On the 737 the nose wheel nut has additional locking with two allen key head fasteners that go through the spacer and nut which are then lockwired.

Exup you got in just before me.

We must not get confused between the degree of urgency applied by the flight crew (MAYDAY/PAN) with the emergency response declared by the airport (usually ATC).

They are not directly correlated.

A mayday in the cockpit might not elicit any emergency response by ATC. A small issue in the cockpit that doesn't warrant a PAN might actually cause ATC to initiate a Full Emergency

Once an emergency response has been initiated by the airport, usually it can only be cancelled by the Airport Fire Service.

In the airport's Emergency Orders, each category of response (Local Stand By, Aircraft Ground Incident, Full Emeregency etc) will have a fixed response level by outside agencies. There is no discretion on the part of the emergency services to dispatch what they think is appropriate.

I wonder if, in this day & age, the 'when in doubt syndrome' will take over very easily and everyone will err on the side of caution in case there is a hiccup and a flock of hungry solicitors descend on you with no airs & graces. I understand there are categories of scenario, but someone has to translate the flight crew's words into action and decide. I assume there is no airfield cost involved, even if over enthusiastic, so why not the full monty. And hey, it's always good to have a practice, for real.
Closing a motorway might seem extreme. What radius from the runway is deemed the danger area? What about the motorway not on finals but downwind or base leg?
Back to the ground response; it does seem the definition of an emergency (Mayday) to us is different to other members of the team. If the a/c was operating under a PAN, and it would seem there was no need for more, why would ground call a full emergency. A PAN is a controllable non normal with no imminent or expect threat to life or property. Or were they operating under a MayDay? (we had enough of this 'not singing from the same hymn sheet with wet/dry runways'. I wonder if the left & right hand talk to each other) Attack & defence might have different coaches but they all report to the manager so both entities now what the other is going to do.
I'm still interested in answers to my earlier technical question: ref. how did the crew know; had they raised the gear; were there any problems with that; what deceleration technique is recommended. This is a Pilots chat forum after all.

In 1978 a Gulf Air Tristar (about two years old) lost a nosewhel on departure from LHR. The crew had no knowledge until informed by ATC that the wheel had been found at LHR. The aircraft was enroute to BAH, and continued through the night. I was working in GF Maintrol at the time, and at about 0500 the Ops Manager called us to inform us that after much consideration he had given the aircraft permission to land. We wondered what plan B was. Anyway it landed without incident and taxied onto the stand. A NLG replacement was required as the axle had sheared off, and it is part of the strut on a Tristar.

According to the Avherald report, the crew were unaware the NW had departed until advised by ATC, which would imply that it was probably found within the STN boundary, or at least in a location close to the airport that allowed the identity of the flight to be deduced.

AH also reports that the axle failed rather than the wheel attachment.

Usual caveats re information originating from Avherald apply. :O

I think you'll find that the origins of the notification to local authority emergency services lies within the accident report recommendations following the Argonaut accident 4/6/67.
"The emergency services under heavily used 'glide in areas' should be notified of an emergency situation"
G-ALHG at Stockport on finals to runway 24 at Manchester Ringway.
Hope it helps

RAT 5,

If I had an aircraft coming in with a missing nose wheel, I might well declare a full emergency even if the flight crew hadn't even declared a PAN.

As I said, the category of urgency decided upon by the flight crew has no direct correlation to the category of emergency response initiated on the ground. They are two very different things.

We need to separate the two in our thinking.

Although it's a long time since I was in a tower, I agree with Gonzo, any aircraft coming my way with 50% of wheels, engines, hydraulics, flaps or even pilots warrants a Full Emergency.

Thank you gentlemen.

Problem with bits that fall off airplanes is not only the missing bit itself but that it hits something as it departs the airplane.

A nosewheel is still a bouncy thing and depending on how fast the airplane was going it could have hit an engine or tailplane on the way out. A 737 nosewheel is pretty small but its quite heavy.. I would like to be in the path of one!

And of course STRICT LIABILITY applies for any damage caused by things falling off ac.
Nothing to argue about for m'learned friends, just the quantum.

I believe that BOAC lost a mainwheel from a 747 in the early days and it landed in the staff car park wrecking 3 cars.

RAT5,

Gonzo is indeed correct in that only airfield fire service can cancel the full emergency. Also, the emergency services do not attend because they are bored. The emergency services are never bored, trust me. It is a locally agreed and pre-determined MAJAX plan that must be adhered to, the local hospitals are made aware, all part of the plan.

It was the bain of my life when I was a controller for the ambulance service twenty odd years ago. The airport on our patch required six ambulances to be sent for a full emergency. I rarely had six free to send to be honest.