Typical sink rate on London City steep approach?

[rsiano]

What is the typical sink rate (rate of descent) for a Dassault 7x while on approach to London City?
Thanks!
Dick Siano
[email protected]

[cheesycol]

http://www.nats-uk.ead-it.com/aip/cu...GLC_8-5_en.pdf

Looks like if you're fully configured, not sure speeds for a Falcon, with a GS of between 120-140 kts, then you're ROD is going to be between 1170-1365 fpm!

Hope that helps.

[rsiano]

unstable approach - go around mandatory

My apologies for not stating the following from the TWA Flight Crew Operating Policy and relying on a memory that was faulty:
"Stabilized Approach -
The aircraft must not continue descent below 500 feet on any approach unless it is in the landing configuration, stabilized on final approach airspeed and sink rate, with the engines spun up. Any time these conditions are not met when the aircraft is at or below 500 feet, a go-around is mandatory."

Thanks to all of you who drew attention to my incorrect posting information.

[Mad (Flt) Scientist]

The London City G/S is 5.5 deg

So to be under 500fpm descent rate would be less than about 5200fpm airspeed in still air. Which is about 52 knots. A tad slow for the typical aircraft there ....

[p51guy]

My typical descent rate, depending on wind, was 1200 fpm landing in TGU Honduras. That was to the threshold and was considered normal. It is very manageable but doesn't meet the stabilized approach criteria for a normal airport. After 600 landings I was very comfortable with that. Just don't get slow. That is a B757 so assume any other aircraft can do the same.

[Zeffy]

A descent rate in excess of 500 feet per minute when below 1000 feet above the ground in my days of flying was considered an "unstable approach" and a go around was mandatory.

Did you mean to type "in excess of 1000 fpm".

5 X GS on a 3.0-deg ILS at 120 kts would yield 600 fpm..

[No_Speed_Restriction]

Typically, an unstabilised steep approach would be considered with an ROD greater than 1500 fpm.

[Jesper]

how could u have 500fpm as the criteria for a stable app?
A normal glidepath of 3 deg would give you approx 700fpm if u ur speed is around 150kts wouldnt it?

[muduckace]

I remember Quito having a 6 deg glideslope due to terrain and experiencing some rough landings. Procedure is to fly down the glide slope until clear to descend to the visual and cross the threshold at a normal as possible rate of descent. Is there not a similar procedure in london? I assume the reason for this G/S in London is noise related?

[Mad (Flt) Scientist]

There's also an obstacle at one end I believe (the new-ish bridge at Dartford?). And operators may be taking credit for increased G/S to reduce the air component of the landing distance, so as to cope with the relatively short runway. Anyone doing the latter should NOT be shallowing the descent at the end, or they are invalidating their perf calcs.

[CJ Driver]

Mad Flt Scientist is absolutely right - you mustn't flatten out a London City approach on visual short final, because then you will run off the other end. The landing distance assumes you follow the glide path all the way down and slam it onto the deck at 1000+ fpm. That's also why part of the London City approval for many types is that each landing counts as up to two "normal" landings when calculating things like gear life limits.

[ATP_Al]

I don't remember slamming it into the deck at 1000fpm being part of my operator's steep approach training!

[PEI_3721]

“That's also why part of the London City approval for many types is that each landing counts as up to two "normal" landings when calculating things like gear life limits.”

What absolute rubbish.

Operations at LCY are based on a relatively normal landing flare and touchdown.
Several years ago, the FAA measured a range of aircraft types and operations to determine/check landing gear specifications; the tests at LCY filmed BAe146 operations. The results showed that the range vertical speeds at touchdown was equal to or less than many wide body aircraft landing from a 3 deg approach.

[Re-Heat]

http://www.nats-uk.ead-it.com/aip/cu..._2_EGLC_en.pdf

p3 - Obstacles

[Chuffer Chadley]

Yes, it's perfectly possible to get a nice, smooth landing at LCY- no need to thump it onto the deck. Having said that, there's no room to risk floating down the runway while trying too hard to grease it on. Add to that the willingness of the ac to land with flap 35, and in reality, most landings at LCY are a little more positive than on regular airports.

Typical RoD in the F50 on finals very roughly 1200fpm (circa 120 kt IAS). Can be quite a bit more from time to time, depending on wind.

CC

[WHBM]

Originally Posted by Mad (Flt) Scientist

There's also an obstacle at one end I believe (the new-ish bridge at Dartford?)

The obstacle when on easterlies to runway 09 is Canary Wharf tower, about 3 miles out. There are other obstacles nearer in that come close to the resulting glide path, the old flour mill by the Victoria Dock and the somewhat elevated Connaught Bridge right at the 09 threshhold.

The obstacle when on westerlies to 27 is the Thames Gateway bridge (not the Dartford one, which is about 10 miles away). If you can't find the Thames Gateway bridge on a map you are correct, it hasn't been built yet, but the airport has to take it into account. It will be an arch bridge which will cross the Thames at the same point that you also cross the Thames on short finals for 27.