Time to Climb

[Hank]

Doggone it! We had to wait for fog to start clearing at our destination, making our departure almost two hours after dark. Didn't get to record any data . . .    there's alays aturday, I'll be much lighter then. At least I had kicking' tail wis tonight! Groundspeed started at 164 knots and ended at 178 knots just before descent. Not bad for a C!  

[pfactor]

On 11/17/2015, 1:45:13, cnoe said:

Now, Vy in my plane is supposed to be 101-94 mph depending on altitude. I assume that's at gross and might go up a little at significantly lighter weights. But I have no expertise in these computations, so maybe someone could help me out.

Generally V speeds are published at max gross weight. Some V speeds are lower at lighter weights. The ones that change with weight are Vs0, Vs1, Vx, Vy, Va and best glide. For these speeds you can calculate the adjusted value with this formula: 

V' = V * SQRT(actual weight / max gross weight)

In plain English, take your actual weight, divide by the max gross weight. Take the square root of that number. Then multiply by the V-speed at max-gross weight.

Phil

[cnoe]

8 hours ago, pfactor said:

Generally V speeds are published at max gross weight. Some V speeds are lower at lighter weights. The ones that change with weight are Vs0, Vs1, Vx, Vy, Va and best glide. For these speeds you can calculate the adjusted value with this formula: 

V' = V * SQRT(actual weight / max gross weight)

In plain English, take your actual weight, divide by the max gross weight. Take the square root of that number. Then multiply by the V-speed at max-gross weight.

Phil

I am very interested in this subject. There's considerable discussion online about reducing Vy for "altitude", and my POH specifically references the reduction of Vy @ 10K feet.

I use your calculation (for weight) to some extent in computing approach and landing speeds but I wasn't sure it was applicable to Vx and Vy. But that does make sense.

But from a practical standpoint I'm not sure an 88 mph climb to 10K would be possible due to cooling issues. Even though my J has great cooling I don't think I could climb at those speeds (even with cowl flaps) open and keep oil temp managed. I may try a short climb at that weight and speed to perhaps 5K feet and see what the temps do.

[pfactor]

19 minutes ago, cnoe said:

I am very interested in this subject. There's considerable discussion online about reducing Vy for "altitude", and my POH specifically references the reduction of Vy @ 10K feet.

Yup. Vy decreases with altitude, and Vx increases with altitude. Also, both are affected by weight.

19 minutes ago, cnoe said:

But from a practical standpoint I'm not sure an 88 mph climb to 10K would be possible due to cooling issues. Even though my J has great cooling I don't think I could climb at those speeds (even with cowl flaps) open and keep oil temp managed. I may try a short climb at that weight and speed to perhaps 5K feet and see what the temps do.

I've also got a J and had no problems with temperatures climbing at Vy all the way up to 17,000ft (see my post on this). The outside air temperature was warmer than standard too.

Phil

[cnoe]

Yes, your post regarding Powerflow is thorough and much appreciated. It appears that your biggest gain was the reduction in CHTs. With cowl flaps in trail I never saw CHTs rise above 380 F and once I passed 10K the highest CHT recorded on my JPI was 374 F. Perhaps in full open position I could have climbed at 88 mph instead of 100 mph and still kept CHTs at 380 or below. I'll have to see.

[Hank]

The Owners Manual for my C says Vy decreases from 100 mph at sea level to 91 mph at 10,000 but gives nothing beyond that. 

[bonal]

Will be making my climb shortly. As for me this will be interesting since I've never thought much about times to altitude even though it is part of flight planning but this will be a maximum effort light fuel no passengers and really nothing to do with real world conditions. I figure CHT will be the limiting factor.

[carl]

Today I took off at 10:45, OAT was 6 c, DA 1,600 (AWOS) and field elevation is1503. ( I'm using 1500 for the math )

23 gallons of fuel , just me 200Lbs.

Wide Open throttle. 2600 rpm, cowl flap open, CHT not exceeding 400, ( it was cold today)

2000        500,  Missed the time         110mph

3000        1000....  2mins            Ram air booster on  110mph

4000        1000 ... .3mins             105 mph

5000        1000.... 4mins               105 mph

6000        1000.... 5 mins              105 mph

7000        1000 .... 5 Mins  What the heck  my clock stopped!!!!   100mph

8000        1000 ....5 mins               100mph

9000        1000....  5 mins               100mph

10000       1000.... 5mins                100mph

10500        500 ...   5mins                100mph

the climb on my other timer looks like 9 minute total,

but I have to repeat this with an improve date recording method and timing device .

Then I flew to Cove Valley airport (grass strip) and dropped the plane off for its annual .

I set some new personal firsts . New max altitude record 10,500 feet .

First Mooney landing on a grass strip.

It was surrealist at that altitude, ultra calm. I took a picture from 10,500 for your viewing pleasure.

The climb out pitch angle was something I never experienced before, except when trying to stall. You can't see a thing.

 

  

[bonal]

Way to go Carl. See it's nice up there. I can't believe it my clock got stuck at around 7000 too must be a conspiracy 

[bonal]

Temp 48 ALT 30.17 field 1380  just me and 50% fuel...speed 100mph. As I'm taxiing I realized I forgot my timer so I figure I'll use the panel clock which stopped advancing somewhere around 7000. 

2000'  1:10  1250fpm

3000'. 2:05TT  

4000'  3:15TT  1100fpm

5000'  4:35   800fpm

6000'  5:55  800fpm    9.8 miles out

7000'  7:25  725fpm    12 miles out

8000'           675fpm     14.7 miles out

9000'           600fpm      17.5 miles out

10000'         700fpm     19.8 miles out

11000'         500fpm.     22.2 miles out

Learned some things like my heading was into the sun so my pics don't look so good I'll post as soon as I can down load them. Also made me understand how much IFR training would help me fly better.  I'll try again tomorrow.

[Hank]

I'll post today's data soon, I left the kneeboard with data in the plane. Only climbed to 6000', the headwinds were pretty strong.

[aviatoreb]

Here's my run from today, but it was not quite all it could be - it was both broken layers I was zigzagging through - and once reduced the pitch slightly, but also a very windy day about 35kts on the ground (straight down the runway) so very bumpy on the way up.  So I think there are a few more seconds I could squeeze out with a better run.  Plus I only went to 10k - the stated contest - but then for cruise went back down to 8500 since the head wind was ferocious.  But on the way home the tail wind was awesome so I went up to 17500 to enjoy up to 270gs.  I went to DC and back today to meet my baby sisters new (first) baby - who is 3 days old today.  I didn't time a climb on the way home because I was coming out of dc and I got steps and restrictions on the way out.

Oh - and the climb from stop was 6:40 I think - I took some data - and its still on my notepad, and I ended up to busy navigating around clouds and keeping level in heavy bumps so I didn't do a very good job recording - but you see in the savvy record - its 6:40 - or so - to 10k from field altitude of 475.

[aviatoreb]

[carl]

awesome job !  impressive winds !

 

[ArtVandelay]

My POH recommends opening ram air on climb, I don't see anybody mentioning if they did that?

[carusoam]

TJ,

It usually will show up as WOTRAO when it does.

Wide Open Throttle, Ram Air Open.

Best regards,

-a-

[Shadrach]

33 minutes ago, teejayevans said:

My POH recommends opening ram air on climb, I don't see anybody mentioning if they did that?

My ram air opens in clear air. This time of year that's pretty much as soon as I'm 100' AGL and clear of possible FOD from the ground. In the summer when the bugs are heavy and pollen is in the air, that might be 5000'AGL.

[Hank]

5 hours ago, teejayevans said:

My POH recommends opening ram air on climb, I don't see anybody mentioning if they did that?

Some of our planes don't have ram air. Some other people have removed the system from theirs.

[carl]

I opened my ram air intake at 3000 feet  on my climb ,  noted on my data entry.

I think it works.

 

[M20F]

Has anyone ever done a chance comparison or know of a chart that looks at cruise climb speed (120 in my F as example) versus Vy?  In just general I don't notice a whole lot of extra FPM going with Vy versus cruise climb and if I am going above 9k I would need to level to get oil temp down to where any initial savings are eaten up by the break in climbing.  

[Andy95W]

There was a whole thread on it, but I'm not sure if I saw a table.  Check out "Hank versus Bonal".

http://mooneyspace.com/topic/16802-hank-vs-bonal/#comment-239374

[Guest]

Just returned from the time to climb check.  Field 1050' ASL, baro 30.40"Hg, OAT 9 C.  80 gallons of fuel,  2 on board @ 420LBS.

From a standing start, climbed at 120KTS, (Vx= 80 KTS, Vy= 104KTS)  Could have climbed steeper but the sun was low and made it hard to see. I will have to do it again to improve the numbers

2000'  0:50

3000' 1:29

4000' 2:06

5000' 2:52

6000' 3:38  less than 5 NM from airport

7000' 4:22

8000' 5:10

9000' 5:54

10,000' 6:43

11,000 7:42.  12 NM from the airport

Clarence

 

[bonal]

Doc, those look impressive I think from now on you should be restricted to only M18 performance numbers

[M20F]

1 hour ago, bonal said:

Doc, those look impressive I think from now on you should be restricted to only M18 performance numbers

Wait those aren't M-18 numbers 

[aviatoreb]

2 hours ago, M20Doc said:

Just returned from the time to climb check.  Field 1050' ASL, baro 30.40"Hg, OAT 9 C.  80 gallons of fuel,  2 on board @ 420LBS.

From a standing start, climbed at 120KTS, (Vx= 80 KTS, Vy= 104KTS)  Could have climbed steeper but the sun was low and made it hard to see. I will have to do it again to improve the numbers

2000'  0:50

3000' 1:29

4000' 2:06

5000' 2:52

6000' 3:38  less than 5 NM from airport

7000' 4:22

8000' 5:10

9000' 5:54

10,000' 6:43

11,000 7:42.  12 NM from the airport

Clarence

 

You got an IO720 hanging on the front of your M18?