BV 234 Performance Class 1 profiles
 

Good morning,

Would any one have a copy of the BV 234 Flight Manual, or any figures/ information on Performance Class 1 profiles for clear area and helipad departures for the BV 234

Any information would be gratefully received.


Thanks


WW

I have not flown a BV234...but i can not imagine it has PC1 capabilities.....

You might be surprised how much weight the Commercial version of the Chinook can carry on a single engine.

20 years since I last flew one, but as far as I can recall there was no weight limitation on the standard WAT curve in the temperature/density altitude ranges on the North Sea.

Mind you, at MTOW single engine climb speed was critical at 84 Kts. Deviate more than a couple of knots either side and the rate of climb fell off dramatically.

I do believe its powerful-but PC1 is not about the weight you can carry, but about the climb criteria you need to meet......

PC-1 of CH-47 / BV-234
 

I suppose I could have been far more detailed in my post....remembering how hard it is for some to carry forward an intellectual concept.

My submission was to suggest that the 234 on a single engine does in fact have a considerable ability.

Not having a 234 Flight Manual with Performance Charts approved by the UK CAA/JARS/EASA at hand, I was not about to quote any precise numbers for all combinations of Temp, Altitude data sets and flight conditions.




Note: I cannot imagine anyone getting any of all that confused, ever.

What's more interesting....I simply do not understand how the Helicopter Industry (to include the various World's Militaries) ever got along without all the bureaucracy we see today.

Simply said that's rubbish!

EASA define PC1 as "‘Operation in performance class 1’ means an operation that, in the event of failure of the critical engine, the helicopter is able to land within the rejected take-off distance available or safely continue the flight to an appropriate landing area, depending on when the failure occurs."

In order to comply with "safely continue...." there are further implications for OEI performance i.e. climb to 1000 feet, or MSA.

It has nothing to do with OEI hover performance!

Why do we seem to have a continuous stream of :mad: uniformed drivel from AW009 and turboshafts of late? :ugh::ugh:

Apate,

Thank you for contradicting my statement....you remind me there is always someone out there that will prove you wrong and your pointing out what you did to AW009 is proof positive of that fact of Life. I hold no malice towards you for causing me to retract my statement as posted.

I shall amend that to begin it with "Except for AW009....I cannot imagine anyone getting any of all that confused, ever.".

To err is human, arrogance also
 

@apate, @SASless: Thank you for politeness and your warm comments. I know very well the EASA Definition of PC-1 to PC-3 and of Cat-A to Cat-C and this might be a little bit earlier than you.

My intention was to explain very simple the complex and voluminously standards of Performance Classes and the procedures due to Categories, also for less experienced and educated pilots or even non-pilots. You really can’t deny the fact or term as "rubbish", if a helicopter is able to OEI HOGE at a certain Gross Weight, it is able within those margins to PC-1, to HHO and to HEC.

So please remember your upbringing and your manners, especially if you are a peer with offshore experience and not only a colleague or fellow.
----------------------------------------

P.S. & Question: How do you land safe in the event of failure of the critical engine within the rejected take-off distance if you have performed rejected or vertical takeoff eg. from a tanker having speed ahead or if you are performing HHO or HEC? E.g. marine pilot transfer or SAR missions.

The complete TECHNICAL MANUAL & OPERATOR’S MANUAL FOR ARMY CH-47D HELICOPTER (EIC: RCD) TM 1-1520-240-10 you will find in http://airspot.ru/book/file/1005/CH-47D.pdf

Nurse....bring AW009 his Meds....Stat!:ugh:

You don't - you go somewhere else where you can land.

I assume you have heard of flyaway performance charts? They normally require drop-down.

Here's the S92 procedure from the Flight Manual SAR Supplement - you will note it makes no mention of hovering!:

SINGLE ENGINE FAILURE – HOVER OGE
Figure 4-3 provides the conditions from which an aircraft can fly away after a single engine failure during an OGE
hover. If a fly away capability exists, the fly away procedure should be followed. If a fly away capability does not exist,
the land/ditch procedure should be followed.
FLY AWAY
1. Rotate the aircraft to no more than 20° nose down while decreasing collective to maintain Nr between 95 and
100%.
2. Rotate to approximately 5° nose up when approaching Vtoss.
3. Climb at Vtoss at 100% Nr.
4. LDG GEAR – UP (when a positive rate of climb is established).
WARNING
Do not select two minute power until obstacle clearance is assured.
5. Select two minute power.
6. When obstacles are cleared, continue climb and accelerate to 80 KIAS.
7. Select continuous power when conditions permit.
8. Land as soon as practical

AW009,

The OP asked about PC1 profiles for clear area and helipad profiles.

You have introduced OEI OGE hover capabilities which is another kettle of canaries: and for you to lambaste others who are addressing the OP is failing to grasp the topic under discussion. I suspect that although there are many years since SASless drove Wokkas, he has a reasonable grasp of their capabilities.

212man also has a very sound background of twin ops and related performance issues, so trying to belittle his perfectly correct assessments does little for your credibility. Do not confuse your voluminous postings (81 in just over a month) with acceptance and competent knowledge.

Brother Eacott,

At some point most will elect to do as I have re AW009....just like when One's neighbor is playing that atrocious Rap stuff....One just shuts the window so One does not have to hear it.:ok:

Hover OEI vs Cat A
 

This thread has run a bit abeam, can I help straighten it out?

1) HOGE and OEI are vastly different performance points, plotted differently and tested differently. We all know this.
2) When we look at Cat A/PC-1/PC-2/PC-2e capability, the power needed to hover OGE and the power available at the Cat A weight are actually locked closely in the same performance equations, so that OGE OEI Hover capability is a good predictor of Cat A from a rig. This should be obvious to us all, the ability to stagger out of a low speed takeoff after an engine failure is roughly driven by the excess power you have in that situation, the excess power to make the climb and acceleration possible.
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.

4) I looked at the D Model Chinook manual (thanks!), it would seem to allow HOGE at SL 20 degrees at about 34000 lbs while OEI, thus it might allow a PC1 takeoff at somewhere around 40,000 lbs from a rig (my 120% rule). With an Army empty stripped weight of 25,000 lbs, and maybe 4000 lbs of seats, interior and other equipment added, it might weigh about 29,000 lbs empty. That would allow 11,000 lbs of useful load. It burns about 2300 lbs per hour at 130 knots, for about 18 lbs per NM.
At 150 nm, it would need 2700 lbs of gas each way, 5400 lbs round trip, plus about 1700 reserve (45min) for a total of 7125 lbs of gas. From 11,000 lbs, that yields about 4,000 lbs of people, or 16 pax at 240 lbs each.

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.

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!

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

He goes on to elaborate that whilst OEI OGE hover is a good predictor for Cat A from a rig,

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 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.

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.

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:
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

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

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

You are charm personified.....

Edit: Point taken, SP.

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.