[Mifnet 🛰 75641] Re: London City Airport

Wed, 11 Mar 2026 07:21:28 -0700 

 Back in the 1980s I flew out of Bardufoss, Norway for a few weeks. The 
approach had 2 glide slopes. The first was about 5 degrees, the second 3.5 
degrees if I remember accurately. The approach plates today are behind a pay 
wall so I can't compare. Lots of fun. 
Eric
    On Sunday, March 8, 2026 at 10:54:37 AM MDT, Jack Keady via Mifnet 
<[email protected]> wrote:  
 
 how scary/hairy is the old appeach? keady

‍LONDON — London City Airport (LCY) has submitted a regulatory application to 
enable operations by larger Airbus narrowbodies, particularly the A320neo, by 
introducing a shallower 4.49° approach angle, replacing the current 5.5° 
profile.

If approved, LCY’s operator states the change would apply to both runway ends, 
potentially expanding the range of aircraft able to serve the Docklands airport 
while maintaining compliance with its constrained airspace and performance 
requirements.

Why glideslope angle matters

According to Skybrary, a glideslope, or glide path, provides vertical guidance 
for aircraft during final approach. On an ILS approach, ground equipment 
generates “above” and “below” lobes, allowing the aircraft’s receiver to 
indicate whether it is above or below the desired descent path.

The normal case: ~3°

Most commercial runway approaches use a 3° descent angle, which supports a 
stable energy profile for configuration changes, speed control, and manageable 
descent rates, while ensuring obstacle clearance. FAA training materials 
describe a typical glide path as a constant 3° to the touchdown zone, provided 
there are no obstructions.

Implications of steeper approaches at LCY

A steeper glideslope:
   
   - increases the required rate of descent for a given groundspeed,
   - increases pilot workload and places greater emphasis on stabilized 
approach gates,
   - can constrain eligible aircraft to those certified for steep-approach 
operations.

The descent-rate rule of thumb illustrates this:
   
   - 3.0° ≈ 5.3 × groundspeed (kt) in feet per minute
   - 4.49° ≈ 8.0 × groundspeed (kt)
   - 5.5° ≈ 9.8 × groundspeed (kt)

At a groundspeed of 140 knots, the approximate descent rates are:
   
   - 3.0° → ~740 fpm
   - 4.49° → ~1,120 fpm
   - 5.5° → ~1,370 LCY’s proposed change from 5.5° to 4.49° is significant. 
While still above the standard 3°, it substantially reduces the steep-approach 
penalty, allowing aircraft not approved or not ideally suited for 5.5° 
approaches to operate at the airport.
Touchdown zoneTDZ3.0°4.49°5.5°LCY proposedLCY current (steep)Steeper angle → 
higher descent rate at the same groundspeedDiagram is illustrative: three 
glidepaths converging on the touchdown zone. The operational effect is 
primarily the required descent rate and stabilized-approach margin.Groundspeed14
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