Airborne_Again wrote:
Actually there is. With an approach category A aircraft you’re not supposed to fly faster than 110 KIAS on final. On the other hand no one seems to care about that.
Isn’t 110 the maximum speeds for final missed approach? With <91 being the Vat? With the range of final approach speeds being 70-100 kias.
Graham wrote:
Two things:1. You have to remember that there’s no ‘book speed’ for the ILS. For visual approaches there is Vref, but for an instrument approach it’s up to you. Anything an instructor or training organisation tells you is because they think that’s a good speed (or they got it from elsewhere), it is not in any way ‘official’ or ‘correct’. I prefer a faster speed, closer to cruise speed. Your mileage may vary ;-)
2. A bounce is not directly caused by being too fast. It is caused by too high a rate of descent in the last few feet above the runway. This is often the result of a prolonged hold-off (due to being too fast!) which gradually climbs away from the tarmac and then drops on suddenly from higher than you’d like.
RobertL18C wrote:
The main reason ATOs teach a reference instrument approach speed (both 3D and CDFA) is partly, attitude plus power equals (consistent) performance, and because there is +/- 5 knots tolerance under the examiner guide for the IR. Higher speed, and tailwind ILS will normally be covered as well.Airline OPC will be configured fully at FAF and will have similar requirements for strict speed monitoring. In practice, when on a coupled approach they would re configure at 4D, with the autopilot taking the strain.
GA in hub airports will typically keep their speed up until 4D, in effect flying clean until 4D – but again the equipment will be on a coupled approach and the types have a high Vle.
So I am right in flying towards the FAF at 108KIAS+ Reducing to a stage of flap, 50% power before any descent along the vertical path being at 20%, roughly 90kias for the DA40? I am all for higher approach speeds, if it helps ATC. Normally when I fly into Southend, they’ll vector GA around to prioritise IFR inbounds. Not sure if this would be the same if I was coming in from Europe on the Airways but I tend to keep the speed up to a point where I have to reduce. You can quite easily have too much energy in the DA40 and it’s uncomfortable to try and slow it.
When I flew for BA as crew, they used to dump the gear at 4DME and put the final flaps in. Once the autopilot did it’s thing, usually a short whilst later they would take the autopilot off. Very rarely did they fly the whole ILS manually. I know in the B744 they did it a lot, as setting the throttle to a certain EPR was better for turbulent approaches.
I guess post IR training. There’s nothing stopping me flying the autopilot in a high energy approach, reducing at 4DME to 90kias and configuring the take-off flaps once below 108kias. It just worries me trusting the autopilot that late in the ILS to deal with such high energy at what 500fpm -VS? I guess if I flew into Frankfurt or Schipol that would be beneficial for everyone.
2. Getting it right every flight is quite difficult, unless you fly weekly? I mean I tend to fly every 2-3 weeks which for doing the IR is probably not enough? But getting those landings to perfection (Okay we can’t always be perfect) takes great skills and amazing understanding of each weather situation and flying conditions on the day. I still think I fly my final third too fast because the stall warner goes off (which is normal for the older DA40s). But doesn’t mean your anywhere near approaching the stall if the IAS and AoA is acceptable.
Ibra wrote:
The only limiting speeds to fly approaches or circles to land is around VLE/VGE as you quickly configure for landing other than that the fastest/cleanest is even betterIf I can’t slow down after becoming visual or stop after landing in GA aircraft at cruise speed it is probably not the right combination of weather/wind/airport for IMC with or without instruments…
Do you apply full stage of flap only on becoming visual? It’s what I’ve been taught in the DA40 for IAPs. So interesting that you mention that. I never really like take-off flap for landing, it just floats.
pilotrobbie wrote:
Isn’t 110 the maximum speeds for final missed approach? With <91 being the Vat? With the range of final approach speeds being 70-100 kias.
You’re right! My mistake.
“Do you apply full stage of flap only on becoming visual?”
I would apply flaps when in VMC (make your go around in IMC easier), how/when it depends on runway length, speed, height, wind as judged by the eye, if you land at Southend/Lydd you can go flapless as it makes your life easier :)
For gear it is much tricky you have to drop it to slow down, retract to accelerate and most importantly to land while it does not change the trim state that much it takes more time to deploy and check, so I better have it earlier in the approach and keep it down in a go around..
In the Mooney I have been taught to drop the gear and reduce power 1 mile before FAF. This gets it below 110 kts pretty quick and then I add T/O flaps. Reduce power a bit more at the FAF and trim for 500 ft/min at 90 kts. Although the new ATO owners won’t let me do it in my own plane no more, so back to the C172 for the rest!
zuutroy wrote:
In the Mooney I have been taught to drop the gear and reduce power 1 mile before FAF
In Mooney you need that gear down for it to keep flying bellow 110kts without you having to pull that nose above the horizon 
Typically a FG SEP will fly a 3 degree slope at KIAS 90-100, with either 10 degree flaps or flapless. The rule of thumb for a 3 degree slope is 300fpm/60 knot ground speed, so 90 knots ground speed would be 450 fpm. The attitude will be around -3 degrees pitch, but varies with ground speed and slope, some approaches are 3 1/2 degrees slope or steeper.
Landing flap would be applied when transitioning to visual, and Vat would be as per POH.
Because a commercial jet has an inertia of around 7 seconds or more, and spool up time, understanding the central attitude value for the approach slope/configuration/ground speed is important as you would then bracket (around 1 to 2 degrees of attitude) to maintain CDFA/glide slope. Chasing the needles is negative training, and not bracketing – ie creating a dangerous technique. In a swept wing CAT jet a minus 5 degree attitude in the approach configuration would be a rate of descent of 3,000 fpm, combined with inertia this is unacceptable. The central value in a swept wing will be around plus 1 or 2 degrees in approach configuration.
While the power curve on propeller aircraft is arguably power for altitude and pitch for speed, most integrated schools would teach ‘point and squirt’, or jet technique. ie attitude controls altitude/rate of descent and power sets speed. Hence attitude plus power equals performance.
This implies re configuring in the run in to FAF, pitching for the relevant descent attitude at FAF, and then setting power for speed, not the other way round.
FWIW, I was taught early on that one should intercept the glideslope at the gear extension limiting speed i.e. Vlo. This is best for fast traffic behind you, and then you can reduce power while down the glideslope, as required, for say 100kt (or whatever is needed for full flap) at the DH. From 200ft, it is easy to get down to say 80kt in the flare with full flap… usually.
RobertL18C wrote:
While the power curve on propeller aircraft is arguably power for altitude and pitch for speed, most integrated schools would teach ‘point and squirt’, or jet technique. ie attitude controls altitude/rate of descent and power sets speed. Hence attitude plus power equals performance.
Indeed – when I did my IMCr I was taught ‘point and squirt’ with the pre-briefing that this is the reverse of how one is taught to control an approach in the PPL. I found it worked for me, and thus I have probably flown the TB10 like that ever since – hence it taking me a while to get the hang of power for altitude and pitch for speed when we were converting me to the Vagabond.
Graham the Vagabond has such an uncomplicated personality it would never pretend to be a Jet!
It may pretend to be a helicopter or vtol with some sideslip an no power and rotary wings are not interested in long fast ILS buisness ;)
