KSDF Louisville Muhammad Ali Intl — Instrument Checkride Guide

What kind of airport is KSDF and what is its IFR environment?

Louisville Muhammad Ali International Airport (KSDF) is located in Louisville, Kentucky, at 500 ft MSL. The airport serves commercial passenger operations and is the global primary hub for UPS Airlines, which bases a large fleet of B747, B767, B757, A300, and MD-11 freighters there. This heavy-aircraft concentration creates a wake turbulence environment that is uncommon at Class C airports and demands heightened awareness from GA pilots.

KSDF operates three runways: 17R/35L at 11,887 ft, 17L/35R at 8,578 ft, and 11/29 at 7,251 ft. Louisville Approach Control handles IFR traffic on 123.675 and 132.075 MHz. D-ATIS broadcasts on 118.725 MHz. Tower is 124.2 MHz; Ground is 121.7 MHz; Clearance Delivery is 126.1 MHz. Under 14 CFR 91.130, two-way radio contact with approach control is required before entering Class C airspace.

What instrument approaches are published at KSDF?

KSDF has one of the most comprehensive approach suites of any Class C airport in the region, sourced from SkyVector current chart listings.

Always verify current minimums on official FAA charts. RNAV (RNP) procedures require authorization (AR) and are typically unavailable to GA aircraft without specific avionics certification. The Y suffix on RNAV (GPS) procedures indicates these are published alongside the (RNP) Z variants.

What is the runway configuration at KSDF?

KSDF operates three runways. The primary instrument runways are 17R/35L and 17L/35R, both with full ILS equipment. Runway 11/29 provides a crosswind option with RNAV and a LOC-only approach.

Runway 35L is the preferred ILS arrival runway under southwest flow and is the longer of the two parallel precision runways. Runway configuration at KSDF is also heavily influenced by UPS overnight sort operations — from approximately 0000–0600 local, heavy freighters dominate the movement area.

What weather should instrument pilots expect at KSDF?

Louisville's Ohio River Valley location produces a distinctive weather pattern for instrument pilots. The valley funnels moisture northward from the Gulf of Mexico during spring and summer, creating a high frequency of low IFR conditions from March through May. Morning radiation fog in the valley can reduce visibility to near zero on otherwise clear days, dissipating by mid-morning. These events are common enough that Louisville is one of the foggiest major airports in the mid-South during spring.

Winter weather brings a mix of freezing rain, sleet, and snow. The Ohio River Valley is particularly prone to ice storms — events where rain falls through a sub-freezing surface layer and freezes on contact with pavement and aircraft surfaces. These events are operationally significant: they coat runways and taxiways with ice faster than deicing crews can respond, and the narrow temperature range during ice events makes PIREPs unreliable predictors of conditions 30 minutes later. The NWS Louisville (LMK) office issues Terminal Aerodrome Forecasts and Special Weather Statements for KSDF.

Summer afternoon convective activity along the Ohio River valley can be intense. Pre-frontal squall lines from the west bring widespread thunderstorm activity from June through September. KSDF's location near the convergence of Gulf and continental air masses makes it susceptible to complex, fast-moving convective systems.

What should you expect on an instrument checkride at KSDF?

A checkride at KSDF presents a unique training environment: the combination of Class C airspace, commercial traffic, and heavy UPS freighter operations gives it a demanding ATC environment unusual at non-Class-B airports. The DPE will expect you to demonstrate proficiency in wake turbulence awareness from the pre-flight briefing forward. The AIM Chapter 7 discusses wake turbulence avoidance in detail, and the DPE may probe your knowledge of vortex behavior, rotation points, and separation standards before you leave the ground.

The ILS RWY 35L is the primary DPE approach at KSDF. At 11,887 ft and certified for CAT II-III, it is one of the most capable instrument runways in Kentucky. The DPE may assign this procedure and ask you to fly raw data — needle and ball — to evaluate whether your instrument scan is independent of flight director annunciation. This is a common DPE technique at airports with glass cockpit-equipped aircraft: remove the flight director, set the aircraft up for the ILS, and evaluate whether the pilot can maintain the localizer and glideslope using only the CDI and altimeter.

Wake turbulence avoidance requires active decision-making at KSDF. If a UPS B747 has just rolled out on 35L, ATC will issue a standard wake turbulence caution. The DPE will note whether you acknowledge it, understand what it means procedurally, and take appropriate action — either by accepting an extended downwind, requesting a different runway, or adjusting your touchdown point per AIM guidance.

The UPS hub context also creates a realistic alternate-planning scenario. A pilot routing from Lexington (KLEX) to KSDF must consider whether KSDF's overnight sort window affects alternate selection — if KSDF is the destination and conditions are marginal, choosing Cincinnati (KCVG) as the alternate means flying into another major cargo hub. The DPE may probe whether the applicant understands the alternate minimums rules under 14 CFR 91.169 and can select a legally compliant alternate from the available options.

Practice Questions

1. Louisville Approach advises a UPS B747 has just departed runway 35L and vectors you for the ILS 35L 5 minutes behind. What wake turbulence avoidance techniques apply, and what AIM guidance governs vortex behavior near the runway?

2. You are flying the ILS RWY 17R at KSDF. At 800 ft AGL, you have the approach light system in sight with red terminating bars. Under 14 CFR 91.175(c), how far below DA may you descend using approach lights alone, and what is the specific visual reference required to continue to a landing?

3. The RNAV (RNP) Z RWY 35L is published at KSDF. Your aircraft has RNAV capability but no RNP authorization. Explain what "authorization required (AR)" means and which aircraft avionics capability is specifically required to fly this procedure.

4. You file KLEX to KSDF with KCVG as your alternate. The TAF for KCVG shows a 900-ft broken ceiling and 3 miles visibility for the ETA window. KCVG has a published ILS with standard Category I minimums. Is KCVG a legal alternate under 14 CFR 91.169?

5. The DPE removes the flight director and asks you to fly the ILS RWY 35L using raw data only. Describe your instrument cross-check sequence, how you identify the outer marker, and what actions you take at decision altitude.

Frequently Asked Questions

Q: What instrument approaches are published at KSDF?

KSDF publishes ILS or LOC approaches to runways 17L, 17R, 35L, and 35R; ILS (SA CAT I and CAT II-III) to runways 35L and 35R; RNAV (RNP) Z approaches to runways 17L, 17R, 29, 35L, and 35R; RNAV (GPS) Y approaches to runways 17L, 17R, 29, 35L, and 35R; and a LOC RWY 29. Data from SkyVector.

Q: What airspace class is KSDF?

KSDF operates within Class C airspace. Under 14 CFR 91.130, two-way radio communication with approach control is required before entering Class C. Louisville Approach manages IFR traffic on 123.675 and 132.075 MHz.

Q: What is the ATIS frequency at KSDF?

KSDF D-ATIS broadcasts on 118.725 MHz. Louisville Tower is on 124.2 MHz. Ground is on 121.7 MHz. Approach operates on 123.675 and 132.075 MHz. Clearance Delivery is on 126.1 MHz.

Q: Does KSDF have CAT III approaches?

Yes. Runways 35L and 35R are certified for Special Authorization CAT I through CAT II-III operations. Standard CAT I ILS approaches are also available to all four runway 17/35 ends. CAT II-III operations require specific aircraft equipment and FAA-authorized training for crew.

Q: Why is wake turbulence a concern at KSDF?

KSDF is the primary hub for UPS Airlines (United Parcel Service), which operates B747, B767, B757, MD-11, and A300 freighters throughout the overnight sort window. GA aircraft operating near this hub must be vigilant about wake turbulence separation and should expect ATC to vector them for spacing behind heavy and super aircraft.

Q: What is the longest runway at KSDF?

Runway 17R/35L is 11,887 ft × 150 ft — the longest runway at KSDF and one of the longest in Kentucky. It is certified for CAT II-III ILS operations on the 35L end. Runway 17L/35R is 8,578 ft and runway 11/29 is 7,251 ft.

Sources

• SkyVector — KSDF Instrument Approach Procedures
• 14 CFR 91.130 — Operations in Class C Airspace (Cornell LII)
• 14 CFR 91.169 — IFR Flight Plan: Information Required (Cornell LII)
• 14 CFR 91.175 — Takeoff and Landing Under IFR (Cornell LII)
• FAA Instrument Flying Handbook FAA-H-8083-15B
• AIM Chapter 7 Section 4 — Wake Turbulence
• NWS Louisville (LMK) — Terminal Forecasts

This article was researched from FAA primary sources (ACS, FAR/AIM, Advisory Circulars, Instrument Flying Handbook), approach procedure data from SkyVector, and citing current 14 CFR Part 91 — drafted by MockDPE Editorial Team. Last updated: May 2026. If you spot an inaccuracy, email corrections@mockdpe.org.