Rob L wrote:You are mistaken, patowalker: it's simply another tool in your armoury to help you avoid such a situation.
What I am trying to understand is why that tool didn't help him avoid the situation. It seems to me that either the tool didn't work as expected, or he wasn't that close to hitting another aircraft.
Even though I've described the situation before, I feel it will be better if I explain it again - apologies to those who have heard this before. It was a Sunday morning and I was returning to my home base. Because of a tail wind, I arrived a few minutes before 9. I circled to the north and waited for the Flugleiter
to respond to my calls and just after 9, I made contact and joined the circuit, calling downwind, base and final (as I typically do).
On joining downwind my Zaon started warning me of a target a couple of miles away, below me - around 400 feet lower. I continued onward, noting the target. On base it was now a mile away, 300 feet below me. It started closing - 0.5 miles, 300 feet. I turned on final and was confused. Nobody was typically in the air that early, the frequency was empty, even Langen FIS had been relatively quiet. I was pretty sure that I was seeing the transponder of someone on the ground.
Now the altitude difference started to reduce, less than 0.5miles, the Zaon was sounding a warning. I was descending - after all, I was on short final to land. My first thoughts was again, there is someone on the field with their transponder on - what I'm seeing is the altitude difference changing because of my descent. But I wasn't.
The Zaon was going mad, flashing alert warnings at me and although I was pretty much focused on landing, I was still looking around seeing if I could see anything. I called the Flugleiter
and asked 'is there anyone on the field with a transponder on?' The Flugleiter started to reply but something told me to glance down and I saw, just appearing from the root of the leading edge of my wing on the left hand side, the spinner of another propellor.
It was a motor glider which had been flying at 500 feet along the river and had recently taken off from an airfield about 5 miles away using the westerly runway and had obviously assumed we would also be landing westerly. He was overtaking me from below as I slowed on short final. I shouted "W T F" over the air and the Flugleiter looked to short final and saw two aircraft where one should be.
He said that he was pretty much convinced that a collision was going to occur and grabbed the binoculars, saw the registration of the second plane, noted it. I decided the only action was to slow myself. I didn't know what the aircraft was doing and slowed myself as far as I dared. What I wanted to do was keep the aircraft in sight as it flew past me. Had I climbed, I would have lost all visibility with the aircraft. On short final, I typically fly 75 knots. I recall that when glancing at the ASI, I had slowed to around 62 knots in an attempt to create separation - but what other options should I have taken? I didn't know what sort of aircraft it was, nor their climb rate, had I also decided to go around. Keeping the intruder in sight was, for me, the best course of action.
The conflicting aircraft was now also climbing through my altitude as the pilot decided he probably needed to gain some altitude over our airfield. What he didn't realise was that he had flown straight through my short final, maybe 10 - 15 feet below me, same position. Even though his motor glider had a glass canopy, he hadn't been paying attention to what was happening above himself, he was believing I would be coming from the opposite direction and was focussed on that. Had I not slowed, we would have collided.
So please don't say the system failed. It worked as it should have. I didn't take the alert and think 'no, it's a spurious report, everything will be ok if I ignore it'. But without it, I would not have had a clue that the aircraft was there and we would have collided. Even the investigation into the event by the BR, based on the transponder returns from both aircraft recorded by Dortmund's radar, showed that it was extremely close.
Interesting was that the Flugleiter called the other aircraft on the local frequency - and he responded. He'd heard me make my calls but was convinced we were flying on 24, even though I'd announced 06. Because he'd heard my calls, he was focussing on looking for me coming from 24, not 06, hence he would not have known what would have hit him......
20.000v in his arms but the bulb inside his head still doesn't light up........