SkyDemon Forums

Standard overhead joins wrong...?

http://forums.skydemon.aero/Topic35520.aspx

By ChrisB - 9/5/2022 12:33:07 PM

Having received the runway in use and circuit direction when close to an airfield I do some hurried mental gymnastics to work out how to approach for a standard overhead join. I recently discovered the SD “Make Approach” function and was very pleased to see there is a “Standard Overhead” join option.

The first time I used it in the air was arriving at Enstone. I selected Make Approach, Runway 26, Standard Overhead. A nice big purple arrow appeared “for guidance on where to join” (to quote the SD video tutorial). I started heading towards the arrow, but after even more hurried mental gymnastics realised I would be joining from the opposite direction to that required and made corrections.

I have since used the same function arriving at other airfields and they are all wrong. According to SD a standard overhead join is approached from the dead side, with descent on the live side to join the circuit. According to the CAA a correct standard overhead join is approached from the live side, with descent on the dead side to join the circuit on the crosswind leg.

This is more than just misleading it is plain wrong. At worst, a pilot following SD’s guidance would conflict with a pilot doing a ‘correct’ overhead join. At best he would be joining high on the downwind leg and making a total hash of the circuit.

I’ve attached below a screenshot from SD and a CAA diagram of a standard overhead join to illustrate my point. Comments welcome – is there something I’m missing here?

Chris



By russellp - 12/20/2023 8:13:30 AM

I’ve always thought that the overhead join arrow should be a full U shape extending back as far as the downwind numbers for full clarity, however knowing this negates the need for it to be displayed that way, you simply have to know that it needs extending. If approaching from the dead side the correct point to join the roundabout in the sky is over the upwind numbers at ohj height and then circle to the downwind numbers without losing height before commencing dead side descent over the downwind numbers. No-one should need more than the runway length for a dead side descent. I guess extending to a full U would require SD to make a stand on the often controversial point about whether the dead side descent should start over the numbers (as most of us were taught) or nearly a mile away as depicted in the CAA diagrams above!