How High and Fast Can You Really be?

[titaniumwings]

Let us assume the basic stabilization height (1000' agl) and criteria (vref, ldg config etc) for typical industry standard.

Can I consult the guide(s) you use for gauging whether you can make stabilization criteria by the required height? I understand this can be aircraft specific so do state your aircraft type with your guide.


Thank you very much for your inputs.


ps: the context is you are caught high (n maybe 'fast') due ATC cutting you in due change in sequence/wx avoidance/restricted airspace/terrain/
Some ATC has a better gauge of you being able to 'make' it than others

[B737900er]

Simple answer is experience and your gut feeling. You can look at the 'picture' and eye ball it and tell if it is realistic.

Having a formula to work it out is making it more complicated than it needs to be. KISS!

Titanium if you are a 'real' pilot you you would know what I'm talking about.

Think about the same scenario but in a C172?

[titaniumwings]

Ironically I never had a case or a feeling of which I never made it. Never had to report to office for ALAR program. Hopefully not.

But I heard of many who land deep into the runway (cos they claim runway very long) or stabilized at below 1000'. I wonder whether they thought they could make it or is it pure violation. I don't want to be one of them.

Then I hear some quarters giving guide like
1. 10nm 5000' clean speed you can make it (throw gear n speedbrake)-A330
2. As long as you are at least F1 on glide you can make it-B777

these kind of simple quick guide. Any inputs on these?

ps: slight off-tangent to airbus operators-any reason why u can't intercept the glideslope from above using OP DES n speedbrake? Technical explanation. Some operators use only VS.

[Meikleour]

Troll alert!!!

[Jwscud]

The VSD for the Boeing is actually fairly helpful for this if you're hot and high. If your vertical path intersects the 3° path before the White (1000') or Amber (500') marks it'll work, assuming you can get the aircraft configured. There was a good discussion here recently about what a 737 could manage Flap 40 idle thrust and the answer is lots.

If you're really worried, slow down and configure and get high, and drop down dirty as ever. And if it looks bad, throw it away early to avoid any paperwork

[B737900er]

Titanium - If you have never felt uncomfortable with at least one approach before, your either not a pilot, or have very little experience, or on the off chance a very good pilot that does good approaches every time.

Rule of thumbs: (B737)

25nm 10,000 ft 250kts

10nm 3000' F5

7nm Gear down , F15

4nm F30 Vref+5

This will get you stable by 1000'AGL

[titaniumwings]

I will take the second one. That's why I try to learn as much as I can. By uncomfortable in this context I take it that we mean initiating a missed approach before 1000' agl.

Apprehension n heightened sense I had when gs mini is doing it's hunting. But not to the extent that I had to initiate a GA.

Thanks for the role of thumb. 25nm 10000. Seems that b737 is really capable of a lot. I hear b777 n a330 are 'slickier'.

[B737900er]

1nm = 300' plus 1nm for every 10kts to lose.

[Naali]

Good rule on speed. I used a mental pic of 2000 per every 6 miles. You need only 2 or 3 ref points to mentally correct R/D and tendency to be high or low xx miles ahead. If flying unpressurised,the relation changes from 1/3 to 1/5 as max,not intending to pop everyone else`s eardrums. Heavier jets,(80, to me) are a nuisance because of their mass,and very slick wing that does not want to slow down. So there`s the third element to calculate in your head. I tried to keep mental track of gradient,by which this thing is slowing,and calculate as i could, how these things may meet each other at 6 miles,2000,and speed as manageable. Sure ATC gives some peas to the soup,but having something to sell,it shouldn`t be a problem.

[Naali]

-Just a short story on speed management. My friend was at 16 mile final to STO 26 at clear night,given free speed. Scandinavian 80 was cleared to follow as number two visually,left circuit. Asking, that he is still to our right,controller`s answer came sharply. Don`worry about him,he`s still doing 300 kts ground speed so You won`t catch him. Da20 Falcon.

[Naali]

As started to write,-flew Bandeirantes quite a while. And as turboprops are,they are very forgiving in speed management. ( passengers excluded) You could bring Bandit to 4 miles with 200kts and still take only minimum time on the runway. Most turboprops almost hit the wall,if You bring power to flight idle.Ground reverse really racks your ears... So at slow speed range,around airports ,-i would prefer to fly a TP.

[TypeIV]

The 737 is quite slick but at 20000', 30nm final with gdn f40 and idle thrust, you can make it.

[titaniumwings]

Probably many jets use 1nm=300' at finals. At distance and height, this may change.

1nm to lose 10kt works rather well in level, on des I reckon probably have to use at least 1.5nm.

All these is without accounting for drag devices which will most probably come in use when caught high.

B737 can really drop. It is more than double the drop rate with 'everything' down. 20 000' 30nm. Impressive.

But I guess the other option would be to drop with speedbrake then configure on level?

Thanks for the input guys.

[B737900er]

Speed brakes are only good when going fast. As you may know that the B737 or any other jet doesn't like to slow down and Descend at the same time.

I personally use the technique of getting it down early then lose the speed. I usually fly between 500-1000' below the Vnav profile to give me some margin. Smaller or less busier airports you can usually follow the Vnav profile. CDA approaches from TOD is are quite hard to do at busier airports.