Sunny Swift Issue 23 - Stabilized Approaches

I see this poster addressing three issues. One is the stabilised approach. Two is spacing from other traffic. Three is noise abatement. As a former advertising man I strongly recommend that only one issue is promoted in one poster.

Microlights are the up and coming end of general aviation. They can and do often successfully fly steeper approaches than shown in the poster

For spacing I suggest that slower traffic flies tighter circuits and faster traffic flies a downwind leg further out from the runway. Traffic at different speeds can then maintain relative positions. Extending downwind may result in following traffic turning unexpectedly inside you. I have flown circuits at Biggin Hill when two aircraft, following aircraft ahead extended downwind so far that they infringed London City Aerodrome Traffic Zone. London city is 12 (yes, twelve)nm north of Biggin Hill!

Noise abatement is best achieved by flying aircraft with Rotax engines rather than Lycoming engines. Varying circuit patterns, height, direction brings a whole new set of problems.

There has been quite a lot of discussion about some of Sunny's points here in the UK. Firstly many don't agree with such long final approaches for light GA under VFR. We teach that the turn onto base leg in 10kt headwind conditions should be made when the RW threshold is 45 deg behind the pilot, Secondly, a 3deg approach angle is too shallow - in general about 4.5 deg is preferable.
Also we dislike 'downwind extensions' - if you are baulked by other traffic, then cross to the deadside at circuit height before turning downwind when the other traffic is no longer a factor.

It may be that the issue which was intended was community relations but many readers believe that it was intended to provide handling advice for GA pilots, and I am afraid the advice which it appears to give is wrong.

Stabilsed approach is wrong ??? David, could you clarify?

The principle is fine and agreed, but being stabilised at VREF 500 feet up, 1.5 miles from the threshold leaves the aircraft to crash off the aerodrome if an engine loses power (note the fatal accident analysis database I sent to the GA CAG). I would regard VREF in a light aircraft as the minimum speed on approach, and in many conditions would prefer to aim for a higher speed at 500 feet, reducing gradually as the runway approached to reach VREF at 50 feet in conditions of moderate wind. I would also leave the decision as to whether my approach was stabilised until 300 feet, because at 500 feet I'd still be turning final with an extra 5 knots. The view of the runway from 3 degrees is poor, and making a long approach to stabilise airspeed at 500 feet takes up space and interferes with faster aircraft behind you.

Hello David, I agree with VREF being a minimum to keep close to.
https://www.skybrary.aero/index.php/Stabilised_Approach
Perhaps the summary was too brief .
Regarding the flight path, please see this reference: https://www.faa.gov/news/safety_briefing/2018/media/SE_Topic_18-09.pdf . It indicates the increased probability of unstable approach with steeper descent ratios. I agree about the risk in case of engine loss of power. The database you mention seems like relevant information.

Hola, Eleana! The Skybrary reference clearly refers to airliner-type aircraft and the FAA reference shows a bizjet graphic on the graph. I am not convinced that either references are applicable to light GA.

I support David's view. When rolling out of the final turn at around 400ft, we would teach:
1. Level wings.
2. Select full flap and trim.
3. Adjust to Approach Speed (63 KIAS in a Piper Warrior) and re-trim.
4. Aim at touchdown point and keep that point fixed in the windscreen.
5. Use small power adjustments to maintain Approach Speed whilst keeping the touchdown point fixed in the windscreen - the 'Point and Power' technique.
6. Shortly before touchdown, close throttle fully, aim at the far end of the RW and hold off until the mainwheels kiss the RW.

With the 'Point and Power; technique, a naturally stable approach is far more likely, because the aircraft is on a fixed descent path with only minor speed corrections needed.

If flying a microlight could I suggest an amendment to point 6. above.
Keep a trickle of power on until you have rounded out. Their momentum is much less and closing the throttle shortly before touchdown leads to the nose pitching down and an unwanted increase in glide angle.

Another good reason NOT to fly a shallow approach! Obviously on a steeper approach you will require a lower power setting, hence less pitch change as you flare when the throttle is closed.

Closing the throttle slowly and managing the pitch attitude simultaneously shouldn't really be a problem.