Can you descend below DH or MDA??

[AC560]

btw...in case you're wondering, you ain't been cold until you've sat in a cold airplane for a couple of hours because you didn't know a particular nuance of the heater

Likewise you haven't been hot for the same reasons. I melted the soles on a pair of sneakers thanks to an old janitrol once. Not sure which is better freezing or sweating.

 

[A Squared]

My students do the same...arrive at the DH or MDA, go missed and keep descending. I usually have them pad the mins say 50' so they don't bust the ride.

You haven't read a single word that's been written, have you?

 

[Way2Broke]

You haven't read a single word that's been written, have you?

There is a big difference between the way most examiners give checkrides and how real flying works. I know at least 3 examiners that will bust you for going below DH while doing a missed and all of them have a background strictly in small GA aircraft.

 

[nosehair]

There is a big difference between the way most examiners give checkrides and how real flying works. I know at least 3 examiners that will bust you for going below DH while doing a missed and all of them have a background strictly in small GA aircraft.

Bongo! You got it.

In 99% of the GA training aircraft where almost everyone gets his/her initial IR, you CAN 'touch' the DH while applying pitch and power to 'skim' the DH and proceed mised, which is what a lot of examiners want to see, and it is how it gets ingrained in the system, but then you get into the real world, and see how you have to 'change your interpretation' to 'fit the actual conditions'.

 

[Papps]

I guess thats why the airlines have to give checkrides every 6 months and line checks every year. If they don't everyone with "change their interpretation" to " fit the actual conditions" thats what i loved about instructing. everyone just made stuff up and pawned it off as standard.

 

[regionalcap]

Here is some reading material. The last part labeled "DH Dilema" discusses this situation.

http://www.terps.com/ifrr/jul95.pdf

 

[Amish RakeFight]

Here is some reading material. The last part labeled "DH Dilema" discusses this situation.

http://www.terps.com/ifrr/jul95.pdf

Good reference. I pasted the pertinent section below.

DH dilemma
When descending on an electronic glideslope to DH, the FAR simply says that approach cannot be continued below DH unless one or more of the runway-specific visual cues (or ALS) is sighted. Most single-pilot operators view this as looking up from the panel at DH and making the decision to either continue visually or miss the approach. While this is certainly practical, it isn’t what the “head-shed” has in mind. The subject is sorely lacking in FAA directives for general aviation, but it’s covered quite well in FAA directives to air carrier inspectors. The visual assessment must be completed not later than DH. The aircraft is permitted to descend through DH without the required visual cues, but only to the extent required to transition to the missed approach climb. Granted, it’s an honor system for the single-pilot operator!​

 

[DrewBlows]

This may be the first time I have ever heard anyone other than an instrument student get 91.175 wrong (seriously). It's really not that difficult. DA and MDA are not the same thing.

If you don't want to go below DA on a missed approach, don't, but please don't teach anyone else the FAA forbids it.

 

[Fedora]

I've had to descend below DH/MDA every time I've landed.

 

[Daveman]

ok.... alot there. You can't go below MDA and you cant continue the approach below DH. Your not continuing the approach your going missed.

You will go below DH 100% of the time unless you have a JATO bottle. If you want to go missed 50 early to stay above DH than go ahead they will bust you on your type ride because you couldent fly the profile.

Why can't the regs be written this way?:beer:

 

[nosehair]

You will go below DH 100% of the time unless you have a JATO bottle.

No, you won't, Papps.

The correct answer here is, "It depends."

It depends on the type of equipment you are flying.

Little Cessna 172's can make an immediate transition from a descent to a climb with no readable descent below the DH. It is done every day in training, and most examiners will expect this type of pilot skill and response. in this type of airplane.

The airplane can do it. So the pilot should be able to do it in his demonstration of executing a timely missed approach.

Moving on to larger equipment, the big machines will take a little time to change direction of motion, and the amount of descent below DH that the examiner allows is dependent on his knowledge of the machine, and his observation of the moment of the pilots control inputs to execute the missed.

So..."it depends."

 

[Lead Sled]

yeah this one has confused people forever. If your in jet doing 140 knots on final and 700-800 fpm to hold glide slope. The pilot not flying will call "minimums no runway" right at DH. In the rj you will say hit the TOGA button push the levers up and say "go around go around thrust flaps 8" and pitch up to the Flight director. The plane will be below DH by the time you start uphill again. And no check airman on earth will fail you for that.

Good discussion that never hurts to be rehashed. You may even touch down on the runway on the runway if you're flying a Cat III missed approach.

LS

 

[JAFI]

You may even touch down ... on the runway if you're flying a Cat III missed approach.

LS

Lead, Good point!

I would like to add: With the appropriate aircraft (read large/long), appropriate runway (CAT III certified), approved procedures, and approved training program. (small print at the bottom of the screen" "Trained Professionals used in this ad, don't try this with out one".)

With the right conditions (low, solid overcast) in the right aircraft (DC 10, 747, etc.) the pilot can decide at DH to conduct a missed approach, have the wheels touch the runway, and go missed approach with out ever seeing the runway. Legal and safe under the above conditions.

DH - The height you make a decision.

MDA - The MINIMUM Descent Altitude.


JAFI

 

[A Squared]

DH - The height you make a decision.

MDA - The MINIMUM Descent Altitude.


JAFI

And there it is in a nutshell, folks.

Isn't it amazing that something that simple and obvious still is misunderstood by folks who should know better?

 

[Lead Sled]

And there it is in a nutshell, folks.

Isn't it amazing that something that simple and obvious still is misunderstood by folks who should know better?

Think "trampoline" not concrete floor.

LS

 

[imacdog]

No, you won't, Papps.

The correct answer here is, "It depends."

It depends on the type of equipment you are flying.

Little Cessna 172's can make an immediate transition from a descent to a climb with no readable descent below the DH. It is done every day in training, and most examiners will expect this type of pilot skill and response. in this type of airplane.

The airplane can do it. So the pilot should be able to do it in his demonstration of executing a timely missed approach.

Moving on to larger equipment, the big machines will take a little time to change direction of motion, and the amount of descent below DH that the examiner allows is dependent on his knowledge of the machine, and his observation of the moment of the pilots control inputs to execute the missed.

So..."it depends."

I disagree. The regs state nothing about "little planes shouldn't go below DH during the execution of a missed, but big airplanes can." DH is just that - a place where you decide to go missed or continue the approach. If you start the missed approach at DH in a 172 and go below DH while transitioning to a climb, then that is fine. DH is not MDA.

 

[Papps]

It doesn't depend. It is what it is.

 

[nosehair]

If you start the missed approach at DH in a 172 and go below DH while transitioning to a climb, then that is fine. DH is not MDA.

Guys, the point I am trying to make is, if you are in a 172, and you let the wheels drag the runway during your missed approach, or go down an appreciable amount, like you could in a Cat III in a heavy jet, I don't think an examiner will allow that on a checkride, or an inspector would agree that you can take as long as you want to, to "effect a pitch and power change that would result in a timely transition to a climb."

We are talking about timely control inputs. If you make the same pitch and power change at DH, the 172 will perk up and fly up within 20 feet, the heavier it is the longer it goes down before changing when the control inputs are the same. That is what we mean about "it depends".

 

[GogglesPisano]

Not to split hairs, but a C172 would be using a DA (unless, of course, it has an RA installed and was shooting a CAT III.)

 

[Papps]

Guys, the point I am trying to make is, if you are in a 172, and you let the wheels drag the runway during your missed approach, or go down an appreciable amount, like you could in a Cat III in a heavy jet, I don't think an examiner will allow that on a checkride, or an inspector would agree that you can take as long as you want to, to "effect a pitch and power change that would result in a timely transition to a climb."

We are talking about timely control inputs. If you make the same pitch and power change at DH, the 172 will perk up and fly up within 20 feet, the heavier it is the longer it goes down before changing when the control inputs are the same. That is what we mean about "it depends".

I guess what im saying is that you don't understand the theory behind DH/DA. Just because a 172 weights nothing, and will get up and go before its caveman era altimeter registers a descent below DH doesn't mean you understand what DH is.

And if you let the wheels drag the runway on the missed in a 172 you either didn't make a decision at DH, or that decision took you 5 minutes to make.

Your right, this is more of a big plane deal, but unless you want to spend your entire career in the C-172 you will want to learn what DH is and isn't