Descent rate - Class G

[Squawk7700]

After an incident in class G airspace recently, I ponder the question.... with no radar guidance/advice, what do you feel should logically be the greatest rate of descent (or climb for that matter) for any aircraft?

If there is a reg, whoops, I haven’t checked :-)

[Lapon]

I'm not aware of the incident but the last thing we need is a rate of decent limit. Completley impractical for skydiving ops, and pretty impractical for all the high capacity jets and turbo props (especially the ones operating above 10000ft), and no doubt impractical for some others.

Airmanship suggests easing the ROD/ROC near crossing traffic you are aware of, but this is class G we are talking about.

The question should rather be focused on how appropriate class G is in a given area.

[Squawk7700]

What descent rate do skydiving aircraft get up to? I’m guessing turboprops would be much higher.

[no_one]

pretty quick descent....

https://www.youtube.com/watch?v=__hxwFZXF-s

[Capn Bloggs]

Squawk, you'll need to give us some info on the incident before we comment.

IMO, as high as possible to minimise time in Ledspace!! :8

[Squawk7700]

Let me just say that the attached video above sums up the issue very nicely!

Perhaps not quite as quick in this case, but 100% relevant.

[Nibbles2310]

What descent rate do skydiving aircraft get up to? I’m guessing turboprops would be much higher.

3500fpm is normal in a C208 and up to 7000fpm in a Blackhawk conversion C208 or PAC750/Cresco

[machtuk]

Under normal Ops 500' ROD for comfort, anything higher is unusual.

[The Green Goblin]

A good rule of thumb is your altitude in fpm

So 10,000fpm at 10,000ft

5000fpm at 5000.

1000fmp at 1000 etc.

Some airlines have 5000fpm to 5000 etc, but with speed brake and a high IAS this is easily breached.

[Capn Bloggs]

Some airlines have 5000fpm to 5000 etc, but with speed brake and a high IAS this is easily breached.
Gobbo, I don't know what leadsled you fly, but that sounds ridiculous. First, you'd be doing 250KIAS max in G below 10, and I very much doubt you'd get anywhere near "easily breached" 5,000fpm even with full boards in an "airliner". Even I would be puckering at 5,000fpm below 10k, let alone approaching 5,000ft AGL.

[blind pew]

Got 10,000 fpm going into Glasgow and Gibraltar on trident 1s with reverse and brakes but my best was positioning a F100 into Fumicino were I saw 16,700 fpm before I chickened out..fair bit below VNE..recon 20,000 was attainable. Happy days when a captain was a captain and could fly an aircraft manually.

[machtuk]

Gobbo, I don't know what leadsled you fly, but that sounds ridiculous. First, you'd be doing 250KIAS max in G below 10, and I very much doubt you'd get anywhere near "easily breached" 5,000fpm even with full boards in an "airliner". Even I would be puckering at 5,000fpm below 10k, let alone approaching 5,000ft AGL.

I agree Bloggsy, complete nonsense!
The thread poster said class G with no mention of pressurised or unpresurized but no Airline machine is going to be doing a high ROD in that environment OCTA neither would a basic GA plane due comfort . There's lots to consider, EPGWS/TAWS etc. Normal Vnav's go down at approx 2500fpm and if programmed correct there's no need for an excessive ROD unless traffic or ATC restrict normal Ops. Airline SOP's also have restrictions during the last 1000 ft. Add in body angle etc there's really no need for it.

[drpixie]

Capn Bloggs - In the baby Citation, we're normally 2-3000 but 4-5000 is needed occasionally and is no great drama - and that's at M.63 into 250. The bigger Citations, Lears, and airliners might be comfortable at double our FPM.

[UnderneathTheRadar]

Under normal Ops 500' ROD for comfort, anything higher is unusual.

That's a good rate for the cabin - not the aircraft.

Back in my skydiving days, objective was to be back on the ground before the tandems landed. Easy in a PAC, bit harder in a 206.

[Sunfish]

Over 1000 fpm unpressurised, I find people start getting aware of their ears............Also instructors start sweating.

1000+ OK for seconds in a good sideslip to renovate an approach.

My planning figure is 500fpm for no good reason.

[drpixie]

Over 1000 fpm unpressurised, I find people start getting aware of their ears............Also instructors start sweating.

1000+ OK for seconds in a good sideslip to renovate an approach.

My planning figure is 500fpm for no good reason.


You need a pressurized aircraft :)

[RatsoreA]

500FPM for unpressurized piston twins (AC50/PA31/PA34) is easy on the ears and seems to keep me nicely in (or out, as required) the control steps and sets up for an easy approach, allowing time for speed management (gear/flap) and engine temps.

Pressurised piston ops (601P) are a little different, but still 1000-1500 is pretty good, the cabin can keep 500 or less at that speed, and still gives you plenty of options for speed control and doesn’t have you in the yellow arc when it’s bumpy.

Adding a ROD/ROC restriction would be a pain in the a$$ and add another consideration to your approach that isn’t really needed.

As for skydiving, isn’t it get down as quick as you think you can get away with without tearing the wings off‽??

[machtuk]

Some years ago a skydiver driver told me he descends at VNE indicated all the way down to circuit height.......I just shook my head and kept an eye on the news,

[The Green Goblin]

Bloggs, a bus will easily pull over 5000fpm with full boards at 250kts, especially if you’ve slowed for whatever reason, say to green dot, then wind it back to 250 and pull out the brake.

If you pull speed at 190kts with flap 2 and brake/open descent, it’ll do it too.

If you’re silly enough to be in expedite descent below 10 with 1/2 brake, you’ll be pulling 6-7000fpm.

[junior.VH-LFA]

A good rule of thumb is your altitude in fpm

So 10,000fpm at 10,000ft

5000fpm at 5000.

1000fmp at 1000 etc.

Some airlines have 5000fpm to 5000 etc, but with speed brake and a high IAS this is easily breached.



Dude you couldn't even do that in a King Air.

[Capn Bloggs]

Ooright, I stand corrected.

[YPJT]

Some years ago a skydiver driver told me he descends at VNE indicated all the way down to circuit height

I flew for a few of them like that. Throttle and prop all the way in to drop height. Descend at VNE -10. Testament I guess to how well constructed and able to withstand abuse the C182 is rather than an example of efficient operation of the aircraft. :ugh:

[Okihara]

For the less initiated amongst us here: why exactly would you need to descend at VNE to CCT height after dropping parajumpers? Why not enjoy a smoother descent?

[Old Akro]

The faster you get down, the more runs in a day. The more runs in a day, the more money you make. Turbines don't suffer shock cooling and the prop acts like a brake, so why not?

Descent rate depends a lot on the aircraft and its Va. Most light GA aircraft need 700 fpm for a 3 deg approach profile. I use 500 fpm for economy and ATC seem to think I can easily do 2000 fpm. Certainly, its common for ATC to leave me with a TOD that requires 1000 - 1500 fpm or greater to get down to circuit height.

[Squawk7700]

I flew for a few of them like that. Throttle and prop all the way in to drop height. Descend at VNE -10. Testament I guess to how well constructed and able to withstand abuse the C182 is rather than an example of efficient operation of the aircraft. :ugh:

I guess when the pilot is wearing a parachute he / she doesn’t care! As long as the wings don’t fall off below say 2,000ft.

[machtuk]

There is a very interesting thought provoking article called "flight High & fast" which appeared on Vans Aircraft site, well worth a read for anyone operating at high ROD's & high IAS's. Another attached fr some light reading and a wake up call to a LOT of pilots who have no idea about TAS!
I am very mindful of this as I own a high perf SE that can easily bust it's VNE
http://vansaircraft.com/pdf/hp_limts.pdf
http://flyingdonald.********.com/2011/03/what-flutter.html Sorry guys the link doesn't seem to want to paste completely, do a search you'll find it.

[YPJT]

For the less initiated amongst us here: why exactly would you need to descend at VNE to CCT height after dropping parajumpers? Why not enjoy a smoother descent?
Because a lot of skydive operators know Jack Schitt about aircraft and just want the fastest turnaround possible to keep the meatbombs in the air.

I recall a LAME once showing me the result of pilots flying down to the circuit at just below VNE levelling out and putting the first stage of flap out. Serious cracking around the rivets on the flap leading edges. God knows what the stresses were doing to the operating mechanisms.

[VH DSJ]

Because a lot of skydive operators know Jack Schitt about aircraft and just want the fastest turnaround possible to keep the meatbombs in the air.

I recall a LAME once showing me the result of pilots flying down to the circuit at just below VNE levelling out and putting the first stage of flap out. Serious cracking around the rivets on the flap leading edges. God knows what the stresses were doing to the operating mechanisms.

Makes you wonder how many pilots in GA write up flap limitation speed exceedences in the maintenance logs.

[KRviator]

Makes you wonder how many pilots in GA write up flap limitation speed exceedences in the maintenance logs.None - Unless they're sure they're not going to hire that plane again...;)

[Okihara]

I recall a LAME once showing me the result of pilots flying down to the circuit at just below VNE levelling out and putting the first stage of flap out. Serious cracking around the rivets on the flap leading edges. God knows what the stresses were doing to the operating mechanisms.
Boy.. I had to read this sentence 3 times until I realised that you wrote LAME and not DAME. Makes perfect sense now, cheers!

[ClippedWing]

Referencing Green Goblin's post,

In the Navy we called this the "minute to live rule", and it has served as a pretty good guide for me over the years.

[The Green Goblin]

Its also the SOP for Max ROD in the Australian national airline.

Nuff said.

Referencing Green Goblin's post,

In the Navy we called this the "minute to live rule", and it has served as a pretty good guide for me over the years.

[Trevor the lover]

Hey Machtuck, I note you say the stupidly high rates of descent quoted by Green Goblin were just that - STUPID. But you also said, for comfort, normal ops 500 fpm, anything else is too much. Serious?? Jets coming down from altitude on a normal profile at descent speeds are doing around 2200 =, 2300 fpm. 500??? Dude you need a new pressurisation system.

[Sunfish]

Modern pressurisation systems are “intelligent “ and easy on pax ears.

[The Green Goblin]

500fpm is normal in an unpressurised aeroplane.

1000-3000fpm is normal in a pressurised aeroplane.

Anything more than that is a short term intervention for profile management.

Anything less than that is for the same reason.

Don’t hit the ground. Enough said.

[Capn Bloggs]

Getting back on thread, it does make it harder to spot dive bombers if they are in the vicinity of the airport. The Mildura near-miss between the Embraer 190 and the GA-8 is a case in point. The GA-8 was 11,000ft at 10.5nm from the runway, diving to 1300ft at 3.5nm. That makes it very hard to pick up. If you're going to dive-bomb near the airport, make sure everybody knows about it.

[machtuk]

Hey Machtuck, I note you say the stupidly high rates of descent quoted by Green Goblin were just that - STUPID. But you also said, for comfort, normal ops 500 fpm, anything else is too much. Serious?? Jets coming down from altitude on a normal profile at descent speeds are doing around 2200 =, 2300 fpm. 500??? Dude you need a new pressurisation system.


i was was ref to unpresurized A/C, seeing as the original thread starter didn't say one way or the other, I thought my comment was obvious!
I fly high perf jets, I think I kinda get it!

[Capt Fathom]

I fly high perf jets, I think I kinda get it!

That is no guarantee! :E

[Trevor the lover]

Mach. Fair enough, since you're right, no he didn't mention whether pressurised or unpressurised. But neither did you,. Maybe you should have said 500 fpm if unpressurised.

[andrewr]

i was was ref to unpresurized A/C, seeing as the original thread starter didn't say one way or the other, I thought my comment was obvious!


The OP asked what should be the maximum rate of descent for any aircraft in class G, mentioning it was in relation to an incident, also asking about regulations.

"Any aircraft" includes pressurised or unpressurised. The question is not in relation to "best" or "most comfortable" rate of descent - it is about the maximum.

AFAIK there is none - if there was it would put most restriction on pressurised high speed aircraft e.g. RPT jets. It could also pose a problem for vertical aerobatic maneuvers.

[andrewr]

The Mildura near-miss between the Embraer 190 and the GA-8 is a case in point. The GA-8 was 11,000ft at 10.5nm from the runway, diving to 1300ft at 3.5nm.

Ah yes, the Magic Airvan report.

The whole report was based on TCAS data that showed the Airvan accelerating to 200 knots on 5 mile final as the jet turned base. If you think an Airvan doing 200 knots is unlikely, and it is more likely that the TCAS data was unreliable during the turn, the near miss never really happened.

If the Airvan maintained more Airvan-like speeds it was perfectly set up for an approach and landing a couple of minutes after the jet.

What seems most likely is that the the jet pilots got spooked by bad TCAS data, and the Airvan pilot got hauled into an investigation of a near miss that never occurred.