The TB20 is the same. However the nose gear extends into the airflow so there are two gas struts to enable that to work.
I suspect quite a lot of SEPs have the same system, not least because an awful lot of them use the same model of the Parker hydraulic pump mentioned earlier, and the same Eaton pressure switch to stop the pump running when the gear is up against the rubber bungs at the top of its travel.
The reason for pulling the CB is to prevent the pump (which presumably has failed for some separate reason) starting up again when the pressure switch re-connects due to the pressure dropping once the hydraulic pressure is released.
One is also normally supposed to place the gear switch into the DOWN position.
I had a situation early on in my ownership of a Tecnam P2002 sierra RG, one of only two LAA RG models in the U.K. Interestingly it had a few changes to the certified model, most notable being pneumatic rather than hydraulic gear.
My little event taught me to test emergency procedures and to especially test them when on jacks.
The gear had been working absolutely faultlessly for many many flights when one day it just didn’t. I got no greens.
I knew that the emergency knob worked by dumping a second cylinders worth of air into the system. I had a feeling that it might not work because I could see the main system had full pressure, so I didn’t try it at first.
The first thing I tried was to get the wheels to lock down. A friendly ultimate high bulldog flew alongside and confirmed all three wheels were hanging limp. I tried low speed, high speed, stalls, a bunt, tight turns, and everything else I could think of! Nothing worked.
I then went for the emergency and BANG! The wheels locked down, much more viciously than usual. I landed and began the investigation.
The cause was a blocked flow restrictor. Blocked by a bit of pipe sealant. I learned that day that the normal gear goes through flow restrictors to make them come down nice and gently where the emergency system just bangs the air into the pistons.
I tested it all regularly on jacks after that!!
Peter wrote:
One is also normally supposed to place the gear switch into the DOWN position.
Otherwise your failed system may raise the gear again at the wrong moment if it decides that it wants to work again… But there are also three-position gear switches with an OFF positon between UP and DOWN which want to be placed into OFF after a manual extension. Again: Don’t do emergency and abnormal procedures (some manufacturers classify the alternate gear extension as “abnormal”, others as “emergency”) from memory unless they need to be done instantly.
In “my” aircraft at work the electrically operated brake system only works when the gear lever is DOWN because of a microswitch next to the gear lever, but the emergency extension can be done with the lever in the UP position. So one could get a nasty surprise after landing with the gear luckily down, but with zero brakes…
This is the emergency gear release on a TB20. I suspect the Lancair is the same, since it uses the same hydraulic pump i.e. gravity for the main wheels and possibly some spring / gas strut system for the nose wheel. However the OP has not been back to add any info on that.
Peter wrote:
Almost all gear problems I have heard of were due to lack of maintenance – lack of lubrication basically.
Well, let me give you a counter example, then.
Top of descent on the ILS in PA31, put down the lever, no resistance, just floppy in my hand.
Got out the checklist, got the RHS passenger to pump, got three greens, landed.
It turned out that a pipe, or rather a join where a pipe attached to the reservoir, had cracked and the contents of the reservoir had dumped out.
The hand pump takes its fluid feed from the bottom of the reservoir, whereas the normal pumps take it from a standpipe, so I was left with enough of a dribble in the bottom for one lowering.
I don’t think maintenance could have spotted it; it was only just out of Annual, which included a full inspection by both FAA and CAA as it was changing registry. The break must just have happened, the way things do sometimes just fail.
Yes – things sometimes do just happen. But how old was that plane?
Peter wrote:
But how old was that plane?
Not as old as me 
But it gives me a run for my money 
1973
…but new planes break as well. It’s middle aged ones which are the most reliable.
Well it depends on what’s actually gone wrong.
The hydraulic systems used in most “old” retractables (all the old twins, stuff like the TB20/21, the various kitplanes which use the same Parker pump, etc) have tons of power. The down pressure is c. 1500psi which with a c. 1" diameter actuator piston is going to give you some 700kg (7000N) of force. That is enough to lift a 1973 Vauxhall Viva right off the ground and will force down even a really seized landing gear and the pilot won’t even notice anything is wrong. Well, unless the other end of the actuator is attached to a fibreglass body and then that will get ripped off
So down failures are usually something else e.g. a pump motor, wiring, some limit switch, whatever. Lack of maintenance of the mechanism is rarely the reason for a down failure. It just costs a huge amount of money at the next Annual to replace all the shagged parts… assuming anybody notices.
But a lack of maintenance is nearly always the reason for a down failure of the emergency gear release mode – unless that is hydraulic also.
My comments are based on what I see around the place and hear about from other owners.
An awful lot of people get very close to a gear up, but most of them manage to avoid it.
Aviathor’s advice about getting the PA-28R gear locked down after an emergency extension is very practical but it is covering up another problem that will eventually result in the gear not locking down unless under hydraulic power.
The usual reason for the PA28R gear not free falling into the downlocked position is lack of lubrcation of the main gear trunnion bearings, the reason that these bearings don’t get grease inside them is that you require a right angle head on the grease gun to get to the grease nipple if the gear is down position or if you only straight grease gun you have to jack up the aircraft and half retract the gear to rotate the grease nipple enough to get the straight grease gun onto the nipple.
A well lubrricated PA28R will fall into the down lock position without the need to yaw the aircraft, an aircraft that has had the lubrication of the trunnion neglected will eventually only downlock if it is driven down by hydraulic power and if that hydraulic power fails the gear will not downlock no matter how much you yaw the aircraft.
I once had a PA28R in the shed after a failed emergency extension and main gear collapse during landing, I could find nothing wrong with the landing gear with the exception of very stiff trunnion bearings, when lubricating the trunnion bearings no old grease was apparent and after lubrication the landing gear functioned correctly.
