Bomber Circuits!

A couple of members of the group had previously reported slight vibration in the climb and recently some vibration in the cruise. The cruise turned out to be plug fowling which was fixed, but the vibration in the climb seemed to be continuing. I think this all started when one of the group went up with an instructor who spotted it and suggested we get it checked out. Needless to say, checking with our maintenance organisation has revealed nothing and it cannot be reproduced on the ground.

Well, of course once something like this is pointed out, we were all getting a bit up-tight about the slightest odd engine noise etc. A couple of members have been reading around the subject and wondered if the propeller needed balancing etc.

What the engineers needed they said was to go up with one of us. On Thursday 9th March, I was at a loose end in the afternoon, and although the weather wasn’t great, it was good enough, so I left early and set up a quick local with an engineer to move this forward.

Dave is an experienced engineer who works mostly on PA28’s and owned and flew an Arrow for a few years, so he came pretty well qualified in my books. We started up and took off. In the climb at 25/25 there was a slight vibration which he felt. He asked me to level out on the same settings and fly straight and level, which I did, and the vibration disappeared. Dave then played with many different power and prop settings, both straight and level and in the climb. The only time there was even slight vibration was in the climb.

Dave explained that he felt quite strongly that there was nothing wrong with the plugs or the engine and that it most certainly wasn’t propeller balance – if it was, it would happen in a narrow range of power / rpm regardless of the angle of attack. He asked if any of the group had experience in operating an aircraft with the three bladed propeller (as ours has). None of us do – he was convinced that it was simply the angle of attack on a three bladed propeller and that they routinely felt like this (where a two bladed propeller wouldn’t). He said that it would probably feel much the same on a power run up in a steady crosswind etc. He advised us strongly not to waste our money chasing this as there was nothing wrong! Well, that was good enough for me and I agreed to write his comments up for the benefit of the rest of the group, but that one or two of them might want to talk to him direct about it.

We headed back to the airfield, where it was pretty quiet. I was given a standard overhead join for 27 with right hand circuits. It seemed that I was joining overhead at the same time as another aircraft. I looked hard, but didn’t see him until I was crosswind, where I saw him at the same level, ahead and to my right. He was too close for spacing, so I elected to extend crosswind as he turned and called downwind. I then turned and pulled the gear down to slow the plane up to gain space. I was given as number 3. I could see both aircraft in front, with the furthest looking like he was about to turn base.

During the downwind checks, I lost the furthest plane in the ‘ground clutter’ but stayed visual with the near aircraft. The near aircraft had also lost the other guy and called ATC to ask where he was and could he turn base? He was advised that the furthest aircraft was now on 2.5 mile base – hmmm… what is he doing out there? So we both extended a long way downwind. Eventually we both saw him now on 3.5 mile final!! It was only a PA28 – what the hell is he doing flying circuits outside the ATZ especially as there were no aircraft in front of him!

I commented to Dave that I had never seen anything like this. We both joked about a certain flying school based at Gloucester who are notorious for flying ‘bomber circuits’. I was on base and the aircraft in front was on final following the ‘Vulcan Bomber (PA28)’. Then Dave heard the offending aircraft and declared that it was ‘one of his!’ (the flying school who also owned his maintenance organisation). Well, from my vantage point at about 1.5 miles, holding height with high power, I could see the PA28 about to land with the aircraft in front of me close, but far enough away to expect a late clearance. The PA28 landed nice and slow and seemed to be certain to stop by the intersection, so he could vacate early. Instead he trundled past a slow walking pace! I heard ATC start to say ‘cleared for short back-track…’ when they stopped as the PA28 trundled slowly to end of the long runway! He hadn’t cleared and the chap immediately in front of me was ordered to ‘go around’. I was by now just inside 1 mile and descending. I was cleared to land and put it down easily in time for the intersection.

Well, I commented on the PA28’s poor airmanship in flying such incredibly wide circuits with no other traffic about. Dave said he would raise it with the flying school so I left it at that (otherwise, I would have gone over there and had a friendly chat. I could only assume it was an early student doing solo circuits, but he really should be made aware that it was very poor airmanship and dangerous as we were forced to overfly Cheltenham town centre a slow speeds and high power settings at 1000’).

I have since corresponded by email with the ATCO who may also look into it. I am certainly no expert and I am sure that I have been guilty of poor airmanship in the past (and will probably make mistakes in the future) and I don’t want to get anyone in trouble, but either he or his instructor really need to know that circuits are not flown like that.

Next time, I will ask to ‘cut in front’.