Interesting Amphibious Event

[pelmet]

C-FLLL, a De Havilland of Canada DHC-3T operated by Northwestern Air Lease was conducting
flight PLR403 from Powder Lake, NWT to Fort Smith (CYSM), NWT with one crew member and 2
passengers on board. Upon departure from Lady Grey Lake, the pilot observed that both hydraulic
pumps were running. The pilot attempted to extend the landing gear (amphibious floats) but the
landing gear did not extend. The pilot then pulled the hydraulic pump circuit breakers. As the
aircraft neared CYSM, the pilot attempted to manually extend the landing gear, but was only able
to extend the main landing gear. The nose landing gear remained retracted. A flyby of the airport
was performed to confirm the main landing gear was down, and recce the airport for an appropriate
place to land the aircraft off of the runway. The pilot subsequently elected to land the aircraft in the
grass on the approach end of RWY 21. A successful landing was completed, there were no injuries
and no damage to the aircraft.

Subsequent inspection by company maintenance found the right hand aft gear hydraulic line
ruptured allowing the hydraulic reservoir quantity to deplete. The affected hose was replaced, gear
swings completed and the aircraft was returned to service.

[PilotDAR]

'Been there, done that - twice! 'Same set of floats, but on different planes, twenty years apart (I forgot about the first event, while I was having the second). Left side would not extend, landed on ice both times, no damage. If the plane has only a manual pump, you may not want a pressure relief valve in the hydraulic circuit!

[pelmet]

Thanks,

I had some difficulty understanding how the gear configuration was for the landing incident. Can you confirm that both aft gear were down and both forward gear were retracted. The last paragraph in the report confused me.

[rigpiggy]

I believe the main gear will drop without hydraulics holding them up, and the forward gear must be pushed forward, requiring hydraulic pressure

[tractor driver]

Yes, the mains were down. The bow wheels extended forward slightly, but not down. Well handled non-event.
Back flying next day.

[cncpc]

Good job.