Is It Just Me...

[MightyGem]

...or do others have the same problem with EFIS IAS displays?

We don't require an IFR rating for the job, but are required to go under the hood every 3 months, 'just in case'. We also have a glass cockpit with what I assume is a "standard" IAS strip down the lefthand side with higher airspeeds moving down the screen past the reference line.

So here's the scenario. I'm under the hood trying to maintain 100kts. I notice that, due to a lapse in concentration, :eek: , that I am only doing 90.

Now, the speed that I want, ie 100kts, is above the reference line, and my natural reaction to move that down to the line, is to operate the cyclic trim in the same direction, ie towards me. But, of course that trims the cyclic back and we slow down. :*

Does anyone else do that. I have plenty of time on instruments, but on dials rather than EFIS.

[BHPS]

Don't have that problem with the IAS strip as I think of moving the rocker switch up to move the datum to the speed I want or down if I want to reduce speed.

However, my aircraft has a 4-axis system and the collective rocker switch can control the altitude or the vertical speed depending on the Upper Modes engaged. I have great problems when I want to either change height or rate of descent/climb as to me the rocker switch works the wrong way. I have to move the collective switch DOWN to go UP and UP to go DOWN. I am always having to look at the collective switch before moving it and I have been flying the aircraft for two years now! It just doesn't seem natural to me.

BHPS

[NickLappos]

Mighty Gem and BHPS,

Your comments on the airspeed tape is right on. I have often found myself going "by the numbers" while flying airspeed because it was not easily decyphered. For the latest family of Sikorsky/Collins EFIS displays, on Black Hawk, Naval Hawks and the S/H-92, our pilots rejected the scrolling tape as unworkable, and use a dial for airspeed, with cruise speed at the 9 o'clock position.

This dial seems to be working its way into other systems, the US Army Collins CAS cockpit has it, and so to does the latest CUP cockpit for the H-60's in the Marine HMX-1 Squadron.

It is really progress to leap forward to get back to the airspeed dial that worked so well for 100 years!

Here is a glance at the cockpit displays of the S/H-92:

http://www.s-92heliport.com/cockpit.jpg

http://www.s-92heliport.com/cockpit2.jpg

[Jcooper]

Ohhh stop showing off Nick :)

[KENNYR]

Nick, is the SH92 display voice activated to change the display or is the display fixed?

[bloodycrow]

Gidday Nick

I have a question also on the S92.

I managed to do an hour or so on the 92 sim at West Palm in March this year and found it to be considerably more difficult (..but not impossible) to hover, land and fly in cruise with no “AFCS” in comparison to the S76 (with AFCS off).

At the time, I was informed by the technicians that the “AFCS” (equivalent on the 92) had not yet been programmed into the sim.

I was interested to know if you found that to be the case on the actual aircraft?

[4dogs]

Mighty Gem et al,

It is funny that with the virtual "analogue" display that Nick has shown, the needle vs speed image at cruise is identical to a speed tape - the only difference is that the needle moves instead of the tape.

I don't know what your mental cues are for speed management (other than they are obviously different from mine) but I find having an almost equal distribution of RW and FW time with EFIS experience on both means that I look to see whether I am fast or slow in relation to my target, what is the relative difference and what other constraints will determine my rate of acceleration/deceleration and then I make the speed change. My mental process is to tell myself what to achieve and then I apply the same handling technique to achieve the change as I would if I had EFIS,analogue or mercury manometer indicators.

In my experience, people who were brought up on speed tapes would not have a problem (other than the absence of all of those other luvverly things that digital displays can do!). For the most part, I figure that familiarity has a lot to do with it.

However, while I believe that digital displays (ie numbers) are a b*tch for getting trend data, speed tapes with acceleration vector overlays are well on the way to matching analogue displays for trend info.

Nick, while I appreciate that your advisers have prevailed in replacing speed tapes with virtual "analogue" displays, the result seems to be very hungry in terms of the screen "real estate". How much of the advice is based on low or no exposure to EFIS speed tapes before being asked the question?

Stay alive,

[212man]

I think the key is the speed tendency arrow, which once understood becomes a very valuable tool. Don't think moving backwards (to dials) is the answer, try education and practice; hey, even fixed wing pilots got it eventually, so it must be simple!

I've seen this (and the reverse) many times and agree it is a consequence of legacy, but do think that with familiarity the IAS tape works very well.

[What Limits]

You wouldn't get sacked for reverting to the correct technique..

Attitude - power - trim

or

Power - attitude - trim

!!

[NickLappos]

The discourse sounds just like our meetings before we settled the design! Note that the S-76 family has speed tapes, because we took the standard Honeywell kit as-is. I think going backwards is entirely relative, the real question is that the control task calls for some display that shows position, rate and the direction of correction. The tape is awfully small to show anything like relative position, and its rotation is not as appearant as a needle. When you have to alter a display and add a change symbol to help it (as with the acceleration vector added) you have as much as admitted the tape is less capable. None of that says it is not usable, or even not desirable. Lots of ways to skin the cat!

Kennyr - The S-92 has no voice activated controls, yet. It might be a while, actually. Having flown voice activated controls and played in sims with them for years, I think they are not all that valuable. For the most part, figuring how to pack MORE ways for us to do the same job is designing backwards. We should think of REDUCING the tasks and removing controls, so things get easier. For example, instead of having pitot heat, windshield heat, rotor de-ice and engine de-ice, how about a single switch that says "Cold conditions" or maybe even just an automatic turn-on if conditions require? You can always put the individual selection somewhere on a back page so you don't lose control, you just don't have to put all the switches on main street.

As the guy in our pilot's office put it, if you want to stick a broom up my butt to get more out of me, I'd rather you made a self-cleaning floor, thank you very much!

bloodycrow,
All sims are just sims, and none are easy to hover. The mistiming and relatively poor motion cues, and the weak visual cues make them only representative, not absolute. I have a term for those who prove something in a simulator and then say that it is fact - "simulitus" the desease where one imagines a simulator is the aircraft! seriously, the Black Hawk and S/H-92 fly similarly, really pretty easy to hover AFCS off. Most pilots who have flown the 92 say that it handles like a smaller aircraft, with a fairly quick control feel. That is because we built in a fairly powerful rotor head, with high offset. Many larger machines have softer rotorheads, for design reasons. The unstabilized hover is sort of like a 206. You are busy, but not working very hard. An unstabilized S-76 is easier, and a Bell 47 is cake, by comparison. None are very hard.

[BlenderPilot]

After flying helicopters for a while, I started flying a Hawker 400A which had full EFIS, and it was HARD for me to get used to the speed tapes.

And I am from the Nintendo Generation!