Hurricane Speed Test in game

[IvanK]

As per the Spit IIA Speed test here is my test on the Hurricane. Wt this time as per the full line on the spec.

METHOD
Each run commenced on altitude with stabilised Oil/Rad temps Oil Temp at 80deg C. Rad Full open (At present I cannot detect any Rad drag so radiator position is not relevant imo)
Each altitude was a specific FMB set up. Altitude maintained +-50ft throughout the test. QNH checked as 992mb on the specific map used.
Each run done 3 times and Vmax average plotted.
Seal level temp estimated 19 deg C based on HEIII OAT gauge on the same map on the ground. TAS calculation based on standard 2 deg C lapse rate from the surface. so at 16,000ft I was using an OAT of -13deg C
My test wt as per the spec wt as it can be achieved in FMB with the Hurricane

Power setting was Full throttle 3000RPM. Indicated Boost +5.2. Now its important to understand that displayed Boost is not I believe actually measured in the FM but represents an angular animation value. We all know that it should be indicating +6.25 in the Hurricane

Results plotted as accurately as I could.

http://i40.photobucket.com/albums/e215/zulu64/Hurrispd-1.jpg
I had to extrapolate the graph in the lower left corner !

[David198502]

As per the Spit IIA Speed test here is my test on the Hurricane. Wt this time as per the full line on the spec.

METHOD
Each run commenced on altitude with stabilised Oil/Rad temps Oil Temp at 80deg C. Rad Full open (At present I cannot detect any Rad drag so radiator position is not relevant imo)Each altitude was a specific FMB set up. Altitude maintained +-50ft throughout the test. QNH checked as 992mb on the specific map used.
Each run done 3 times and Vmax average plotted.
Seal level temp estimated 19 deg C based on HEIII OAT gauge on the same map on the ground. TAS calculation based on standard 2 deg C lapse rate from the surface. so at 16,000ft I was using an OAT of -13deg C
My test wt as per the spec wt as it can be achieved in FMB with the Hurricane

Power setting was Full throttle 3000RPM. Indicated Boost +5.2. Now its important to understand that displayed Boost is not I believe actually measured in the FM but represents an angular animation value. We all know that it should be indicating +6.25 in the Hurricane

Results plotted as accurately as I could.

http://i40.photobucket.com/albums/e215/zulu64/Hurrispd-1.jpg

thx IvanK for your testing!
and thank you for confirming my observation, that rad settings dont have any effect on speed.
i got flamed a year ago by stating this on this very forum(i tried it with the 109s though)

[camber]

Thanks IvanK,

I got very similar data at height from my previous test (although my FTH for Hurri and Spit were a little lower in climb, perhaps CloD does model ram air effect on intake.)

Patch+hotfix Rotol Hurri:

FTH 15500ft
2700 rpm +6.1psi
235mph@15500 ft = 305mph TAS

[Crumpp]

Try the dry adiabatic lapse rate of 3 degree C / 1000 feet....

[IvanK]

Crumpp you said "Try the dry adiabatic lapse rate of 3 degree C / 1000 feet.... "

Why ?

The International Standard Atmosphere (ISA) lapse rate is 1.98 deg C per 1000 feet !

Its going to give a TAS even lower than what the IAS to TAS conversion above gives.
e.g. Based on the assumption Surface Temp is 19C then using the DALR at 3C/1000ft gives an OAT at 16,000ft of -29C so the 231MPH IAS I got would result in TAS of 289MPH versus the 298MPH TAS value I got using the ISA lapse rate.

[bongodriver]

I think Crumpp just wanted to quote from his text book....


But while on the subject of ISA......I have been getting strange ideas in my head about the QNH the game seems to model of 992 and can't get the idea out of my head about the US 29.92 inches of mercury and wonder if someone porked the atmosphere model that way.......crazy I know.

[Bounder!]

Just wanted to post and say thanks for the all testing IvanK, always nice to see how the current simulated ac in CoD perform against real data.

[IvanK]

Thats some lateral thinking Bongodriver but worthy of a mention to the devs .... Done.

[DC338]

Yes the QNH is strange, given that during the battle the QNH didn't often go below 1005.

[Crumpp]

Why ?

The International Standard Atmosphere (ISA) lapse rate is 1.98 deg C per 1000 feet !


I miss read your FTH and thought it might line it up better.

Your raw test data FTH aligns with the data converted to standard. In otherwords, the game is showing the FTH to be 17,500 ft, without conversion right?

If that is the case, the atmospheric conditions in the game are standard.

What was your Vy in the test, too?

[IvanK]

Its a SPEED test not a climb test so what is the relevance of Vy. As discussed in the in the initial thread these are level speed runs looking for max TAS at each altitude tested.

[Crumpp]

Your raw test data FTH aligns with the data converted to standard. In otherwords, the game is showing the FTH to be 17,500 ft, without conversion right?


OOPS, I was locked on the altitude you found FTH and started thinking climb for some reason.

As discussed in the in the initial thread these are level speed runs looking for max TAS at each altitude tested.

Look guy, I did not ask for the TAS. I wanted to confirm that you did not convert the FTH data from your test to standard conditions.

Is the raw data showing the FTH to be 17,500 ft?

If it is then that is definative proof the atmospheric model is not agreeing with the Flight Models.

FTH is a function of density altitude. Your supercharger does not care what your altimeter reads.

[IvanK]

Rather than using terms like "Look Guy" ... (pull your head in by the way ). I tactfully suggest you read the posts carefully before flying of on a tangent and throwing your two bobs worth in.

So far in the Spit and Hurris speed test threads the 3 tangents you have gone off on are:

1. Suggested using the dry Adiabatic lapse rates instead of the ISA Lapse rate.
2. Asked about Vy speed in a level speed test.
3. Suggested that airfield field elevations varied with pressure.

I clearly stated in all the posts no adjustments were made to standard conditions the data is as it is. I also indicated in the Spit test post the FTH quoted was as stated the Altitude at which during the Speed run I first noticed the Boost drooping off. So in the test case was the Rammed FTH. As I indicated in the Spit test no attempt at converting to a standard atmosphere was made ... and I invited anyone who wanted to to go for it !

[Crumpp]

As I indicated in the Spit test no attempt at converting to a standard atmosphere was made

There is no question or issue here. The atmospheric model is not correct or is using a very non-standard lapse rate.

That is fact. You cannot have an OAT of 19C @ Sea Level, a pressure of 992mb, and have a density altitude that equals 17500 ft with any standard lapse rate.


Find Pressure Ratio at Sea level,

992mb = 29.29inHg
Pressure ratio, delta , at sea level is 29.29”/ 29.92” = .978944

Find Pressure Altitude,

Usually we only know the pressure at sea level. We can use charts to find pressure ratio if we know pressure altitude. So Let’s determine Pressure Altitude. Using the rule of thumb, 1” Hg =1000 ft. This is an approximation, but it works pretty good. So with a barometric altimeter setting of 29.29 we can see how far off we are from Standard day. 29.92-29.29 = .63 “ which roughly equals 630 ft. Now, do we subtract or add? This is how I look at it, If I roll the altimeter setting to 29.92 what happens to my altimeter. Since I am increasing the setting, then I am increasing the altitude to get to pressure altitude. SO Pressure altitude is 17500 + 630 = 18130 ft

Find Pressure Ratio at Altitude,

Look in a STD Atmospheric table, 18130 ft equates to a pressure ratio of .4967475

Our value lies 130 feet above the 18000 ft level. You should be smart enough to figure out how to extrapolate it.

Find Temperature Ratio,

19C + 2 degree per 1000 ft lapse rate = 17500/1000 = 17.5*2 = 35 = 19C - 35C = -16C
-16C = 3.2F

Theta = T/To at sea level , where T = Actual Temperature in deg K or Deg R and To = Standard sea level Temperature in deg R or deg R.
At altitude Theta = (3.2F + 460R)/(59F + 460R) = .892486

Find Density ratio,

You can’t just read off the table. Temperature influences density. We use the ideal gas law relationship to find density ratio.

Sigma = Delta / Theta = .556589

Look in a STD Atmospheric table, 18000 ft equates to a density ratio of .56991

In case you don't know how to extrapolate on the table:

.56991-.556589 = .013321

19000 ft density ratio = 0.55112

.56991 - 0.55112 = .01879

.01879/1000 = .000019

.013321/.000019 = 709ft (Ti-89 uses 1.879e-5)

Density altitude at 17,500 ft indicated is 18709 ft

Do you think any Merlin II or III engine had a FTH of 18700 feet?????

NO...

Does anybody have weather reports from the Battle of Britian? They only possible explaination the data is correct is to change the lapse rate adding more moisture to the air. If it is dry, the FTH is even more out of wack.

[bongodriver]

992mb = 29.29inHg


Wrongggg! 1013.25 Mb or Hpa = 29.92 inHg, yet another example of lack of basic knowlege for an apparent professional pilot.

29.29”/ 29.92” = .978944


Wronggg!! 29.92 divided by 29.92 = 1

Why do I get the feeling the rest is pure comedy?

[Crumpp]

Wrongggg! 1013.25 Mb or Hpa = 29.92 inHg, yet another example of lack of basic knowlege for an apparent professional pilot.



Our pressure at sea level is not 1013.25Mb....

It is 992Mb......

992mb = 29.29inHg or more precisely 29.2938592inHg

http://www.csgnetwork.com/pressinmbcvt.html

Why do I get the feeling the rest is pure comedy?

Start laughing.....

[bongodriver]

992mb = 29.29inHg or more precisely 29.2938592inHg




first of all I think you must mean 29.921373825 inHg

And how exactly do you figure? I suggested in a thread that perhaps the atmospheric model was porked by someone equating 29.92 to 992, but that does not mean it is equal to 29.92 inHg.


Start laughing.....


Chuckle worthy as it is

[bongodriver]

Ok....I see my mistake, forget it .92 looks an awfull lot like .29 when surrounded by numbers.

see that...humility, try it sometime.

And I will ease on the itchy trigger finger.

[phoenix1963]

Amazingly, I do think Crumpp has a valid subsidiary point about rather oddly low pressure at sea level in CloD.
Most of BoB was fought in good - high pressure - weather.
Apart from one period of low pressure in August, I think.

Look here for great historical weather charts http://www.wetterzentrale.de .

56RAF_phoenix

[phoenix1963]

Now if I could find my old link for the historical surface pressure charts we could work out the actual lapse rate...

(of course the 500hPa charts kind of measure atmospheric thickness, i.e. some sort of temperature variation)

56RAF_phoenix

[bongodriver]

Annoyingly without going into graphs it seems Crumpp is right, if FTH in standard atmosphere is 17,500ft density altitude, then if ambient temps are ISA + then density altitude is higher than pressure altitude therefore boost drop off should happen lower than 17,500 ft on the altimeter.

There are simpler graphs showing a density altitude conversion from pressure altitude just using ISA deviation temperature, again Crumpp may have a point about dry lapse rates as I think density alt is based on it, relative humidity comes in and complicates matters.

Crumpp, your working out was done with a standard 2 degree lapse rate, I believe a 3 degree lapse rate would work in 'favour' of performance in that case.

19C + 3 degree per 1000 ft lapse rate = 17500/1000 = 17.5*3 = 52.5 = 19C - 52.5C = -33C

using -33C at 17,500ft pressure altitude I find a density alt of 16,000ft so in effect I could go to more than 17,500 pressure alt before boost drop off.

I will look at this again tomorrow.

p.s. I forgot to add....the key to this would be to test and find the in game actual OAT (outside air temp) at 17,500 ft pressure altitude and see what the deviation is from a 3 degree lapse rate.

p.p.s. I think the test is worth doing using standard setting on the altimeter 1013mb, which RAF aircraft use an OAT gauge?, might be worth doing the test as a co op so someone can check temp at various pressure altitudes.

P.p.p.s reverse engineering the games atmosphere model at 1 in the morning is nuts

[Crumpp]

Find Pressure ratio,

Delta at sea level is 29.29”/ 29.92” = .978944

Find Temperature Ratio,

19C =66.2 F

Theta = T/To at sea level , where T = Actual Temperature in deg K or Deg R and To = Standard sea level Temperature in deg R or deg R.
At altitude Theta = (66.2F + 460R)/(59F + 460R) = 1.01387

Find Density ratio,

Sigma = Delta / Theta = .965552

Find Standard Means Of Evaluation:

SMOE = 1/SQRT(sigma) = 1.01768

Hurricane Mk I sea level TAS @ standard conditions = 263mph TAS = 263mphEAS

Under game atmospheric conditions with a standard lapse rate:
263mphEAS * 1.01768 = 268mphTAS @ Game Sea Level

The Hurricane Mk I should be in the vicinity of 268mphTAS at sea level in the game under the atmospheric conditions recorded.

[bongodriver]

With a decent graph you don't need to find any ratios, some geek has already done it for you.

[MiG-3U]

The full throttle height is function of pressure altitude as seen directly from altimeter, given the altimeter base level setting. Supercharger increases manifold pressure and that ability depends on outside pressure and dynamic pressure on intake regardless density of the outside air. Air density is, of course, funtion of pressure and temperature but supercharger only sees the pressure.

BTW Gaming wise it's more important that the relative performance of the planes is about right and that is pretty easy to test regardless atmospheric model of the game, given that all the planes can be tested in the same conditions.

BTW2 I just looked in my crystal ball a saw that soon my sayings will be denied and scans from various books will be posted with thick, red underlinings :)

[bongodriver]

BTW2 I just looked in my crystal ball a saw that soon my sayings will be denied and scans from various books will be posted with thick, red underlinings :smile:


I'd hate to dissapoint so here goes.

No it is a function of density altitude, a supercharger produces an excess of pressure which it can only maintain until it reaches a certain level of air density due to volumetric efficiency,atmospheric density is very much affected by temperature and atmospheric pressure is not, if conditions were ISA exactly then density altitude would equal pressure altitude, inevitably temparature varies and whenever things are on the hot side performance is reduced and vice versa, so it stands to reason performance is dependent on density, you only have to look at aircraft performance charts to see this is true, jet engines have the same problem, after all a supercharger is just a centrifugal compressor just like you find on some jets.

[MiG-3U]

I'd hate to dissapoint so here goes.

No it is a function of density altitude, a supercharger produces an excess of pressure which it can only maintain until it reaches a certain level of air density due to volumetric efficiency,atmospheric density is very much affected by temperature and atmospheric pressure is not, if conditions were ISA exactly then density altitude would equal pressure altitude, inevitably temparature varies and whenever things are on the hot side performance is reduced and vice versa, so it stands to reason performance is dependent on density, you only have to look at aircraft performance charts to see this is true, jet engines have the same problem, after all a supercharger is just a centrifugal compressor just like you find on some jets.

I'm glad to be corrected on this, preferably in layman's terms without underlined scans :)

My thinking is that supercharger keeps constant pressure up to the FTH and the mass flow through the engine and power is at maximum at FTH. Below FTH intake air is warmer and hence density at the intake manifolds is lower at given pressure and mass flow and power lower than at FTH, above FTH supercharger can't keep the pressure which reduce mass flow and power.

Let's assume that pressure altitude is keeped constant but temperature is higher. Then the mass flow through engine is reduced due to lower density and less mass flow is needed through supercharger to keep constant pressure due to same reason. The power is, of course, lower at this situtation, however, pressure ratio between manifolds and outside is still unchanged and hence the FTH unchanged as well.

[Crumpp]

it is a function of density altitude

Correct

I'm glad to be corrected on this, preferably in layman's terms without underlined scans

It would be nice if people would not stick to their guns when they are wrong so that such things are not required.

My thinking is that supercharger keeps constant pressure up to the FTH and the mass flow through the engine and power is at maximum at FTH. Below FTH intake air is warmer and hence density at the intake manifolds is lower at given pressure and mass flow and power lower than at FTH, above FTH supercharger can't keep the pressure which reduce mass flow and power.

Let's assume that pressure altitude is keeped constant but temperature is higher. Then the mass flow through engine is reduced due to lower density and less mass flow is needed through supercharger to keep constant pressure due to same reason. The power is, of course, lower at this situtation, however, pressure ratio between manifolds and outside is still unchanged and hence the FTH unchanged as well.

Unfortunately, that is not the case and people continue to argue their point.

[Crumpp]

'Full throttle height' is defined as that altitude above which the supercharger is unable to compensate for the reduced air density and both the BHP and airflow decrease in direct proportion to any further increased altitude.

http://www.keenzo.com/showproduct.asp?ID=3192182

Most of the flight data and engine data you guys argue about is converted to standard day conditions.

On non-standard day's FTH will change true altitude to maintain the same density altitude.

[IvanK]

Courtesy of Klems data tool and his work it has been established that the basic CLOD atmospheric temperature lapse rate is 1.97 deg C per 1000feet (corrected to 2 decimal places). This has now been measured up to 26,000feet. So its only 0.01 deg C per 1000 feet out ... not much and well and truly in the ball park to the ISA value of 1.98 deg C per 1000feet.

[bongodriver]

Courtesy of Klems data tool and his work it has been established that the basic CLOD atmospheric temperature lapse rate is 1.97 deg C per 1000feet (corrected to 2 decimal places). This has now been measured up to 26,000feet. So its only 0.01 deg C per 1000 feet out ... not much and well and truly in the ball park to the ISA value of 1.98 deg C per 1000feet.

You beat me to it but a squad member from the dogz and I have been doing a little experimenting and found something interesting, much like you we have found the lapse rate to be in the 2 degrees per thousand feet but in addition we stumbled upon an element in the FMB that changes the the atmospheric temperature not sure of its function but it is the mission parameters box, there is an option for 'Breeze/Thermal Activity =0/10' with a sliding scale, default seems to be 0 and this gives an ambient temparature of ISA +10, but if the slider is set to 10 the temp almost lines up with ISA, so far no indication that the temps can be brought to an ISA - figure.

I have attached a screenshot of the FMB tool and a graph showing the results of our quick test today.

p.s. I mean to add the test mission was done on a clear day at 12:00 midday, no other tests done to check for diurnal variations.

p.p.s. also added a usefull graph for density altitude calculations.

[Crumpp]

You beat me to it but a squad member from the dogz and I have been doing a little experimenting and found something interesting, much like you we have found the lapse rate to be in the 2 degrees per thousand feet but in addition we stumbled upon an element in the FMB that changes the the atmospheric temperature not sure of its function but it is the mission parameters box, there is an option for 'Breeze/Thermal Activity =0/10' with a sliding scale, default seems to be 0 and this gives an ambient temparature of ISA +10, but if the slider is set to 10 the temp almost lines up with ISA, so far no indication that the temps can be brought to an ISA - figure.


Amazing.....

Almost as amazing as all the "I am real world pilot" on this forum who are testing away, screaming about their favorite gameshape is porked, but don't bother to worry about the atmospheric model or understand it first.

[bongodriver]

Amazing.....

Almost as amazing as all the "I am real world pilot" on this forum who are testing away, screaming about their favorite gameshape is porked, but don't bother to worry about the atmospheric model or understand it first.


What?


If that is the case, the atmospheric conditions in the game are standard.

If it is then that is definative proof the atmospheric model is not agreeing with the Flight Models.

There is no question or issue here. The atmospheric model is not correct or is using a very non-standard lapse rate.

So how much research did you do before making these assumptions? what is really amazing is how you spew out all this 'know it all' crap thanks to your text books but spend little to no time actually trying to find solutions to a problem.

Still waiting for the evidence you are what you claim to be.

[Crumpp]

What?

I have been talking about the atmospheric model from the beginning. It does absolutely no good to conduct any performance testing without understanding the conditions.

http://forum.1cpublishing.eu/showthread.php?t=32259

Conditions are everything in aircraft performance. That fact is very much on your mind when piloting a real aircraft.

Every take off you calculate V1,V2, Vmcg, Vr, BFL and as well as acceleration checks. All are effected by density altitude.

It looks like you have found the controls to set conditions to standard. That will save time in converting performance under other than standard conditions.

Now that the atmospheric conditions are known, conclusions can be made about specific aircraft performance.

[bongodriver]

Conditions are everything in aircraft performance. That fact is very much on your mind when piloting a real aircraft.

Every take off you calculate V1,V2, Vmcg, Vr, BFL and as well as acceleration checks. All are effected by density altitude.



Rubbish, real pilots only have to calculate how much rest they earn at the end of the duty period and pray they don't end up on a split-shift, I pitty the poor guy that has to go into the Flight Manual and work this stuff out instead of having it ready in tabular abridged form on the checklists based on T/O weight and temparature or in fact have the entire performance schedule handed to him by operations who worked it out for him, occasionally with GA operations there are times when you will dust off the Flight Manual if a customer has an unusual destination.

you failed to notice nobody argued 'against' the density altitude but you did go on and on and on about it like it was a 'eureka' moment.


Now that the atmospheric conditions are known, conclusions can be made about specific aircraft performance.


You're welcome.

[IvanK]

Great stuff Bongodriver on the Thermal factor setting. Any idea if this affects pressure as well ?

[Crumpp]

Rubbish, real pilots only have to calculate how much rest they earn at the end of the duty period

Yeah....OK......

you failed to notice nobody argued 'against' the density altitude

I did not fail to notice about 3 other "performance" threads appeared without finding out what the atmospheric conditions.

Still waiting for the evidence you are what you claim to be.


I think it is pretty self evident....read the last few pages of this thread.

Crumpp says:
V1,V2, Vmcg, Vr, BFL and as well as acceleration checks. All are effected by density altitude.


Bongo says:
with GA operations

You don't even know what V1,V2, Vr, and BFL are do you?

Back to ignoring you.

[bongodriver]

You don't even know what V1,V2, Vr, and BFL are do you?

GA is the all encompassing term for anything 'not airline', basically the Learjet is a GA aircraft here in Europe and to be honest I thought it's the same in the states, another indication you don't really have anything to do with the industry.


I think it is pretty self evident....read the last few pages of this thread.



Yes, you are still using a good textbook.


Back to ignoring you.


Sure.

[bongodriver]

Great stuff Bongodriver on the Thermal factor setting. Any idea if this affects pressure as well ?

Didn't check that, the test was started from 1000 feet on 1013mb in both cases and it didn't look wildly different, the surface temps were projected based on the linearity of the test results.

[Crumpp]

Bongo says:
'not airline',

I had to respond, it is just too rich!!

You need a shovel for the hole you are digging!!

It is a Part 121 regulation. Part 121 is the airlines......

Flight operations are often referred to by the part of the regulations that governs them. So, large operators such as American Airlines, Delta Air Lines, Federal Express, Southwest Airlines, and United Airlines are typically referred to as Part 121 carriers.

http://www.nap.edu/openbook.php?record_id=12795&page=56


Part 121 - OPERATING REQUIREMENTS: DOMESTIC, FLAG, AND SUPPLEMENTAL OPERATIONS

http://www.risingup.com/fars/info/121-index.shtml


Sec. 121.189 — Airplanes: Turbine engine powered: Takeoff limitations.

The accelerate-stop distance must not exceed the length of the runway plus the length of any stopway.

http://www.risingup.com/fars/info/part121-189-FAR.shtml

V1 concept is critical to takeoff planning. The FARs require the flight crew of a transport-category airplane to ensure that the runway intended for use (including any clearway or stopway off the end of the runway) is long enough to allow the takeoff to be safely continued or rejected from a predetermined go/no-go point on the runway. The go/no-go point is where the airplane reaches V1 while accelerating for takeoff



http://www.ce560xl.com/Blackberry/BalancedFieldLength.html

Dispatch and the PIC both have to sign the release and the flight plan. You are both jointly responsible for the planning. If you are not doing the planning, you will not catch mistakes and they do happen. In short, you are not doing your job and will be held responsible for not doing your duty as PIC.

[Crumpp]

1000 feet on 1013mb

Sea level pressure at 1000 feet......

[bongodriver]

i had to respond, it is just too rich!!

you need a shovel for the hole you are digging!!

it is a part 121 regulation. part 121 is the airlines......



http://www.nap.edu/openbook.php?record_id=12795&page=56




http://www.risingup.com/fars/info/121-index.shtml






http://www.risingup.com/fars/info/part121-189-far.shtml



http://www.ce560xl.com/blackberry/balancedfieldlength.html

dispatch and the pic both have to sign the release and the flight plan. You are both jointly responsible for the planning. If you are not doing the planning, you will not catch mistakes and they do happen. In short, you are not doing your job and will be held responsible for not doing your duty as pic.


pmsl......

http://www.aopa.co.uk/index.php?option=com_content&view=article&id=568&Itemid=559

[bongodriver]

Sea level pressure at 1000 feet......


No, flying at 1000 feet with 1013 set on the altimeter......you know 1013....standard setting.......QNE.....the pressure pilots set in order to fly at flight levels..

Seriously Crumpp, just scan a copy of your license and I will get off your back, I will be horrified at the thought you are qualified but I will lay off.

[Crumpp]

Bongo says:

pmsl......


Wow, that shovel is getting worn. Why don't you read your sig a few times. The part right under my name.

Let's read what you are laughing about. Only pull out your english dictionary this time.

General aviation (GA) refers to all flights other than military and scheduled airline/cargo flights, both private and commercial.

Is english your second language?

That is a real hinderance when you surf around the internet looking for answers.

As a part 121 PIC, you have to plan V1,V2, Vr, and BFL. That means airline pilot or any flight other than cruising around for 100 dollar hamburgers or cool shopping places to take the wife so she won't bitch about the annual.

No, flying at 1000 feet with 1013 set on the altimeter

Ok, being at 1000 feet with the altimeter set to 1013 is different from setting sea level pressure at 1000ft true altitude.

[bongodriver]

Is english your second language?



According to my pilots license I'm proficient.

That is a real hinderance when you surf around the internet looking for answers.


You are the expert so i will bow to that knowlege


As a part 121 PIC


FAR121?......I'm not FAA


Ok, being at 1000 feet with the altimeter set to 1013 is different from setting sea level pressure at 1000ft true altitude.


You think?

[bongodriver]

As a part 121 PIC, you have to plan V1,V2, Vr, and BFL. That means airline pilot or any flight other than cruising around for 100 dollar hamburgers or cool shopping places to take the wife so she won't bitch about the annual.



What would I know I only passed perf 'A' back in 1998 and qualified on the Learjet in 2008.

[Crumpp]

FAR121?......I'm not FAA


JAA follows the same requirements as the FAA....keep digging.

JAR/FAR 25.107


V1 is the maximum speed at which the crew can decide to reject the takeoff,and is ensured to stop the aircraft within the limits of the runway.

25.107 Takeoff speeds.


http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&rgn=div5&view=text&node=14:1.0.1.3.11&idno=14#14:1.0.1.3.11.2.155.11

[JG52Uther]

Well done, another FM thread closed. I think thats four now. Next time another thread is derailed like this action will be taken against those concerned.