Not such an unusual sight.
They usually follow the river, which explains the Hammersmith sighting, and occasionally land at Chelsea Barracks.
Impressive sight - I agree.

http://www.vhfcn.org/pics/anihook.gif

Whatchecks,

I think you'll find a brief summary of the DASH functions about 4 posts above yours, in the dit from timmccall.

Agree about it being the right heli to be in when going somewhere iffy, though.

I live just the other side of the Chelsea Barracks, and frequently have the big boys coming and going!

I too saw the Chinook, wonderful site!

I'm surprised that this is the first time you've seen us. The London heli-lanes are an easy way to get to the Stamford Training Area from Odiham and return. It is good training for the new guys as well because you really have to get on top of the radio calls, the nav (on the legs away from the river) and the required height changes. Thames Radar can get seriously p****d off if you f**k up. Of course the fact that the view is spectacular is merely coincidental.

------------------
Through S**t to the Bar

Very interesting thread. I can see I'll need to do some serious revision before my next standards check.
One minor point, the Chinook doesn't handle quite like a normal helicopter in roll. In a normal helicopter, once you have banked, the pendulum force of the cab tries to pull you wings level again, forcing you to keep some into-turn cyclic to maintain your angle of bank. For some unknown reason Boeing decided that the Chinook should fly like a fixed wing aircraft in roll. When you push the stick sideways the AFCS interprets this as a demand for a rate of roll proportional to the displacement. It will keep rolling the aircraft until you are upside down if you let it. You have to put the stick back in the middle to stop the roll, at which point the AFCS will automatically hold the angle of bank.

Lu: Your sideways stick stuff is not a problem in autorotation. As has been said, we can fly just like any other helicopter. It does play a major part in Vortex Ring or "settling with power" as the Americans would say. Although I know people who say that you can power out of Vortex Ring in the mighty wocca, and they have, the best solution is to accelerate, as it's impossible to maintain Vortex Ring above 30kts. Trying to pitch forward in the Chinook would only lead to an increase in collective pitch on the aft head which would go deeper into Vortex Ring and fail to pitch up. The way out of Vortex Ring in the Chinook is to accelerate sideways because, as you pointed out, this cyclically pitches both heads which gets round the problem.

Arm: All very good points and I wouldn't argue with any of them. The Chinook has a wind limit of 45kts from any direction and is very tolerant of downwind approaches/hover with very little increase in power demand. Even single engine, at training weights, the pilot would have plenty of power in hand, especially if he did a running landing (max speed 60kts). Into wind is better, but downwind at 10kts is not a problem.

Vfrpilotpb: Ever since the Wessex crash a few years ago, in which three ATC cadets died, the MOD have become EXTREMELY resrictive about carriage of civilians. It has to be approved from on high, and then only for a good reason. We would love to take you flying but, normally, they won't let us. I suggest you try to think of a cunning reason and write to the Station Commander at Odiham to ask. What have you got to lose?

------------------
Through S**t to the Bar

POAA

Its called a negative stick gradient and it really is VERY nice to fly - move the stick until you have the right attitude and then centralise; even pilots can do it!!!!!!!!!!!!

Good morning POAA,
Thanks for the suggestion, will try, like you say , Nothing ventured!!!( if I had Flying Lawyers software I'd show a little Woca flying about , but alas )

VFRpilot
You don't need any special software to insert these little pictures. You just need to make a reference to an image file held elsewhere on the web. Take a look at this message by editing it - you'll see what I mean (and how it works).
http://www.vhfcn.org/pics/anihook.gif

A good source of 'smilies' and other aviation related gifs like the one above can be found at
http://www.stopstart.fsnet.co.uk
It even shows you how you can insert them into your text
http://www.stopstart.fsnet.co.uk/smilie/awink.gif

Regards
Balance!

Oh, and make that 3 please.... I'll get in the queue with FL http://www.stopstart.fsnet.co.uk/smilie/cheesy.gif


[This message has been edited by Balance! (edited 21 May 2001).]

Hi Balance, it must be an age thing, but I'll keep on trying, thanks for the tip.
Regards :)

Down wind landings. The Chinook has a lot of flexibility in this area but every thing has a limit. I'll tell on myself a bit. This was back in my early Chinook days.
The aircraft was a "small C", L-7C engines, I believe, and metal blades. Landing at 8400'MSL and about 25deg C. Slight down wind. Not much down wind but when you’re too fast, which can happen very easy at that altitude, a little down wind is allot.
My last thought before touch down was that if I can keep the VSI at less than 492FPM at touch down then, according to the book, I shouldn't do any damage. The book is a bad bet when you are using it as a hedge against poor technique.

And then....?

Boeing Completes First CH-47F Chinook Flight
 

PHILADELPHIA, June 29, 2001
http://www.boeing.com/news/releases/...q2/010629o.jpg
Press Release
Boeing has launched another chapter in the history of its longest-running continuous aircraft production program. The new CH-47F Chinook prototype heavy-lift helicopter, the sixth Chinook type designed for the U.S. Army, recently completed its first flight at the Boeing Philadelphia manufacturing facility. The June 25 flight, which involved hover and basic maneuvers, capped a series of comprehensive system checks leading to takeoff precisely as scheduled in the CH-47F program agreement completed three years ago.
"The first flight was flawless," said Roger A. Krone, vice president and general manager, Boeing Army Programs/Rotorcraft. "Our Chinook Team demonstrated not only technical excellence, but also a total commitment to our U.S. Army customer. The entire first- flight crew-pilots, engineers, technicians and support personnel-accomplished our program-schedule goals with consistently good performance and solid teamwork. They set a high standard for all our production programs." A Boeing Philadelphia flight crew consisting of Erik Kocher, Chinook program chief test pilot; Randy Wells, test pilot; Joe Schluck, flight test engineer; and John Rose, crew chief, lifted off shortly before 7 p.m., EDT, and remained airborne for about five minutes to validate aircraft handling qualities. "It was wonderful," Kocher said. "The aircraft performed right up to expectations while we completed rotor blade track and balance and crosswind hover as scheduled. The aircraft controlled nicely, and all systems functioned as advertised." The CH-47F modernization program will sustain the U.S. Army's Chinook fleet to provide rotary-wing heavy-lift capabilities well into the 21st century. Modernization will include aircraft remanufacturing, vibration reduction, improved avionics with integrated digital mission management systems and a digital map, and installation of more powerful Honeywell T55-GA-14A-714 engines. These core elements of the program will reduce operational and support costs to below those of the original CH-47D and provide at least another 20 years of economical and effective service. That means Chinooks will wind up serving in the Army's inventory for more than 70 years, an unprecedented record of service for military aircraft. The Boeing Company develops and produces military rotorcraft and provides support services worldwide from its production facilities in Philadelphia and Mesa, Ariz. Among its products are the AH-64D Apache Longbow attack helicopter, CH-47 Chinook, the RAH-66 Comanche armed reconnaissance helicopter and the V-22 Osprey tiltrotor aircraft.

...like it!! :)

“Modernization will include aircraft remanufacturing, vibration reduction, improved avionics with integrated digital mission management systems and a digital map, and installation of more powerful Honeywell T55-GA-14A-714 engines. These core elements of the program will reduce operational and support costs to below those of the original CH-47D and provide at least another 20 years of economical and effective service. That means Chinooks will wind up serving in the Army's inventory”.

The article did not indicate if the new elastomeric rotor system was installed on this aircraft. If and when this new rotorhead design is incorporated the operational costs at least for the rotorhead will be higher than the existing design and that design is the highest maintenance cost driver on the CH-47. The elastomeric concept on paper reduces operational costs and maintenance by reducing parts count and eliminating the need to lubricate the rotorhead elements. However, what they can’t eliminate are the stresses and strains that exist in the rotorhead because a great deal of the flight time is in a hover or at speeds less than 60 Knots which is at hover pitch.

The steel elements of the existing design are 70-80% scrapped when the rotorhead comes in for overhaul or refurbishment. With this high level of operational stresses the elastomeric elements will degrade at a much higher level than on similar designs using elastomeric bearings. Because of the nature of the elastomeric bearings they must be matched to within 5% of each other relative to durometer (stiffness). If these elements go outside of that range the offending bearing must be changed and the remaining two bearings removed and tested for stiffness which runs up the ground maintenance times on the aircraft. If the remaining two bearings can’t be matched to the new bearing two new bearings must be installed and the other two put into the supply room to be referenced against the next bearing failure. This runs up the maintenance costs.


------------------
The Cat

[This message has been edited by Lu Zuckerman (edited 02 July 2001).]

Nice........
Wished I owned one, Bet the are 'bout 5mil. Oh well, maybe I'll win the lotto some day.
Is this going to be used in the navy as well as the US Army?

Cody

CH-47D Fuel Flows
 

G'Day Guys and Girls

Need some help i need to know the chinooks fuel flows by tomorrow

thanks

hun

Sorry, reply is probably too late. However:

At a basic weight (std crew/fuel) of 30k-32k lb you can plan on about 2400 lb/hr. Remains fairly steady until about 42k lb, where it climbs to around 2750 lb/hr at a 135 TAS cruise. At 50k lb it can exceed 3000 lb/hr in hover, or with large external loads, and probably drops back to around 2800 lb/hr in cruise. Endurance/holding - about 2100 lb/hr. Start/taxi uses about 600 lb for first start of day plus IFR checks.

All info is off the top of my head, and for a '47D with the -712 engines (nil FADEC). If you need grater accuracy I can get you a fuel flow chart.

Cheers BFSC

cheers man every little bit helps

Hover FF on a cool day at 1000'PA with a 23,400 LB. F-4 on the end of 125' of rigging will be about 3200 PPH and the engines will be nice and warm.

Two kinds of helicopter, Cargo and external load.

VRS in Tandem rotor air craft
 

Here is my question.

Is possible to get vrs in on tandem (ch46/47)rotor system (front or rear) independantly of the other. I would guess it wouold be the rear rotor.

Can this happen?

Can anyone explin it to me..

Thanks

RB

Rotorboy,
for the reasons behind VRS in any helicopter I would recommend that you read the excellent thread about the Blackhawk accident which covered it in detail. Nick Lappos has a link to a site that explains it fairly clearly.
To get into VRS you need to be in the parameters for your aircraft with power applied. In a tandem rotor helicopter you can't tilt the discs as you would normally in a single rotor because you will chop the cabin in half. I order to pitch the CH47 forward the pitch is increased on the rear head and decreased on the front head when the stick is pushed forward. This is known as Differential Collective Pitch (DCP) as the blades on each head are pitched collectively but differently between the heads. If you were in the speed and ROD limits for VRS and then pitched forward or backwards it would be possible to get one head into VRS by itself.
In addition to this, the normal recovery technique for single rotor helis is to pitch forward to gain some flying speed. In a tandem this will probably only settle the aft disc further into VRS and you probably won't pitch forward at all. The recommended tandem recovery technique is to pitch sideways which only puts a cyclic input to each head and not a collective one.

Chinook info wanted please
 

Alot!
I miss your pictures!

Hey WINNIE answer me on this one and the pics will flow ... ;)

Is this what you are after???

From the RAF Flight Information Handbook:

Chinook HC Mk2:
AUW/MTWA/OWE = 50044lbs - 22700kgs
Tyre Pressure in PSI = 87

Rigid pavement subgrades:
High = 11
Med = 11
Low = 12
Ultra Low = 12

Flexible Pavement subgrades:
High = 8
Med = 10
Low = 12
Ultra Low = 13

Given that they land in fields/car parks I guess you wouldn't need too much LCG.

Cheers

Thanx a lot !
 

Many many thanks AlanM !

Exactly what we needed !

Many thanks !

Gunsss :ok:

You are welcome - the only note of caution comes from the fact that I have just realised that MY FIH expired on 22 JUN 99!!

Should be fairly accurate for planning though - can't imagine much as changed a great deal.

Can Winnie have his pics now!?

Alan

Lo ALAN,

Yip - I pressume that is somethng that should remain "within limits". We just realized we might have ANOTHER real B I E G visitor ... Mi-26 ( 56 tons) ...

So back to the drawing board ... you will actually see on a photo I have posted a while ago - the Mi-26's used to operate from our strip (and Chinooks) but now we are extending and the original drawings and engineer - they are not with us any more !

Cheers and if Winnie is Winnie as in Pooh - that is ok but if he / she is anything to do with the Mosquito Mandela ... then NO :*

Just kiddin .. :p

Will publish soon .. ;)

GUNSHIP!

Yaya

Nothing to do with the Mandela Family, I am a HE, and Winnie the Pooh is correct!

If you want to know the AUW of the Schweizer 300CB it is 1750 lbs!!:D

Just missing your impressive pictures of the "Aligator/Crocodil" and wish I was flying some russian heavy iron!:ok:

Gunsss, MAUM of a UK CH-47 is 24,500 Kgs. Some cabs can only go to 22.7 but some others can go all the way up to 24.5. Just thought I'd let you know, but I guess it doesn't matter if you're having a 56t visitor!!

Fly safe.

EnnArr.

Lo Winnie - tx for the Schweitzer weight - you never know it might have a higher PCN ;)

EnnAr, many thanks. Although we are battling to find the Mi-26 tyre pressure, I am sure we will have to follow the Mi-26 specs.

Many thanks in any way ! :ok:

Cheers and best regards,

Gunnss

Hovering Differences in Chinooks
 

Hello,

I'm a fixed-wing pilot who knows almost nothing about rotary-wing ops, but I've always wondered if twin-tandem (I think that's the correct term) helis such as the Chinook are any easier to hover. It seems that the torque effects of the rotors would cancel each other out and make things much easier for the pilot.


-WN

No-one is really sure if they are actually easier but designed to be more difficult, or if they are more difficult but designed to be easier.

They feel quite conventional, though, just bigger.

Being a former Chinook pilot....who is now forced by economic necessity to endure mere single rotor devices...I will wholeheartedly confirm real helicopters are easier to hover. We Chinook pilots of years past, certify that is due to the very careful selection process that manned the cockpits (with some small assistance from sheer mass and inertia), Chinooks do hover better.;)

SASless,

Yep. Some Chinook pilots do have sheer mass and inertia! :p

The Chinook, and it's smaller brother, the CH-46 are helped immensely by a very capable automatic flight control system that provides attitude hold. Basically, when you have the attitude you want and have trimmed up the cyclic and pedals, the system will hold that until you run out of gas.
But even with the AFCS off, it is still quite easy to hover - helped not only by the lack of torque reaction, but also by the lack of side force and roll changes with tail rotor changes required by power changes.

CH 47 are easy
 

Its even easier if you have the radalt hold engaged and taking in to account that it will hold heading unless you push the pedals.

Crew Chief bring me another coffee;) :E

One thing Ive wondered is the yaw weird in the chinook. Seems like a big thing to be whipping around with the pedals and I am guessing it yaws around the CG which would prolly be somewhere inbetween the two rotors. Any thing to relate it too or am I talking out of my not so sunny side.

Jcoop....Chinook pilots are used to swinging large things around thus tromping on the footrests is a snap. One interesting fact about the CH-47 is the length of the allowable CG travel....on the order of 144 inches range....just under four meters (metres) for Euro spenders in the crowd.

Shawn...your statements might mean something when describing the C model and later variants. The B model with the square tail fin was somewhat better than the A model with the sharp tail....but the A model without SAS was real sport in Yaw. Felt as though you were pedalling the thing to keep the rotors turning or something. With SAS on...the old A model was rather docile, the B even better, and the C with Pitch SAS and SAS was pretty tame. Add the modern goodies and sooth....what more could a guy ask for...."white with two sugars" maybe.:O

So what then is the difference between the Boeing 234 and a CH47, and what model CH47 would the 234 be closest it, if any.

Autorotate.

P.S. I watched them moving a drill rig in the PNG jungles and it was an amazing site to watch with a 260 ft longline. :eek: