MD Explorer
Joined: Nov 1999
Posts: 7
Likes: 0
From: Cornwall
Having the privilege of flying both the EC135 and MD902 in the Police role they both have their strong points and, as always, we could make a perfect Police machine by blending the two together.
Plus points of the MD902, compared with the EC135, IMOH:
Engine handling and EECs (FADECs), although why PAS had to put the wiper switch where it interferes with #2 manual throttle, I don't know.
Cockpit headroom and visibility (no overhead console) - for lanky people like me
Built in test and recording equipment - IIDS (CDS in 135)
Low vibration
Comprehensive autopilot but beware SAS dropping out on manoeuvring
Negative points:
Heading control - fenestron giving 50 kts sideways and backwards in 135 is MUCH more precise
Rear cabin space and visibility
Seating - OK once you're in but small door and diagonal seat brace make it impossible to look punchy getting in or out!
Intercom/radios on the machine I fly - difficult to achieve a good balance between i/c, ATC and tactical radios
Access for daily checks
It's a shame that both aircraft have been plagued by the rumour mill as they both do the job extremely well and, as has been pointed out, they are both immature aircraft which are getting better all the time.
Just a brief thumbnail - if anybody wants anymore, let me know!
Plus points of the MD902, compared with the EC135, IMOH:
Engine handling and EECs (FADECs), although why PAS had to put the wiper switch where it interferes with #2 manual throttle, I don't know.
Cockpit headroom and visibility (no overhead console) - for lanky people like me
Built in test and recording equipment - IIDS (CDS in 135)
Low vibration
Comprehensive autopilot but beware SAS dropping out on manoeuvring
Negative points:
Heading control - fenestron giving 50 kts sideways and backwards in 135 is MUCH more precise
Rear cabin space and visibility
Seating - OK once you're in but small door and diagonal seat brace make it impossible to look punchy getting in or out!
Intercom/radios on the machine I fly - difficult to achieve a good balance between i/c, ATC and tactical radios
Access for daily checks
It's a shame that both aircraft have been plagued by the rumour mill as they both do the job extremely well and, as has been pointed out, they are both immature aircraft which are getting better all the time.
Just a brief thumbnail - if anybody wants anymore, let me know!
Joined: Oct 2001
Posts: 764
Likes: 0
From: 48 Deg South
Just a question for the guys flying the 902. Do you operate with the new upgraded engines or the original ones. I understand the new engines make it a dream machine. I had some comments from the Suffolk County Police in NY and they seem to think its the bees knees. Would be interested in your comments.
Joined: Jun 2000
Posts: 37
Likes: 1
From: Long Beach
Try this link to MD Helicopters. You can access the performance charts (ie. IGE, OGE, OEI, etc). The chart performance is pretty impressive. Funny, I went to the Eurocopter site and they didn’t have any performance information about the 135, just dimensions and a pretty picture.
MDHC homepage
MDHC homepage
Joined: Jun 2000
Posts: 37
Likes: 1
From: Long Beach
Actually, my apologies, on further review I found some performance information for the 135. follow this link, go to the bottom of the webpage, click on the tiny link and download the pdf file. It seems like the performance goes directly into the crapper above 6,000 lbs. Maybe I'm just reading it wrong.
Eurocpter Website
Eurocpter Website
Joined: Nov 2000
Posts: 2,018
Likes: 73
From: Pewsey, UK
Guest
Posts: n/a
from the HOGE charts EC135 at 5000 ft isa +10 ( 25 deg c) MGW= 6250 lbs Md902 = 6250
at isa +20 (35 deg c ) ec135 = 6250lbs md902 6200 lbs.
PW207 in Explorer 206B2 in Ec135.
If I am reading the charts right there is not much between the 2 , what is criteria for CAT A performance is it OEI ?.
Ec135 has lower empty weight but carries more fuel.
it is not clear in either doc what the empty weight of the helicopter includes , is any mission equipment included or is this bare bones weight ( excluding radios, autopilot seat cushions etc ). Can any of you guys give actual weights of your equipped aircraft ( including Flir , searchlight etc). You could then compare performance between two equally equipped helicopters.
at isa +20 (35 deg c ) ec135 = 6250lbs md902 6200 lbs.
PW207 in Explorer 206B2 in Ec135.
If I am reading the charts right there is not much between the 2 , what is criteria for CAT A performance is it OEI ?.
Ec135 has lower empty weight but carries more fuel.
it is not clear in either doc what the empty weight of the helicopter includes , is any mission equipment included or is this bare bones weight ( excluding radios, autopilot seat cushions etc ). Can any of you guys give actual weights of your equipped aircraft ( including Flir , searchlight etc). You could then compare performance between two equally equipped helicopters.
Joined: Jun 2000
Posts: 37
Likes: 1
From: Long Beach
Hi Widgeon,
The reference numbers you chose at 5,000 and ISA +10C on the HOGE chart do show the same weight capability since they are limited by Maximum gross weight and not aircraft performance at that altitude. I would like to mention though that your calculation of ISA +20 at 5,000 ft may be in error at 35C. Standard temperature at 5,000 ft is only 5C, therefore the figure should be 25C. Here again we have the gross weight limit line interfering, so never mind that either. I propose to go to 7,000 ft and ISA +20, which should be 21C. The 135 will do approximately 5,800 lbs with the P&W engines (which seem to give a few more lbs), the MD902 will do 6,250 lbs. That's 450 lbs. Now you have an excellent point. Maybe that extra performance is taken up in airframe or equipment weight. At this point we really don't know, but Eurocopter is listing the 135 empty weight at 3353 (1524Kg) and MD is listing theirs at 3375, a pretty nominal difference on the surface of things. You have to assume that both companies have done an equally misleading job of estimating empty weight, so they're just about even. I'd also go out on a limb and say that the installed equipment you would want on either machine would be equal too. That brings us back to the 450 lbs of difference in performance. Then again, I still may be reading the charts wrong, I usually do.
The reference numbers you chose at 5,000 and ISA +10C on the HOGE chart do show the same weight capability since they are limited by Maximum gross weight and not aircraft performance at that altitude. I would like to mention though that your calculation of ISA +20 at 5,000 ft may be in error at 35C. Standard temperature at 5,000 ft is only 5C, therefore the figure should be 25C. Here again we have the gross weight limit line interfering, so never mind that either. I propose to go to 7,000 ft and ISA +20, which should be 21C. The 135 will do approximately 5,800 lbs with the P&W engines (which seem to give a few more lbs), the MD902 will do 6,250 lbs. That's 450 lbs. Now you have an excellent point. Maybe that extra performance is taken up in airframe or equipment weight. At this point we really don't know, but Eurocopter is listing the 135 empty weight at 3353 (1524Kg) and MD is listing theirs at 3375, a pretty nominal difference on the surface of things. You have to assume that both companies have done an equally misleading job of estimating empty weight, so they're just about even. I'd also go out on a limb and say that the installed equipment you would want on either machine would be equal too. That brings us back to the 450 lbs of difference in performance. Then again, I still may be reading the charts wrong, I usually do.
Joined: Jun 2001
Posts: 173
Likes: 0
From: UK
Before our force bought their 902 we looked very carefully at the empty weights / fitted equipment in both the 902 & 135. At that time there was a considerable difference between the equipment fitted to the two aircraft with the 902 having a much higher spec (inc AP) included in the empty weight. It's fair to say that the role equipment fits should weigh much the same whichever aircraft you choose but look carefully at the standard equipment that you will need before role equipment is fitted. Both manufacturers publish a list of standard equipment fitted to their green airframes and of all the options (and weight thereof) that you willneed to add to bring the aircraft up to the spec you want.
)
Joined: Apr 2001
Posts: 496
Likes: 4
From: Norfolk
Both manufacturers disappointingly seem to use takeoff power ratings for OGE hover figures. How do the two compare at max continuous ratings? [I don't want to get into the old argument of how frequently takeoff ratings can be repeated]. I've heard "not a problem" from exponents of both types, but what margin is typically in hand at MTOW? 5%? 10%?
Joined: Jul 2000
Posts: 28
Likes: 0
From: West Yorkshire
MD902 for me I'm afraid - the 135 is a big 105 with a window at the back of the tail!!!
Autorotate - PW207E 's are the business, as much power as you can use.
Kipper - the 902 WILL drop the SAS if you hack it around the sky, try a little trim in the turn and the system will beep at you less!!!!!
Autorotate - PW207E 's are the business, as much power as you can use.
Kipper - the 902 WILL drop the SAS if you hack it around the sky, try a little trim in the turn and the system will beep at you less!!!!!
Guest
Posts: n/a
Arent the 206B2 and the 207 virtually the same engine ?.
I actually remember seeing pictures of the BO108 prototype many years ago and it basically looked like a 105 with a fancy nose ( no fenestron though )
The EC135 became a very different machine after the merger.
I actually remember seeing pictures of the BO108 prototype many years ago and it basically looked like a 105 with a fancy nose ( no fenestron though )
The EC135 became a very different machine after the merger.
Joined: Jul 2000
Posts: 28
Likes: 0
From: West Yorkshire
Psyclic,
having the SAS out is a brill idea - if you have time drop it before the aerobatics start!! our observers are not the vomit kind - sad but true (but if you try you can get them to FAB!) fill a bag!!
Did prefer the 105 for the twisty bits though.
FLIR.
having the SAS out is a brill idea - if you have time drop it before the aerobatics start!! our observers are not the vomit kind - sad but true (but if you try you can get them to FAB!) fill a bag!!
Did prefer the 105 for the twisty bits though.
FLIR.
Joined: Feb 2000
Posts: 118
Likes: 0
From: UK (Wilts)
MD Explorer
I'd be grateful for any top tips on said MD 902 esp VSCS and any handling quirks. Thanks
[email protected]
[email protected]
Last edited by Grey Area; 17th May 2002 at 14:54.
Joined: Jul 2002
Posts: 111
Likes: 1
From: just left of a valley,dorsetestishireland
MD Explorer rotor speed
Watching the Dorset police Explorer ( notar ) out of the office window and wondering what speed the rotors are doing as they seem to rotate excedingly fast. Just a though,as it`s a beauty of a day and i`m bored! 
Regards to all.
and i`m bored! Regards to all.