Just an experience from the desert back in '91...
________________________________________
"Boomed"
The last step of a phase inspection is a maintenance engine run. This can range from a fairly complex trip to the trim pad with a truck full of test equipment if a high-power afterburner run is required, to a ten minute idle run on the flightline for leak checks. Most our recent inspections had only needed a quick line run, which was really helping to keep the aircraft moving through the inspection process. By this time we were doing phases in just over 24 hours, start to finish - which was convienent as the way flying hours were accumulating each acft was due a 150 hour phase - every 24 days...
Since the aircraft had to return to the hangar for some final work after the run, and we wouldn’t be outside for long, we didn’t want to carry much with us. So quickly, in order to not let all of the days heat into the hangar, we opened the doors hooked up the tow bar to the nose landing gear, and sent PJ – our crew leader/engine mechanic/engine run man up the ladder to act as a ‘brake rider’ for the tow.
When towing an aircraft it is required to have ‘wing walkers’ to watch for clearance at the wingtips (less important on a F-16, much more so with a B-52) and a brake rider sitting in the cockpit. It is the brake rider’s responsibility to bring the aircraft to a safe halt in the rare instance of a towbar separation or failure. In the even more rare instance of a brake failure, following a towbar separation or failure, it is the brake rider’s added responsibility, in coordination with the wing walkers (who will probably be attempting to throw wooden wheel chocks in front of the wheels) to act as witnesses for the upcoming accident…
We pulled the aircraft out onto the flightline, not far in front of the hangar, chocked the wheels, and disconnected the towbar. One of the guys ‘borrowed’ a fire bottle and PJ lowered the canopy signifying that he was ready to go. As I was ‘running ground’ – sort of a ground control or communications point between PJ up in the cockpit and the guys that would be doing the checks under the aircraft – I walked over to the ‘traditional’ marshalling position. For good visibility, both of the aircraft, and for the guys on the ground and in the cockpit, you stand at a point roughly in front of the left wingtip launcher and forward to just about the radome.
As the canopy closed and locked, the aircraft battery power was turned on and PJ gave me the signal for engine start. A quick look at the jet insured that the intake, exhaust and JFS areas were clear and that the guys were ready, I repeated the hand signal followed by a thumbs up and as PJ went to ‘Start 1’ the jet fuel starter (JFS) doors opened and the starter engine began to spool up.
In most cases when an F-16 is running, either during an actual launch, or for maintenance, the crew chief on the ground can speak to the person in the cockpit via a headset and comm cord interphone connection – although, if it is required, most technical information can be communicated through a series of formally (or somewhat more informally) recognized hand signals. Because this should be a maximum ten-minute, straightforward idle run, we decided to just use hand signals.
The JFS surges slightly as it comes up to speed – it is itself a small jet engine, geared through the accessory drive gearbox (ADG, every crew chief’s nightmare) which turns the core of the General Electric F-110 up to starting speed. PJ lifts the throttle over the horn to idle, there’s fuel flow and ignition – from the ground you can feel it as a low deep rumble as the aircraft comes to life while the engine accelerates. The anti-collision strobe comes on as the generator comes online then the engine settles to idle speed with its familiar F-16 inlet scream.
PJ gives the ‘all clear’ from the cockpit and I relay the message to the technicians. They immediately move under the aircraft to begin their checks. It’s loud out in front of the jet and much more so down where the guys are. Someone would have to yell directly in your ear to even have a chance of being heard, so most of the ‘inspection plan’ is worked out ahead of time. There’s a ‘thumbs-up’ from the main landing gear wells, it looks like no leaks from the hydraulic filters that we had changed, or any of the myriad of lines that are accessible in the wheel wells. Now both guys are down under the engine, opening the JFS and its opposite constant speed drive (CSD) hinged access doors, armed with flashlights and towels they are just inches from this living, fire-breathing beast, looking for anything that could be out of place. It’s hot and unbelievably loud. They’re finishing up now, it looks as though we’ve got another good jet…
“Boom, boom, boom, boom-boom, boom”
Deep, heavy concussions roll across the flightline that I can easily hear over the jet’s inlet scream. I look around quickly and back to the aircraft. A second glance shows everyone else looking, and then running for the sandbag bunkers that surround the flightline and that the security police had raised their Mk 19 automatic grenade launcher to the firing position. I wave away the guys that had come out from under the jet and give PJ, who can see little of what is going on, the ‘fingers across the throat’ sign to shut down. Knowing that something was up, PJ camly hunches his shoulders and raises his hand and asks, “What’s up?”
With visions of F-4 Phantoms mortared in their revetments in Vietnam, and feeling very exposed - and by this time – alone, on the flightline, I was at a complete loss for what hand signal might express our current situation…
I made a gun with my fingers, pointed it at the cockpit, and ‘pulled the trigger’ a couple of times. That obviously did the trick because PJ now looked as anxious as I felt, the throttle pulled straight to cutoff and the canopy was coming up. We hadn’t brought an entry ladder with us and PJ wasn’t waiting. He was a pretty big guy and I did my best to at least slow him down as he went over the side. We ran across the flightline and took shelter in the nearest sandbag bunker over on the runway side of the ramp. Once I got there, I realized that, for the first time since the war had started, I didn’t have my chem gear ‘within arms reach’. In the hurry of getting the aircraft out and run I’d left it sitting in the hangar. So there I sat in the bunker wearing my helmet surrounded by people in masks and gear, feeling like someone who didn’t get a memo. As the Canadian alert sirens faded away, it was nearly silent on the flightline. Looking over the sandbags and down the ramp I could see helmeted heads looking out of the next shelter, about 100 yards down the line. It looked as though we hadn’t been attacked, there was no smoke, no sirens, and within a few minutes (although it seemed like a lot longer) the ‘all clear’ sounded. Everyone looked around with an expression that said, “What the hell was that?” Later that afternoon we heard that the concussions were sonic booms, probably caused by Canadian Hornets.
________________________________________
Mike Kopack
Visit the Lucky Devils in the Gulf War at:
http://www.lucky-devils.net
________________________________________
"Boomed"
The last step of a phase inspection is a maintenance engine run. This can range from a fairly complex trip to the trim pad with a truck full of test equipment if a high-power afterburner run is required, to a ten minute idle run on the flightline for leak checks. Most our recent inspections had only needed a quick line run, which was really helping to keep the aircraft moving through the inspection process. By this time we were doing phases in just over 24 hours, start to finish - which was convienent as the way flying hours were accumulating each acft was due a 150 hour phase - every 24 days...
Since the aircraft had to return to the hangar for some final work after the run, and we wouldn’t be outside for long, we didn’t want to carry much with us. So quickly, in order to not let all of the days heat into the hangar, we opened the doors hooked up the tow bar to the nose landing gear, and sent PJ – our crew leader/engine mechanic/engine run man up the ladder to act as a ‘brake rider’ for the tow.
When towing an aircraft it is required to have ‘wing walkers’ to watch for clearance at the wingtips (less important on a F-16, much more so with a B-52) and a brake rider sitting in the cockpit. It is the brake rider’s responsibility to bring the aircraft to a safe halt in the rare instance of a towbar separation or failure. In the even more rare instance of a brake failure, following a towbar separation or failure, it is the brake rider’s added responsibility, in coordination with the wing walkers (who will probably be attempting to throw wooden wheel chocks in front of the wheels) to act as witnesses for the upcoming accident…
We pulled the aircraft out onto the flightline, not far in front of the hangar, chocked the wheels, and disconnected the towbar. One of the guys ‘borrowed’ a fire bottle and PJ lowered the canopy signifying that he was ready to go. As I was ‘running ground’ – sort of a ground control or communications point between PJ up in the cockpit and the guys that would be doing the checks under the aircraft – I walked over to the ‘traditional’ marshalling position. For good visibility, both of the aircraft, and for the guys on the ground and in the cockpit, you stand at a point roughly in front of the left wingtip launcher and forward to just about the radome.
As the canopy closed and locked, the aircraft battery power was turned on and PJ gave me the signal for engine start. A quick look at the jet insured that the intake, exhaust and JFS areas were clear and that the guys were ready, I repeated the hand signal followed by a thumbs up and as PJ went to ‘Start 1’ the jet fuel starter (JFS) doors opened and the starter engine began to spool up.
In most cases when an F-16 is running, either during an actual launch, or for maintenance, the crew chief on the ground can speak to the person in the cockpit via a headset and comm cord interphone connection – although, if it is required, most technical information can be communicated through a series of formally (or somewhat more informally) recognized hand signals. Because this should be a maximum ten-minute, straightforward idle run, we decided to just use hand signals.
The JFS surges slightly as it comes up to speed – it is itself a small jet engine, geared through the accessory drive gearbox (ADG, every crew chief’s nightmare) which turns the core of the General Electric F-110 up to starting speed. PJ lifts the throttle over the horn to idle, there’s fuel flow and ignition – from the ground you can feel it as a low deep rumble as the aircraft comes to life while the engine accelerates. The anti-collision strobe comes on as the generator comes online then the engine settles to idle speed with its familiar F-16 inlet scream.
PJ gives the ‘all clear’ from the cockpit and I relay the message to the technicians. They immediately move under the aircraft to begin their checks. It’s loud out in front of the jet and much more so down where the guys are. Someone would have to yell directly in your ear to even have a chance of being heard, so most of the ‘inspection plan’ is worked out ahead of time. There’s a ‘thumbs-up’ from the main landing gear wells, it looks like no leaks from the hydraulic filters that we had changed, or any of the myriad of lines that are accessible in the wheel wells. Now both guys are down under the engine, opening the JFS and its opposite constant speed drive (CSD) hinged access doors, armed with flashlights and towels they are just inches from this living, fire-breathing beast, looking for anything that could be out of place. It’s hot and unbelievably loud. They’re finishing up now, it looks as though we’ve got another good jet…
“Boom, boom, boom, boom-boom, boom”
Deep, heavy concussions roll across the flightline that I can easily hear over the jet’s inlet scream. I look around quickly and back to the aircraft. A second glance shows everyone else looking, and then running for the sandbag bunkers that surround the flightline and that the security police had raised their Mk 19 automatic grenade launcher to the firing position. I wave away the guys that had come out from under the jet and give PJ, who can see little of what is going on, the ‘fingers across the throat’ sign to shut down. Knowing that something was up, PJ camly hunches his shoulders and raises his hand and asks, “What’s up?”
With visions of F-4 Phantoms mortared in their revetments in Vietnam, and feeling very exposed - and by this time – alone, on the flightline, I was at a complete loss for what hand signal might express our current situation…
I made a gun with my fingers, pointed it at the cockpit, and ‘pulled the trigger’ a couple of times. That obviously did the trick because PJ now looked as anxious as I felt, the throttle pulled straight to cutoff and the canopy was coming up. We hadn’t brought an entry ladder with us and PJ wasn’t waiting. He was a pretty big guy and I did my best to at least slow him down as he went over the side. We ran across the flightline and took shelter in the nearest sandbag bunker over on the runway side of the ramp. Once I got there, I realized that, for the first time since the war had started, I didn’t have my chem gear ‘within arms reach’. In the hurry of getting the aircraft out and run I’d left it sitting in the hangar. So there I sat in the bunker wearing my helmet surrounded by people in masks and gear, feeling like someone who didn’t get a memo. As the Canadian alert sirens faded away, it was nearly silent on the flightline. Looking over the sandbags and down the ramp I could see helmeted heads looking out of the next shelter, about 100 yards down the line. It looked as though we hadn’t been attacked, there was no smoke, no sirens, and within a few minutes (although it seemed like a lot longer) the ‘all clear’ sounded. Everyone looked around with an expression that said, “What the hell was that?” Later that afternoon we heard that the concussions were sonic booms, probably caused by Canadian Hornets.
________________________________________
Mike Kopack
Visit the Lucky Devils in the Gulf War at:
http://www.lucky-devils.net
