Steep take-offs and landings
 

Hey, does any one have information on steep take-offs and landings? i.e. why they aren't used more around residential areas like heathrow etc.
Is it because it would lower the lifespan of an aircraft landing at 6 degrees rather than 3 degrees?
Any info would be much appreciated.
Thanks
Ghostie

"Is it because it would lower the lifespan of an aircraft landing at 6 degrees"

Not really.

But landing a 747, or 777 from a 6 degree approach, might lower the life expectancy of the pilot a tad!

Try being on an aircraft landing into London City airport and you'll find your answer. Not so much a landing as controlled descent into terrain! :sad:

So its a saftey issue more than anything then?
Thanks for the replies so far, keep them coming.
Ghostie

6 degrees in a 757 / A321 would be interesting....no more landings for us first officers....and a shorter life span for the Captain!!!;)

there are also limitations for autopilots and autoland,and also for landing systems considering low visibility landings.
And I doubt also that this type of approach will significantly lower the noise.During landing phase ,the engines should not be fully retarded,for go-around reasons-so another obstacle for your theory.

G31...

You are getting some "roundabout" answers, but I suspect you don't know enough about the matter to understand these.

In short, "X degree takeoffs" are performed according to the perofmance of that type / weight / weather. A lightweight at full power 757/A319 can climb at 20+ degrees nose up, giving a climb angle of over 15 degrees. A heavy A340 on a hot day will struggle to make 3 degrees... let alone before it loses an engine.

A 757/A320 series has enough trouble on 3 degrees slowing to approach speed, even with full flap. A 6 degree glide is basically impossible in general use (someone might claim on such and such a day they could achieve it)...

HTH
NoD

Didn't they test an A319 into City to see how it would perform not so long ago?

If the airport authorities could upgrade their facilities to provide a nice steady 20-30 kt breeze straight down the runway -

'twould improve opportunity for both landing and TO noise reduction!

:}

(Almost as good as a conveyor belt, perhaps?)

Autopilots are considered to be capable of up to 4 degrees Glideslopes after that you're in "Steep Approach" territory. The appropriate rules are NPA-25D and the critical requirement is that the aircraft must be able to fly down a slope 2 degrees steeper than the desired approach without the engines hitting idle - no mean feat. The same autopilot control laws are used by aircraft both capable and not capable of carrying out steep approaches - it just comes down to aerodynamics.

It amused me some years ago that when getting the Partenavia approved for LCY 5.5/6 degree approaches, I needed to use full flap, and the power required (and therefore the noise generated) was significantly greater than that used for a normal 3 degree approach using the standard intermediate flap setting!

P.P.

It's the steep approach which is difficult - most aircraft can't generate enough drag to stablise their speed. You need damn good brakes and/or propellors rotating at high speed and in fine pitch to keep the speed under control.

First Officer flying.
5NM on final, and still at 3000agl, with full flaps, due to lousy ATC.
He closes the throttles, pushes the nose way down, accelerates to max flap speed (200 knots) and....

Finds himself at one mile on final, at 300agl, engines spooled up, nicely stabilized at Vref +10, and makes a perfect landing, right in the touchdown zone.
Type of aircraft, Lockheed Tri-motor, near max landing weight.

Normall ops?

Absolutely not but, if you are very familiar with your aircraft, and it (and you) are up to the task, then it generally works out.

Not for junior guys.

Take off pitch attitude (around the 15 degree mark) is a function off the take off power used & maintaining a speed of around V2 +15Kt. Any steeper, & the speed will decrease leading to possible VMCA & stick shake/stall issues. (V2 porvides a 20% buffer of the stall margin). Full power will probably only allow you to use 20 degrees of pitch.

On landing, the Rate Of Descent for a 3 degree approach is about 750 FPM. Therefore 6 degrees will require a ROD of 1,500 FPM. Assuming there is no flare, a 3 degree approach will probably result in nothing more than a firm landing - but it will be firm! A 6 degree approach will bend the airplane, or more probably break it.

From a 3 degree approach, the flare manoeuvre is relatively simple; raise the nose a couple of degrees at 20ft above the R/W. Not so easy - or safe - form a 6 degree approach. I'm sure you can do the maths!

There was a rather fine demo at the recent autumn air show at Duxford by a RAF C130J, showing how to get into a tight spot that had nasty people around it. I would estimate about a 30 degree approach, followed by nifty (and stomach-churning!) flare and short landing.

Now, how did they do that in terms of keeping all the gravity-induced momentum in check? Props in reverse all the way down perhaps?

Either way it looked most impressive, and I'm glad to have had my videocamera running on that occasion.

I once witnessed a C130 doing such an "arrival" at EMA without realising what was going on. Heart-stopping.

Then there was the Buffalo!

The Buffalo
 

Especially the "arrival" Bill Loverseed did at Farnborough about 20 years ago following his display.

That was one occasion when they didn't get to use the aeroplane again :uhoh:

You mean this Buffalo?

Bent Buffalo
 

That's the one ..... a classic for Uncle Roger's

"a little late on the round-out" series of 1,000,000

If I remember correctly after the dust had settled Bill walked out of the ruin with a perplexed look on his face ... Why did it do that .... ? :confused:

Another guy I knew said that Bill's eyesight was always being called into question when he was in the arrows.