Tornado GR.1 auto-land question...

[Lightning Mate]

I have not flown the Tornado F3, but I'm fairly sure all it required for engagement was the weight-on-wheels squat switches to be closed.

I stand to be corrected by those qualified on the jet.

[just another jocky]

LM, yes it did require the WoW switch to be made on both models, but I was enquiring about the max permitted speed for selection of T/R on the F3.

[Lightning Mate]

I don't think there was an airspeed limit.

By definition, even at max landing weight, the airspeed is below any dynamic pressure limitations.

[Dak Man]

They were called WoG switches in my day, bloody PC brigade.

[artyhug]

There were a few different limits for T/R selection based on whether you were using Idle or Max Dry and whether you were asymmetric or not.

Most all of them elude me now however! Sorry.

Ps 140kts was one, I think...

[LOMCEVAK]

The F3 T/R engagement speed limits were, with symmetric thrust, 200 kt at idle then max dry at 150 kt. With asymmetric thrust 140 kt at idle and then at max dry.

[just another jocky]

arty....indeed, there were several on the GR1 but I was wondering if they had the same on the F3.

The main reason for overrun cable engagements was because you were too fast to engage the T/R on a swept landing. IIRC, most guys briefed using the wheel brakes to slow down to T/R engagement speed.

I think.

edit: thanks LOM, you posted whilst I was slow typing.

[just another jocky]

Originally Posted by Courtney Mil

Quite right, AGS. The plan would be to land and use thrust-reverse and then brakes to kill the speed and then lower the hook for a departure end engagement if required. Thing is that the TR and brakes did such a good job that the overrun wasn't usually needed - except in the sim.

So how did you slow from 240-ish kts to 200kts so you could engage the T/R?

I completed a couple of 'higher speed' approaches in the GR and they usually ended up in the overrun cable because it took time to slow to T/R engagement speed which used up a lot of runway at those speeds (except at Dhahran, where we turned off before the end, cos the runway was humungously long).

[essdee]

... auto wing sweep (lack of clearance cost two lives)

Seems a pretty sweeping statement, Courtney (no pun intended). What were the circumstances?

[AGS Man]

At Dharhan you obviously had a much longer Runway but you also had BAK 14 Arresting Systems which have a 180 knot max safe engaging speed as opposed to the RHAGs 160 Knot

[Courtney Mil]

Crew unloaded at low altitude to accelerate and selected the wings fully back, but still at relatively low speed. The aircraft stared to decend as the speed was still in the 25/45 speed range. Pulling like a bastard did not stop them hitting the sea. Actually, I think the nav may have survived. But auto wing scheduling would have put the wings in the right place and they may not (I suspect would not) have hit the sea. Slamming the wings forward became second nature after a while, but it could still be a gotcha.

My details there are pretty sketchy for which I appologize. Someone please put me right on this one.

[Fox3WheresMyBanana]

This is a very difficult one Courtney. The nav survived. I was flying the F3 on the same base at the time. Indeed, I flew that day and, IIRC, there was a low level haze over the North Sea at the time. The pilot deliberately selected max sweep (so the auto-wing sweep argument is irrelevant, as he would have deliberately over-ridden it) and his reasons for doing this are highly debatable, i.e. we don't know why he did it. I suspected it was because he believed the reduction in both drag (unloaded) and visual signature were more important, and I think it was because these factors were overemphasised in OCU training vs the loss of nose authority (I did the OCU course immediately before that pilot). The nav was, as usually briefed, maintaining tally in the '6' and noticed the decent rate too late for the pilot to avert the accident. The pilot was an ex-Lightning pilot and would have instinctively expected reasonable nose authority at low speed with swept wings. The loss of another ex-lightning pilot in the Red Arrows roll-back accident a few years earlier may be relevant, as a similar expectation of greater nose authority may have caused this accident too.
You may recall I subsequently emphasised the low nose authority of the F3 swept wing/slow speed during the OCU flying controls lecture I gave to you 3 years later, by which time I was the lecturer not the student.
I'm very willing to hear the thoughts of others on this one.

[Courtney Mil]

I recall only too well. And, to be honest, that is where the story was lodged in my tiny brain. After all these years this is an accolade to your lecture: the importance of wing sweep became and remained in my head to this day even though I clearly cracked neither the details of the story nor the issues behind it at the time. Cool. And thank you.

[Fox3WheresMyBanana]

If a point made saves one life (and doesn't kill anyone else), then it was all worth it.

[Courtney Mil]

It was. It certainly was. Worked for me!

[Courtney Mil]

Oh, and no one's mentioned the wonders of 35 wing yet. Including the fatigue issues.

[essdee]

Thank you Fox3 and Courtney for adding to the corporate memory about a tragic accident. I thought that was probably the one Courtney was thinking about in his original post, and agree with Fox3 that the lack of AWS was not a cause of this accident. I don't recall the conclusions of the BoI at this distance in time, but would have been surprised if they had said more than that AWS, had it been fitted and not overridden, might have prevented the accident. As with most aircraft accidents, many factors come into play, and it is clear from Fox 3's post that weather and lack of experience on type were in the mix here.

[Courtney Mil]

Yes, I can see that now.

As for TR. yes, 200kts at idle, 150 kts at max dry, 85% RPM max to select, weight on wheels and TR (and LD White for pre-arm) captios out, down to reinjest audio = idle again. What else was there?

Losing the speed down to 200kts. The worst case landing speed was 217 kts plus 10 kts for the realy big tanks - 5 for the smaller ones. We could decide to jetison the tanks. Allowncw for fuel weight with wings swept was 6 kts per 1000kgs, but tht was above 16,000 kg. So we could dump a lot of weight and obtain a reasonable (comparatively) touchdown speed in the F3. With stick fully back on the runway we could be at idle TR speed with plenty of runway to spare. Select TR at 200kts (and move the stick forward again or else) which was very effective at that speed. 150kts, full chat. With brakes as well, it could, as we have seen, be done. If you need the overrun, so be it. That's one of the reasons it's there.

[just another jocky]

Ok CM.

I was just curious as to the perception that the F3 needed fewer overrun cable engagements than the GR1 for high speed approaches.

For the life of me I cannot remember the T/R limits for the GR.

Oh, and I was shown, by my German instructor at TTTE, that 33 wing was 'ze most eefficcient', despite not being R2S.

[Courtney Mil]

...and on a long cruise/transit, just get high at the right AOA and keep inching the wings back to all the non-existant sweep settings as the girl burnt the fuel and watch the fuel consumption keep going down.