Dear All:Was reqading Mike Ray's 737 checkride book. In it he talks about CDAP - Constant Descent Approach Procedures. He says that by 2004 these new aproach methods were supposed to be in place. Does anyone know if they are? Apparently it only effects the portion of the approach from the Final Approach Fix until touchdown. Is this something that all pilot's now do universally?Thanks.Chris Catalano

FYI:On his site www.utem.org download section he has additional info on CDAP.

Thanks for the link. The download is actually an abbriged section of the complete chapter of the book I already own, In a nutshell, do you know if these CDAP profiles are in effect as of now, and if they are, are all pilots required to follow them as of now?Thanks for the link.Chris Catalano

I don't think so. I think commercial Ops Manuals may require them and I am quite sure that controllers are trained and possibly required to vector traffic to non-precision approaches in a way that would permit a stabilized descent approach but I don't think that the pilot is REQUIRED to fly one.I think you can still do a "slam dunk" or "dive and drive" approach which are overly dramatic expressions in the first place.I was trained to "expedite" down to the MDA at around 1,000 fpm which is hardly a "dive." (in singles and light twins)There are positives and negatives regarding an expedited descent profile but I never felt that 1,000 fpm was any particular challange. In addition, while I have never been forced by ATC instructions to have to descend at any greater rate in an NP approach, if I was held too high for too long, I would have just declined the approach clearance and asked to be vectored back around for another shot.In my mind, the worse the weather, the more inclined I would be to hustle down to the MDA. That way, I would be less inclined to be too high at the MAP and have to go missed.I could be obsolete on any reg requiring a pilot to shoot a stabilized approach but the subject has not been raised on my last two IPCs...but, luckily, I shot the VOR approaches on those rides pretty much dead on so the instructor may not have felt the need to give any refresher comments on the descent phase...but I DID book on down at 800-1,000 fpm in the Arrow used to fly the rides.Regards,Jim

If ATC issues pilot's discretion descents for FMS equipped aircraft for CDAP down to final approach levels, these navigation systems can offer assistance to the pilot in maintaining an efficient start of descent usually at engine idle to stated crossing restrictions of altitude and speeds. They have predictive displays that show you altitudes and speeds at entered waypoints. The idea is to accommodate efficiency by reducing stepping requiring frequent power adjustments.For aircraft without these there are formulas to establish aircraft performance parameters to establish CDAP for the approach path even where stepped final descents are anticipated. The IAP plates in the vertical profiles show an equivalent glide slope angle such as VOR/DME approaches and in the hard copy TERP books have tables in the back to help determine descent rate (VSI) for ground speed to average out these stepped descents assuming the specific approach allows a constant angle of descent at some point. Think of it as a virtual glide slope.The term CDAP applies in context however for larger aircraft descents from higher altitudes and not as common to final approach from the OM forward but it is achievable as long as the checkpoint minimum altitudes are maintained.

The noise abatement procedures at major UK airports state:"When the aircraft is approaching the aerodrome to land it shall commensurate with its ATC clearance minimise noise disturbance by the use of continuous descent and low power, low drag procedures. Where the use of these procedures is not practicable, the airctaft shall maintain as high an altitude as possible. In addition, when descending on initial approach, including the closing heading, and on intermediate and final approach, thrust reductions should be achieved where possible by maintaining a 'clean' aircraft condition and by landing with reduced flap, provided that in all the circumstances of the flight this is consistent with safe operation of the aircraft"Flights are monitored for noise abatement purposes and a descent will be deemed to be continuous provided that no segment of level flight longer than 2.5 nm occurs below a specified altitude (6000ft QNH in the case of Gatwick) and level flight is interpreted as as any segment of flight having a height change of not more than 50ft over a track distance of 2 nm or more.Facilities for using the airport can be withdrawn from the operator if the requirements are not met. Even occasional and exceptional breaches run the risk of financial penalties, so pilots tend to take these requirements seriously.