

Can someone explain why these are the common mistakes made on final approach...

 

Pitching for speed or Power for height – this is a basic prop pilot error

 

I think it relates to the fundamental differences in how the power is applied to the airframe and how each airframe reacts. The Q400, for example, you really shouldn't use much pitch adjustment on final, and instead the power levers can control descent, to a point. This is due to the prop wash over the wing, the wing itself, and a few other factors. A 777 or 737, on final, you tend to pitch for altitude and follow up with application of more power, to maintain speed. (you have effectively traded speed for altitude, and regained that speed with more power) more power alone won't do the job. (you will speed up, but still be below GS, for example)

 

I think you find pilots who learnt on props, going to a jet, may make the mistakes you imply, but the corollary holds true, someone who has primarily flown jets, who try's a prop such as the Q400 or ATR, may make the reverse mistake.

Can someone explain why these are the common mistakes made on final approach...

 

Pitching for speed or Power for height – this is a basic prop pilot error

 

Not looking out the window enough.

 

It sounds stupid, but gauge fixation is very common in the sim. Granted, without the tactile/inner-ear sense of the real thing, the gauges are infinitely more important, but the core issue is there. When getting to the point of flare, look out at the far end of the runway and listen to the GPWS calls. It's not as effective as the perspective you'd get in the real plane, but it definitely helps your landing when you get used to it.

 

To be honest, pitch for speed / power for rate is a generic concept for both props and jets. The issue is that each airframe will handle those inputs differently. The concept applies to the 737, but it will follow that rule differently from a prop.

 

Example: Idle path descent. The throttles roll back to idle and your speed is adjusted with pitch. You can shallow the rate by adding power (though the AP will automatically reduce pitch to hold that airspeed with the increased thrust). In a SAAB 340, you can essentially get the prop pretty close to disc at flight idle and it will drop like a brick (even the choice of Dowty versus HamStand props would have an effect here). It isn't this prop follows the concept and the jet doesn't; it's that the jet follows the concept slightly differently.

The most practical way is to always think of it as a tradeoff. Idle power on descent pitching the nose down will increase both your speed and rate of descent.

 

Now on final, you already have about a 3-5 degree nose up attitude with a given airspeed and rate of descent. Adding a bit of power here will arrest the rate of descent> If you only pitch the nose down it will give you a bit of airspeed but will also increase the rate of descent. You have to play with both to get it right.

 

Altitude for speed, that's the name of the game. You can't dive for the runway on final. You wont need power if you are carrying the extra speed, but when you level off you run a huge risk of SINK RATE !!

This question would be great for you kyle as you fly props!?

 

 

Some students that have difficulty in landing tend to focus too much of their attention inside the flightdeck. This can lead to a student trying to chase either the Glide Slope or the Flight Director at low level which is damaging to a stable approach. In addition, changing the focus from the electronic display of the PFD/ND and adjusting to the dynamic external visual cues of the runway, aiming point, centre-line tracking, PAPIs and peripheral vision is difficult for an in-experienced pilot. It is imperative that you look out of the aircraft at the touchdown point on the runway more frequently the nearer you get to the runway. Once the runway is in sight a good rule of thumb is to:

 

1,000ft Look out 25% of the time.

 

500 Look out 50% of the time.

 

250 Look out 75% of the time.

 

100 Look out 100% of the time.

 

When looking out, you should keep the touchdown zone as the primary focus and then use the PAPI’s as a guide to maintain the 3 degree glide path.

When looking into the flightdeck you should maintain your radial scan as indicated above. However, once through 500’, this scan reduces to Speed, V/S and N1. At this stage the majority of the time is spent looking out.

Wouldn't this depend on the type and size of aircraft that you are flying? I am no pilot, but I get the impression that airliners on final approach have a much higher power setting than they would be when in a "powered glide" (so as to make a quick escape in an emergency), but that small GA planes are virtually gliding in to the runway. I fly all of my planes the same way (since trying to emulate real world procedures perfectly is of no interest to me), so I let the aircraft settle into a powered glide, and then use throttle to control the descent rate.

Wouldn't this depend on the type and size of aircraft that you are flying? I am no pilot, but I get the impression that airliners on final approach have a much higher power setting than they would be when in a "powered glide" (so as to make a quick escape in an emergency), but that small GA planes are virtually gliding in to the runway. I fly all of my planes the same way (since trying to emulate real world procedures perfectly is of no interest to me), so I let the aircraft settle into a powered glide, and then use throttle to control the descent rate.

 

Depends on the flight profile you've been taught, or prefer.

 

A lot of the GA schools teach power off landings as an indirect way of teaching energy management, a tight pattern, and contingency planning (engine power cuts and you're close enough to the runway to glide to it and land...in theory). Others teach power on landings that drag the plane in with flaps, and on the 3 degree GS. I was taught the former. In airline ops, you're usually flying the latter (which is why proponents of it tend to be the Part 141 schools that have airline training programs).

 

You're right though - it definitely depends on the aircraft. The DC-3, as an example, shouldn't be flown with the power at idle to avoid wear on the engine due to improper oil circulation (stemming from the plane driving the prop - or, the condition that happens when the props are used for drag). As such, you fly a lower, draggy approach with power applied. The JS41 is similar in this requirement, but it has an automated function to ensure constant positive power.

I trained with T-41s under 141, and we were power on approaches.

 

90mph, all the way down to "the float," as my instructor would say (the point above the threshold where we would chop power).

 

As speed fell, i could feel the slight change in pitch and definite change in VS when i would apply power.

 

I may be imagining things, but it seems the same with the NGX.

The main reason using thrust to control the glidepath on jets is discouraged is because of the mechanics of the jet engine vs a piston engine.

 

Jets (and particularly large high-bypass turbofans as used on most modern transports) take some time to spool up and down. Therefore, adjusting power to (indirectly) adjust the glidepath is very inefficient. Add the thrust/pitch couple that you get with underslung engines and you have a recipe for PIO.

 

Adjusting pitch to correct the glidepath produces a much more rapid result. Of course any speed decay must then be countered by adding thrust, whilst continuing to pitch the aircraft to follow the glide.

 

Piston engines, on the other hand, respond very rapidly to changes in power demand and therefore a change in power setting will very quickly result in a change in flight path.

 

It should be said that most jet transports fly very nicely according to the numbers: set the correct power for the weight and configuration and in smooth-ish conditions you should barely need to adjust the thrust at all during the approach.