Reduce to minimum speed

[Pace]

Had this today in a biz jet! Reduce to minimum speed.

Minimum speed is obviously a whisker above stall not a good idea on windy shear type days.

Given you are asked to reduce to minimum speed what does that mean to you ????

Pace

[Piper.Classique]

Slow safe cruise?
Which in the case of a Cub means the sparrows are overtaking me
:D

[Lord Spandex Masher]

Either minimum clean or minimum approach.

[flybymike]

May be wrong but I don't think I have often, if ever, heard the phrase used for GA operations; but certainly very common for airliner approaches.
The most common reply seems to be a rather disgruntled
"There is a limit to how slow we can go you know....."

[tmmorris]

Most of us will have been taught a 'slow safe cruise' speed at some point, perhaps as a bad weather technique, or perhaps a 'loiter speed' or max endurance speed. Doing my IMCR we did non-precision approaches in a PA28 at 75kt/25deg flaps, for example, which was also the bad-weather circuit speed. I guess that's what I'd use if asked. Having said that we are usually the slow ones everyone else is adjusting for not the other way round...

Tim

[Tarq57]

Define "whisker"

If by "whisker" you mean "vref" (1.3 vso for a particular configuration) plus any margin for gusts or windshear, that, at least in the approach scenario, is what is being requested.

If what you consider minimum safe speed on the day, for that flight, is significantly different from the norm, it would be good airmanship to advise ATC of that speed.

[sevenstrokeroll]

NO ONE EXPECTS YOU TO PUT YOUR PLANE IN JEOPARDY , you are expected to fly as slowly as practicable for your plane in its particular situation.

advise atc of the speed and attempt to maintain it

and if they want you slower, they will give you delay vectors 9assuming radar contact

min speed for my 737 is 280 knots in rough air (below mach levels).

smooth air is min clean for weight

Vref plus 5 configured on final conditions good

vref plus 20 conditions mediocre


so get with it...and you can even ask ATC one day to see their expected speeds and climb rates for particular planes...they all have to memorize what plane can do what.

stop by center and ask for a tour...terrorism may prevent too much, or go to the nearest FSDO office and ask them.

[Pace]

I think slow to minimum speed is relevant to light GA especially a faster aircraft catching up a slower one on final.
I wondered what formula PPLs will use and what their minimum speed would be ? Mine yesterday was caused by an obstruction on the runway!

Pace

[Sillert,V.I.]

Given you are asked to reduce to minimum speed what does that mean to you ????


An instruction to fly as slowly as I feel comfortable with in the prevailing conditions. The distinction from 'minimum clean' is that I'd reconfigure as necessary to comply with the instruction.

[HEATHROW DIRECTOR]

"There is a limit to how slow we can go you know....."

Well, there's always one......

The phrase I used a million times was "reduce to minimum safe approach speed". It doesn't require discussion - it's what it says on the tin - and never got any snide remarks in response.

[chevvron]

Funny I would have thought any bizjet driver with a bit of experience would be familiar with the term although, as HD says, it should be 'minimum safe approach speed'. Maybe the controller was undergoing OJT.

[2 sheds]

ICAO
An arriving aircraft may be instructed to maintain its “maximum speed”, “minimum clean speed”, “minimum speed”, or a specified speed.

Obviously, it's minimum safe speed - isn't it?

2 s

[S-Works]

Funny I would have thought any bizjet driver with a bit of experience would be familiar with the term although, as HD says, it should be 'minimum safe approach speed'. Maybe the controller was undergoing ojt.

It's these FAA boys who refuse to do the EASA stuff because they know everything innit....... :p:p:p:p

[octavian]

Although, in his original post, Pace didn't given us the context in which the request was made, a later post showed that it related to an aircraft on final approach.

Given that the instruction was given to a biz jet there is a reasonable expectation from controllers that pretty well all turbo prop and jet aircraft will be capable of flying at the generally accepted approach speeds of 240kts below FL100, reducing to 210, then 180 and be expected to maintain 160kts to 4nm final once established and within about 10-12nm. Inside 4nm no speed control can be issued by ATC. Some of the new "mini biz-jets" do have significantly slower approach speeds inside 4nm than other jets including such types as the broad Citation series.

Elsewhere there is a thread running about maintaining separation, and it is the use of speed control during the approach phase which establishes and then maintains the spacing on final approach, whether a distance specified by the tower controller to get best runway utilisation for arriving and departing aircraft or the application of a wake turbulence spacing should this be greater.

Should the spacing be reducing below that which the tower, or indeed radar, controller requires then the phrase identified by Heathrow Director "Reduce to minimum safe approach speed" is a very safe option and in my experience is never queried. Given that a light 757 might have a final approach speed inside 4nm of 125kts (let us know if it is please) perhaps even less and a heavy MD11 could be batting along at 155kts I might ask what the speed might be just to help me decide what happens to the following aircraft, but it is the pilot's call as to the speed flown.

Although Pace did not specifically refer to Cherokees, Chipmunks, Comanches, Cubs and the like, if they are mixing it with pretty much any turbo-prop or jet types the phrase you are most likely to hear is along the lines of "give me your best (fastest safe) speed to short final, what will that be?"

I've just noticed Pace's comment in a later post about a runway obstruction relating to his situation. Perfect example of why "reduce to minimum safe approach speed" might be used. Drag it in fella, we're expecting the obstruction to be cleared it might save a go-around and another 15 minutes in the pattern.

Hope this helps.

[chevvron]

Possibly a slow moving vehicle or aircraft under tow crossing the runway? In any case, it's still a perfectly valid instruction from ATC.

[Pace]

Funny I would have thought any bizjet driver with a bit of experience would be familiar with the term although, as HD says, it should be 'minimum safe approach speed'. Maybe the controller was undergoing OJT.

Chevron

Maybe in our exact Uk airspace but this was in Lubeck Germany and he just said " reduce to minimum speed "
Yes in this situation there was a blockage of some kind on the runway.
On the ILS you can reduce to Vref for the configuration and weight but I was not thinking of Biz jets but how a PPL will slow up if need be and what they do to gain seperation.
In my piston twin days with an aircraft ahead even S turns helped

As for fastest speeds I remember on numerous trips into Dublin being asked the fastest speed I could maintain on the approach in a Seneca piston twin! To fit in with jet traffic!
Leaving 10 k I could usually pick up the glideslop indications way out and adjusted the descent rate to that so it was a continual descent all the way in and hence a better speed to boot .

Pace

[Tay Cough]

It's the slowest you can safely fly, either clean or in approach configuration. By all means tell ATC what that speed is at it may help their planning.

[BackPacker]

Drag it in fella,

Obviously it depends on circumstances, and if the instruction is for spacing you have to try and comply with the instruction to the fullest extent. But if it's for a runway closure which will be lifted momentarily, then I think I would not "drag it in" but use best endurance speed, which is at the bottom of the drag curve. Very close to Vy.

[octavian]

As backpacker says, it depends on circumstances - situational awareness plays a part here, but finally it is the pilot's call. Which is best; a go around, with all the fuel considerations or a slower, but safe, approach and landing. In the end we're all trying for the best outcome for the crew. CRM isn't just a cockpit function.

[Gertrude the Wombat]

how a PPL will slow up if need be
I was given to understand by instructors and examiners that it's my choice whether to fly the ILS at cruise speed (105+), circuit speed(80-90) or approach speed(70-75). If I'm doing either of the former I could have a go at reducing speed to the latter, with any luck without completely falling out of the glidepath.

[octavian]

Gertrude,

Without wishing to get into a detailed discourse about approach speeds, I would ask you to accept that at the busier airfields/airports the vast majority of approaching aircraft will be able to achieve 160kts to 4nm. Where we are dealing with the integration of MEP/SEP types with significantly slower approach speeds at all stages of the approach I might suggest that most, but perhaps not all, controllers will make due allowance for the performance of those types. If you are more comfortable flying the ILS at 85kts tell the controller and he/she will work the rest around you. Aviate, navigate, but don't forget to communicate - its what CRM is all about.

[Local Variation]

Flying an SEP on an ILS at a relatively busy A/P, the problem is keeping the speed up not down and as Gertrude eludes, keeping the glideslope in check when you eventually do pull back on the speed and drop the flaps.

Encountered more of slow SEP approaches in Florida. Going into Ormand Beach, position approx left base, cleared to land No. 3 with the preceeding pair visible in close formation in front. No surprise that the check ride included focus on maintaining slow flight (obviously with flap) at just above the stall speed (less the buffett) for this very reason. Spent quite abit of time doing that and the need was pressed far more than we see over here.

I can recall a number of occasions in the UK in the pattern at various airfields, where spacing was affected due to an apparent inability to consider and apply lower speeds to that of the 'norm'.

[Pace]

With high speed approaches how well you do is very often type specific.
Slippery aircraft with low gear and flap extension speeds can be a handful holding high speed down the ILS and then knocking it off quickly for landing.

I used to fly a Cessna 303 which was a doddle knocking off speed late in a descent on the ILS as the gear extension speed was high! Higher infact than the cruise speed at 175 kts which was a high speed extension for a light twin.

The same with flaps and if your lucky speed brakes. Even prop pitch can help slow down if your careful with it.

Mooney and I would imagine the Cirrus are both slippery aircraft and would both lead to embarrassment if you slide down the ILS too fast and expect to slow up in time to land.

High or low speed and the secret is accurate flying

I might suggest that most, but perhaps not all, controllers will make due allowance for the performance of those types.

I think a lot depends on where you are ?? I am sure at Dublin main they will not be very happy if you drag in at 75 kts from 6+ miles out :ok:


Pace

[phiggsbroadband]

Quote...

I think a lot depends on where you are ?? I am sure at Dublin main they will not be very happy if you drag in at 75 kts from 6+ miles out http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/thumbs.gif

It also depends on what you are flying...

Anything aerobatic, that can prop-hang.
or
A Helicopter...

[foxmoth]

I think a lot depends on where you are ?? I am sure at Dublin main they will not be very happy if you drag in at 75 kts from 6+ miles out

If they have asked for minimum speed then they SHOULD be happy - they have asked and know what type you are so should have an idea what speed you would normally fly, normally somewhere like DUB they will more likely ask a light a/c to keep its speed up, but generally if asked for min speed it means min safe speed using available lift devices, so if you are in a larger aircraft you normally do 180 reducing to 160 and final approach speed inside 4, you instead reduce to approach speed and fly that from when you are asked. Even in a light ac if asked the same applies, you might not know the reason, but if you do not comply don't moan when told to go around!

[ShyTorque]

It also depends on what you are flying...

Anything aerobatic, that can prop-hang.
or
A Helicopter...

It does indeed. Sometimes, if asked to hold on base leg and report visual with another aircraft on a longer final approach than I need, I prefer to hover rather than orbit. This allows me to point my aircraft towards the other and the airfield and to keep both in sight.