Maximising chance of glider Class D zone crossing.

[Jim59]

As a cross-country glider pilot it is becoming increasingly difficult, in some areas, to conduct long-distance flights whilst avoiding all class D airspace. Which of the following are most likely to get me/improve my chances of getting a zone clearance? My glider is equipped with radio but not a transponder at present. I have a FRTO licence.

Call for clearance 5min / 5 miles before boundary.
Fitting a Mode S transponder.
Submitting a VFR flight plan prior to take off.
'Phone call prior to take off.

Any other suggestions?

P.S.: I don't want to loiter in your zone - I'm aiming to complete my task as fast as I can - but I may need to stop at some point to gain height - particularly when flying into wind.

[HEATHROW DIRECTOR]

I'm long retired, but suggest that having a transponder would be very useful because then ATC could see you..
Standby for a more updated response..

[ShyTorque]

Suggestions 1, 2, 4 are all good.

Suggestion 3 will be of no benefit.

[slackie]

Fit a Lycoming!!

[Jim59]

Slackie wrote:
"Fit a Lycoming!! "

Why? I already have a retractable solo 2350 engine that does 200 nm on 13 litres of avgas fitted.

Thanks for other comments.

[Glamdring]

Having never really dealt with gliders transiting class D, what kind of level would you usually be requesting? And would you be able to hold if required? That would be the 2 main questions I would be asking as a radar controller. The answer to these questions would determine if IFR traffic were going to be delayed and subsequently if your transit will be approved.

[ADIS5000]

Fit a transponder, it'll double your chances of getting a prompt clearance. Also a call 5-10 mins before you reach the boundary also helps. Many of us have had our fingers burned by non-transponding traffic and being able to accurately monitor your progress gives us the warm and fuzzy feeling we like especially when dealing with non-standard traffic,

Regards, ADIS

[Jim59]

Having never really dealt with gliders transiting class D, what kind of level would you usually be requesting? And would you be able to hold if required? That would be the 2 main questions I would be asking as a radar controller. The answer to these questions would determine if IFR traffic were going to be delayed and subsequently if your transit will be approved.

Gliders using thermals to fly cross-country tend to use the height band from cloudbase down to halfway to the ground so if cloudbase is 4,000' then from 2,000' to 4,000' is the preferred soaring band. Of course gliders cannot maintain a specific level - they are always descending or climbing. If you get lower than the halfway height then you start to move from cross-country mode to 'survival' mode; trying to stay up becomes more important than trying to make progress on track until a better height is regained. When crossing a MATZ it is common to be asked to report if you are expecting to descend below a minimum height.

Holding is a bit tricky in that circling in sink will result in the glider being on the ground pretty quickly! However, a glider can circle in lift for quite a time - although it will be drifting with the wind. Depending on conditions it might well be feasible to fly to a nearby thermal to wait for onward clearance.

A modern glider should be able to achieve 6-7 nm for the loss of 1,000' (through the airmasss) so getting high before e.g. crossing a centre-line should result in uninterupted progress. Assuming a couple of thousand feet is available for a glide through a zone an uninterrupted 10+ nm glide should be achievable. If flying straight up or downwind, following lines of lift, often much better is achievable - sometimes 20-30 nm between thermals.

Gliders will usually have an airspeed between thermals in the 70-90 kt range.

[Jim59]

Fit a transponder, it'll double your chances of getting a prompt clearance. Also a call 5-10 mins before you reach the boundary also helps. Many of us have had our fingers burned by non-transponding traffic and being able to accurately monitor your progress gives us the warm and fuzzy feeling we like especially when dealing with non-standard traffic,

Regards, ADIS

I would like to be able to fit a transponder. There are potential difficulties in fitting transponders to many gliders that tend to be glider-type specific so I won't bore you with all the details. For continuous operation lack of a power supply is a big issue but for use only when crossing e.g. controlled airspace that is manageable. In my glider finding panel space is the main issue. It really is a question of which esential instrument would I remove to find space to fit one. I have made up cardboard models to the exact dimensions to try and find a home for one - so far unsuccesfully.