PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rotorheads (https://www.pprune.org/rotorheads-23/)
-   -   BV 234 Performance Class 1 profiles (https://www.pprune.org/rotorheads/580667-bv-234-performance-class-1-profiles.html)

AW009 1st Jul 2016 20:20

@Nick Lappos: Thank you!
And OEI HOGE in HHO and HEC is a further aspect in offshore work!:)

SASless 1st Jul 2016 20:32

Make your Fuel enough for the return trip plus reserve fuel and minimum inflight contents and you could add another 2400 pounds of payload assuming fuel being available at the Rig.

AW009 1st Jul 2016 20:57

https://www.youtube.com/watch?v=BIkbhLXNg2w

I'm just waiting that the weisenheimer are spoofimg and tolling against Nick Lappos? but this courage they won't have!

John Eacott 1st Jul 2016 23:25

Again, AW009, you are not addressing the OP relating to PC1 for clear area and helipads. You have introduced OEI OGE hover to this thread and all the performance charts and videos you choose to show here do not address that. Nick has even pointed out that


1) HOGE and OEI are vastly different performance points, plotted differently and tested differently. We all know this.
He goes on to elaborate that whilst OEI OGE hover is a good predictor for Cat A from a rig,


3) I have cross plotted the performance of several helicopters, and it appears that when the helo has a weight of about 120% of the weight where it can HOGE OEI, it can make a rig takeoff with dip down and then fly the full Cat A profile. In other words, if it has OEI power equal to the twin power needed to HOGE, it can then be loaded to 20% more weight and make a PC-1 takeoff.
That 20% extra is a significant variation from the weight restriction demanded by adhering to OEI OGE hover limits; which is the topic of this thread.


I'm just waiting that the weisenheimer are spoofimg and tolling against Nick Lappos? but this courage they won't have!
I know Nick very well and am quite happy to take on anything we disagree about, but the weisenheimer in this (and some other threads) is you, AW009. Burst into a forum and throw your opinions and weight around and you should eventually expect a resistance, especially when you denigrate others who are debating the topic and not your offshoot/pet theory.

SASless 1st Jul 2016 23:44

The empty drum makes the most noise as I heard it from my Grandpaw....AW is certainly making the most noise here at Rotorheads.

When Brother Dixson and Brother Lappos post....I read what they have to say and generally defer to them with scant argument. I might pose a question to them in hopes of having the esoteric principles that are the root of their input....but only in the hopes of learning more.

AW009 should try that for a while and listen to what so many are telling him.

For sure he doesn't know what he doesn't know and seems to think what he does know is correct when that is not necessarily the case.

JimL 2nd Jul 2016 14:31

There is a world of difference between the performance required for a helideck category A departure, HEC Class D and SAR HHO.

Whilst Nick is likely correct in his estimation of a correlation of 1.2 between the OEI HOGE and the departure from a hover whilst hoisting for SAR (where a fly-away with drop-down might be permitted) it does not necessarily carry across to rig departures.

HEC Class D is totally different in that the permitted reduction in height following an engine failure must not be more than the greater of 4ft, or 10% of the height established at the time of the failure.

When modelling the PC2e rig departures, establishing an accurate 'single' correlation between OEI HOGE and RTOM (for all types modelled) was quite difficult.

The rig departure has to take account of two elements: the deck-edge miss; and the single engine fly-away and recovery.

The deck-edge miss is sensitive to a number of elements:
The AEO vertical speed attained at the Rotation Point (TDP);

The height of the Rotation Point (TDP);

The rate and magnitude of the pitch down (- PA); and

The length of time negative PA is held before recovery is started.
These elements also have a bearing on the drop-down in addition to the reserve of power discussed by Nick. The length of fuselage also has an effect on the maximum mass for deck-edge miss - a smaller helicopter benefitting in this respect (for fairly obvious reasons).

The profile flown can also have a detrimental effect; this was shown in modelling by varying elements of the manoeuvre – e.g. the rate and magnitude of the PA as well as the time negative PA is held.

Variability was also observed in the flight trials of one of the types flown offshore; two flights with the same mass and environmental conditions (flown by different pilots) had a reduction of half the deck-edge miss and an increase of drop-down of up to 50 ft when negative PA was held for about a second longer. This difference could be explained by the lack of accuracy of the required cue (a set airspeed indication on the ASI) rather than just pilot variability.

Later procedures appear to address this inaccuracy by using ground speed on the PFD as the pitch up cue.

Jim

SASless 2nd Jul 2016 20:15

For those with not a lot to do.....wade through this document.

http://dtic.mil/dtic/tr/fulltext/u2/a243805.pdf

212man 4th Jul 2016 08:55


I'm just waiting that the weisenheimer are spoofimg and tolling against Nick Lappos? but this courage they won't have!

wisenheimer

/ˈwʌɪz(ə)nˌhʌɪmə/

noun
USinformal

noun: weisenheimer

a person who behaves in an irritatingly smug or arrogant fashion, typically by making clever remarks and displaying their knowledge.
You are charm personified.....

whoknows idont 4th Jul 2016 11:13

Edit: Point taken, SP.

Senior Pilot 4th Jul 2016 11:56

I think that the point has been made: it would be best not to make AW009 feel unwelcome in our forum, he may well have valid contributions to make in the future.


All times are GMT. The time now is 18:09.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.