London City 27 ILS

[TShan1]

Is there a reason why the 27 approach to London City is as steep as the 09 approach? As far as I can see, the 27 approach has no terrain/buildings to make a 5.5 degree approach necessary. Is it for continuity, to avoid confusion between the 09 approach? Or is it an airspace issue?
Thanks.

[Mad (Flt) Scientist]

I believe the current GS at EGLC are based on noise abatement rather than obstacles.

[A Squared]

I believe the current GS at EGLC are based on noise abatement rather than obstacles.

That was my understanding as well.

[DaveReidUK]

According to the CAA, their policy is that approaches above 3.0° can only be approved for obstacle clearance or operational reasons, not for noise abatement.

Because of that, for example, Heathrow has had to obtain an exemption for the current 3.2° approach trial.

http://www.heathrow.com/file_source/HeathrowNoise/Static/Steeper_Approach_trial.pdf

[underfire]

Isnt there a bridge on final? Looks like #7 and #10 are controlling... a bridge with light poles on final? no problemo...jack you up to 5.5...
great place for #7 obstacle as well...

http://i65.tinypic.com/5etjcm.jpg

http://i68.tinypic.com/2uzuuxc.jpg

these are frangible....

http://i67.tinypic.com/kf4e9h.jpg

[Mad (Flt) Scientist]

Looking at the pages of the AIP (I admit it's dated 2011, so maybe it changed ...) I see a long list of obstacles at the other end, but nothing listed at the 27 approach end. (UK AIP AD 2-EGLC-1-3 is the page, Table "EGLC AD 2.10 — AERODROME OBSTACLES")

[Mad (Flt) Scientist]

London City has a document about noise policy etc on its corporate website:
Noise & Track Keeping System (http://www.londoncityairport.com/aboutandcorporate/page/noiseandtrackkeepingsystem)

para 6.15 includes the following statement;
In addition to the above, aircraft approaching LCY
follow a steep approach angle of 5.5 degrees
(compared to 3 degrees in place at other airports)
which helps keep aircraft higher for longer, reducing
the noise impact on local communities.

that seems to suggest that it's a noise issue, at least as far as the airport is concerned.

[safetypee]

The underlying history of LCY focussed on noise. The airport’s initial approval was based on the DHC-7 aircraft which had been ‘certificated’ (FAR 121 approved) for steep approaches under a US/Canadian ‘STOL’ category, which for straight in IFR approach and landing was 7.5 deg.

The subsequent airport expansion to enable BAe146 jet operations had to consider docklands developments and planning in the surrounding area. The BAe146 was expected to be certificated for a 6 deg approach based on the Canadian ‘STOL’ requirements (Flight Working Paper 705?), which would be acceptable to the UK CAA for commercial aircraft. This work was the basis for the JAA/EASA CS 25 steep approach requirements.
BAe proposed the use a 5.5 deg GS; this provided wiggle room in certification and insurance against the final obstacle clearances.

The obstacles to the west were the planned / commenced building of Canary Warf and existing docklands structures, and to the east the proposed “East London River Crossing” (ELRC) bridge over the Thames which would impact the 27 approach path 1.5-2.0 nm out (400ft towers?).
Complex negotiations involving airport planning, building regulation, and noise enabled a compromise solution. This involved adjusting the already displaced thresholds of the existing runway inwards to enable a 5.5 deg ‘Cat2’ ILS and PAPI which would meet a lower margin obstacle clearance over the near-in dockland buildings and cranes, also a compromise in the height of Canary Warf and ELRC; a senior BAe executive took tea with Mrs ‘T’ who ‘was able’ to reduce the tower height by 1 story – London/UK economic development.
To the east, the bridge was redesigned / realigned so that the dominant obstacles were the reduce-height lampposts and a London double-decker bus; this allowed a similar 5.5 deg approach to a revised threshold.
A further limiting factor was the usable runway length which could not exceed 1199m so to qualify as a code 2 runway; this involved the side-line proximity to water and the obstacle clearance slope over the terminal buildings/parking (BAe146 fin height).

Canary Warf was duly ‘modified’, the other docklands buildings and cranes removed, thresholds displaced, and the ELRC became a figment of political planning providing the steep approach satisfied the then active anti-noise lobby.
The rest is history, probably resulting in local building expansion up to the 5.5 obstacle clearance limit, and thus the near-in obstacles, the small bridges at each end now dominate.

[DaveReidUK]

that seems to suggest that it's a noise issue, at least as far as the airport is concernedOr that LCY has a good PR department. :O

https://en.wiktionary.org/wiki/make_a_virtue_of_necessity

[underfire]

mad scientist,

post #5 shows the obstacle clearance survey for the airport. Several obstacles penetrate the 2% surface. The lightpoles are certainly obstacles...