Date: 201701
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Flight conditions: IMC
Weather elements / visibility: Rain; Turbulence; 10
Light: Daylight
Aircraft: PA-28R Cherokee Arrow All Series
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Ferry / Re-Positioning
Flight phase: Final Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Tablet
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Situational Awareness; Training / Qualification
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Unstabilized Approach
Detector: Person Air Traffic Control
When detected: In-flight
Result: Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: I did a mediocre to poor LOC approach in actual. It wasn't dangerous; but not as safe as it should have been and below acceptable for me.I intended to shoot the ILS; which I anticipated being easy. I did know that my glideslope sometimes failed and thought I was prepared for that. I was not!When the glideslope failed (known failure mode is that the glideslope centers without the glideslope OFF flag showing). This has been an intermittent problem for about 3 years with at least 3 previous attempts by the avionics shop to fix. I was heading to [this airport] for yet another attempt (it always worked when they looked at it and I already replaced the indicator; glideslope receiver; and Nav/Com and asked them to find it or replace the harness as the last thing not replaced).I figured that when I heard the OM I'd do a fast descent to the MDA; but never heard the OM. Was still descending (but well above the MDA) when the Tower said I was over the airport and 'say intentions'. I said 'standby'. I should have gone missed then.I thank the tower for shortly thereafter ordering me to execute the missed while I was still thinking (too long).My recollection from ground school 25 years ago was that the OM was a necessary component of an ILS. I was wrong; the OM is optional and may be replaced by an intersection or RADAR (the controller calling that point).While trying to do this my 6 month old iPad running ForeFlight and showing the plate locked up showing nothing of value and I had not written down the MDA; etc. I also was trying to figure out how to identify a subsequent point that would then allow me to descend more than the initial MDA only 100 feet below the reported ceiling.My altitudes deviated by about 200 feet and my headings by up to about 25 degrees. I'm better than that having flown Instruments for 27 years and even having held Cat II ILS authorization in my previous plane; a 172!On the missed I got the iPad working right; studied the plate and saw the start of the final approach depicted as an intersection and also RADAR and how to identify that subsequent point and set up my radios and adjusted ForeFlight display.Second time I broke out and landed without incident. (The Tower did not scold me or ask for a call.)This was the first approach in more than very light actual in years. I had done several ILSs recently in very light IMC; one even at night.This flight was VERY educational for me. Lessons learned:1. Don't just do ILS approaches when I do my every 6 month 6 approaches!2. Don't do my practice just at my home airport and the uncontrolled airport; each of which have a full ILS with OM! At least pick other nearby approaches.3. Some ILSs do not have an OM and require an intersection or ATC to call the point! (I don't have DME for that method.)4. In moderate or low IFR; at least; have a printed plate in case my iPad fails!5. Thoroughly study and understand all likely approaches before setting out; especially in actual!




Synopsis: PA-28R pilot reported difficulty with the glide slope and his iPad approach chart display contributed to a poorly flown LOC approach in instrument conditions.