IFR Approach Speeds

[Txbyker]

I am a relatively new Mooney M20J owner and recently switched my IFR training from a C-172 to the Mooney.  Can anyone please comment on your best speeds for approach training maneuvers and for IFR approach patterns?  I have been told 90 KTS at 18 inches is a good setting to accomplish.

Thanks,

Russ

[74657]

18", 90 KTS with approach flaps in and gear down is what I have been trained to do.  On descent I go 13" for a precision approach and 11-12 for a non-precision.  Works out to 500 / 700 fpm descent if the plane is trimmed properly in approach configuration.

[Txbyker]

Thanks so much.  I will use these.  Do you do flaps down, gear down, 18" a couple of NM before FAF?

[KSMooniac]

I usually trim to level flight just below my gear speed with flaps up before FAF, and then at FAF drop the gear and follow with approach flaps when the speed drops to flap speed and leave the power alone.  (It will vary with weight.)  Dropping the gear will give you a nice stable descent that will follow a glideslope pretty well.  I don't put in full flaps until short final when the landing is assured.

Transitioning from a 172, you should be more comfortable flying at 90 knots, but as you get more experience in the Mooney, try flying faster (unless in a hold that is used to kill time!) as this will ultimately give you better flexibility fitting into the flow at busy airports.  Trudging along at 90 knots on an approach will cause problems and might get you vectored off the approach to let faster traffic in, so being able to fly an approach at a higher airspeed is a good tool to keep in your bag of tricks.  Sometimes I even practice an approach keeping hi-cruise to the FAF and even start the descent above gear speed, which makes it tricky to slow down to gear speed without speed brakes.    

[74657]

I drop the gear at FAF.  Gear down, power down, flaps down.

[Immelman]

I like to slow enough to get the gear down at a convenient time prior to the FAF. Even with the power all the way off (potentially hard on the engine during a fast desent) its difficult to go down and slow down at the same time. Plan things out to be able to be in level flight on some segment of the approach prior to the FAF where you'll be able to get to gear speed... once there you're golden. This can be tricky when getting vectors.. some controllers like to give you a more or less continuous descent and vector to join the approach right outside the FAF. This is very efficient and you can tell they're good at it, but they aren't in the cockpit trying to slow a Mooney down! With practice I've come to recognize when this will occur and decided to get on with my power reduction schedule sooner than later if it looks like that will happen.

The other caveat will be getting slowed to a good final approach speed for landing. With a non-precision approach this usualy isn't a problem because the minimums are high enough to permit you to slow further and get the flaps out with visual contact to the airport. On an ILS to minimums I would want to go ahead and at least partially configure for landing (takeoff flaps, for example) to be in the flap speed-range and be ready to dump the rest o the flaps if the approach is continued to a landing.

[John Pleisse]

15"/24RPM for a level 120 KIAS IAF speed. At the FAF-glide slope, no flaps... drop the gear. The nose gently comes up for two seconds and then takes 2 more seconds to nose over ever so gently to exactly -500fpm/105KIAS. With typical winds, GS almost always ends up being 90KTS. I can accomplish this without ever touching the yoke or trim.

I have an awesome PAC chart I created for every config possible. I can pdf it for you. But after test flying and 13 years of completely over-doing it, I have arrived at the above. Your final power and trim adjustment happens right after your decent. All you do is drop the gear when you hit the glideslope.

[Cruiser]

Approach: turn R heading 360° you are 3.6 miles from the FAF maintain 3100 until established, best speed there is a Southwest 737 landing behind you. I was 149kts over the FAF.

I rarely get to setup for a "normal" approach going into busy areas. I practice slowing down as fast as I can, that usually means pulling the MP and RPM and holding altitude until I can get the gear down then recapturing the glideslope and settling in for 90 kts to the MM then trim for touchdown.

[John Pleisse]

Quote: Cruiser

Approach: turn R heading 360° you are 3.6 miles from the FAF maintain 3100 until established, best speed there is a Southwest 737 landing behind you. I was 149kts over the FAF.

I rarely get to setup for a "normal" approach going into busy areas. I practice slowing down as fast as I can, that usually means pulling the MP and RPM and holding altitude until I can get the gear down then recapturing the glideslope and settling in for 90 kts to the MM then trim for touchdown.

[mikefox]

In my M20J I slow to holding /pre-approach speed prior to beginning any approach maneuvers , using 16" MP/2600 RPM.  This gives me 120 kts clean.

For a precision approach, gear goes down 1/2 dot prior to glideslope intercept and power to 14" MP.  This gives about 100 kts on the precision approach, which is fast enough for most airports and provides good responsiveness.

Non-precision, just follow the same recipe, but power goes to 12" for descents.

[midlifeflyer]

New member here. I plan to transition into a Mooney J next month and this thread was exactly what I was looking for. Other than the 1" difference in MP, mikefox and N4352H seemm to be talking the same language - a configuration that produces a comfortable approach configuration without flaps - a preference I have had since my initial instrument training and followed me through flying Bonanzas.

Follow-up question: Like the two of you I live a vectoring speed of 120 but prefer to get to my precision approach speed before glideslope intercept. mikefox, using your numbers, if I reduce MP from 16" to 14" in level flight, will that produce the 100kts, leaving me to simply drop the gear and do nothing else to produce the ILS descent?

Thank you.

Edit: OK, where'd the avatar photo come from? It's definitely mine; have used it on other forums. It's the airport cat at Steamboat Springs sitting on the wing of the Comanche I used to fly. But I did not add it to this forum!

[gregwatts]

I am typically at 18" and 2400rpms till FAF........drop the gear and put in Takeoff flaps and power back to between 12" and 14" as needed.

[jetdriven]

I like to slow enough to get the gear down at a convenient time prior to the FAF. Even with the power all the way off (potentially hard on the engine during a fast desent) its difficult to go down and slow down at the same time. Plan things out to be able to be in level flight on some segment of the approach prior to the FAF where you'll be able to get to gear speed... once there you're golden. This can be tricky when getting vectors.. some controllers like to give you a more or less continuous descent and vector to join the approach right outside the FAF. This is very efficient and you can tell they're good at it, but they aren't in the cockpit trying to slow a Mooney down! With practice I've come to recognize when this will occur and decided to get on with my power reduction schedule sooner than later if it looks like that will happen.

The other caveat will be getting slowed to a good final approach speed for landing. With a non-precision approach this usualy isn't a problem because the minimums are high enough to permit you to slow further and get the flaps out with visual contact to the airport. On an ILS to minimums I would want to go ahead and at least partially configure for landing (takeoff flaps, for example) to be in the flap speed-range and be ready to dump the rest o the flaps if the approach is continued to a landing.

I have found that if you need to slow down and get down, set the power to 17" or so and dive for the next altitude. when you level off, then it will slow down to approach speed in 2 miles or so. tryign to do both at once will leave you high and too fast.

Or, in other words, if you have to choose between slowing down and getting down, get down first.

[rbridges]

in my plane, 20.5" and gear down gives me ~90 knots straight and level flight. I pull it back to around 14" or so for the descent. Technically, 85 knots is flap speed in my plane.

[Hank]

Rob--

I've been flying a friend's F model a little bit lately, and it handles much differently than our C's do. Landings with full flaps are wonderful, where I normally use Takeoff flaps and tweak them as necessary on final; must remember to reduce power on descent, instead of leaving the throttle at my cruise setting [WOT for the F, pulled back out of auto-enrichment for my C]; more speed than I am used to at my normal power settings; the gear horn squalls passing through 15" instead of 12"; etc.

Gear and flap speeds are the same, but J's get much higher gear speed so they have the option to drop gear as speed brakes above flap speed. My C and the F both have 125 mph for flaps, 120 mph for gear, so I use approach flaps to set myself up for approach and drop the gear to come down the glideslope.

With low ceilings, I don't think I would try to change flap setting after breakout, since that drops the nose and makes changes in descent rate, yoke pressure and trim setting. Most ILS approaches go into long runways, so land a few knots faster [stall speed difference between Takeoff and Landing flaps is only 2 or 3 mph] and use a few hundred extra feet of pavement. Even if you're at 90 knots, you can still set it down between the 500' and 1500' stripes and stop easily in the next 1500 feet. Practice this a few times in good weather, hold 90 knots to 200-300' agl with approach flaps, retard the throttle and see how she settles down. A little long, but not a problem for most ILS runways.

[Marauder]

Rob--

I've been flying a friend's F model a little bit lately, and it handles much differently than our C's do. Landings with full flaps are wonderful, where I normally use Takeoff flaps and tweak them as necessary on final; must remember to reduce power on descent, instead of leaving the throttle at my cruise setting [WOT for the F, pulled back out of auto-enrichment for my C]; more speed than I am used to at my normal power settings; the gear horn squalls passing through 15" instead of 12"; etc.

Gear and flap speeds are the same, but J's get much higher gear speed so they have the option to drop gear as speed brakes above flap speed. My C and the F both have 125 mph for flaps, 120 mph for gear, so I use approach flaps to set myself up for approach and drop the gear to come down the glideslope.

With low ceilings, I don't think I would try to change flap setting after breakout, since that drops the nose and makes changes in descent rate, yoke pressure and trim setting. Most ILS approaches go into long runways, so land a few knots faster [stall speed difference between Takeoff and Landing flaps is only 2 or 3 mph] and use a few hundred extra feet of pavement. Even if you're at 90 knots, you can still set it down between the 500' and 1500' stripes and stop easily in the next 1500 feet. Practice this a few times in good weather, hold 90 knots to 200-300' agl with approach flaps, retard the throttle and see how she settles down. A little long, but not a problem for most ILS runways.

I've flown my F for a lot of years and do get envious of the higher gear speeds on the J models. With the lower flap and gear speeds on earlier models, I found it always easier as Hank suggests to set up a stabilized approach by getting down to flap extension speed, throwing out approach flaps and stabilizing at 100 knots prior to the FAF. At the FAF, drop gear and depending if I am flying a precision approach or dropping to the MDA adjust power accordingly.

The last thing I want to do is be above VFe or VLo at the FAF. Just really hard to get down to those speeds while descending.

[RJBrown]

15" level flight, speed will be good at about 90 trim will be about take off position. I drop the gear and go to take off flap position. This gives you the proper decent. It also sets you up for a clean missed approach. At the miss all you do is go full throttle then pick up the gear then flaps, the trim and flaps are already close enough for a clean miss. At pattern altitude dropping the gear gives you the decent. Without the gear down you don't go down. Hard to have a gear up if the dropping of the gear is the thing that starts your decent.

The point in the pattern or on the approach where in a 172 you pull power to begin the decent is where I drop the gear to start the decent. IFR I never use full flaps. Sometimes I land with the flaps full UP.

Try it sometimes. 15" auto pilot on it trims to straight and level. once established straight and level disengage alt hold and drop gear speed wont change plane comes down right on glide slope.

[wishboneash]

I would really like to be able to come in at 120 KIAS up to the FAF. Then drop the gear and approach flaps to get down to 90 KIAS. Dump all flaps and slow to 70KIAS on short final. I also don't want to see more than 20 deg CLD on the JPI if possible.

N4352H said "15"/24RPM for a level 120 KIAS IAF speed",

mikefox said using 16" MP/2600 RPM. This gives me 120 kts clean.

I will report my numbers!

[WardHolbrook]

I would really like to be able to come in at 120 KIAS up to the FAF. Then drop the gear and approach flaps to get down to 90 KIAS. Dump all flaps and slow to 70KIAS on short final. I also don't want to see more than 20 deg CLD on the JPI if possible.

N4352H said "15"/24RPM for a level 120 KIAS IAF speed",

mikefox said using 16" MP/2600 RPM. This gives me 120 kts clean.

I will report my numbers!

You should probably want to practice the occasional approach where you keep your speed up as much as possible to the FAF for those occasions when ATC has a couple of jets sequenced in behind you. A lot of jets will be using ref speeds of 120+ knots, sometimes a lot more. It's good practice.

[mikefox]

Yes, if you set 14" you will get about 100 kts clean. You can then drop the gear at GS intercept for the descent. I just prefer the responsiveness and ability to fight a downdraft that 16", 120 kts gives me, and I still have comfortable margin for gear extension.

Cylinder head temps have always been comfortably in the bottom of the green using this procedure, cowl flaps closed for descent of course!

[midlifeflyer]

I agree about the downwind, mikefox. I would move to that 14" setting clean just about the time of being given that final "three miles from ABCDE, fly heading..." final intercept vector.

Thanks for the info. I hope to put it to use soon.

[wishboneash]

You should probably want to practice the occasional approach where you keep your speed up as much as possible to the FAF for those occasions when ATC has a couple of jets sequenced in behind you. A lot of jets will be using ref speeds of 120+ knots, sometimes a lot more. It's good practice.

Not a problem. I have done that many times.