Engine malfunction (20) of which 5 were complete failure or confirmed engine damage, running across the range of GA engine types.

Suction pump Failure (1) It is likely that no report is raised for many of these failures.

Electrical / Alternator Failure (2).  Same comment applies.

Airspace Infringements

 A few excerpts from reports (36):

Carrying out a general handling flight in a C150 in Class G airspace the instructor noticed that the flap indicator had failed.(This is probably a sliding vertical pointer on the left door/windscreen post).Instructor checked normal flap function.  Moving map on a tablet had shut down.  These distractions caused him to miss a familiar VRP and infringe a CTA.  Had possibly changed frequency to the destination A/G radio earlier than necessary.
At Southend the features of Hanningfield Reservoir, VRP Billericay and the 1,500ft CTA base are wholly or partially obscured on the chart by excessively thick boundary lines.
An instructor had left the iPad behind.
A/c cleared for immediate TO runway 03 with an early right turn onto an easterly heading as soon as safe to do so due to instrument approach traffic on the reciprocal runway 21.The pilot was distracted ‘…I was also looking out trying to see the ILS traffic, which I did not see’.  The pilot infringed CAS above.  Having departed and turned right as cleared, the aircraft was well clear of the ILS and concern about the inbound aircraft was an irrelevant distraction. Better to look ahead where other threats may appear.
A warbird pilot took a paying passenger to see her house in a large city.  ‘Although there was no time to plan the sortie as an ex-military [and other pilot] I’m very used to high pressure sorties.  With regard to a listening squawk, it was a conscious decision not to as the passenger was moderately apprehensive at the start of the sortie and I wished to be able to talk to her without the distraction of a busy ATC frequency…’The best way any pilot can look after passengers is to fly the aircraft safely and comfortably.  Numerous infringements cite pilot concern for passengers but there is nothing the pilot can do except fly safely and in some rare cases land at the earliest safe opportunity.
An aircraft eastbound into Shoreham had passed Yeovilton MATZ and was planning to cross underneath Solent CTA.‘I seem to remember I was on frequency with London FIS 124.750…’This is the least suitable frequency to be using when in the vicinity of CAS; they have no radar and cannot issue instructions.  They can issue clearances e.g. if used to file an airborne flight plan, but they have obtained that clearance from the relevant unit and are not themselves a controlling authority. It is a common misconception that calling London Information transcends more local ATC providers.
A pilot more accustomed to flying in the USA reports ‘…I was using the Foreflight map on my iPad to orient myself…I misread my map…I was monitoring XXXX radio…given the complexity of UK airspace…’.The pilot had not seen the base of LTMA in that area.
In two cases aircraft planned to fly beneath LTMA at 2,400ft which is OK, but close to the base; it’s doubtful that such accurate flying can reliably be maintained.  Very possibly this is done to give 100ft separation from numerous aircraft flying in the same area at 2,300ft.One infringement occurred while distracted by and avoiding other VFR aircraft in the area.
‘I had the route planned on Sky Demon and used the Garmin 430 as back up.  About 4 minutes into the flight the iPad became password locked.I tried to restart it without success.  Airspace vertical limits are not easily viewed on the Garmin 430.
Altimetry (5)
On the first flight in a new and faster aircraft type the pilot reports: ‘… it is possible the error occurred when I contacted Elstree and got the QFE and the autopilot then climbed…’  The aircraft had not departed Elstree and was heading towards the northwest for general handling.  It is hard to see why the pilot would want to set the Elstree QFE when flying beneath LTMA.
In an SR22 with Avidyne cockpit and climbing on course, the pilot read back the QNH correctly but for some reason the altimeter display reverted to a setting 10 HPA lower.  We cannot know whether there is some switching peculiarity with that display as described, but the lower setting ties up with the departure airfield QFE which should not be used for flights leaving the local circuit when beneath CAS.
On a low pressure day an aircraft climbed into Class A airspace.  The pilots were using a 1:250,000 chart which does not display CAS above 5,000ft.  The airspace concerned is not accurately identified in the report and the infringement may have occurred in an area defined by a flight level or an altitude.
A motor glider was wave soaring beneath CAS defined by a flight level with altimeter set to QFE.
An aircraft with instructor departed a London area airfield for general handling with altimeter still set to QFE.
Transponder over reading (3), intermittent (1), would not accept the digit 0 until restarted (1).  The latter is very distracting and resulted in an infringement.  We might wonder if current Mode S transponder types have been properly flight tested for ease of use, reliability and accuracy of transmitted pressure altitude. 
Cost Sharing Flight.  An airfield operator raised a report regarding a C172 that taxied for departure on runway 25 with a surface wind of 360/16G28.  Wind passed prior to departure 340/24G28.  When airborne aircraft requested a return to land but carried out a go-around from 300-400ft.  On the second approach with wind 340/27G30 the aircraft appeared unstable on final and bounced six or seven times during the landing.  When the wind is directly north or south and approaching crosswind limits, an alternate with a more into wind runway may be hard to find.  In this case, other aerodromes may have been suitable.  The aircraft was on a cost-sharing flight advertised on a website.