Date: 201201
Local time of day: 0601-1200
Location: HIF.Airport, UT
Flight conditions: VMC
Light: Daylight
Aircraft: Hercules (C-130)
Operator: Military
Operating under: Part 91
Flight plan: IFR
Mission: Training
Flight phase: Final Approach
Airspace: Class D HIF
ATC / advisory: Tower HIF
Reporter organization: Military
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Multiengine; Flight Crew Flight Engineer; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP); Flight Crew Flight Instructor
Human factors: Situational Awareness; Distraction
Second reporter function: Captain; Pilot Not Flying
Anomaly: Deviation - Altitude Crossing Restriction Not Met; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Automation Aircraft TA; Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance
Contributing factors: Airspace Structure; Human Factors; Procedure
Primary problem: Airspace Structure

Narrative: While flying a TACAN approach to Runway 14 at Hill Air Force Base; we received a TCAS TA for an aircraft flying into Ogden-Hinckley airport. While both pilots were visually searching for the aircraft we inadvertently descended below our step down fix altitude prior to reaching the next fix. It is a regular occurrence to receive a TCAS advisory while on an instrument approach into HIF with simultaneous instrument approaches in to OGD. The TCAS TA is distracting to pilots especially during VMC conditions because the pilots then try to visually acquire the other aircraft. The best solution to this issue would be to eliminate simultaneous approaches to both OGD and HIF or at a minimum avoid having aircraft on short final into OGD and while having aircraft inbound HIF on 4 to 6 mile final. Either of these solutions would minimize the TCAS advisories thus allowing the pilot to dedicate his full attention to the approach during this critical phase of flight.


Second narrative: While flying; on an IFR clearance; the TAC 14 Circling approach at Hill AFB; my aircraft inadvertently dipped below the step down fix of 5;700 at 4.0 DME. This step-down exists to preserve the airspace over Ogden airport while flying all IFR approaches to Hill AFB. Ogden is Tower controlled and we received notification from Hill Tower to maintain 5;700 FT. This notification was relayed from Ogden Tower to Hill Tower to my aircraft; we were on the assigned Hill Tower frequency during the approach.While flying IFR in VMC (clear) conditions on final at 5.0 DME an aircraft appeared on TCAS which was on final approach to Runway 03 at Ogden. The crew became distracted by this traffic attempting to gain a visual identification. This area is very busy with GA VFR aircraft following I-15 at the edge or within Hill Class D airspace. During this time; the pilot flying allowed my aircraft's altitude to deviate below the published step-down fix. The crew did gain a visual identification on the light aircraft and remained well clear without additional maneuvering.The source of the traffic conflict is active Class D airspace 2 miles north of Hill AFB. All approaches to 14 are over the top of Ogden's Class D airspace creating distracting conflicts while flying IFR approaches. A solution is to sterilize the Ogden traffic pattern while Hill AFB landing aircraft are conducting an IFR approach. This would prevent distractions and potential traffic collisions.


Synopsis: C-130 flight crew on a Tacan approach to Runway 14 at HIF experience a TCAS TA on traffic approaching Runway 3 at OGD. The distraction results in deviating below the 5;700 FT minimum altitude required for that segment of the approach and is detected by ATC.