What I learned: It surprised me how easy it was to allow the adrenalin of an “urgency” situation to distract me from the important things – even though I know “Aviate, Navigate, communicate” an tried to keep it in mind.
Setting: EC120 single turbine unstabalised helicopter on route back to EGKR after 4 hrs flying (with fuel a fuel stop an hour back), slightly tired with 12 miles to run, at 2400ft and 120knt. Heading towards Bough Beech and the Gatwick CTA so thinking about getting the ATIS for EGKR on box 2, and swapping from Farnborough East LARS to Redhill ATC, changing transponder code and getting down below 1500ft. In the middle of all that the Master Caution light / gong and notification of a GEN failure.
Initial reaction – that is important but not urgent as the battery is good for 20 min and EGKR is now 7min at this speed. Decision – ignore until established at 1400ft, north of the railway and talking to EGKR ATC for joining instructions. That done, begin problem solving the GEN warning but keep in mind the critical order of activity – Aviate (an unstabalised helicopter has to be flown constantly), navigate (busting Gatwick CAT is 30 sec away at most above / left of track), communicate. Toggle the GEN switch, no benefit. Press ELEC RESET, no benefit. Decide to leave this problem alone and simply run on battery for the 6 minutes remaining.
New Master Caution for Electrical Systems. Scroll through the FLI screens to BATTERY, and find voltage and amps have dropped (setting off the Caution). Scroll to GEN screen and find good voltage but no amps. Interpreting the data, I have lost the GEN but the BAT should have given me 20 min. As it is a NiCad, voltage tends to stay constant as the battery drains until close to exhaustion, when it drops rather quickly to zero. Given that I have a voltage and amps drop on the battery, it might be about to run down and I would have no electrical power. That removes my engine management screens, radio, transponder, AH, DI, etc but leaves NG, NF Airspeed, Alt, VSI and the old-fashioned compass. Time to communicate!
First, check height and location, then PAN call to EGKR; advise electrical problems, possible imminent loss of communication, request direct approach at 1400ft, autorotation profile from the airfield boundary and power recovery (engine permitting). Cleared No1, 1400ft approach and autorotation profile to any surface. Head back inside, 4 miles to run. I begin shutting down non-essential electronic systems (flymap, Box2, Box 3, Radio nav, AC, etc. Call at the VRP (3 miles), and repeat cleared No1 with 1 R22 in the circuit; wind 260/5. I announced intention to auto into area 1. Head back to battery screen, and then fly the aircraft.
2 miles…. 1 mile…. The R22 calls downwind and is told “no.2 to the EC120 declared PAN on final”. I was then completely distracted by his opinion that he could land 26H ahead of me; though he was told “that’s very interesting, and you are still No2 to the EC120 PAN.
Airfield boundary, 1400 ft. Collective down full and flare to 75knt, cyclic up to contain NR, aim right of the crash truck (who has rolled to area 1) and wait for the ground to get close enough to flare. Kill the decent to zero and hold until fwd speed drops below 30 knt then cyclic fwd and collective up…. Engine still working so we come to a hover; cleared airtaxi to hangar “if you are happy”. On landing, found I was quite stressed and sweating.
Looking back – an electrical problem that was (and should have been) a non-event that I could easily have turned into an accident or a CTA bust through being distracted. I was amazed how distracting a “minor” problem can be, botht he electrical failure and the R22 radio traffic. It was a useful lesson to me of the importance of “Aviate,Navigate, Communicate”.
Last edited by John R81; 28th Feb 2013 at 13:26.