Narrative:

I just successfully completed my chkout flight into uio. The night arrival to runway 35 was in VFR conditions as was the day departure from runway 17. During preparation study and observations during operations; particularly during departure; I have noted some apparent point altitude discrepancies or omissions when comparing commercial chart runway 17 engine out procedures; ILS runway 35 chart; in the area south through sse within 6 mi of uio airport. This issue is of concern as it relates to the engine out procedures for runway 17. In all 4 runway 17 engine out procedures; a 15 degree bank turn to the northeast is required when passing uio NDB (1.425 NM from the south end of the runway) through a saddle in a north/south oriented ridgeline. I do not know what the width or elevation of this narrow saddle is; but it appears quite narrow when viewed in-flight and the obstructions along the ridges are likely to be very close to a heavy single engine B757 altitude achieved during the 15 degree bank turn. Since this turn can be accomplished in takeoff WX as low as 200M ceiling and 3KM visibility; it is highly likely the ridge will be shrouded in clouds and the aircraft in IMC while making this turn. I realize the safe accomplishment of these procedures in are heavily dependent on precise heading control to uio NDB followed by a prompt turn and precise bank control through the saddle. In visual flight conditions; I am confident that I can safely accomplish these procedures for runway 17; but in IMC I have serious reservations. Part of my reservations arise from the apparent point altitude discrepancies charted in the area of this turn and are highlighted below. On one page of commercial chart; have a highest point elevation on the left side of the flight path of 9806 ft; but a corresponding high point on the other page of 9986 ft or 180 ft higher. Similarly; on the right side of the first chart flight path; the highest point elevation shown is 9534 ft but a corresponding high point on the other page of 10180 ft or 646 ft higher! Obviously; I do not know if the point altitudes on the various charts necessarily correspond with each other due to chart scale differences but the omission of the higher points near the engine out turn track certainly begs the question. I urge a review of the current obstruction elevations in the area south of the airport for actual changes in elevation or new high points. Including the 9986 ft and 10180 ft point obstructions on the engine out depictions would be beneficial as they are higher than those currently depicted. I would like to know what the engine out at V2 performance calculations for at a typical maximum takeoff weight on runway 17 in terms of altitude; airspeed; and rate of climb before and after clean-up as well as during the 15 degree bank turn. Finally; based on the predicted altitude and climb rate through the saddle; what is the minimum obstruction clearance over what saddle width? The resultant review may provide good material for training.

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Original NASA ASRS Text

Title: AN ACR CAPT NOTICED A DISCREPANCY BTWN CHARTED ELEVATIONS IN THE SEQU ARPT ENG OUT AND APCH CHARTS.

Narrative: I JUST SUCCESSFULLY COMPLETED MY CHKOUT FLT INTO UIO. THE NIGHT ARR TO RWY 35 WAS IN VFR CONDITIONS AS WAS THE DAY DEP FROM RWY 17. DURING PREPARATION STUDY AND OBSERVATIONS DURING OPS; PARTICULARLY DURING DEP; I HAVE NOTED SOME APPARENT POINT ALT DISCREPANCIES OR OMISSIONS WHEN COMPARING COMMERCIAL CHART RWY 17 ENG OUT PROCS; ILS RWY 35 CHART; IN THE AREA S THROUGH SSE WITHIN 6 MI OF UIO ARPT. THIS ISSUE IS OF CONCERN AS IT RELATES TO THE ENG OUT PROCS FOR RWY 17. IN ALL 4 RWY 17 ENG OUT PROCS; A 15 DEG BANK TURN TO THE NE IS REQUIRED WHEN PASSING UIO NDB (1.425 NM FROM THE S END OF THE RWY) THROUGH A SADDLE IN A N/S ORIENTED RIDGELINE. I DO NOT KNOW WHAT THE WIDTH OR ELEVATION OF THIS NARROW SADDLE IS; BUT IT APPEARS QUITE NARROW WHEN VIEWED INFLT AND THE OBSTRUCTIONS ALONG THE RIDGES ARE LIKELY TO BE VERY CLOSE TO A HVY SINGLE ENG B757 ALT ACHIEVED DURING THE 15 DEG BANK TURN. SINCE THIS TURN CAN BE ACCOMPLISHED IN TKOF WX AS LOW AS 200M CEILING AND 3KM VISIBILITY; IT IS HIGHLY LIKELY THE RIDGE WILL BE SHROUDED IN CLOUDS AND THE ACFT IN IMC WHILE MAKING THIS TURN. I REALIZE THE SAFE ACCOMPLISHMENT OF THESE PROCS IN ARE HEAVILY DEPENDENT ON PRECISE HDG CTL TO UIO NDB FOLLOWED BY A PROMPT TURN AND PRECISE BANK CTL THROUGH THE SADDLE. IN VISUAL FLT CONDITIONS; I AM CONFIDENT THAT I CAN SAFELY ACCOMPLISH THESE PROCS FOR RWY 17; BUT IN IMC I HAVE SERIOUS RESERVATIONS. PART OF MY RESERVATIONS ARISE FROM THE APPARENT POINT ALT DISCREPANCIES CHARTED IN THE AREA OF THIS TURN AND ARE HIGHLIGHTED BELOW. ON ONE PAGE OF COMMERCIAL CHART; HAVE A HIGHEST POINT ELEVATION ON THE L SIDE OF THE FLT PATH OF 9806 FT; BUT A CORRESPONDING HIGH POINT ON THE OTHER PAGE OF 9986 FT OR 180 FT HIGHER. SIMILARLY; ON THE R SIDE OF THE FIRST CHART FLT PATH; THE HIGHEST POINT ELEVATION SHOWN IS 9534 FT BUT A CORRESPONDING HIGH POINT ON THE OTHER PAGE OF 10180 FT OR 646 FT HIGHER! OBVIOUSLY; I DO NOT KNOW IF THE POINT ALTS ON THE VARIOUS CHARTS NECESSARILY CORRESPOND WITH EACH OTHER DUE TO CHART SCALE DIFFERENCES BUT THE OMISSION OF THE HIGHER POINTS NEAR THE ENG OUT TURN TRACK CERTAINLY BEGS THE QUESTION. I URGE A REVIEW OF THE CURRENT OBSTRUCTION ELEVATIONS IN THE AREA S OF THE ARPT FOR ACTUAL CHANGES IN ELEVATION OR NEW HIGH POINTS. INCLUDING THE 9986 FT AND 10180 FT POINT OBSTRUCTIONS ON THE ENG OUT DEPICTIONS WOULD BE BENEFICIAL AS THEY ARE HIGHER THAN THOSE CURRENTLY DEPICTED. I WOULD LIKE TO KNOW WHAT THE ENG OUT AT V2 PERFORMANCE CALCULATIONS FOR AT A TYPICAL MAX TKOF WT ON RWY 17 IN TERMS OF ALT; AIRSPD; AND RATE OF CLB BEFORE AND AFTER CLEAN-UP AS WELL AS DURING THE 15 DEG BANK TURN. FINALLY; BASED ON THE PREDICTED ALT AND CLB RATE THROUGH THE SADDLE; WHAT IS THE MINIMUM OBSTRUCTION CLRNC OVER WHAT SADDLE WIDTH? THE RESULTANT REVIEW MAY PROVIDE GOOD MATERIAL FOR TRAINING.

Data retrieved from NASA's ASRS site as of January 2009 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.