Getting high on profile

[Olendirk]

Hello,

when you are getting high on profile, what are your actions?keeping the plane clean and speeding up or putting the flaps out and get the plane dirty to slow down?

byebye

od

[FougaMagister]

Depends what type of aircraft we are talking about, i.e. SEP, MEP, twin-turboprop, jet, etc.

On a SEP, it's usually OK to try to regain the profile by keeping it clean and pushing the stick forward momentarily (fairly small momentum). On a heavier a/c, when on profile (assuming you refer to an instrument approach), the aircraft should already have some flaps out. Any alterations would be done through power, not by messing about with the attitude or the config. These have to be kept within very specific limits (much more so than on a light aircraft) in order to get the right performance.

That is, obviously, within reason; if the loc or glideslope merely start to creep one way or another, then a quick correction on the control column would do the trick - but keeping an eye on the speed too! If you happen to be close to an airliner on short finals, you may hear the quick power alterations (even with autothrottle on).

Cheers :cool:

[Vee One...Rotate]

Not sure how relevant this is to you question but in the Cessna 152 I'm training on (PPL) I'd reduce power first (while keeping the attitude about the same) to increase the descent rate - this would keep me at my approach speed. I'd also consider adding a bit more flap if I wasn't already at full. All the while I'd be ready to go-around if things were getting a bit too sporting! Would depend on how the individual approach was going, prevailing conditions and the state of the a/c (i.e. how soon to I want to be on the ground).

I've also heard side-slipping can help - never tried it.

On approach I use the 'power for descent rate, attitude for speed' rule of thumb - works a treat.

If you're question is about anything bigger than a 152 (whici i suspect it is), I've got nothing :bored:

V1R

[OneIn60rule]

then I think you'd go around. If you mean a Cessna 172-152 or any single GA aircraft then I'd simply side slip it down to 200 feet, then put approach flaps on and land it.

It's amazing what you can do on small aircraft if you botch the approach!

[Maude Charlee]

In commercial operations each operator will have a set of criteria which must be met by a particular point on the approach profile. These criteria are what determine a stabilised approach. If a stabilised approach is not achieved by the specified point, then a missed approach is usually mandatory. Certainly this is the case in my company. As has been mentioned, on an instrument approach the a/c is already configured with gear and flap usually extended by the final approach fix.

If your question refers to descent profiles as opposed to instrument approach profiles, then I would suggest that slowing down early and then increasing the rate of descent to regain the profile is the better option. By reducing the groundspeed, you are able to lose a greater amount of altitude per mile than at higher speeds (for any given ROD) and so regain the descent profile in the shortest possible distance. This gives the advantage of buying both time and distance to stabilise the a/c for the subsequent instrument approach. This doesn't necessarily involve any selection of gear or flap, as turboprops can be slowed by altering the prop pitch, and jets invariably have speedbrakes.

It is very easy to lose height quickly in light singles, if this is the a/c type your question refers to. There is no need to dump gear and flap to achieve high rates of descent. In a C150 for example, it is perfectly possible to achieve 3000fpm ROD in a controlled sideslip with power at idle and pop the a/c out at the altitude and speed of your choosing. Light a/c have so little momentum and responsive piston engines that speed control is very easy and requires only a little practice.

[TCXCadet]

Hi! As already mentioned it depends on aircraft type. For a jet (for me anyway) it depends how far out fom the airport I am. When on my line-training I was taught to think of the approach as a funnel. Wide diameter at the top getting narrower the closer you get to the airport.

This is because further out from the airport the more options you have. On one hand you can increase the airspeed - drag component increases as square of the speed. You can use this to get low on the ideal profile and then when sufficiently low start bringing the speed back to that desired. Normally about 300' low for every 10kts extra speed. On the other hand you can use the speedbrakes.

As you get closer to the airport your options become more limited. You won't have the time or distance to use the method above so are limited pretty much just to the speedbrake, or if really high or doing a tight circuit, putting the gear and flap down works a treat! :)