Nice.. what? the trick is the losing 7000ft from the 11DME to be below 8000ft at the 020 radial on the arc. figure 240kts so 4miles/min.. 5miles to the arc, 7 miles to the 020...12 miles would require a 3000fpm descent to make the restriction, right?
Definitely a ground brief before flying.
http://204.108.4.16/d-tpp/0904/00354HI21.PDF
Oh yeah.....definite one you'd like to ground brief if you could.
Just to demonstrate how much of a royal pain in the ass this IAP was, esp single pilot and in the WX, wanna run through it. You math guys will love this one. For you OA, this could be a good AFR 51-37 refresher for you!
First, we have to establish the ground of what one had to deal with when flying this. In the old F-117 I used to fly, our jet penetration speed was 300 kts, and we had a 14 CFR 91.117d exemption for it. The jet didn't like maneuvering when much slower than that due to the permanent 72.5 degree wing sweep. The jet was single pilot, had no flaps, had no speed brakes, and only 1 NAV radio and 1 UHF Comm radio, however the HSI has an RMI function within the instrument.
The biggest thing with flying these kinds of approaches...the full approach....is knowing your numbers well ahead of time for performance. In a light GA aircraft, you can wait until you're nearly on an arc or about 0.5nm from it before you start your turn; and similarly, you can wait until after the CDI comes alive before turning from an arc to a radial. Not so in a fighter. At 300kts, you do any of these, and you're going to WELL overshoot any radial/arc. So this is where a little bit of public math comes in known as the 60 to 1 rule.
For fast aircraft, knowing when to turn to intercept an arc/radial is key. Using 60-1 I can easily figure this out.
First, radial to arc:
radial to arc: Turn Radius equals Indicated Mach Number minus 2. Therefore TR=IMN - 2; or mach minus 2, where mach equals miles per minute. In my case, 300 knots equals 5 miles per minute. So 5 minus 2 equals a 3 mile turn radius to make a 90 degree turn; ie- lead the radial to arc by 3 miles.
Now arc to radial (need to compute a Lead Radial):
arc to radial: 60 to 1 rule. 60/DME arc x TR, DME arc distance divided into 60, multiplied by Turn Radius. So, on a 15 DME arc (yes, I know it's 16 for this IAP, but for sake of public math ease), 60/15 equals 4....times 3 (TR) equals 12. Or make the lead radial 12 degrees short of the desired radial.
Yes, it's public math, but it's pretty simple public math that can be figured out in pre-mission planning, or enroute.
Now getting to the IAP. Am inbound at 300kts on the CME R-080 at at/above 15,000, Channel 108 tuned in and headed for JENOM (IAF). Crossing JENOM, continue inbound on the R-080 until 5 DME, where I have to start my right turn to intercept the CME R-360 (Gotcha #1). Continue outbound on R-360 to begin the right turn to the arc at no later than 13 DME due to radial-to-arc needs(Gotcha #2). Have to simultaneously begin a descent from at/above 15,000 to at/below 8000 while turning onto the arc (about 3500+ fpm descent....normal to what many Jet Penetrations are planned for), and have this completed prior to crossing CME R-020 (Gotcha #3)....because when crossing R-020, I now have to make a descent to a hard-alt 6500 for LOC intercept (Gotcha #4). I await the Lead Radial of 043 (round it to 040) from CME to begin the turn to intercept the LOC (Gotcha #5). Crossing the LR, I have to quickly change from CME to the LOC freq I-ROW Ch 36 ...(big Gotcha #6).....double check the morse code....and set the inbound course of 215 into the HSI, to where I should see the CDI already off the case by this time (halfway through the turn), and maneuver to intercept it. Drop the landing gear, perform final landing checks, slow to 180 (or computed basic weight + fuel + ordnance + 1/2 crosswind gust component), and descend to at/above 5400 when tracking the LOC (no need to be centered up, just intercepting) in prep for glide path intercept. No frequency change to tower should be necessary, since SFA procedures are in effect when IMC. Have no ADF to identify TOPAN, nor do I have CME tuned up anymore, so DME is all that's available. Intercepting the GP and crossing 7 DME, crosscheck the glideslope check altitude and run through the 5-Ts, noting timing for 180 kts, or interpolating for 190 kts; and proceed down the GP to the DH of 3837 (3900)...noting the other MDAs in case a transition to non-precision is needed. Once breaking out and transitioning to visual, land; throw out the drag chute if less than 15kts x-wind, slow and exit the ruway.kicking the chute off before pulling off.
All of this while in the soup, and single pilot...with the aircraft limitations listed above.
Talk about a nice mental workout.
