Sebastian_G wrote:
Using the gear that high up is not risk free. In the PA46 the fluid can get too cold and cause all kind of issues.
Sebastian – I sometimes have to use the gear to descend rapidly into Sion from FL150 in a PA46. What can happen if it gets too cold?
Getting the gear down that early is interesting. It is known to be done in emergency descents on older types (such as the Boeing 707) but on the Airbus, never seen that happen. I do see descents like @Dan mentioned quite regularly when flying as SLF though.
Side slips were fun to do on both the Caravelle and the TU154. They looked quite scary on the latter, particularly from the outside. There were approaches where passengers did get to see a lot more of the runway ahead than normally.
The TU was quite interesting if you needed to descend fast too on full spoilers and once below the speed the landing gear. The way that thing folds out of the wells, the 6 wheel gears are a very effective airbrake too. I had the pleasure to fly with a real artist on that airplane and he flew it to perfection. I remember some very interesting circuit work at Skopje (“You are cleared to land if you can make it from this position” followed by “Beautiful!!” from the tower) and an approach into ZRH with “Speed at your discretion” 300 kts at 6 NM final (3 minutes before night curfew) followed by full spoilers and gear down and a perfect landing at 21:59 LT. That flight was ferry btw and the cabin was warned. That deceleration feels pretty intense.
Happy memories indeed.
I can see one can drop the gear safely in icing conditions, and the worst outcome would be a frozen up wheel, which will do “funny stuff” because of assymetric ice buildup, but the chunk of ice will probably fall off when it hits the tarmac.
What is the lowest OAT for hydraulic fluid? Skydrol is apparently good down to -60C but is not normally used in GA. The GA stuff is normally MIL-H-83282 which on a quick google shows -40C.
Peter wrote:
this was LIMF
My bad Peter, too quick a read. Still, also very familiar with LIMF, and since this is Italy (…) anything can happen, including what you experienced 
dInkognito wrote:
slip an Airbus all the way down – is that not an option?
Well, not a recommended one, at least not to loose altitude at these kind of speeds and altitude… generally speaking, flaps equipped airplanes are not designed for slips, which doesn’t mean one cannot do them. In any case, crosswind landings will result in a slip to the final decrab, the preferred Airbus technique.
greg_mp wrote:
Even an emergency descent is not flown with gear down
Correct. As in “Peter’s case”, if one chose this method, he/she will have first to decelerate to gear extension speed/mach < 250 / 0.60, then extend said gear, before being able to accelerate (all done by reducing/increasing the ROD by whatever mode is chosen) to < 280 / 0.67.
As a comparison, using the preferred method I briefly alluded to above, clean limits are MMO/VMO 0.82 / 350, at which speeds and using full speed brakes one can exceed 7K FPM… the subsequent slowing down phase is more effective at the lower levels since the air is then denser, and the opposite holds true to extend the gear higher up, as the air is so thin that the effect is largely mitigated.
Mooney_Driver wrote:
Happy memories indeed.
Indeed.
On the other hand the implementation of FDM and further safety measures have brought flying to the low accident rates we have today.
Correct. As in “Peter’s case”, if one chose this method, he/she will have first to decelerate to gear extension speed/mach < 250 / 0.60, then extend said gear, before being able to accelerate (all done by reducing/increasing the ROD by whatever mode is chosen) to < 280 / 0.67.
Notice that it is also putting a mess in regular SOP sequence, and this deviance could led to serious issue if the crew is not fully concentrate and up to the task. The unfortunate ghosts of PIA 8303 flight could witness that after a belly landing followed by a GA… they forgot to lower the gear again after having retracted them at the end of such descent… you would argue its just a “gear down 3 green” to really check.
He told me he once had to slip an Airbus all the way down
„had to“
Oh my.
On the other hand the implementation of FDM and further safety measures have brought flying to the low accident rates we have today.
This.
Procedure is very much type-dependant . On Cessna 210 there are no limitations for operation with gear extended, only IAS limits for gear extension/retraction. In fact SOP for emergency descent is gear extended from any altitude up to aircraft ceiling (depending on model up to 25000FT+).
I would not worry about icing on the gear unless you really need to retract it after the extension and before landing. Although 210 was the first FIKI SEP, with attendant extensive icing tests, I am sure gear down was not part of attendant icing tests. It is nonetheless interesting to see the reports with different effects of icing protection types on aircraft performance in icing.
Another typical GA hydr fluid is MIL-H-5606/MIL-PRF-5606 which is good for -54C to +135C.
On Cessna SEP’s a large part of the fluid will also be contained within the cabin positively affecting fluid temps at high altitudes.
Antonio wrote:
Procedure is very much type-dependant .
Affirmative. The CJ/M2 actually has a Max FL180 limitation for gear (& flap) extension.
I asked a bizjet pilot and he says he’s never heard of a limitation other than IAS.
The CJ/M2 actually has a Max FL180 limitation for gear (& flap) extension.
What would be the reasons?
We’re still maintaining a critical control system written in CORAL 66
It doesn’t like Class A airspace (only in the US, of course)?
