Pilot Briefing
Everything you need before flying into KRIR Flabob Airport — frequencies, pattern information, instrument procedures, and departure notes.
Airport data & frequencies
Essential information for pilots flying into and out of KRIR Flabob Airport, including frequencies, runway data, traffic patterns, and local procedures.
KRIR CTAF
122.8
KRAL TOWER
121.0
KRAL ATIS
128.8
KRAL WX ASOS
(951) 352-4392
SOCAL APP & DEP
135.4
RUNWAY 24 & 6
3190’ long, 50’ wide
ELEVATION
767’
TPA (day)
1467’
TPA (night)
1767’
FUEL
100LL
VFR ARRIVALS
First-time pilots into Flabob sometimes get intimidated by Mt. Rubidoux sitting off the downwind for Runway 24. Usually, that just means you’re too high. Our daytime pattern altitude is 1,467 MSL (700 AGL), lower than most airports. Fly the published pattern altitude and the mountain stays comfortably outside your base turn.
Back in the Flavio-Bob days, Flavio liked to say: “Fly toward the cross on top of Mt. Rubidoux until you feel an irresistible urge to cross yourself — then turn base.”
Night pattern altitude is 1,767 MSL (1,000 AGL), with traffic flown outside the mountain for better visibility and terrain clearance. Runway lights are pilot-controlled on CTAF 122.8 with seven clicks. One note: the runway lights are slightly offset, so favor the lights on the right side of the runway.
Flabob sits just 2.8 NM from Riverside Municipal (KRAL), tucked into a cutout of Riverside’s Class D. If approaching from or departing to the south or west, it’s a good idea to coordinate with Riverside Tower on 121.0. Riverside ATIS on 128.8 is usually accurate for local weather.
Traffic is left pattern for both Runway 24 and Runway 06. Runway 24 is in use most of the time. Arrivals from the east generally enter left upwind for 24, while arrivals from the north typically enter on left crosswind.
And yes — we’re proudly tower-free.
Instrument approach and DEPARTURES
ARRIVALS:
Flabob has a published RNAV (GPS)-A approach. Since it’s a circling approach, it works for either runway, although Runway 24 is usually the calm wind runway and the one most commonly used.
The approach begins at BAYJY intersection, where V186 and V363 meet south of Brackett, and follows a series of GPS step-down fixes westbound toward the airport. Category A minima are 1860 and 1¼ miles, which works out to roughly an 1,100-foot ceiling. The procedure is not authorized at night because of surrounding terrain.
Before the RNAV approach was published, many local IFR pilots used Riverside Municipal as the practical alternate. When Riverside is reporting at least a 1,000-foot ceiling and one mile visibility, it’s common to fly the ILS Runway 9 into KRAL, break out around 1,800 MSL, cancel IFR, and request Special VFR north westbound for Flabob. From there, follow the river north until Mt. Rubidoux comes into view, then make a left base for Runway 24. These days, the RNAV approach offers similar minimums, but the Riverside option still works well for pilots without IFR-approved GPS equipment.
As always, carry current charts, approach plates, and departure procedures. The information here is intended only as general operational guidance.
DEPARTURES:
Terrain and obstacle clearance around Flabob require attention, especially in low weather. Standard takeoff minimums apply with published climb gradients for both runways.
For Runway 6, plan on climbing runway heading (064°) to 4,000 before turning direct PDZ VORTAC. For visual climb departures, cross southwest of the airport at or above 2,700 before joining PDZ R-039 inbound to PDZ.
For Runway 24, climb on heading 244° while tracking PDZ R-031 to PDZ VORTAC. Visual climb departures follow the same southwest crossing procedure at or above 2,700 before joining PDZ R-039.
All IFR departures ultimately climb in the PDZ holding pattern east of the VORTAC with right turns on the 258° inbound course until reaching MEA for the direction of flight.
There are numerous obstacles in the departure environment, including trees, poles, tanks, antennas, and buildings near both runway departure paths. Review current obstacle departure procedures carefully before operating IFR at KRIR.
departure procedures
TAKEOFF MINIMUMS: Rwy 6, std. w/min. climb of 670′ per NM to 4000 or 400-2 w/min. climb of 480′ per NM to 4000 or 2100-3 for climb in visual conditions. Rwy 24, std. w/min. climb of 630′ per NM to 3000 or 800-2¾ w/min. climb of 305′ per NM to 4600 or 2100-3 for climb in visual conditions.
DEPARTURE PROCEDURE
Rwy 6, climb via heading 064° to 4000 then right turn direct PDZ VORTAC, or for climb in visual conditions cross Flabob Airport.
Southwest bound at or above 2700 then via PDZ R-039 to PDZ VORTAC. Rwy 24, climb via heading 244° and PDZ R-031 to PDZ VORTAC, or for climb in visual conditions cross Flabob airport Southwest bound at or above 2700 then via PDZ R-039 to PDZ VORTAC.
All aircraft climb in PDZ VORTAC holding pattern (hold East, right turns, 258° inbound) to cross PDZ VORTAC at or above MEA for direction of flight before proceeding on course.
NOTE
Rwy 6, trees beginning 3763′ from DER, 1152′ right of centerline, up to 40′ AGL/1119′ MSL. Rwy 24, antenna on tank 6193′ from DER, 2057′ right of centerline, 38′ AGL/1237′ MSL. Trees beginning 2494′ from DER, 434′ right of centerline, up to 40′ AGL/1519′ MSL. Pole 6261′ from DER, 1950′ right of centerline, 30′ AGL/1230′ MSL. Building 1.52 NM from DER, 1154′ right of centerline, up to 29′ AGL/1369′ MSL. Antenna on tank 1.26 NM from DER, 2047′ right of centerline, 54′ AGL/1254′ MSL. Tank 4043′ from DER, 794′ right of centerline, 66′ AGL/961′ MSL. Tree 1.79 NM from DER, 434′ right of centerline, 58′ AGL/1138′ MSL.