Cessna TC206H Supplement

[Flying Pig]

Today I received a supplement for my POH for the TC206H.  It reads:

Approaches with flaps UP throughout the decent to Decision Height (DH) or Minimum Decent Altitude (MDA) should be avoided in IMC.

If flap UP approches are required, add 60 ft. to the Decision Height (DH) or Minimum Decent Altitude (MDA) when operating in IMC.

So basically, if Im on an IFR approach without flaps, I need to add 60ft to my mins.  Why?

[Al Sayre]

Probably turbo lag when adding power as you approach mins, keeps you from busting them.

[Flying Pig]

I tried calling Cessna but get nothing.  Its not critical.  But they did choose to issue a POH supplement for it so I was just curious. 

I dont know that Turbo lag would be the reason.  The 206 gets up and goes when you advance the throttle.  Ive never had an issue with the Turbo lagging behind.

[Al Sayre]

I've never flown the turbo 206, but I've worked on a lot of turbocharged cars.  When going to wide open throttle, it's seldom a problem, but when advancing from a low power setting such as you would have in a descent, to a only slightly higher setting to arrest the descent, the turbo can actually lag behind a bit and cause a slight initial power drop since it's speed is controlled by exhaust flow which is minimal at lower RPMs and takes a second or so to catch up to the actual engine demand for airflow.

[dbaran]

I fly a turbo Mooney, and turbo lag is not the problem on a go around - the power comes in plenty fast.  Besides, you're already at a 500 fpm descent (DH) or level (MDA) so you shouldn't have a scary sink rate at that point.

Maybe they found that the altitude indication was found to be unreliable with the flaps up due to airflow around the static source being different than the flaps down config (and they did flaps down for the flight testing).

[Flying Pig]

OK.  So nobody actually knows.  Got it.

[bosshawk]

Rob: in one of your idle moments around FAT, give Cessna a call and ask them.

You may find out that the supplement was written in China and then the fun begins.

[Flying Pig]

I called Cessna and they couldnt find anyone.  They sent a message to the administrator who signed the supplement.  Also, Corporate Aircraft here at KFAT is going to research it for me also.

[bosshawk]

You mean that Cessna couldn't find anyone who spoke Chinese to talk to the person who wrote the supplement?  Or maybe they needed to speak Urdu.

[PHall]

You mean that Cessna couldn't find anyone who spoke Chinese to talk to the person who wrote the supplement?  Or maybe they needed to speak Urdu.

More like, they read it, realized it was stupid and now nobody wants to be associated with it.

[simon]

This is interesting, someone actually trying to work their way back through the manufacturer to get an answer from the person who actually wrote this stuff.

If left to the pilot community, over enough years you know there would be twenty different supposedly factual explanations that would emerge from various pilots. Then the original POH documenter would die of old age and the rear reason would forever remain a mystery...

I hope you get your answer. It's a great question. I've never heard of a DA or MDA being raised for a configuration change.

[flyguy06]

CAP has Turbo aircraft? I never knew that. I wondered why on the new Form 5, it had a turbo check line. what wings have Turbo aircraft?

[vento]

^^^ COWG for they are more prone to cosmic radiation due to high terrain.

[bosshawk]

IIRC: CAWG has one new C-182 Turbo.  What Flying Pig was referring to was the C-206 Turbo that he flies for his day job.

[Flying Pig]

I got a call back from Cessna believe it or not.

The supplement only applies to Turbo 206H models, specifically serial number T8682 and serial numbers 8705-8882.

In those serial numbered models the static ports for the altimeter and airspeed indicator were determined to have sensitivity issues relating only to that one specific serial number, and then the other range of serial numbers.  The corrective action can be located in document 09-34-11.  So in other words.....it doesnt apply to the one I fly.

As far as flyguys06 question, Sq112 in Fresno has the only Turbo 182 G1000 in CAWG.  At least that I know of as I am no longer a member of CAP.

[SarDragon]

As best I can determine, CAP had three turbo 206s a year ago. One got crashed a couple of months ago, so now there are just two.

[sardak]

The numbers haven't changed much since this 2009 thread about turbos in CAP - http://captalk.net/index.php?topic=7511.msg138957#msg138957

Currently 13 T182s -

One in AZ, CA (at FAT, Bob) and NV.

Seven in CO, though one is assigned to Region, and one is a retract.

Three in UT.

There are two T206s - AK and WA.

Mike

[SarDragon]

Guess I misremembered. So, there's only two listed in WMIRS.

The WA asset is the one that crashed. That leaves one flyable turbo 206.

One article. There are others with additional pix.

Original thread from March. I used the FAA database for the numbers there.

[NIN]

I've actually had occasion to call a manufacturer on more than one occasion...

I once got to do a demo jump out of a Maule, and the pilot/A&P offered to take the door off to ease the exit, but then wasn't sure if it was just one door, or you had to take both doors off.  Back into the shop we go (mind you: I'm all geared up, ready to go..), and he calls the Maule factory down in Moultrie, GA and gets an engineer on the horn.  (the A&P swore to me that he'd "spoke to Mother Maule many times.") Sure enough, take off one door, or the other, but never both.  (nice to get the word straight from the horse's mouth)

Back when I was in the Army, we had a question about our aircraft that wasn't covered in the operator's manual or the maintenance manuals.  Our local Boeing rep scratched his head and said "Y'know, I don't have a @#% clue what you're even asking.."   9pm that night, we're on the phone back to Ridley Park and got an answer from one of the guys who actually _designed_ the part.    That was quite a surreal experience.

[Flying Pig]

Thats the thing about smaller aircraft and their doors.  Many times the CLOSED doors are part of the structural integrity of the airframe.